20th International Nondestructive Testing and Evaluation ... NDTE Conference Gui… · Welcome 20th...

20th InternationalNondestructive Testingand Evaluation of Wood SymposiumSeptember 12–15, 2017Madison, Wisconsin USA

Conference G

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Welcome20th International Nondestructive Testing and Evaluation of Wood Symposium

Conference Co-ChairsDr. Xiping WangDr. Adam SenalikDr. Robert J. Ross

International Organizing Committee Dr. Ferenc Divós, University of Sopron, HungaryDr. Raquel Gonçalves, University of Campinas, BrazilDr. Francisco Arriaga Martitegui, Universidad Politécnica de Madrid, SpainRoy F. Pellerin, Emeritus Professor, Washington State University, USADr. Robert J. Ross, Forest Products Laboratory and Michigan Technological University, USA Dr. László Bejó, University of Sopron, HungaryDr. C. Adam Senalik, Forest Products Laboratory, USADr. Xiping Wang, Forest Products Laboratory, USADr. Houjiang Zhang, Beijing Forestry University, China

Local Organizing Committee Dr. Richard Bruce Allison, University of Wisconsin–Madison and Allison Tree Care, USAMs. Pamela Byrd, Forest Products Laboratory, USAMs. Nancy Ross Sutherland, Forest Products Laboratory, USA

USDA FOREST SERVICE • FOREST PRODUCTS LABORATORYMADISON, WISCONSIN, USA

• Hosted by the Forest Products Laboratory• Co-sponsored by the Forest Products Society and the International Union of Forest Research Organizations

Program Schedule .............................................................................2

Map Guide ................................................................................................4

Sponsors and Exhibitors ..............................................................5

Welcome Letters .................................................................................6

Bios

Conference Chairs ........................................................ 10

Keynote ............................................................................................... 13

General Session ........................................................................... 14

Keynote and General Session ..................................... 17

Technical Sessions ............................................................ 21

Session 1 ............................................................................ 22

Session 2 ............................................................................ 27

Session 3 ............................................................................ 30

Session 4 ............................................................................ 35

Session 5 ............................................................................ 40

Session 6 ............................................................................ 43

Session 7 ............................................................................ 45

Session 8 ............................................................................ 47

Session 9 ............................................................................ 51

Session 10 ......................................................................... 55

Session 11 ......................................................................... 60

Session 12 (Poster Session) ..................................... 65

Notes ....................................................................................... 79

Contents

USDA FOREST SERVICE • FOREST PRODUCTS LABORATORYMADISON, WISCONSIN, USA

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Tuesday, September 12, 20175:00 – 7:00 pm Registration and Welcome Reception

Best Western Plus InnTowner

Wednesday, September 13, 20177:30 – 8:00 am Coffee and Registration Forest Products Laboratory (5th Floor Lobby)

8:00 – 9:00 am Opening of the Symposium and Keynote Presentation Forest Products Laboratory (Room 500)

9:00 – 9:30 am Break

9:30 –11:30 am General Session Forest Products Laboratory (Room 500)

11:30 am –12:30 pm Lunch Forest Products Laboratory

1:00 – 2:30 pm Concurrent Technical Sessions 1, 2, 3 Forest Products Laboratory (Rooms 500, 501, 300)

2:30 – 3:00 pm Break


4:30 pm – 6:00 pm Poster Session and Exhibits Forest Products Laboratory, Centennial Research Facility Note: Posters available each day from 8:30 am – 4:00 pm.

Thursday, September 14, 20177:30 – 8:30 am Coffee and Registration Forest Products Laboratory (5th Floor Lobby)

8:30 – 10:00 am Concurrent Technical Sessions 4, 5, 6 Forest Products Laboratory (Rooms 500, 501, 300)

10:00 – 10:30 am Break


12:00 – 1:00 pm Lunch Forest Products Laboratory (5th Floor Lobby)


2:30 – 3:00 pm Break

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Program Schedule

Thursday, September 14, 2017 (continued)


4:30 – 5:00 pm Transportation to Pyle Center, University of Wisconsin–Madison

5:00 – 7:00 pm Social Hour Pyle Center Rooftop Terrace

7:00 – 9:00 pm Banquet Pyle Center Alumni Lounge

Friday, September 15, 20177:30 – 8:30 am Coffee and Registration Forest Products Laboratory (5th Floor Lobby)

8:30 – 10:00 am Concurrent Technical Sessions 10, 11 Forest Products Laboratory (Rooms 500, 501)

10:00 – 10:30 am Break

10:30 – 12:00 am Concurrent Technical Sessions 10, 11 Forest Products Laboratory (Rooms 500, 501)

12:00 – 12:30 pm Close Out Forest Products Laboratory (Room 500)

12:30 – 1:30 pm Lunch Forest Products Laboratory (5th Floor Lobby)

1:30 – 3:00 pm Tours of FPL available (Meet in 5th Floor Lobby)

4:30 – 5:00 pm Transportation to Dinner Cruise

5:00 – 7:00 pm Betty Lou Dinner Cruise (Extra charge, pre-registration required)

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Gifford Pinchot Drive

University Avenue

CentennialResearchFacility

ResearchDemonstrationHouse

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Bldg. 33

Walnut Street

Walnut Street

Walnut Street

Highland Avenue

Highland Avenue

Highland Avenue

Campus Drive

Best Western Plus InnTowner

Campus Drive

Campus Drive

Campus Drive

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FPL

Bldg. 1

Highland Avenue

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Sponsors and Exhibitors

Forest Products Laboratory

Special thanks to our sponsors and exhibitors

László Bejó

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Conference Chair Bios

Xiping WangDr. Xiping Wang is a research forest products technologist at the USDA Forest Service, Forest Products Laboratory (FPL), Madison, WI. He has more than 20 years of research experience in the areas of nondestructive evaluation of wood, wood quality assessment, condition assessment of wood structures, and heat sterilization of wood. He has led and conducted fundamental and applied research in the development of new methodologies and procedures for evaluating wood quality of standing trees and logs and assessing the structural integrity of historic wood

structures. He has published more than 160 research papers, been granted eight U.S. and foreign patents, and received the Outstanding Service Award and two Innovations Awards from the University of Minnesota system. In 2014, he received the Markwardt Award from the Forest Products Society and the George G. Marra Award from the Society of Wood Science and Technology for distinguished research contributions in the field of wood and fiber science.

Xiping received his BS and MS degrees in mechanical engineering and forest engineering, respectively, from Beijing Forestry University, and a PhD in wood science from Michigan Technological University. He is an elected fellow of the International Academy of Wood Science (IAWS) and the associate editor of the Journal of Materials in Civil Engineering (published by the American Society of Civil Engineers). He also serves as the research group coordinator of IUFRO D5.02 (International Union of Forestry Research Organizations) and holds adjunct faculty appointments at the University of Minnesota-Duluth, Mississippi State University, and Beijing Forestry University. He currently serves on the organizing committee for the International Nondestructive Testing and Evaluation of Wood Symposium series and is co-chair for the series’ 2017 symposium.

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Adam SenalikAdam Senalik is currently a research general engineer with the United States Department of Agriculture (USDA) Forest Service (FS), Forest Products Laboratory (FPL). Prior to his employment with FPL, Adam was a forensic engineer specializing in heavy truck collisions. His work in quality control, failure mechanisms, and pattern recognition led him toward deeper study in the area of evaluation of materials and systems. At the age of 32, he left the field of forensic investigation and returned to school to obtain his PhD from the University of Illinois, Urbana-Champaign, in

the area nondestructive evaluation. The focus of his research was wood products and utility poles. Previous research had largely modeled wood as a solid uniform material, but Adam combined simulation with practical testing to develop non-destructive evaluation techniques that took advantage of the unique structure of wood.

After graduation, Adam sought a job with FPL. Scientists from FPL were respon-sible for much of the foundational understanding of concepts used in his the-sis. Since starting with FPL in 2013, his areas of focus have been nondestructive testing of wood, analysis of timber bridge structures and abutments, and moisture cycling effects on the strength of wood composites. He is currently involved in evaluating the use of ground penetrating radar as an inspection tool for wood structures. Adam now serves on the organizing committee for the International Nondestructive Testing and Evaluation of Wood Symposium series and is co-chair for the series’ 2017 symposium, which will be hosted by the FPL in Madison, Wisconsin. His position at FPL gives him opportunities to work with people who have similar interests both in the workplace and globally.

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Robert J. RossBob Ross has served as project leader for several research work units at the USDA Forest Service, Forest Products Laboratory (FPL) since 1988. In addition to his assign-ment at FPL, he is a research professor at Michigan Technological University. His current research focus is on the development and use of nondestructive evaluation technologies for various wood products and structures, from standing trees to historic buildings and ships. He has written or co-authored more than 250 technical reports and articles about nondestructive evaluation,

and he jointly holds several U.S. and foreign patents. He served as team leader and editor of the centennial edition of the Wood Handbook—Wood as an Engineering Material, FPL’s flagship publication, and has been the lead on or contributed to several widely used reference documents including Marks’ Standard Handbook for Mechanical Engineers, Nondestructive Evaluation of Wood, Undervalued Hardwoods for Engineered Materials and Components, Wood and Timber Condition Assessment Manual, and Nondestructive Testing and Evaluation of Wood—50 Years of Research—International Nondestructive Testing and Evaluation of Wood Symposium Series.

He has been formally recognized for his technical accomplishments, publications, and professional service by the Federal Laboratory Consortium for Technology Transfer, Forest Products Society, Michigan Technological University, U.S. Forest Service, Society for Experimental Mechanics, Society of Wood Science and Technology, and USDA. He has received recognition from The Arc Dane County, U.S. Forest Service, Greater Madison Federal Agency Association, Madison Area Rehabilitation Centers, and USDA (President’s Volunteer Service Award) for his community service.

He is a member of the School of Forestry and Environmental Sciences’ (Michigan Technological University) Honor Academy, holds adjunct faculty appointments at the University of Minnesota Duluth, Beijing Forestry University, Northeast Forestry University (Harbin, China), and Mississippi State University. He currently serves as co-chair of the International Nondestructive Testing and Evaluation of Wood Symposium series. He holds BS (wood and fiber utilization) and MS (engineering mechanics) degrees from Michigan Technological University and a PhD in engineer-ing science from Washington State University.

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Keynote Bio

Melissa VanLanduyt (USA)Missy VanLanduyt is the Recreation Partnership Section Chief at the Wisconsin Department of Natural Resources. Missy has been with the Department for nearly seven years, primarily focusing on development projects at state parks. Projects included in Missy’s portfolio include hundreds of small repair projects and range to multi-million dollar infrastruc-ture replacement projects. After receiving her Bachelor’s degree in Agriculture Science from UW-Madison, Missy has gone on to obtain her Project

Management Professional (PMP) certification, Leadership in Energy and Environmental Design (LEED) accredited professional certification, and Facility Management certification. She has also spent the past several months on the local town park commission board. Missy lives in Middleton, Wisconsin, with her husband and two girls, ages 3 and 5. In her spare time, Missy enjoys kayak-ing, biking, hiking, gardening, and spending time outdoors with friends.

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Moderator

Lon Yeary (USA)Lon Yeary was assigned as the deputy director of the USDA Forest Service, Forest Products Laboratory (FPL) and Northern Research Station (NRS) in November 2015. He joined FPL in May 2009 as the assistant director of administration. In 2012, Lon worked as the chief of staff and assistant director of business operations for NRS and FPL. Lon joined the Forest Service after 30 years in the United States Marine Corps. While in the Marine Corps, Lon commanded a national joint military and civilian unit responsible for enforcing mental, physical, and moral

enlistment standards for the Department of Defense and a tactical marine corps helicopter squadron, HMM-364. His career provided opportunities to develop skills in areas such as leadership, operations, safety, training, information technology, aviation, and human capital management. Lon is a proven leader with abilities to build high performance organizations and solve complex issues. Lon is a graduate of the United States Naval Academy (BS oceanography), the Naval Postgraduate School (MS computer science), and the Marine Corps Command and Staff College (MS military studies).

Speakers

Richard Bruce Allison (USA)Richard Bruce Allison, PhD, received his undergraduate degree from Brown University. He received his MS and PhD from the University of Wisconsin–Madison where he teaches tree risk assessment within the Department of Forest and Wildlife Ecology. He was awarded the qualifica-tion of Board Certified Master Arborist by the International Society of Arboriculture. In addition, he conducts arbori-cultural consulting and tree-related product development through his company Allison Tree, LLC (allisontree.com). He specializes in nondestructive testing of trees.

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Jason Miesbauer (USA)Jason “Jake” Miesbauer is an arboriculture scientist at the Morton Arboretum in Lisle, Illinois. His research focuses on tree pruning, tree biomechanics, and tree risk man-agement. Jake earned his Bachelor of Science degree from University of Wisconsin–Stevens Point and his PhD from the University of Florida. Prior to pursuing a career in research, Jake spent several years in the arboriculture profession as an International Society of Arboriculture (ISA) certified arbor-ist. He currently serves as the secretary and treasurer for

the Arboriculture Research and Education Academy (AREA) as well as the research director for the Illinois Arborist Association. He also actively engages in outreach to the tree care industry and has presented on topics that include urban tree care and management practices, tree biomechanics, restoration of storm-damaged trees, and tree planting and stabilization.

Udo H. Sauter (Germany)Since 2003, Udo Sauter has been head of the Department of Forest Utilisation of the Forest Research Institute of Baden-Wuerttemberg (FVA) in Freiburg, Germany. His work at FVA focuses on nondestructive testing methods for evaluating and characterizing round and sawn timbers. The work is mainly related to the interface between round timber pro-duction in forest stands and (saw) mills of the wood indus-try to determine quality and value of the resource. Together with his scientific team members and in close cooperation

with the leading technology producers, he works on developing and implementing new and modified algorithms for automated detection of inner stem structures and 3D-roundwood parameters by computer tomography (CT) and optical 3D scanner technologies. Furthermore, he conducts a wide variety of research projects focused on optimization technologies and processes along the forest–wood chain, such as tracing and navigation systems. His research achievements are documented in more than 150 publications.

Udo studied forest sciences at the Universities of Göttingen and Edinburgh. He received an MS in Forest Sciences from the University Göttingen and a PhD in Wood Science from the University Freiburg. Currently, he serves the forest and wood industry with his expertise in many national committees and advisory panels and holds the convenorship for round timber of the German and European Standardization Committee. He worked as a senior researcher at Forintek Canada Corporation (today FPInnovations) in Vancouver for a better Canadian forest and wood industry and kept several leading management positions at the state forest of Baden-Wuerttemberg. Throughout his career, he took teaching duties at the University Freiburg and University of Northern British Columbia, Canada.

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Carlito Calil Junior (Brazil)Carlito Calil Junior is a professor at the Department of Structural Engineering, School of Engineering of São Carlos, University of São Paulo, Brazil. He graduated in Civil Engineering in 1975, and received his MS degree from São Paulo University in 1978. In 1982, he received his PhD from the Polytechnic University of Barcelona, Spain. He has been a visiting professor at University of Twente, Netherlands (1988); University of Karlsruhe, Germany (1988); and USDA Forest Service, Forest Products Laboratory, USA (2000). He is mainly interested

in the education, development, design, and research of timber structures in Brazil. He is the director of The Laboratory of Wood and Timber Structures, president of the Brazilian Institute for Wood and Timber Structures, and member of the International Association of Wood Products Societies (IAWPS) – Japan and the Organización Sdamericana para la Construcción en Madera (OSCM).

Voichita Bucur (Australia)Dr. Voichita Bucur currently holds an honorary appoint-ment as Adjunct Professor at RMIT University’s School of Science in Melbourne, Australia. Dr. Bucur received her undergraduate degree (Engineering) from the Polytechnic Institute, Brasov, Romania, in 1962. She was awarded a PhD (Engineering Mechanics and Ultrasonics) in 1984 from the Institut Supérieur des Materiaux, St Ouen, Paris, France. Dr. Bucur has conducted research in the nondestructive

testing and evaluation area since 1964. She served as a project leader at the Wood Research Institute in Bucharest from 1964 to 1978. From 1978 until 2015, she led a program that focused on the development of ultrasonic nondestructive tech-niques for quality improvement of wood and wood-based products at the Forestry Research Centre in Nancy, France. During this time, she guided the graduate research efforts of students pursuing MS and PhD degrees at the Université “Henri Poincaré” in Nancy, France. In 2005, she moved to Australia, becoming associated with CSIRO – Materials Science and Engineering Division. Dr. Bucur is the author of nearly 150 scientific articles, with most focusing on the development of ultra-sound-based techniques for use with biomaterials. She has published six widely cited books, many of which are used as university texts around the world. Because of the broad scope of her efforts, she serves as a technical reviewer for several international scientific journals. Her fields of research encompass development of nondestructive techniques (vibrational, acoustic, ultrasonic, X-rays) for assessing the quality of trees, wood products, and wood-based composites, mechanical characterization of materials with nondestructive techniques, wood science and technology, and mechanical characterization of wood for musical instruments.

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Keynote and General Session

KEYNOTE PRESENTATION

Importance of Nondestructive Evaluation in Public Safety and Historic PreservationMelissa VanLanduyt (USA)

GEneral Session

Nondestructive Evaluation—Application and Research NeedsModerator: Lon Yeary (USA)

• Nondestructive Testing in the Urban Forest R. Bruce Allison, Jake Miesbauer (USA)

• Nondestructive Assessment of Wood Quality throughout Wood Supply Chain and Manufacturing Process

Udo Hans Sauter, Franka Brüchert, Jörg Staudenmaier (Germany)

• Preservation of Timber Structures: Inspection Methodology, Risk Assessment, and Rehabilitation Techniques Carlito Calil Junior, Leandro Dussarrat Brito (Brazil)

• Dendrochronology—A Nondestructive Technique for Dating Historical Stringed Musical Instruments

Voichita Bucur (Australia)

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• Nondestructive Testing in the Urban ForestR. Bruce Allison, Jake MiesbauerTrees are remarkable organisms that have critical functions across the entire planet. Beyond wood product value, people are unified in their appreciation and affinity for trees. We desire to bring them into close proximity to where we live. To live safely among large trees, urban forest dwellers are dependent on nondestructive testing (NDT) to evaluate risk of tree failure from concealed decay and defects. Because of current academic research and promulgation of International Society of Arboriculture tree risk assessment standards, NDT tools and knowledge are a growth industry for the urban forest. New tools and standards have been brought to market and made available to a growing international network of arborists and researchers.

Keywords: Urban forest, tree failure, inspection, nondestructive testing tools

• Nondestructive Assessment of Wood Quality throughout Wood Supply Chain and Manufacturing Process

Udo Hans Sauter, Franka Brüchert, Jörg StaudenmaierFor an optimized wood supply chain, a decisive factor is the proper allocation of raw wood materials to the mills. This includes aspects such as accurate volume, adequate quality, and timely delivery. Therefore, a comprehensive resource alloca-tion and raw material presorting along the supply chain is the basis for successful process flows in any active forest and wood enterprise. Log dimension, wood density, and wood mechanical properties are key parameters for downstream production decisions in the wood processing industry. A second rational is directed to the fundamental stages along the supply chain: forest stands, standing trees, roundwood after felling (on site and road side), and logs (mill gate and log yard). Depending on the stages, a wide range of nondestructive testing (NDT) methods can be applied. Technologies for forest assessment are focused on tree dimension, volume, and first attempts to derive tree quality criterions such as branch dimen-sions. Measurements rely on air-borne scanning systems with different resolutions. One technology for individual tree assessment is terrestrial laser scanning by LiDAR systems for stem shape and knots. Other assessment tools for use on individual trees either directly derive a measure for wood density or produce rapid readings that allow a preselection in terms of wood stiffness. During harvesting, proces-sor heads are able to measure log dimension and volume. With the integration of acoustic devices, new harvester heads, such as fibre-gen Hitman PH 330, allow presorting based on wood stiffness. Log assessment at road sides, mill gates, or log yards can also aim at wood property assessment, that is wood density and stiffness, using tools of similar testing approaches, such as stress waves, Eigenfrequency mea-surements, and microwave or laser scattering (tracheid effect). Especially at the mill gate, volumetric assessment and external log characterization by optical systems

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(laser cameras, etc.) has already gained a certain importance. At this stage, high resolution X-ray based computed tomography log scanning is playing an increas-ingly important role. Technologies in front of the saw line can help to transfer the log-specific quality information into value by orientation and positioning of logs for optimized breakdown through optical cameras, simple X-ray sources for reidentifi-cation of already scanned logs, and adapting sawing optimization. After breakdown of the log, further processing of semifinished and end products is accompanied by a set of NDT tools for wood quality assessment of sawn products. Multisensor technologies are high-end solutions that combine light, laser, X-ray, vibration, and mechanical testing.

Keywords: Logs, trees, dimension, volume, wood density, wood stiffness, nondestructive technologies

• Preservation of Timber Structures: Inspection Methodology, Risk Assessment, and Rehabilitation Techniques

Carlito Calil Junior, Leandro Dussarrat BritoThe objective of this study was to present proposed inspection methodology for identifying pathological manifestations in timber structures in Brazil. This work was part of a doctoral thesis developed in the LaMEM (University of São Paulo). For this study, a systematic literature survey was conducted in Brazil and abroad, followed by research in situ and experimental laboratory tests. In the first stage, the major pathological manifestations were investigated, indicating a proposed inspection methodology for nondestructive techniques (NDT) to assess timber structural members. This study proposed rehabilitation techniques for decayed timber structural members in the Piracicaba Suspension Footbridge. The second step in this work consisted of performing the proposed rehabilitation techniques with scabbing of Eucalyptus citriodora, for which experimental results of pieces subjected to static bending tests were adequate. The samples also showed good technical and economic feasibility.

Keywords: Structures, timber, pathologies, assessment, conservation, rehabilitation

• Dendrochronology—A Nondestructive Technique for Dating Historical Stringed Musical Instruments

Voichita BucurSince 1967, historical musical instruments have been defined as objects belonging to the cultural heritage of humanity. Historical stringed instruments are mainly instruments of classical music belonging to the violin family (the violin, viola, cello, and double bass) but can also include the guitar, harp, harpsichord, and piano. These instruments have been made in Europe since the 17th century. The

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main material used for the table of these instruments is the resonance spruce —Picea abies from the Alps (Italian Alps, Apennines, Austrian Tyrol, Bavaria, and Switzerland). Master chronologies for spruce from European alpine regions have been established for a period ranging between 1276 and 1974. Dendrochronology is a nondestructive technique that can be applied to dating the table of these historical musical instruments by analyzing the width and pattern of annual growth rings. The pattern of annual rings is observed on the longitudinal radial section of the top of violins and other instruments. The pattern of growth rings of a given instrument is compared with the reference master chronologies related to specific geographic areas. Dendro-provenance of spruce, related to the geographic location of the source area of timber, can be detected with Fourier transform near infrared spectroscopy. In this study, dating of several historical instruments was discussed. It was possible to demonstrate that

• some instruments have been made by different luthiers using wood from the same tree;

• some instruments made by the same violin maker have the two sides of the table made from the same tree or sometimes from different trees;

• some instruments made by an unknown master were made with wood from a well-defined geographical area.

The nondestructive techniques discussed in this study illustrate how it is possible to demonstrate the authenticity of period historical instruments.

Keywords: Dendrochronology, annual ring width, nondestructive X-ray techniques, Fourier transform near infrared spectroscopy, historical stringed musical instruments, violin, violoncello, double bass

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Technical Sessions

In-Forest Wood Property AssessmentModerators: Brian Brashaw (USA) and Shan Gao (China)

Evaluation of Structural TimberModerators: Ferenc Divós (Hungary) and Yann Benoit (France)

Evaluation of Engineered Wood ProductsModerators: Udo Hans Sauter (Germany) and Türker Dündar (Turkey)

Urban Tree Defect Assessment and Risk Analysis IModerators: Richard Bruce Allison (USA) and Guanghui Li (China)

Condition Assessment and Evaluation of Wood Structures IModerators: Jorge Daniel de melo Moura (Brazil) and Houjiang Zhang (China)

Wood Material Characterization IModerators: László Bejó (Hungary) and Cinthya Bertoldo (Brazil)

Urban Tree Defect Assessment and Risk Analysis IIModerators: Peter Carter (New Zealand) and Evgenii Sharapov (Russia)

Condition Assessment and Evaluation of Wood Structures IIModerators: Carlito Calil Junior (Brazil) and Eric Brandt (Chile)

Wood Material Characterization IIModerators: Francisco Arriaga (Spain) and Peter Niemz (Switzerland)

Evaluation of Seedlings and Young Trees for Genetic ImprovementModerators: Mark Rudnicki (USA) and Raquel Gonçalves (Brazil)

Evaluation of RoundwoodModerators: Rubin Shmulsky (USA) and Frederico José Nistal França (USA)

Poster SessionModerators: Tamara França (USA) and Lujing Zhou (China)

Moderator Coordination: Adam Senalik (USA)

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• Partial Resistance Drilling to Assess Wood Density in TreesXiping WangThe basic increment core method has dominated research for more than a half cen-tury and has been used as a standard method for assessing basic wood density in forests, for determining biomass of ecosystems, and for investigating climate history through dendrochronological analysis. Comprehensive wood density models have been developed for commercially important species that allow the use of outer wood cores and knowledge of internal tree density distribution for fairly accurate prediction of the density of major tree components. With the development of SilviScan and near infrared (NIR) spectroscopy instruments, more wood and fiber properties can be obtained from a single increment core sample, allowing com-prehensive wood quality evaluation of plantation trees for genetic improvement, forest management, and optimal wood utilization. However, for many users or in many applications, increment core sampling and subsequent laboratory analysis are time-consuming and expensive. A rapid field-type nondestructive method to deter-mine wood density is needed in various research programs and forest operations. This paper provides an in-depth analysis of the capability of electronic resistance drilling tools and proposes a new concept of partial resistance drilling for more efficient and economical collection of wood density data from trees.

Keywords: Amplitude, friction, increment core, Resistograph, resistance profile

• Investigating Stress Wave Propagation Patterns in Standing Trees Using a Numerical Simulation Method

Fenglu Liu, Xiping Wang, Fang Jiang, Houjiang ZhangStress wave technology has gained popularity in the forest industry as a robust field method to assess wood stiffness and fiber properties in standing trees. However, the mechanism of a stress wave propagating in a tree trunk is still not well under-stood. In this study, we examined propagation patterns of longitudinal stress waves in standing trees through numerical simulation using COMSOL Multiphysics® software (COMSOL, Inc., Burlington, Massachusetts). The simulation was based on wave propagation theory of solid medium with the assumption of orthotropic material for standing trees. Both two-dimensional and three-dimensional wave propagation patterns in virtual tree trunks were obtained, and effects of tree diam-eter and propagation distance on stress wave velocity were investigated. Our sim-ulation results indicate that the wave front initially propagated in impact direction with a spherical wave front. As the wave continuously travelled, the flow of stress wave energy gradually shifted toward the longitudinal direction and its wave front gradually became flattened and close to perpendicular to the longitudinal axis, implying that the wave propagated as a dilatational wave in the early phase, then gradually changed to a quasi-plane wave. For a regular log model, the wave began to travel as a quasi one-dimensional wave when the distance-to-diameter ratio


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reached around 40, whereas the ratio decreased to 20 for a tapered log model. It was also found that both distance and tree diameter had an effect on the propaga-tion patterns of the stress wave. Travel distance had no effect on wave velocity, but wave velocity generally increased with increasing tree diameter.

Keywords: COMSOL Multiphysics software, logs, orthotropic, stress wave, standing trees

• Nondestructive Wood Quality Assessment Methods and Potential Application to Forest Inventory Assessments, Models, and Forest Management

Mark Rudnicki, Yvette Dickinson, Xiping Wang, Robert RossFor wood production to effectively meet the growing demand for wood, producers will need to deliver more than increased volume. Technologies now exist for more comprehensive and efficient nondestructive evaluation of wood quality in standing trees, which can allow for more value extraction by enabling highest best use for each individual tree. A systematic, large-scale sampling of wood quality can give modeling efforts the information necessary to understand wood quality at the landscape scale and improve silviculture and forest management.

Keywords: Methods, modeling, forest inventory, forest management

• Multivariate Modeling of Acousto–Mechanical Response of 14-Year-Old Loblolly Pine to Variation in Wood Chemistry, Microfibril Angle, and Density

Charles Essien, Brian Via, Qingzheng Cheng, Thomas Gallagher, Timothy McDonald, Lori EckhardtPolymeric angle and concentration within the S2 layer of a softwood fiber cell wall are critical for molecular and microscopic properties that influence strength, stiff-ness, and acoustic velocity of wood at the macroscopic level. The main objective of this study was to elucidate the effect of cellulose, hemicellulose, lignin, micro-fibril angle, and density on acoustic velocity and material mechanical properties of 14-yr-old suppressed loblolly pine. Cellulose, hemicellulose, and density are consistently the most important drivers of strength, stiffness, and velocity. Cellulose and lignin are the greatest and least contributors to velocity, respectively, with lignin acting as a sound wave dispersant. Cellulose is the most important conduc-tor of sound waves at the molecular level, whereas hemicellulose acts as a special coupling agent between these components. The polymeric constituents are thus important drivers of sound wave propagation at the molecular level, whereas den-sity plays a subsequent role at the macroscale.

Keywords: Microfibril angle, hemicelluloses, lignin, acoustic velocity


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• Acoustic Technology — Enhanced Tools for Research and Operations

Peter CarterAcoustic technologies are progressively being used in forestry and wood processing operations particularly where end wood product values are dependent on stiffness. Hitman technology has been developed to enable application of acoustic tech-nology in harsh operational environments that demand robust ruggedized tools. Significant values are associated with stiffness in log supply for laminated veneer lumber veneer production and structural lumber manufacture. Measurement of acoustic speed allows stiffness to be captured through better decision-making, allo-cation of resource to highest value uses, and application of best processing meth-ods dependent on log-by-log measures. This study reviews recent improvements of acoustic tools available for research and operational use to measure the stiffness of trees and logs in tree improvement, midrotation and preharvest inventory, harvest-ing and log-making, the mill yard, and processing operations. Technology improve-ments for easier use, improved precision, and better results are highlighted.

Keywords: Acoustic technology, stiffness, robust ruggedized tools, tree improvement, inventory, wood processing

• Relationship between Dendrometric Variables and Mechanical Properties with Grain Deviations in Eucalyptus Trees Grown in Two Environments in Brazil

José Clailson Franco Coelho, Graziela Baptista Vidaurre, João Gabriel Missia da Silva, Daniela Minini, Brunela Pollastrelli RodriguesThe objective of this study was to evaluate the influence of growing conditions of eucalyptus trees in the maximum angular deviation (MAD) and the relationship of these conditions with the dendrometric variables and mechanical properties. Five trees were collected from sixteen Eucalyptus grandis × E. urophylla clones (7 years old) from two sites in Brazil. The two sites had contrasting conditions with regard to precipitation. The dendrometric variables were measured on the standing trees. After cutting down the trees, disks were cut from the base part of tree and then each one was used to measure the dynamic modulus of elasticity (MOEdyn) using ultrasound equipment. The amplitude of the MAD values within each clone were low, ranging from 1.89 to 4.46 degrees. The growing conditions did not affect the MAD. However, higher values tended to occur on wood that grew in sites with high altitude and low precipitation. In just six clones, there was a significant correlation between dendrometric variables and grain deviation angle. The MAD had a positive correlation of 37.5% in the clone studies. The MAD showed significant and positive correlation with diameter at breast height and volume. There was significant


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negative correlation between MAD and the form factor and commercial height, which positively affected the stability of the wood and the timber yield. Two of sixteen clones had significant negative correlation between MAD and ultrasonic velocity, and four of sixteen had significant positive correlation for the MOEdyn.

Keywords: Maximum angular deviation, growing conditions, wood quality, genetic factor

• Nondestructive Evaluation of Hybrid Poplar PlantationsTürker Dündar, Hüseyin Akkılıç, Ümit BüyüksarıWe aimed to evaluate hybrid poplar plantations from two growing sites by stress wave and fractometer nondestructive test techniques to determine the effects of growing site, clone differences, and initial plant density on the wood quality of standing trees. The experiments were carried out on 11- and 12-year-old stands in the Ipsala and İzmit districts, respectively. These stands consisted of adjacent parts where five hybrid poplar clones, I-214 (Populus nigra × P. deltoides), I-45/51 (P. nigra × P. deltoides), 89M (P. nigra), 77/51 (P. deltoides), and S307 (P. nigra), were planted with initial spacing of 2 by 2, 3 by 2, 3 by 3, and 4 by 3 m, respectively. Twenty-five sample trees for each clone and initial spacing in two growing sites were measured to determine wave velocity parallel to grain. A wood core 5 mm in diameter was extracted from the breast height of each tree with an increment borer for the bending fracture strength and compression strength. The results showed that there were no significant differences in stress wave velocities of the clones between the growing sites, with the exception of 77/51. However, bending fracture strength and compression strength of poplar wood from Ipsala were slightly greater than those from Izmit. We found significant differences between wave velocities of trees from different clones. Similarly, bending and compression strengths obtained from the core samples by fractometer changed significantly between the clones. In general, the lowest values were obtained from I-214 followed by I-45/51 and 89M at both growing sites. The highest values were observed in S307 and 77/51. As for plant density, we did not observe any comprehensible results in wave velocities and fractometer tests.

Keywords: Nondestructive test, stress wave, fractometer, poplar clones, plant density, growing site

• Using a Time Domain Reflectometer to Monitor Internal Moisture Content and Ice Content of Standing Trees at Different Temperatures

Huadong Xu, Yuting Wang, Lihai WangTo investigate the effect of environmental temperature on the moisture content (MC) and ice content (IC) of standing trees, a time domain reflectometer, an


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electromagnetic-wave-based device, was used to test larch and poplar tree spec-imens at different outdoor temperatures (between 10 and –26°C). Continuous change of temperature and electromagnetic wave propagation time in the tree were obtained, which were used to deduce the dielectric constant of standing trees under different temperatures. Based on these, some regression models between dielectric constant and MC were constructed. Then, the MC and IC data of stand-ing trees were calculated respectively. The diurnal and seasonal variations of MC and IC of standing trees are also discussed. The results indicate that it’s feasible to evaluate MC and IC of standing trees using a time domain reflectometer because they are significantly affected by environmental temperatures.

Keywords: Standing trees, moisture content, environmental temperature, ice content, time domain reflectometer

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Evaluation of Structural Timber

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• Experimental Study on Material Damping in Dimensional Lumber for Cross-Laminated Timber Panels

Alexander Opazo Vega, Franco Benedetti Leonelli, Sergio Alarcon CamposCross laminated timber (CLT) is a multilayer wooden panel that has received much attention in the last two years in Chile. Dimensional lumber is the main input material, and knowing its material damping is desirable, especially for vibration performance assessment. This study focuses on evaluating material damping in lumber specimens with dimensions that are typical for CLT panels. With the impact test method, 60 lumber boards made out of radiata pine were subjected to flexural vibrations. The tests involved different visual grades and lumber board orientations (edgewise and flatwise). A total of 240 material damping evaluations were per-formed, through logarithmic decrement and circle fit methods. The findings of this study suggest that lumber boards for CLT panels had low material damping ratios, with a mean value of 0.72%. Lumber boards with lower visual grades had the high-est damping ratios for edgewise vibration. However, both logarithmic decrement and curve fit methods are useful for estimating material damping ratios, with good accuracy. Finally, the exhaustive material damping database presented in this work may improve knowledge about damping mechanisms and vibration performance of CLT panels.

Keywords: Material damping, dimensional lumber, vibration performance, transverse vibration

• Effect of Visual Characteristics on Stiffness and Strength of No. 2 Southern Pine 2 by 8 Lumber

Tamara França, Frederico Jose Nistal Franca, R. Daniel Seale, Rubin ShmulskySouthern pine is one of the most used softwood resources in the United States. It is commonly used in trusses and light frame construction. To use wood as struc-tural lumber, a strength and stiffness evaluation system is required to ensure the mechanical properties of the material. To increase the per acre returns of forest land and to meet the demand for wood products, landowners are decreasing the rotation ages, which results in a material with a higher percentage of juvenile wood and lower stiffness and strength. The majority of southern pine lumber is visually graded, which is based on knots, slope of grain, and wane. However, the presence of pith is not included in the visual grading rules. The identification of pith is easy and fast, and it is an indicator of high or low percentage of juvenile wood. The objec-tive of this study was to evaluate the effect of pith and other visual characteristics (rings per inch and percentage of latewood) on modulus of elasticity (MOE) and modulus of rupture (MOR) in 292 samples of No. 2 Southern Pine 2 by 8 lumber.

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When compared with lumber with pith, lumber without pith showed a signifi-cantly higher number of rings per inch (5.4 compared with 3.3) and percentage of latewood (46.3% compared with 37.7%). Similar results were found for mechanical properties and specific gravity; lumber without pith was significantly greater in MOE (11.1 compared with 10.0 GPa), MOR (41.0 compared with 37.3 MPa), and specific gravity (12% MC) (0.55 compared with 0.53) than lumber with pith. The results showed that the presence of pith is an important factor that can improve the prediction of lumber properties and it could be included in the visual grading system.

Keywords: Southern pine, lumber, pith, mechanical properties

• Sclerometric and Ultrasound Methods Applied to Timber Beams under Different Stress Levels

Nádia Veiga, Julio Soriano, Davi Berling, Rafael Lorensani, Paulo NunesVariation of stress by incremental loading applied on a structural element can influence the results of some nondestructive testing. For example, near-infrared (NIR) applied to pieces of wood can detect this behavior. In this context, the goal of this research was to evaluate if the stress increase in timber beams can produce some significant difference in the sclerometric impact and ultrasonic velocity applied in the direction perpendicular to the wood fibers. Three beams with a cross section of 50 by 100 mm and a span of 2100 mm of Apuleia leiocarpa species were submitted to the four-point bending test, with load intensity varying from 0 to 50% of the estimated rupture load. For each level of imposed bending load, sclerometric impacts were applied at nine fixed points on each lateral face and the ultrasonic wave propagation velocity was determined by these corresponding points. The statistical analysis, using the Tukey method at 95% confidence, showed that the results obtained by sclerometric test were statistically equal. However, for some of the stress levels, we obtained differences in the wave propagation velocity, implying nonhomogeneity of the results of the ultrasonic method. The results of this research are an important contribution indicating that the nondestructive sclerometric test has potential for estimating some properties (density, for exam-ple) independently of the stress level of the beams in service.

Keywords: Nondestructive testing, sclerometry, incremental loading

• Quantification of Knot Size in Wood with TomosynthesisChul-Ki Kim

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• Assessing Southern Pine 2 by 4 and 2 by 6 Lumber Quality Using Longitudinal and Transverse Vibration

Frederico J. N. França, R. Daniel Seale, Tâmara S. F. Amorim FrançaThe main procedure during the lumber grading process is the identification of the strength-reducing characteristics that impact modulus of rupture (MOR). Nondestructive evaluation technology can be used to identify material with greater stiffness. This study investigated the use of longitudinal and transverse vibration methods to evaluate mechanical properties of 2 by 4 and 2 by 6 southern yellow pine lumber. A total of 1,240 samples were conditioned to 12% equilibrium mois-ture content. All samples were first nondestructively tested using edgewise and flatwise transverse vibration equipment (Metriguard E-computer) and three differ-ent longitudinal vibration equipment (Fakopp Portable Lumber Grader, Director HM200, and Falcon A-grader) to obtain the vibration properties in the transverse and longitudinal directions. Dynamic modulus of elasticity (MOE) of each sam-ple was calculated based on the fundamental wave equation. Static bending was subsequently conducted according to ASTM 198, and the speed of testing followed ASTM D4761. The results showed significant correlations between the properties determined by nondestructive techniques and the static MOE. No strong correla-tions were found for MOR because it is related to the ultimate strength of material, often associated with the existence of localized defects (such as a knots) on the board. This study indicates that nondestructive techniques can potentially be used to evaluate 2 by 4 and 2 by 6 southern pine lumber stiffness. The tools were suitable in this case.

Keywords: Modulus of elasticity, transverse vibration, longitudinal vibration

Evaluation of Engineered Wood Products (Wood Composites, CLT, Mass Timber Building)

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• A Free Vibration Method for Evaluating the Mechanical Properties of Full-Sized Oriented Strandboard

Lujing Zhou, Xiping Wang, Houjiang Zhang, Robert J. Ross, Cheng GuanThe flexural properties of wood composite panels are typically determined through static bending testing of half-sized panels or small specimens cut from the full-sized panels. In this study, we investigated the feasibility of using a free vibration method to directly evaluate the mechanical properties of full-sized oriented strandboard (OSB) without cutting the panels. The hypothesis was that the plate vibration theory with all free edges can be applied to a simple vibration test setup in which the OSB panel is simply supported at the first nodal lines. Full-sized OSB panels in different quality ranges and different thicknesses were obtained and subjected to free vibration testing using a specially designed laboratory setup. The panels were then cut into half-sized and small specimens and the static bending tests were performed to determine the modulus of elasticity in both major and minor axes as well as the in-plane shear modulus. The results indicated that free vibration testing with two line supports is a valid approach to assess the mechanical performance of full-sized OSB panels.

Keywords: Frequency, full-sized panels, modulus of elasticity, oriented strandboard, plate vibration, shear modulus, vibration mode

• Modal Testing and Theoretical Modal Analysis of Full-Sized Medium-Density Fiberboard Supported at Four Nodes

Cheng Guan, Houjiang Zhang, Lujing Zhou, Xiping WangIn this study, modal parameters of full-sized medium-density fiberboard (MDF) panels supported at four nodes were analyzed for determining modulus of elasticity in both major and minor axes as well as in-plane shear modulus of the panels using a vibration testing method. Modal testing was conducted on five full-sized MDF panels of three different thicknesses (12, 15, and 18 mm) to measure the natural frequencies and mode shapes of the first nine modes of vibration. Results of modal testing were compared with those obtained through theoretical modal analysis. A sensitivity analysis was then performed to identify sensitive modes for calculating modulus of elasticity (major axis: Ex, minor axis: Ey) and in-plane shear modulus (Gxy) of the panels. Mode shapes of the MDF panels from model testing were in agreement with results from finite element analyses. A strong linear relationship was found between measured natural frequencies and calculated frequencies of the panels. The frequencies of modes (2, 0), (0, 2), and (2, 1) were determined as char-acteristic frequencies and used for calculation of Ex, Ey, and Gxy of full-sized MDF panels under four-node support condition. The results indicated that four-node


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support can be used in vibration testing to determine elastic properties of full-sized MDF panels for on-line quality control.

Keywords: Modal testing, theoretical modal analysis, mode shape, natural frequency, panels, sensitivity analysis, vibration testing

• Hygrothermal Performance and Monitoring Protocols of Cross-Laminated Timber

Evan Schmidt, Mariapaola Riggio, Frederik LaleickeHygrothermal performance of cross-laminated timber (CLT) is still not well understood, although the material’s exposure to varied climatic conditions and moisture events, from layup to assembly to post-occupancy, is virtually inevitable. Because invasive and destructive methods for assessment are impractical and costly, a practicable method of material performance prediction coupled with monitoring must be established that guarantees safety and serviceability. The aim of our research is to both elucidate hygrothermal characteristics of CLT as well as to develop a practicable monitoring protocol that can be used to further the establishment of a norm for holistic CLT structural health monitoring in North America. To this end, laboratory tests of the hygrothermal behavior of CLT scaled samples and floors were carried out in a state-of-the-art environmental cham-ber—the multichamber modular environmental conditioning system. These tests explore dimensional stability, wetting and drying potential, checking, and cyclic exposure effects. The resulting monitoring protocol will be implemented in a full-scale scenario to compare nondestructive testing data collected on hygrothermal performance of as-built CLT assemblies in a case study structure over the long term. Finally, a hygrothermal modelling program will be evaluated for the analysis of CLT assemblies. The hope is that these tests will serve to create both prescriptive and assessment-based procedures for the use and maintenance of CLT in the future.

Keywords: Cross-laminated timber, hygrothermal behavior, monitoring, water, wood

• Ambient Vibration Testing and Modal Analysis of a Four-Story Mass Timber Building

Andre Barbosa, Ignace Mugabo, Mariapaola RiggioInterest in mass timber construction has recently increased in North America. With this rise in interest, there are many areas of study related to mass timber construction that are needing further investigation, including structural dynamic behavior of mass timber structures. A four-story mass timber building located in Portland, Oregon, was tested to determine the modal parameters (natural frequen-cies, damping ratios, and mode shapes) of the building. The building’s footprint is


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approximately 85 by 46 ft. The building is made of glue-laminated timber (glulam) columns and beams and the more innovative cross-laminated timber (CLT) floor panels. The testing was done under ambient vibration excitation and 16 acceler-ometers distributed throughout the building. Two test setups were considered by roving the accelerometers between the third and first floors because of the limited number of accelerometers. Six or four accelerometers were placed on each floor considering accessibility of certain areas of the floor plan. Results are presented for an output-only analysis that was conducted on the data collected to extract the modal parameters of the structure. The results will be used to improve the under-standing of the dynamic behavior of mass timber structural systems. These results can be compared with more traditional structural systems such as structural steel and reinforced concrete, and they will also help shape mass timber code provisions as the sector grows in North America.

Keywords: Mass timber, vibration testing, modal analysis, cross-laminated timber

• Effectiveness of Grading Oriented Strandboard Panels made of Eucalyptus grandis Bark and Yellow Pine Shavings using Ultrasound Techniques

Bruno Eduardo Mazzetto Domingos, Jorge Daniel De Melo MouraSolid waste generated by human activities in large quantities and often inappropri-ately disposed of becomes a concern because of the negative impact on the envi-ronment. Civil construction is always in search of systems increasingly industrialized and concerned with the environment. In this context, two materials are considered waste from the sawmill industry: tree bark and shavings. They are leftovers from the primary processes. The main form of use of these wastes in these industries is burning for energy generation. However, not all the waste generated is used. This study aims to evaluate these materials as raw materials for oriented strandboard (OSB) made from eucalyptus grandis bark and shavings of Pinus spp. The panels were manufactured with varied percentages of eucalyptus bark and fixed percent-ages of pine shavings with the application of 6% of phenol formaldehyde resin based on the dry mass of particles. This study presents the ultrasound tests on the panels. The results were analyzed according to European international standards with relation to the physical characteristics and mechanical properties.

Keywords: OSB panels, eucalyptus bark, wood waste, ultrasound tests


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• Assessing Bond Strength of Small Specimens of Yellow Pine and Giant Bamboo using Nondestructive Techniques for Manufacture of Cross-Laminated Bamboo–Pine Panels

Maria Isabel Barreto, Jorge Daniel De Melo MouraThe cross-laminated timber, or CLT, construction system, first developed in Austria and Germany, has recently emerged as an excellent alternative for civil construction. The objective of this study was to analyze the quality and perfor-mance of bonding through tests of small specimens, using pieces of giant bamboo (Dendrocalamus giganteus) and yellow pine (Pinus taeda) for future use in struc-tural panels of cross-laminated bamboo/pine (CLB/P). Four adhesives with four bonding combinations were used: (1) bamboo external cane surface in the parallel and orthogonal directions, (2) bamboo internal cane surface in the parallel and transverse directions, (3) bamboo internal cane surface with external surface in the mentioned two directions, and (4) bamboo and pine wood glued together in both directions of fiber. For each combination, 13 test specimens were made totaling more than 1,000 specimens for testing. Ultrasound tests were performed and the results were compared with the destructive tests to assess the use of the ultrasound technique in selecting structural adhesives for CLB/P. The results obtained from the shear tests will determine the course of future research, especially in the selection of the adhesive most suitable for use in CLB/P panels.

Keywords: Cross-laminated bamboo–pine panels, wood construction, bonding performance, ultrasound tests

• Determination of Mechanical Properties of Wood-Based Materials by Modal Updating

Torben Marhenke, Jens Twiefel, Jörg Hasener, Jörg WallaschekFor optimization of nondestructive testing methods, such as inline delamination detection, simulation methods are becoming increasingly important. With this approach, it is possible to investigate influences, which can otherwise be difficult to research experimentally. The material parameters are crucial input variables for creating a reliable simulation model. There are few complete material parameter sets for wood-based materials in the literature. Also, because of the large variance of characteristic values of wood-based materials, a model validation between mea-surements and simulations made on the basis of literature values is only possible to a limited extent. For this reason, the nine material parameters for an unequivocal description of wood materials as an orthotropic material must be determined experimentally. One possible method, which is described in detail in this paper, is modal updating, in which the mechanical characteristic values of a simula-tion model are adjusted until the modal parameters between measurement and


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simulation match. For this purpose, an experimental modal analysis was performed and the material parameters of a subsequent numerical simulation were optimized until the difference between numerical and experimental eigenvectors and values fell below a threshold. The parameter set, which represents the smallest deviation, provided a very good approximation for the characteristic values of the wood structure. The main advantage of this nondestructive method is that the measure-ments can be made on the real structure and no special sample bodies are needed. In addition, only one test setup is necessary to determine the values.

Keywords: Mechanical properties, wood-based material, model updating, material characterization

• Roughness Determination of Different Types of Surface Boards using Speckle Phenomena

Erik Baradit, Cristobal Gatica, Miguel YañezThe optical speckle interferometry technique was applied to determine surface roughness of some particleboards: melamine, medium-density fiberboard (MDF), and high-density fiberboard (HDF). The experimental setup consisted of a laser source, a detection system based on an optical lens and camera, and an acquisition system. Image processing was used to correlate different speckle intensities under different incidence angles. The roughness parameters obtained using the speckle technique were compared with those obtained using a mechanical roughness meter. A good correlation was found between the two sets of parameters. The roughness parameter Rq was estimated using regression analysis. The roughness parameters Rq for melamine 1 and 2 were 1.55 and 12.69 µm, respectively; HDF, 4.3 µm; MDF, 6.1 µm; and plywood, 6.22 µm.

Keywords: roughness, speckle interferometry, particle boards, laser applications

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Urban Tree Defect Assessment and Risk Analysis I

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• Reliability and Applicability of Nondestructive Testing Instruments for Risk Assessment of Urban Trees

Xi Wu, Guanghui Li, Zhi JiaoNondestructive testing technology such as stress wave, radar wave, and microdrill-ing resistance has been applied for evaluating the internal condition of live trees for many years. Detection results with different instruments sometimes generate different conclusions, which may lead to deviation from the actual situation of the trees. The main purpose of this paper is to analyze and evaluate the applicability and reliability of various instruments. A method was proposed to estimate the defective area of tomography by extracting the pixels of the defective region on the geometric image. The nondestructive testing experiments were performed in Yangzhou Slender West Lake Park, Jiangsu Province, China. Not only the live trees were assessed, but also three kinds of logs were chosen as samples to eval-uate the accuracy of different equipment. The experimental results showed that, the PiCUS acoustic tomography (Argus Electronics, Germany) and the resistance curve generated by the Resistograph instrument (IML Wood Testing Systems, Moultonborough, NH) accurately reflected the position and degree of decay within the live trees and agreed well with each other. In addition, the detection accuracy of the radar scanner TRUTM system (TreeRadar, Inc., Silver Spring, MD) was lower than that of the other two instruments and gradually decreased with increasing tree radius.

Keywords: Nondestructive testing, risk assessment, tomography, live trees

• Dynamic Tree Trunk Stability EvaluationBalázs Major, Ferenc DivósThe weather and other biotic factors can cause serious defects and damage in urban trees. Urban tree inspections are very important to preserve as much tree as possible and to maintain safety in public areas. The goal of this research was to make the conventional pulling test more realistic and dynamic by changing the static pulling device to realistic wind load. We measured the elongation of the tree trunk with a high-sensitivity displacement sensor and wind velocity. The displacement sensor resolution was 260 nm. About 50 trees were investigated with two displacement sensors. A ball-type anemometer was used, and sampling rate was 1 Hz. We measured not only the wind velocity but the wind direction as well. Distance between the anemometer and the tree was less than 500 m. We found a linear relationship between tree trunk elongation and wind pressure. Wind pressure was calculated using wind speed and air density. Critical wind pressure and tree trunk safety factor were determined.

Keywords: Tree trunk, dynamic evaluation, displacement sensor, wind load


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• Quantitative Detection of Internal Decay Degree for Standing Trees Based on Electric Resistance Tomography, Stress Wave Imaging, and Resistograph Techniques

Xiaoquan Yue, Lihai Wang, Xiaowen Ge, Xinglong WangComparisons of nondestructive testing (NDT) techniques are necessary to deter-mine the appropriate technique for specific conditions of standing trees. An investigation into the accuracy of different NDT methods was carried out in the Experiment Forest of Northeast Forestry University in Harbin City, Heilongjiang Province. Four methods were used to test 100 cross sections of Fraxinus mand-shurica and Populus simonii standing trees: electric resistance tomography (ERT), stress wave tomography (SWT), resistograph, and estimated weight loss ratios of wooden increment cores. Es determined by estimating weight loss ratios of wooden cores was regarded as the true value of degree of decay. Results showed that three NDT methods were able to make different degree estimations for the degree of decay. When Es < 30%, Ed (degree of decay determined by ERT) had a strong positive correlation with Es (R = 0.823, P < 0.01), whereas when 30% ≤ Es < 50%, Ey (degree of decay determined by SWT) had a significant positive correlation with Es (R = 0.658, P < 0.01) and Ez (degree of decay determined by resistograph) had a strong positive correlation with Es, and when Es > 50%, Ez had a positive correlation with Es (R = 0.914, P < 0.01). In conclusion, ERT can better diagnose incipient decay of standing trees than the other two, whereas SWT can significantly be used in the middle stage of decay testing, and resistograph can be used in different stages of decay.

Keywords: Weight loss rate, electric resistance tomography, velocity of stress wave, wood core resistance loss, decay degree

• Ultrasonic Tomography in Logs of Urban Trees with Different Levels and Types of Hollows

Mariana Nagle dos Reis, Danilo Profeta Ziller, Stella Stopa Assis Palma, Raquel Gonçalves, Mar Ainhoa BasterrecheaUltrasonic tomography has been used for inspection aiming to assess the internal condition of trees. The correct interpretation of the tomographic images can help to obtain a precise and safe diagnosis about the risk of falling of a particular tree, especially in urban areas where there is an increased risk against life and property. The objective of this research was to analyze, qualitatively and quantitatively, the results of ultrasound tomography with different levels and types of hollows in urban tree disks. Tests were carried out on six disks from four different tree species, three of which contained natural decay and three of which contained artificial holes. The images generated by the ultrasound tomography contained different colors to indicate different velocity ranges and were visually compared with the


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photographs obtained from the surface. In addition to this visual analysis, the per-centage of deteriorated area, inferred by tomographic images generated using two colors, was compared with the percentage of deteriorated area obtained from a mask from the photograph of the disk surface. In general, hollowed areas decreased velocity by greater than 70%, and identifying hollowed areas using this velocity loss resulted in less than 10% error compared with the areas obtained using the mask. If we considered the zones with velocity losses greater than 50% as holes, the area of the hole was 30% overestimated. In general, the ultrasonic tomography images were adequate to provide important information regarding tree risk assessment.

Keywords: Ultrasound, image pattern, hollowed wood

• Assessment of Ultrasonic Tomography and Drilling Resistance in Decay Evaluation of Trees

Mariana Nagle dos Reis, Stella Stopa Assis Palma, Mar Ainhoa Basterrechea, Raquel Gonçalves, Miguel Esteban, Guillermo Íñiguez-GonzálezVisual inspection, practiced in many parts of the world for tree risk assessment, is a very important tool, because it allows the identification of pathologies at low cost. However, this method is highly dependent on the inspector's experience and it may not identify internal tree decay. In many cases, it is necessary to complement this method with technologies capable of assessing and monitoring the internal condition of the tree to accurately assess the risk of the tree falling. Both tomog-raphy and drilling resistance have shown great potential for tree inspections, but both have limitations inherent to any technology. Therefore, the objective of this research was to evaluate the nondestructive tools, ultrasound tomography and drilling resistance, for identifying internal tree condition. The results showed that tomography is sufficient to predict the condition of a region with severe and exten-sive deterioration. However, when it is necessary to have more precise information about the size and location of the deteriorated zone, drilling resistance becomes essential to ensure a precise and safe diagnosis. Drilling resistance gives a very efficient diagnosis of areas with hollows. However, in specimens with different levels of deterioration, the numerical value of the amplitude does not indicate the degree of deterioration. Amplitude graphs of drilling resistance without large variations are indicative of sound wood, although the velocity range obtained with tomography can assure a more secure diagnosis.

Keywords: Ultrasonic tomography, drilling resistance, deterioration of wood, tree risk assessment


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• Interferences of Pith, Knots, and the Interpolation System in Ultrasonic Tomography Images

Stella Stopa Assis Palma, Raquel Gonçalves, Cândida Pereira da Costa, Guilherme A. MartinsIdentification of the internal condition of trees is a current and important problem. Internal conditions can be evaluated by ultrasonic tomography techniques using images generated by velocity ranges associated with colors. But, the velocities are affected by stiffness and anatomical properties of the material. Therefore, it is important to know how much these characteristics may affect the tomography results. Also, is important to recognize interferences generated by the interpolation system used to obtain the images. The aim of this research was to evaluate the interferences caused by the presence of knots, different positions of the pith, and the interpolation system used by the software adopted. The tests were performed in 24 disks of Pinus spp. using ultrasound equipment and software developed by the authors. The results indicate that although velocities in knots were higher than on clean wood, grain deviation in the wood surrounding the knot caused a decrease in these velocities and, in general, very low interference on the image. In the pith, velocity was lower, but in the central part of the disk, there was no dis-turbance in image interpretation. However, if the pith was displaced, the reaction wood presented velocities with a maximum of 30% lower than normal wood. In all images, there were zones as arrows caused by the interpolation system. However, none of the conditions caused severe interference in the image, once the maximum variation in velocity was lower than 30%, which is a normal value in a heteroge-neous material such as wood.

Keywords: Ultrasonic tomography, nondestructive testing, tree inspection

• Assessing the Anchorage of Trees by Measuring Root Plate Inclination in High Winds

Lothar Göcke, Steffen RustThis study explains a method to assess the anchorage of urban trees by quanti-tative analysis of the relationship between root plate tilt and regional wind data. We tested more than 200 trees in more than 53 storms using tilt sensors installed at their base. The data show that there is a correlation of root plate tilt and wind speed data of weather stations several kilometers away from the tree. However, the distance between tree and anemometer necessitates the introduction of a time lag and the aggregation of data over periods of up to 2 hours. The longer these periods are, the better the correlation will be. The quality of the wind speed–tilt correlation also depends on local conditions and topography. We found that an exponential function can make a good approximation of the relationship between the maxi-mal hourly gust wind speed and maximal hourly root plate tilt. The approach to use a simple empirical regression is justified by the fact that although mechanistic


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models of the relationship between wind and tree tilt might be available in the literature, most input parameters of individual trees, such as coefficient of drag, are not. It is important to emphasize that the wind–tilt curves presented here show the relation of root plate tilt to regional wind. The wind at the site of the tree might differ from the regional wind because of tunneling or sheltering effects of the surroundings.

Keywords: Root plate tilt, wind speed, wind tipping curve

• Technical Challenges of Dynamic Tilt Measurements of Trees in Natural Winds — Assessing Wind Reaction of Trees with High Timewise Resolution

Lothar GöckeTo measure root plate tilt and the deflection line of a trunk, one can use tilt sensors mounted along the axis of the tree. However, under natural wind conditions, measured tilt data are affected by horizontal components of trunk motion caused by root plate tilt and stem bending. On many trees, not every tilt event recorded at the base of the tree has its corresponding tilt reading higher at the trunk and vice versa. High speed measurements along the trunk axis with strain gauges show the dynamic forces in the stem. This may explain the observations. We also show data of tilt measurements of groups of trees to illustrate the effects of sheltering, which may have a significant impact on wind–tilt curves. The deflection line of tree trunks can be recorded under different loads that are exerted into the crown. They can be extrapolated downwards. The extrapolations intersect at some point below ground level, which is the virtual point of zero. We examined what effect the depth of this point had on anchorage strength. Strain gauges can be mounted along the axis of a trunk during load tests. The strain over height diagram is affected by stem geome-try and wood properties. Some trees show nearly constant strain distribution along the axis. This may be the perfectly grown trunk or just random.

Keywords: Root plate tilt, stem bending, deflection line, natural winds

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• Structural Condition Assessment of a Historic TowerRobert J. Ross, Xiping Wang, C. Adam Senalik, R. Bruce Allison, Lujing ZhouThis paper presents the use of several nondestructive evaluation techniques in the structural condition assessment of a historic timber viewing tower. Visual, laser, mechanical probing, and acoustic techniques were used to evaluate the structural integrity of a timber viewing tower.

Keywords: Timber, tower, visual, lasers, probing, acoustic, condition assessment

• Density-Based Evaluation Method of Degraded Timber for ISO 13822

Nobuyoshi YamaguchiISO 13822-2010 provides a concept for a method of assessment using time- dependent reliability of existing structures. The standard is applied for all struc-tural materials, including timbers. The time-dependent reliability is based on the degradation of mechanical performance of structural materials over a long period. Reliability analysis needs quantity-based evaluation. Timber density is an index correlated to the mechanical properties of timbers. Mechanical properties and den-sities of clear timbers are listed in Wood Handbook Japan, and regression formulae between mechanical properties and densities of the major structural timber species are obtained from the handbook. Mechanical properties of degraded timbers are also correlated with their weight loss or density loss. The author has developed an inspection method for timbers using withdrawal resistances of probes screwed into timbers. The withdrawal resistances of the inspection method are well correlated with timber densities and can be used to estimate densities of new and degraded timbers. By using the regression formulae, these estimated timber densities could predict mechanical properties of timbers. This method can apply for the predic-tion of residual mechanical properties of degraded timbers. Predicted residual properties of timber components are compared to the loads acting on the timber, and safety of the degraded timber components is analyzed. The ratio of residual mechanical properties of degraded timbers to the nominal properties of new clear timbers is obtained by this method. Structural design values for degraded timbers would be the product of structural design values of new timbers and the residual ratio.

Keywords: Assessment, inspection, evaluation, degradation

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• Procedural Considerations for the Assessment of Mechanical Properties in Existing Timber Structures

Francisco Arriaga, Guillermo Íñiguez-González, Daniel F. Llana, Ignacio Bobadilla, Miguel EstebanThis paper presents the main points of a draft procedure for the estimation of mechanical properties in existing timber structures, which is the focus of a three-year Spanish research project. The estimation of mechanical properties in exist-ing timber structures with the aid of nondestructive techniques presents some important peculiarities in comparison to its application to the grading of new sawn timber. A procedure should be defined for the different tasks of the evaluation. The irregular geometry of the cross section and the possible existence of different batches of timber in the building require some preliminary considerations. The opportunity for visual grading is very limited by the difficulties in access, and non-destructive techniques help to complete the necessary information. The most fre-quently used techniques are estimation of density and determination of velocity of wave transmission. This paper proposes different options and addresses questions that arise in each in order to elaborate a more consistent and practical evaluation procedure.

Keywords: Assessment, dynamic modulus of elasticity, existing timber structures, mechanical properties, non-destructive methods

• Methodology Evaluation and Rehabilitation Techniques for Timber Structural Members of the Piracicaba Suspension Footbridge, Brazil

Leandro Dussarrat Brito, Carlito Calil JuniorIn bridges and timber footbridges, areas with the most critical potential biodeteri-oration risk generally occur in the beam-deck interfaces and in certain connection regions that are susceptible to moisture retention in the wood. During detailed NDT inspections carried out in situ during assessments for the rehabilitation of Eucalyptus citriodora structural members of the Piracicaba Suspension Footbridge, high levels biodeterioration were detected in upper transverse beams in the con-nection areas of the decks pieces, truss connections, lower transverse beams, posts, diagonals, and bracings. In view of the need to rehabilitate the partially biodeteri-orated Eucalyptus citriodora structural members, proposals of methodology and rehabilitation techniques were studied. To validate the work, laboratory tests were carried out on structural members removed from the structure and on Eucalyptus citriodora pieces proposed for the rehabilitation technique with juxtaposed

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scabbing. The results were satisfactory, validating the adequacy of the proposed methodology. Finally, rehabilitation of structural members of the Piracicaba Suspension Footbridge was carried out between August 2013 and June 2014 using the main techniques studied.

Keywords: Engineering, timber structures, evaluations, rehabilitation, conservation

• Evaluation of Historical Arch Roofs of Nailed Laminated Timber Structures in Votuporanga-SP, Brazil

Leandro Dussarrat Brito, Carlito Calil JuniorThe large roof timber structures in Brazil originated with the engineering company HAUFF, whose production of timber structures contributed greatly to technological advances of construction engineering with wood in the country. Roof timber struc-tural systems of the HAUFF type were built in several regions of Brazil. However, this work presents evaluations on the conservation of historical arch roofs of the nailed laminated timber structures of the type HAUFF constructed in Votuporanga, São Paulo Estate, Brazil, based on descriptive documentation, photographs, pub-lications, and in loco inspections in 2014. The methodology used for structural member evaluations were nondestructive techniques by visual inspection, among others. This paper also offers examples of historical details for other structures built by HAUFF, focusing on arch roof nailed laminated timber structures systems that constitute part of HAUFF’s production and that of successor companies. For deter-mination of the essential properties in this inspection, were also performed tests on members of structural dimension wood with visual characteristics of Peróba Rosa (Aspidosperma polyneuron), such as bending, compression parallel to grain, shear, moisture content, and density.

Keywords: Engineering, timber structural, historical buildings, evaluations, conservation

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• Moisture-Dependent Elastic Characteristics of Wood by Means of Ultrasonic Waves and Mechanical Test

Erik V. Bachtiar, Sergio J. Sanabria, Peter NiemzIn this study, two types of hardwood, walnut (Juglans regia L.) and cherry (Prunus avium L.), were tested using both ultrasonic and mechanical testing methods. These species frequently appear in cultural heritage objects in museums (e.g.,musical instruments, furniture). In analyzing the ultrasound data, the elastic moduli can be accurately estimated from stiffness data only if the Poisson’s ratios are available. Three data evaluation techniques that differ in how to incorporate the Poisson’s ratios (full-stiffness-inversion, simplified uncorrected, and simplified corrected) are used to estimate the elastic moduli from the ultrasonic results. The full-stiffness-inversion method, which requires four specimen types, gives the best estimation for the elastic moduli (deviating 5% with compression results). The sim-plified uncorrected method requires only one specimen type, but leads to an over-estimation of elastic moduli (44% for L Young’s modulus). The corrected method, which is based on the Poisson’s ratios obtained from mechanical tests, only partially reduces the overestimation to 27% for L Young’s modulus. The present results clearly show that the chosen data evaluation method influences the accuracy of the calculated elastic moduli.

Keywords: ultrasonic test, mechanical test, moisture content, Poisson’s ratios, walnut, cherry

• Correction Factors in the Determination of Moduli of Elasticity of Orthotropic Material Using Ultrasonic Longitudinal Wave Propagation Method

Bambang SuryoatmonoIn an orthotropic material such as wood, there are nine independent coefficients in the constitutive matrix, namely six diagonal coefficients and three off-diagonal coefficients.To determine the moduli of elasticity of the material accurately, one needs to establish not only the diagonal coefficients but also the off-diagonal coefficients. For simplification, many researchers assume that the moduli of elas-ticity are the same as the first three diagonal coefficients so that the off-diagonal coefficients do not have to be evaluated. In this paper, a statistical-based method is developed to establish modulus of elasticity in any one principal axis of an orth-otropic material that uses a correction factor that represents the influence of all other elastic properties. The method is developed using known elastic properties of many wood species. By using the correction factors proposed in the method, moduli of elasticity of an orthotropic material can be established easily and more accurately.

Keywords: ultrasonic longitudinal wave propagation method, correction factor, modulus of elasticity, orthotropic material

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• Variation of Dielectric Properties Due to Changes in Moisture Content

Roberto Aedo, Dr. Erik Baradit Allendes, Dr. Ricardo Bustos Placencia, Dr. Cristhian Alejandro Aguilera Carrasco

• Young’s Modulus Determination of Turkish Red Pine Wood by Destructive and Nondestructive Test Methods

Tuğba Yilmaz Aydin, Murat Aydin

• Shear Modulus Determination of Black Pine Wood Using Ultrasound

Murat Aydin, Tuğba Yilmaz Aydin, Hasan Hüseyin Ciritcioğlu

• Determination of Elastic Constants Using Ultrasound for Scots Pine Grown in Turkey

Ergün GüntekinElastic constants of Scots pine (Pinus sylvestris L.) grown in Turkey were deter-mined by means of ultrasonic waves. Three Young’s moduli, three shear moduli, and six Poisson ratios were determined at three different relative humidity levels (45%, 65%, and 85%). Three longitudinal and six shear wave velocities propagating along the principal axes of anisotropy and three quasi-shear wave velocities at 45° with respect to the principal axes of anisotropy were measured using EPOCH 650 ultrasonic flaw detector. Cubic samples 18 mm on each edge were used in measur-ing sound velocities. The measured average longitudinal wave velocities in L, R, T directions at 12% MC were 4795, 1713, and 1117 m/s, respectively. The measured average shear wave velocities ranged from 800 to 1530 m/s. The measured quasi-shear wave velocities varied between 682 and 1434 m/s. The calculated average modulus of elasticity values using sound velocities in L, R, T directions at 12% MC were 10556, 1096, and 475 N/mm2, respectively. The calculated shear moduli in LR, LT, and RT planes were 1186, 1049, 359 N/mm2. Elastic constants of the Scots pine samples were also determined on 20- by 20- by 60-mm samples using compression tests. Comparing with compression tests, most of the predicted elastic constants are comparable.

Keywords: elastic constants, prediction, Scots pine, ultrasound

• Determination of Compression Properties in Radial Direction of Oriental Beech Exposed to Temperature Using Ultrasound and Static Tests

Tuğba Yilmaz Aydin, Murat Aydin

Urban Tree Defect Assessment and Risk Analysis II

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• Review of Current Research of Bioacoustic Technology in Nondestructive Diagnostic Testing of Trees

Richard Bruce AllisonBioacoustics is the science concerned with the production of sound by living organ-isms and the effect of sound on living organisms. Advancements in digital acoustic devices and software have allowed researchers to detect and analyze sounds within trees, potentially revealing changes in vitality and the presence of damaging insects. A review of current published international research showed advancement in both sound wave detection devices and data analysis software. Research activity is being driven by regulatory inspection concerns of imported tree products and the increased presence of bark beetle threats to trees.

Keywords: Nondestructive testing, bioacoustics, invasive insect detection, tree diagnosis

• Forestry Mobile Unit for Assessment of Bogota’s Heritage Trees

Yolima Cortés Cortés, Patricia Méndez RoaThe Secretaria Distrital de Ambiente, as environmental authority in Bogota, issued an administrative decision that patrimonial trees and cultural interest trees are pro-tected and held in high regard. Because of their historical, environmental, and cul-tural importance, these trees were catalogued for conservation and are considered the natural heritage of the city. The species of these trees are cedar, cypress, and palms, such as palm of wax and fenix palm. Some of them are more than 100 years old. In 2015, a project was carried out to preserve and improve the physical and health conditions of these trees. Forty-three nondestructive tests were performed to determine the internal status of the trees and to establish more appropriate silvicultural treatment.

Keywords: Nondestructive wood testing, hazardous trees, urban trees, forestry mobile unit, heritage trees

• Analysis of External Condition Variables of Trees Compared with Results of Nondestructive Testing of Wood

Yolima Cortés Cortés, Patricia Méndez RoaBogota has more than two million trees in its urban area, of which, 42,153 are Australian blackwood. These trees are in public spaces and have a high rate of falling over. Australian blackwood is among the 10 species with the highest fre-quency of falling, with an index of 2.23 fallen trees for every 1,000 located in public spaces. As a precaution against this risk as well as conservation, nondestructive

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measurements have been made on trees of this species that have been identified as at risk for falling. Another goal of this effort was to promote a quality woodland because of the environmental importance of the species. It fulfills functions such as regulation of the climate, habitat of bird fauna, and mitigation of pollution in a city that deals with high levels of it. In tests carried out with equipment from the forestry mobile unit (acoustic tomograph and resistógraph), external characteristics such as physical deterioration, inclination, localized rot, cavities, and poor anchor-age were analyzed as indications of the internal state of the trees.

Keywords: Australian blackwood, nondestructive measurements, climate, pollution, tomograph, resistógraph, deterioration

• Dynamic Root Stability Assessment: Practical ExperienceLászló Bejó, Ferenc Divós, Shadabeh FathiSeveral factors affect the stability of trees in an urban environment. These include soil type, damage caused by utility construction and maintenance, fungal attack, and lowering of the water table underneath the pavement. All of these factors may cause invisible damage in the root system. Dynamic root testing is analogous to the pulling test: we measure the inclination of the tree but instead of loading via a cable, actual wind load is used. This way, we can examine the root system in actual real-life conditions. The method is viable at wind velocities higher than 25 km/h. Dynamic root stability tests were carried out on deciduous trees in both winter and summer, that is, with and without the foliage. The safety factor determined without foliage was typically 50% higher. The effect of crown reduction was also studied. A 50% decrease in crown area doubled the safety factor value. Prevailing wind direction also affected the safety factor, which was higher in the prevailing direction and about 20% to 30% lower perpendicularly. One maple tree, for which the safety factor was very low at 120 km/h wind speed, was indeed uprooted a few weeks later. Luckily, no one was hurt.

Keywords: Wind load, root stability, dynamic assessment, safety factor

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• Evaluation of the Old Timber Members of a Masonry Building by Using Combined Ultrasonic and Destructive Test Methods

Gülru Koca, Türker Dündar, Nusret AsThis research is part of the assessment of the structural timber members of an existing old building. An experimental project on the mechanical characterization of historic timber members using combined destructive (DT) and nondestructive test (NDT) methods were carried out in order to determine correlations between test results. In particular, fir (Abies cilicica), spruce (Picea abies), and chestnut (Castanea sativa) woods were evaluated. Ultrasonic stress wave testing was used as the nondestructive method. Modulus of elasticity in bending and bending strength tests were carried out as destructive tests. The evaluation showed that the coefficients of determination varied according to species, and strong correlations were obtained for softwoods (fir and spruce). About 57% to 73% of the strength properties could be explained by MOED for fir and spruce specimens. However, the coefficient of correlations for chestnut were found to be relatively weak, which can be explained by the small number of specimens and also the heterogeneous structure of hardwoods. Based on correlations between the acoustic measurements and the strength and stiffness properties of structural member, we can conclude that the acoustic nondestructive techniques can be used efficiently together with visual inspection in the in situ assessment of the timber building safety and residual structural capacity for fir and spruce. However, further investigations are needed with larger sample size for chestnut.

Keywords: Nondestructive methods, wood structures, destructive tests, fir wood, chestnut wood, spruce wood

• Assessing the Ability of Ground-Penetrating Radar to Detect Internal Moisture and Fungal Decay in Douglas-Fir Beams

C. Adam Senalik, James P. Wacker, Xiping Wang, Brunela Pollastrelli Rodrigues, Frank JalinoosThis paper describes the testing plan and preliminary results in an ongoing project to assess the efficacy of using ground-penetrating radar (GPR) to detect internal moisture and fungal decay within Douglas-fir beams. Initially, the beams were assessed using a variety of physical, mechanical, and nondestructive evaluation (NDE) test methods including micro-resistance drilling, Janka hardness, ultra-sonic transmission, and GPR. After initial baseline assessment, beams were inoc-ulated with brown rot fungus, Fomitopsis pinicola, and exposed to above-ground


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conditions approximately 25 miles (40 km) north of Gulfport, Mississippi, USA. Beam specimens were inspected in the field at 6 and 12 months of exposure using GPR, moisture measurements, and stress wave transmission. Select specimens were removed from the field during each site visit and returned to Forest Products Laboratory (FPL), where the NDE tests were repeated. In addition, computer tomography (CT) scans were taken of a subset of the returned specimens. Finally, destructive Janka hardness testing provided insight into mechanical property change during exposure. The GPR scans were compared to the NDE, CT scans, and hardness results. It was found that GPR has sensitivity to the presence of internal moisture, which is useful in locating areas of potential decay.

Keywords: Ground-penetrating radar, fungus, brown rot, Douglas-fir, sawn timber, glulam

• Mechanism Research on the Hammering Detecting Method for Internal Defects in Wood Members from the Ancient Architectures

ChunHui Liao, Houjiang Zhang, Xiaochun Song, Tao ChenChina, one of the world’s four major ancient civilizations, has an abundance of ancient timber buildings that are partially or wholly built out of wood. Defects have a serious impact on the load-carrying capacity and safety of these ancient archi-tectural wood members. The methods usually used for screening defects always cause some damage to the wood members. The hammering method is a common and truly nondestructive testing methods; however, detection on the basis of the hammering method excessively relies on the experience of detection personnel. Therefore, it cannot be accepted completely from the perspective of science and accuracy. This paper reports on the mechanism of internal defects of wood members detected by the sound hammering method, and reveals the relationship between the character of the acoustical signal and the size and form of internal defect. It was found that a hit can produce different kinds of vibration in a wood member, which could be expressed as three separate vibrations: local surface vibra-tion, whole structure vibration, and defective-part vibration. Mathematic models were developed, and the feasibilities of those models were verified by experiments.

Keywords: Historic wood structural members, internal defect, screening, hammering sound

• Evaluation of Variability of Ultrasound Measurements in Detecting Artificial Defects in Pinus spp. Structural Beam

Ângela do Valle, Vinícius Pierri dos SantosThe ultrasound technique presents several possible applications, and one of them is in the investigation of the presence of internal defects such as cracks and


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galleries of wood-destroying insects. This paper presents the results of experimen-tal research in progress to evaluate the sensitivity of the ultrasound technique in detecting internal nonhomogeneities in solid timber structural elements. In this stage of the research process, the objective was evaluating variability in repeated measures of ultrasound velocity in the same specimen and positions. To achieve this objective, a batch test was performed in a solid Pinus ssp. beam with dimen-sions 7 by 11 by 300 cm. The testing piece was prepared by cutting a 6-cm-deep cut with a circular saw along a longitudinal plane of the piece. The wave propaga-tion time through the cross section was measured using ultrasound equipment and transducers of 2 cm diameter with flat faces and 200 kHz. We selected testing positions to measure the ultrasonic vibrations through the cross section with or without a cut. Testing was conducted at 28 different positions with six repetitions per point. The average, standard deviation, and coefficient of variation of ultra-sound velocities were computed for each position measurement. The maximum coefficient of variation value at which ultrasound velocity reached a unique point is 4.7%. The test results of ultrasound velocity were compared with experimental values reported in the literature.

Keywords: Wood, structure, assessment, ultrasound, variability

• Static and Dynamic Load Testing of a Novel Bridge DesignVanesa Baño, Leandro Domenech, Carlos Mazzey, Agustín Spalvier, Laura MoyaThe first full-scale prototype of a new timber bridge design was manufactured in Uruguay for passage of agroforestry machinery and vehicles up to 180 kN. This 8-m-long and 6-m-wide bridge had two tracks, each conformed by two double glued laminated (glulam) beams and a 1.6-m-wide cross-laminated timber (CLT) deck. Timber employed in the prototype came from Uruguayan fast-grown species (Pinus taeda and Pinus elliottii) and as usual in Uruguay, lacked a grade-stamp. Therefore, a first step involved visual grading and assessment to C14 strength class. Becuase in Uruguay production of engineered wood products is not standardized, a second step involved supervision of the manufacturing process of glulam beams and CLT panels based on European Standards. Dynamic moduli of elasticity of glulam beams were estimated from their experimental natural frequencies. The use of no grade-stamp structural timber, as well as the proposal of a new timber bridge design, implied the need to validate analytical estimations by nondestructive eval-uation of the prototype. Static and dynamic load tests were performed to assess the integrity of the bridge. A truck load of 82.4 kN was applied at different posi-tions along the bridge, and the respective deflections were measured. In addition, dynamic amplification was measured while the truck passed to velocities between 5 and 10 km/h. Linear and elastic responses were obtained from static load test. Experimental results showed an intermediate behavior between the theoretical considerations of collaborating and no-collaborating joint between glulam beams


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and CLT panels. The results of the dynamic tests showed that the dynamic amplifi-cation was low for the considered passing velocities of the truck.

Keywords: Timber bridge, agroforestry, load testing, non-destructive evaluation, glulam, CLT panels

• Assessment of Deterioration in Timbers with Time and Frequency Domain Analysis Techniques

Robert J. Ross, C. Adam Senalik, Lujing Zhou The research reported in this paper focuses on the use of time and frequency domain analysis techniques for assessing the condition on timbers. Several large timber obtained from a viewing tower were evaluated with acoustic nondestruc-tive testing techniques. Waveforms were captured and analyzed in both time and frequency domains.

Keywords: Timber, acoustic, condition assessment, time domain, frequency domain

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• Correlations between Mechanical Properties of Scots Pine Wood Determined by Micro- and Standard-Size Test Specimens

Türker Dündar, Ümit Büyüksarı, Nusret AsThe aim of this study was to investigate correlations between mechanical proper-ties determined by micro- and standard-size test specimens in Scots pine (Pinus sylvestris L.) wood. Eight trees with straight stems were selected as sample trees. Logs 3 m in length were cut from each tree at a height of 0.30 m, and then 6-cm-thick planks, including the central pith, were cut from those logs. The micro- and standard-size specimens for bending, tensile, and compression tests were prepared from the planks. The bending strength, modulus of elasticity in bending, tensile strength, and compression strength values were determined using micro- and standard-size samples. A regression analysis was used to determine the relationship between the micro- and standard-size specimens in individual trees and all trees. The regression analyses indicated a strong, positive linear relationship between the mechanical properties of the micro- and standard-size specimens. The correlation coefficients ranged from 74.9 to 83.9 for bending strength, from 73.7 to 79.8 for modulus of elasticity, from 71.9 to 82.1 for tensile strength, and from 72.0 to 85.2 for compression strength.

Keywords: Micro-size test, standard-size test, mechanical properties, scots pine

• Effects of Decrease in Dimension and Number of Faces of Polyhedral Specimens used in Characterization of Wood by Ultrasound

Cinthya Bertoldo, Renata Flores, Raquel Gonçalves, Carlos VazquezWood characterization using ultrasound in 26-face polyhedral specimens has been performed with adequate results, mainly to obtain Young’s and shear moduli considering the three symmetric axes. However, Poisson ratios determined using this methodology have shown significant interferences from growth ring slopes. To decrease the growth ring slopes in the specimen, it is necessary to decrease the dimension of the specimen face. However, the theoretical bases of the test indi-cated that it is necessary to have the dimensions of the specimen faces greater than the transducer diameter. This research aimed to study the influence of decreas-ing, in dimension and number of faces, the polyhedral specimens in values of the 12 elastic parameters involved in wood characterization. To achieve the objective, we used polyhedral specimens with 26 faces of two different sizes and polyhedral specimens with 18 faces in the ultrasound tests for wood characterization. Of the specimens with 26 faces, one had face dimensions greater than the diameter of the transducer and the other had face dimensions less than the transducer diameter. The polyhedral with 18 faces had face dimensions greater than the transducer diameter. The tests were performed using ultrasound equipment and longitudinal


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and shear 1000-kHz transducers. The results indicated that three (ER, ET, and GRT) of the twelve elastic parameters calculated showed statistically significant differences according to the size and/or specimen geometry used. The remaining parameters had statistically equivalent values using the three polyhedrical specimens.

Keywords: Poisson’s ratio, elastic constants, modulus of elasticity

• Correlations between Nondestructive and Destructive Test Results of Bent Beech Wood at Different Radii

Ümit Büyüksarı, Nusret As, Daniel Hindman, Türker DündarThe aim of this study was to investigate the relationships between nondestructive and destructive test results of bent Beech wood at different radii. The sample trees were harvested from Duzce Forest Enterprises in the northwestern part of Turkey. Two trees from each wood species with straight stems and approximately 40-cm diameter were selected, and two 4-m-long logs from each tree were cut. The logs were sawn to 8-cm-thick timbers. Samples with 2- by 2-cm cross sections and different lengths were prepared from this timber. The prepared samples except for the control group were steamed, bent, and set. The steaming was carried out at two different steam pressures (0.2 and 1.3 atm) and steaming times (36 and 6 min). The samples were bent at 300-, 200-, and 100-mm radius. The setting process was performed with a drying room setting and a high frequency setting. Nondestructive (ultrasonic velocity) and micromechanical (modulus of elasticity, bending, tension, and compression strength parallel to fibers) properties of bent and unbent samples were determined. Nondestructive measurements in the parallel direction were taken on one surface of unbent samples and on the two (convex and concave) surfaces of bent samples. Micromechanical test samples were cut from convex and concave surfaces of bent wood. Relationships between nondestructive and micromechanical tests were determined with regression analyses. The regression analyses indicated that the velocity parallel to the fibers and the bending strength, modulus of elasticity in bending, tension strength, and compression strength from both surfaces had a good relationship at the 95% confidence level.

Keywords: Bent wood, bending radii, nondestructive test, destructive test

• Relation between Linear Thermal Expansion Coefficient of Wood and P-Wave Velocity

Ferenc Divós, Marton PribelskyOne of the advantages of wood materials compared with metals is the low thermal expansion coefficient. Direct determination of the thermal expansion coefficient is rather difficult because we need to measure minor dimensional changes. A high-sensitivity extensometer is necessary. Based on the microstructure of wood, we assumed that microfibril angle has an effect on linear thermal expansion coef-ficient: the higher the microfibril angle is, the lower the linear thermal expansion


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coefficient in the fiber direction is. If this assumption is correct, we need to find correlation between the thermal expansion coefficient and the P-wave velocity in the fiber direction. This study deals with the experimental verification of the described assumption. Clear Robinia pseudoacacia wood samples were prepared: length of the samples was 300 mm, and cross section was 5 by 5 mm. The applied temperature range was 25 to 45 °C. Finally, an easy prediction formula was devel-oped for determining the linear thermal expansion coefficient in the fiber direction using the P-wave velocity.

Keywords: Heat expansion, microfibril angle, P-wave velocity, experimental verification, extensometer

• Ultrasound Characterization of Brazilian Tropical WoodRecieli Knoner Santos Gorski, Monica Ruy, Cinthya Bertoldo Pedroso, Raquel GonçalvesThere is a wide variety of tropical species in Brazil that could be used as a sustain-able source for timber. However, it is necessary to know the elastic properties of these species. This research aimed to characterize wood species from the Brazilian amazon region by ultrasound wave propagation. For the tests, we used 18 polyhe-drons with 26 faces from 6 tropical species grown in the Amazon forest. Ultrasound equipment and 1000-kHz frequency longitudinal and transverse wave transducers were used to determine the stiffness matrix. The elastic properties and Poisson’s ratio, obtained by nondestructive tests, were compared with the results from static compression tests in prismatic specimens withdrawn from three symmetric axes of wood. The values of modulus of elasticity, obtained by ultrasound using the stiffness matrix inversion, were not statistically equivalent to those obtained in static tests. However, on the three symmetric axes, there was a significant statis-tical correlation between modulus of elasticity obtained through both methods (P-value < 0.05). Once the use of big-scale equipment (test machines) and strain-gages is not necessary, characterization by ultrasound, being simpler and less onerous, can be used to determine the modulus of elasticity in different directions using the regression models.

Keywords: Modulus of elasticity, Poisson’s ratio, elastic parameters

• Effect of Chemical Treatment on Speed of Ultrasonic Wave Propagation on Amazonian Wood Species

Elian Meneses Oliveira, Alexandre Florian da Costa, Ricardo Faustino TelesUltrasonic wave technology has been used for nondestructive evaluation of wood quality, although the speed of wave propagation can be affected by intrin-sic or extrinsic wood characteristics. Marupá (Simarouba amara) and curupixá (Micropholis melinoniana) can be found in Amazonian forests and exhibit low


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(0.34 g/cm3) and medium (0.67 g/cm3) specific gravity, respectively. They have low extractives content and have been widely used in the furniture industry. The chemical treatment performed by the Bethell process decreased the speed of wave propagation by 6.2% in these woods. The results indicated that pressure treatment provides more significant changes in the speed of ultrasonic wave propagation than does immersion treatment.

Keywords: Nondestructive evaluation, ultrasonic wave, chemical treatment

• Thermal Conductivity and Elastic Properties of Some Wood Boards Using Ultrasound and Metallic Plates

Erik Baradit, Freddy Guzmán, Ariel BobadillaIn this work, the thermal conductivity and elastic properties of different boards (fiberboards, particleboards, and agglomerated boards) were characterized. The boards were of middle density, and different percentages of additive were used. Thermal conductivity properties were obtained using two parallel metallic plates and according to Chilean standard classification norm NCh853. Elastic properties were obtained by means of elastic modulus of elasticity measured using a Pundit Lab+ ultrasound generator and 154 kHz transducers. Results show good correla-tion between thermal conductivity, elastic properties, and additive content of the samples. Thermal conductivity values for medium-density fiberboard (MDF) with different percentages of additive were around 0.2 W/m °K; modulus of elasticity values were between 718 and 912 MPa. The techniques used are good tools for physical characterization of new materials.

Keywords: Thermal conductivity, elastic properties, wood boards, ultrasound

• Investigating Fire Performance of Heat-Treated Bamboo Scrimber Flooring

Zhijia Liu, Jingxin Wang, Benhua Fei, Changle Jiang, Tao Zhang, Fang LiangFire characteristics of bamboo scrimber flooring produced from different heat treatment processes were investigated by thermogravimetric analysis and cone calorimeter. Results showed that the combustion process of samples included moisture removal, oxidative and char combustion. All characteristic temperatures shifted to higher ones with the increase of heating rates. Activation energy of oxi-dative combustion stage was lower than that of char combustion stage. Compared with untreated samples, LBSF had a lower activation energy in both combustion stages. HBSF had a higher activation energy in the oxidative stage and a lower activation energy in the char stage. LBSF and HBSF had lower heat release rates and larger time to ignition. However, both had a higher total heat release, total sus-pended particulate, and higher heating value.

Keywords: Bamboo, bamboo scrimber flooring, heat treatment, thermogravimetric analysis, cone calorimeter

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Evaluation of Seedlings and Young Trees for Genetic Improvement

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• Ultrasonic Method for Evaluating Wood Quality of Poplar Seedlings

Houjiang Zhang, Dan FengIn China, quality of seedlings is typically evaluated based on physical qualities such as root-collar diameter, seedling height, root diameter, and root length, but wood properties of the seedlings are not taken into consideration. The latest research has shown that wood properties of seedlings such as stiffness and microfibril angle are highly heritable and they determine the wood quality of future plantations. Ultrasonic velocity, as a nondestructive measure, is closely related to wood quality and has been recognized as a reliable predictor of stiffness. In this study, we investi-gated the use of an ultrasonic device as a potential nondestructive tool to monitor and assess the wood quality of poplar (Populus×euramericana cv.’74/76’) seedlings, a common plantation species in China. A total of 200 poplar seedling samples were selected and their ultrasonic velocities were measured at four times during the first growth year. Following ultrasonic measurements, 61 seedlings were randomly selected and cut down and the acoustic velocity of each sample was measured using a resonance method. Each ultrasonic velocity measurement of the seedlings was in a normal distribution and had a strong positive correlation with the number of growth days. The coefficient of determination for the linear relationship between average velocity and growth days was 0.99. No significant correlation was found between ultrasonic velocity and root-collar diameter of the seedlings. Ultrasonic velocity measured on the seedlings was found to have a strong correlation with the velocity of the cut samples measured using a resonance method (R2 = 0.81). The results of this laboratory study indicate that ultrasonic measurement can be used to assess quality traits of young seedlings in future genetic programs.

Keywords: Poplar seedlings, resonance acoustic velocity, ultrasonic velocity, wood quality

• Evolution of Parameters Obtained Nondestructively in Eucalyptus Clone Nursery Seedlings up to Cutting Age

Rafael Gustavo Mansini Lorensani, Raquel Gonçalves, Gabriela Müller, Cilene da Silva Alves, Guilherme Alonso Martins, Mônica Ruy, Nádia Schiavon da VeigaKnowledge of wood properties is important for decision-making and production management in the wood processing industries. Therefore, genetic improvement programs are essential for the forestry sector. In these programs, it is important to know how some characteristics propagate with time because this information can be used to differentiate a clone or species as soon as possible. The objective of this research was to analyze the evolution of ultrasonic wave propagation velocity and diameter and height from 3-month-old nursery seedlings to 6-year-old trees, which


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is the cutting age used in Brazilian pulp and paper companies. The experimental part was conducted on 121 seedlings and 270 trees of three eucalyptus clones. Within the age range analyzed, the results allowed us to conclude that all parame-ters have potential to be used in a predictive model to anticipate genetic selection of clones, but the degree of anticipation would not be the same. The velocity of ultrasonic wave propagation was the only property that maintained, at the cutting age (6 years old), the coherence of the differentiation between clones obtained on seedlings. Diameter and height could be distinguished from 12 months old.

Keywords: Seedlings, eucalyptus, clones, ultrasound

• Prediction of Wood Properties in Trees from Parameters Obtained Nondestructively in Nursery Seedlings

Rafael Gustavo Mansini Lorensani, Raquel Gonçalves, Esther Merlo, Oscar Santaclara, Manuel Touza, Manuel Guaita, Francisco José LarioEarly selection of trees is of great interest, both for pulp and paper companies and for those that use sawn wood. This concept accelerates the process of genetic improvement and supports forest management aiming to improve the quality of wood produced. The goal of this research was to study parameters that are non-destructively measurable in seedlings and that could be used in models to predict stiffness, strength, and basic density of wood in trees. The trials were performed in 240 nursery seedlings (between 3 and 6 months) and in 52 trees that were 72 months old. In the nursery seedlings, longitudinal velocity of ultrasonic wave propagation, height, and diameter were measured, whereas in the trees, basic density, strength, and stiffness were measured. The multiple regression model involving the height and velocity of ultrasonic wave propagation in the nursery seedlings was the most adequate for predicting stiffness in wood from trees. For strength and basic density of the wood from trees, it was not possible to obtain statistically significant models using only parameters obtained nondestructively in nursery seedlings.

Keywords: Seedlings, clones, ultrasound, stiffness, strength, basic density

• Effects of Clone Differences and Initial Plant Density on Acoustic Measurements in Hybrid Poplar Trees

Türker Dündar, Hüseyin Akkılıç, Ümit BüyüksarıWe examined the effect of clone differences and initial plant density on the acoustic measurements and mechanical properties in hybrid poplar wood from different clones: I-214 (Populus nigra × P. deltoides), I-45/51 (Populus nigra × P. del-toides), 89M (P. nigra), 77/51 (P. deltoides), and S307 (P. nigra). The experiments were carried out on a 12-year-old stand composed of adjacent parts planted with


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different poplar clones with initial spacings of 2 by 2, 3 by 2, 3 by 3, and 4 by 3 m. Twenty-five sample trees for every clone and initial spacing, 500 trees in total, were measured by a Fakopp Microsecond Timer (Fakopp Enterprise Bt., Hungary) to determine the wave velocity parallel to grain and dynamic modulus of elasticity (MOED) in standing trees. A total of 100 sample trees, five from every clone and initial spacing, were cut down, and a 1-m-long log was taken from breast height (1.3 m). The standard-size test specimens were tested for basic density, bend-ing strength, static modulus of elasticity in bending (MOES), and compression strength parallel to grain. The results showed that basic density varied from 0.32 to 0.42 g/cm3. The lowest wood density occurred in the I-214 clone, whereas the highest value occurred in the 77/51 clone. We found significant differences between wave velocity and MOED of trees from different clones. The lowest velocity and MOED values were obtained in I-214 and I-45/51 clones, whereas the highest values were found in 77/51, S307, and 89M. Conventional destructive test results also confirmed the acoustic measurement results obtained from the stand-ing trees. As for plant density, the results were complicated. We didn’t observed any comprehensible results in nondestructive and destructive test results in terms of plant density.

Keywords: Acoustic measurmenets, poplar clones, plant density, wood density, wood strength

• Grain and its Relationships with Physical–Mechanical Properties of Eucalyptus Wood Clones Planted in Brazil

José Clailson Franco Coelho, Graziela Baptista Vidaurre, José Tarcísio Oliveira, Daniela Minini, Pedro Gutemberg de Alcântara SegundinhoThe objective of this study was to evaluate the relationship of maximum angular deviation (MAD) with the physical–mechanical properties of the wood of seven clones of Eucalyptus grandis x Eucalyptus urophylla (13 years old), planted in the south of Bahia State, Brazil. Six trees from each clone were sectioned into logs, three disks were cut along the trunk, and tangential boards of 5 to 7 m were sawn from the logs. The MAD, specific gravity (ρ), compressive strength parallel to the fibers (fc0), and modulus of rupture (MOR) and elasticity (MOE) were evaluated. Wave propagation velocity (stress wave, ultrasound, and transverse vibration) was used to determine the dynamic modulus of elasticity (MOEd). Low amplitude of MAD values for the seven clones was observed, varying from 5.27 to 7.13. The mechanical properties evaluated did not present correlations with MAD in the clones evaluated together. The wave propagation velocity decreased with increas-ing MAD. In the evaluation of each clone separately, correlations between the properties and MAD were more evident, highlighting the significant correlations between MAD and MOR, stress wave timing MOE, ultrasound, and transverse vibration for some clones. The three-dimensional behavior of grain deviations


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caused difficulty in determining the actual behavior of MAD in the log or sawed wood. The nondestructive techniques of stress waves, ultrasonic waves, and trans-verse vibrations can be used in the analysis of angular deviations because they were efficient in evaluating the relationship between MAD and MOEd.

Keywords: Maximum angular deviation, wood quality, nondestructive techniques, radial division method

• Nondestructive Techniques as Tools for Evaluating Wood Quality of Loblolly Pine in Genetic Breeding Programs in Brazil

Jorge Luis Matos

• Early Determination of Wood Density in a Teak Clonal Trial in West Java, Indonesia

Iskandar Z. Siregar, Merind Mustikaningtya, Lina KarlinasariAttempts to produce fast-growing teak clones have been carried out in Indonesia through a breeding program that resulted in teak clones with desirable growth traits (for example, diameter and height). However, information on growth rates and their associated wood traits such as wood density is mostly not available. Research on tree growth and wood quality is important, especially for young teak clones (45 months after planting), for predicting wood quality at expected harvest age. The objectives of this research were to (1) examine the performance of 41 clones including the estimates of genetic parameters and (2) evaluate the wood density of the best-growing and poorest-growing teak clones. This research was conducted in a clonal trial in Purwakarta (West Java). Randomized complete block design was used to test 41 teak clones plus a local seed lot as a control. Data were collected by measuring the desired growth characteristics of the trees including survival rate, penetration depth of pylodin, and wood density. The results showed that the survival capability of teak is high on average (>90%). The results also showed that repeatabilities of diameter and height were Rc

2 = 0.62 and Rc2

= 0.70, respectively. The genetic correlation value for both diameter and height was rG = 0.061, whereas phenotypic correlation was rP = 0.842. The genetic gain esti-mation showed that height can be recommended as a selection criterion because of bigger gain. The wood penetration depth using pylodin showed an average value of 15.21 mm. It was also reported that wood density of the clones at age 45 months was still not stable because of low correlation between wood density and penetra-tion depth of both contrasting clones.

Keywords: Teak, clonal test, pilodyn penetration, wood density, genetic correlation


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• Solid Wood Quality Prediction Capacity with Acoustic Methods in Young Trees

Esther Merlo Sánchez, Gonzalo Caballé, Raquel Gonçalves, Rafael Mansini, Oscar Santaclara, Manuel Guaita F., Francisco J. Lario LezaMaking predictions of technological wood properties from nondestructive meth-ods on standing tree at early ages accelerates the processes of selection and genetic improvement of a species and improves forest management that aims to produce high-quality timber. This study was carried out on 9-year-old Pinus pinaster (n:40). The measurements were made in standing trees, and then the trees were felled. In each tree, growth and shape variables were measured and the acoustic wave velociy propagation in the longitudinal and radial directions were also measured. Standard test methods were performed in all trees for modulus of elasticity (MOE) and mod-ulus of rupture (MOR) of the entire stem and other variables such as wood density, microfiber angle (MFA), fiber length, and wood traits. Subsequently, multivariate regression models were developed to predict these properties. The three models developed had coefficients of determination close to or greater than 50%. The slenderness, the inclination of the tree, and the wave velocity propagation in the longitudinal direction were the variables that best related to MOR, MOE, and MFA. As for density, the diameter of the branches and the velocity of propagation in the face of compression were relevant. These variables should be taken into account in silvicultural management and genetic selection to obtain high-quality structural timber.

Keywords: Models, wood properties, Pinus pinaster, wave velocity

Evaluation of Roundwood

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• Grading of Eucalyptus Wood Poles Using UltrasoundYann Benoit, Michel NjankouoWood poles are commonly used around the world to carry power and telecom lines. If species and impregnation of these poles are key factors for overhead network design, mechanical property variability within the same species requires a specific grading to ensure both reliable design and an extended life expectancy. Luxpole is a nondestructive concept using ultrasound to optimize grading of new wood poles. This objective technique is based on measurement of the time of flight of low frequency ultrasonic waves (22 kHz). ENEO, the national energy provider of Cameroon, uses local wood poles for their overhead networks and plans to continue to use them. ENEO receives the rough poles from their suppliers before impregnating them in their own facilities. This paper presents the project led jointly by the National Advanced School of Engineering of Yaounde, ENEO, and CBT SA. The goal was to validate the Luxpole concept on the local eucalyptus species and ensure traceability of the measurements. The outcome shows that nondestructive ultrasonic measurements are a viable solution for grading tropical wood poles.

Keywords: Ultrasound, eucalyptus, wood poles, grading

• Drill Bit Friction and Its Effect on Resistance Drilling Measurements in Logs

Evgenii Sharapov, Xiping Wang, Elena SmirnovaThe main objectives of this laboratory study were to determine the effect of drill bit friction on resistance drilling measurements conducted on green logs and to assess the potential of using relative resistance and feeding force to predict density and hardness of wood in logs and ultimately in standing trees. Two freshly cut yellow birch (Betula alleghaniensis) logs, one with central rot and the other decay free, were used as test specimens. Drilling measurements were conducted on the logs using an IML-RESI PD 400 tool equipped with a standard spade needle drill bit. Following drilling measurements, nine 5.1-cm-thick disks were cut from the decayed log, one at each drilling location, and a 5.1-cm-wide strip was cut from each disk. A series of hardness tests were conducted on each strip based on a procedure modified from ASTM D143-2012. Then each strip was cut into 1.8-cm segments to determine wood density using the volumetric method. In addition, 195 drilling measurements were conducted on the decay-free log to specifically examine the friction effect. Statistical analysis was conducted to determine friction variations along the drilling path and develop density and hardness prediction models using measured resistance and feeding force as predictors.

Keywords: Drilling resistance, feeding force, Janka hardness, logs, wood density


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• Grading Round Eucalyptus Timber by UltrasoundMônica Ruy, Raquel Gonçalves, Douglas Pereira Moraes, Rafael Mansini LorensaniUse of wood from planted forests for furniture and construction is growing. Using wood, both round and sawn, as a structural material requires knowledge of wood properties, and grading of these properties is essential. The literature shows that nondestructive methods are efficient to sort timber, and wave propagation tech-niques are among these methods. The objective of this research was to evaluate the viability of using Brazilian’s wood grading standard by ultrasound for round pieces, verifying the influence of diameter on the efficiency of grading. Ultrasound tests were performed on green roundwood (30%) and on roundwood at equilib-rium moisture content (12%). Static bending tests were performed on roundwood at equilibrium moisture content to determine strength and stiffness. In addition to the ultrasound and bending tests, log diameter was measured and the pieces were segregated into visual classes. Diameter showed a negative correlation with acoustic and static parameters, as well as with the visual classes. Thus, grading of roundwood was evaluated considering a range of diameters. We concluded that the classes proposed by the Brazilian standard (NBR 15521 2007) can be used in the grading of round eucalyptus timber with the application of a velocity correction coefficient. The correction coefficient decreases as roundwood diameter increases.

Keywords: Strength in bending, modulus of elasticity in bending, wave propagation, logs

• Detecting Internal Defects in Hardwood Logs Using Ultrasonic Tomography based on Distorted Born Iterative Algorithms

Feng Xu, Yunfei Liu, Dan Zhang, Ling Jiang, Xiping WangAccurate determination of location and nature of internal defects in hardwood logs can provide significant benefit to the wood industry in terms of making accurate quality assessments, making accurate volume estimates, and optimizing utilization of hardwood resources. The objective of this study was to develop an ultrasonic tomography technique based on an inverse scattering theory for accurately detect-ing internal defects in hardwood logs. Poplar and camphorwood log sections were obtained and subjected to multipath ultrasonic measurements. Wave equations in scattered field and whole field were established based on the characteristics of ultrasonic wave propagation. The equations were discretized using the method of moment and then reconstructed using the distorted Born iterative (DBI) and Born iterative (BI) algorithms. The resulting tomograms showed high contrast between severely defected areas (such as a void) and the surrounding area. A defect was detectable in tomogram images when the defect area exceeded 5% of the cross


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section. Both location and size of internal defects in logs can be detected using ultrasonic tomography. Compared with acoustic tomography, ultrasonic tomogra-phy has greater accuracy because of the high frequency and short wavelength.

Keywords: Ultrasonic tomography, internal defect, inverse scattering, log, scattered field, inversion algorithm

• Combining Acoustic and Laser Scanning Methods to Improve Hardwood Log Segregation

Xiping Wang, Ed Thomas, Feng Xu, Yunfei Liu, Victor Krause, Brian K. Brashaw, Robert J. RossThe objective of this research was to examine the technical feasibility of combining acoustic wave data with high-resolution laser scanning data to improve accuracy of hardwood log defect detection and segregation. Twenty-one yellow poplar logs obtained from the central Appalachian region were evaluated for internal and external defects using acoustic impact testing and high-resolution laser scanning techniques. These logs were then sawn into boards, and the boards were visually graded based on NHLA grading rules. The response signals of the logs from acoustic impact testing were analyzed through moment analysis and continuous wavelet transform to extract time domain and frequency domain parameters. The results indicated that acoustic velocity, time centroid, damping ratio, as well as the com-bined time and frequency domain parameters are all effective quality predictors for segregating low-end logs. Acoustic data combined with high-resolution laser scanning data provide a more complete picture of the log in terms of size, shape, surface defects, and degree of soundness. Indications of “soundness” in a particular log allow the internal prediction system to flag suspicious defects as potentially unsound. Thus, a combined system is able to discriminate much more precisely with respect to log quality and potential lumber recovery than is either method independently.

Keywords: Acoustic velocity, damping ratio, impact testing, laser scanning, log defects, wavelet analysis, yellow poplar

• Assessing Internal Soundness of Hardwood Logs by Acoustic Impact Testing

Feng Xu, Xiping Wang, Yunfei Liu, Brian K. Brashaw, Lon YearyThe quality of hardwood logs varies widely within species, harvest sites, and even the same tree. Internal decay, holes, knots, and other growth defects on logs decrease the grade and yield of the resulting boards and cause a substan-tial monetary loss to timber buyers and wood manufacturers. Early detection of internal defects in hardwood logs could provide significant benefits to the wood industry in terms of making accurate quality assessments and volume estimates


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and optimizing utilization of the hardwood resource. In this study, we explored the potential of acoustic impact testing as a nondestructive evaluation procedure to assess the soundness of hardwood logs in terms of internal rot, void, and defect ratios. Fifteen hardwood logs including black cherry, white oak, red oak, and cot-tonwood were obtained and subjected to acoustic impact testing. The logs were subsequently dissected for visual examination and physical mapping of the internal defects. The response signals were analyzed using a modern signal processing method, continuous wavelet transform, to derive first and second order damping ratio. Our results indicated that acoustic velocity had a negative relationship with defect ratio in general but lacked sensitivity to small defects and was affected by species. Wavelet-based damping ratio was found to have a close linear relationship with log defect ratio. Compared with the first order damping ratio, the second order damping ratio had a better predicting power and was not affected by type and location of defects and log species.

Keywords: Acoustic impact testing, acoustic velocity, damping ratio, defect ratio, wavelet transform

• Nondestructive 3D-Measurement of Roundwood for Volume and Quality Determination

Udo Hans Sauter, Jörg Staudenmaier, Franka BrüchertThe importance of electronic roundwood measurement systems used in saw mills for accounting and optimizing purposes has increased continuously in recent decades. Today, many softwood processing saw mills are equipped with 3D scanning systems. Based on recorded high-resolution data, the outer shape of each single log can be described in detail. Volume and relevant log dimensions can be derived from this information as well as certain quality parameters. For calculating diameters and volume, there are various mathematical approaches. For determining volume of a stem or log, the ideal geometry of a cylinder is commonly assumed in practice. On the basis of log length and diameter or its cross-sectional area, a cylinder volume can be calculated. Depending on the intention of the mill, the 3D volume of a log can also be derived. Additionally, there are several different approaches for calculating roundwood quality parameters such as taper, sweep, and ovality, which significantly affect sawn timber yield. Another approach is the deduction of knot scars on the surface of the bark as a first indication of inner knot structures of logs, especially for valuable hardwoods. Based on a representative data set, relevant guidelines and theoretical approaches for calculating log volume are simulated and evaluated. Next to volume, the determination of quality parameters is simulated on the same data set using various mathematical models. For evalu-ating scaling and grading results on a reliable basis, detailed knowledge has to be obtained regarding the effects of measurement technologies and applied measure-ment methods.

Keywords: Roundwood measurement, scaling, grading, log quality

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• Predicting Stiffness of Wood I-beams Manufactured from Small-Diameter Logs

Thomas Gorman, Bradley Miller, David KretschmannThe solid wood I-beam produced from a single log is an innovative new concept for structural use of small-diameter logs. We tested a set of 28 I-beams made from 15.25-cm-diameter lodgepole pine (Pinus contorta) logs in bending to determine the MOE and MOR, to demonstrate the concepts, and to determine if conventional stress design values for lodgepole pine logs could be applied. We also nondestruc-tively assessed the MOE of individual logs prior to processing to determine if stress rating logs could predict final I-beam properties. I-beam stiffness was reasonably well correlated with the stiffness of the log it was produced from, which suggests that nondestructive evaluation of raw logs could be a method for sorting to select high-strength components.

Keywords: I-beam, small log utilization, nondestructive evaluation, timber construction, beetle-killed pine

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• Relationship between Drilling Resistance and Wood Anatomy in Young Eucalypt

José Tarcísio da Silva Oliveira, Xiping Wang, Brunela Pollastrelli Rodrigues, Graziela Baptista VidaurreThe objective of this study was to evaluate the relationship between Resistograph amplitude and wood anatomy along the stem diameter of trees at a young Eucalyptus plantation grown for pulpwood production. The genetic material used in this study consisted of two trees, one 34 months old and one 62 months old, from Eucalyptus grandis × Eucalyptus urophylla hybrid clonal plantations located in the north of Espirito Santo State, Brazil. The relationship between drilling resistance and wood anatomical parameters in the clone hybrid wood from two ages changed with tree age; the correlation coefficients between Resistograph amplitude and ana-tomical parameters were better in the 62-month-old tree than in the younger tree. In the older tree, the anatomical parameter that better correlated with drilling resis-tance was fiber wall thickness. When all data from the two ages were combined, all anatomical parameters were correlated with drilling resistance. The wood of both ages showed a good correlation between drilling resistance and wood specific gravity.

Keywords: Eucalypt wood, Resistograph® amplitude, anatomical parameters, correlations.

• Relationship between Wood Moisture Content and Drilling Resistance in Eucalypt Trees

José Tarcísio da Silva Oliveira, Xiping Wang, Graziela Baptista Vidaurre, Brunela Pollastrelli RodriguesThe objective of this study was to evaluate the relationship in the radial sense to moisture content with drilling resistance along the stem diameter in trees at a young Eucalyptus plantation grown for pulpwood production. The genetic mate-rial used in this study consisted of 50 trees of age 34 months and 50 trees of age 62 months of the clonal hybrid Eucalyptus grandis × Eucalyptus urophylla from a forest plantation situated in the north of Espirito Santo State, Brazil. In 34-month-old trees, correlation coefficients between drilling resistance and wood moisture content were low, and in some situations not significant at 1% probability. In 62- month-old trees, correlation coefficients between drilling resistance and mois-ture content improved, with correlation coefficients of –0.65 and 0.81 at diametric distances of 10 and 15 mm in the first half of the diameter. When the trees were combined, good correlation coefficients were found in the different diametric distances for the first half of the diameter. The best correlation coefficient when combining the trees of two ages was –0.75 between amplitude and wood mois-ture content in the first half of the diameter at 5 mm of the periphery of the stem.

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The good correlations were found mainly in the 64-month-old trees, and when combined, the two tree groups confirm the possibility of a successful use of the Resistograph to evaluate moisture content of eucalypt logs with good accuracy and relatively low cost.

Keywords: Eucalypt wood, Resistograph amplitude, wood moisture contents, correlations.

• Evaluation of X-Ray Images of Eucalyptus Grandis Trees under the Effect of Water Stress and Fertilization with Sodium and Potassium

Vinicius Resende de Castro, Mario Tomazello Filho, Paula Gabriella Surdi, Luiz de Queiroz, Angélica de Cássia Oliveira Carneiro, Marcos Oliveira de Paula

• Evaluation of the Modulus of Elasticity of the Wood Using a Portable Device Based on Stress Wave Method

Antonio Alves Dias, Jairo Ribas de Andrade Jr., Pedro Gutemberg de Alcântara SegundinhoThe objective of this study was to evaluate the modulus of elasticity of timber using a stress wave method and to compare the results with values obtained from static bending tests. Tests were performed in 260 visually graded pieces of Pinus elliottii from São Paulo State, Brazil, with nominal dimensions of 45 × 105 × 2500 mm. Dynamic moduli of elasticity (EMTG) were obtained by nondestructive testing of longitudinal vibration using a portable device Brookhuis Microeletronic Timber Grader (MTG) based on a stress wave method. Static moduli of elasticity (MOE) were obtained from a three-point static bending test. Results show good estimation of MOE from the results obtained using the MTG device (EMTG). The correlation coefficient ranged from 0.76 (S3 grade) to 0.91 (SS grade) and was 0.86 for the complete lot.

Keywords: Stress wave, Microeletronic Timber Grader, structural grading

• Prediction of Compression Strength of Timber by Resistograph and Screw Withdrawal Methods

Shuo Xue, Haibin Zhou, Xiaona Liu, Weibin WangUltimate compression strength parallel to grain (UCS) of timber is known as one of the important strength properties of post-type members to evaluate the structural safety status of ancient timber buildings. The UCS and density from three tree spe-cies, poplar (Populus tomentosa Carrière), larch (Larix gmelinii (Rupr.) Kuzen.), and Chinese fir (Cunninghamia lanceolata (Lamb.) Hook), were estimated by using two

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different methods of Resistograph and screw withdrawal tests. Two kinds of screws with single-start thread and double-start thread were selected in screw withdrawal tests. The relationships between UCS and density were respectively established with the resistographic measure (RM) and the screw withdrawal resistance by regression models. The results showed that the correlation coefficient between the RM and the UCS ranged from 0.5 to 0.8. The correlation coefficient between the double-start thread screw withdrawal resistance (SWDST) and the UCS ranged from 0.45 to 0.7, whereas values of coefficients for the single-start thread screw withdrawal (SWSST) ranged from 0.15 to 0.65. The correlation coefficient of poplar for the regression model of screw withdrawal resistance with UCS and density were higher than those of Chinese fir and larch. By comparison with the screw with-drawal test, the Resistograph test method was more reliable for predicting UCS and density of timber.

Keywords: Ultimate compression strength parallel to grain; density; Resistograph; screw withdrawal

• Portable Profilometer Dr. Alex J. Trinca, Ms. Ney B. A. Sidou, Railson S. FerreiraNondestructive test development continues; for that development, it is essential that results be expressed as much as possible as accurate measurements. We have developed equipment capable of expressing the real perimeter of the element to be measured, feeding the tomography, and providing exact data for accurate reports. The research has been conducted to make a portable device, with a platform that can be connected to other software, quickly and dependably profiling the element from sclerometric techniques, using software, to generate interchangeable data with other systems. The system can even identify precisely the length between two aleatory points when requested. The results obtained generate the perimeter delineation with millimetric precision, and allow the elaboration of images with real proportions of the sample, giving greater accuracy to nondestructive tests.

Keywords: Perimeter of trees, measures of trees, profilometer

• Estimation of Moisture Content of Japanese Cedar (Cryptomeria Japonica) Large-Diameter Logs by Measuring Relative Permittivity and the Phase of Low-Frequency (52 MHz) Electromagnetic Wave

Kiyohiko Ikeda, Youki Suzuki, Akihiro Sugiyama, Takeshi HoshikawaThe purpose of this research is to develop a method and device for evaluating large variations in moisture content, particularly heartwood moisture content distri-bution, towards efficient kiln-dried lumber production from large-diameter Sugi

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(Japanese cedar) logs, which is expected to increase supply. For measuring relative permittivity, a needle-type terminal was driven into the heartwood of a cedar log surface; for phase, a device was used to measure phase when the log moved between the transmitting and receiving antenna of a low-frequency (52 MHz) elec-tromagnetic field. After measuring relative permittivity and electromagnetic wave phase of the cedar log (end diameter 30 to 40 cm, sample number of 90) using these devices, the total dry moisture content of the specimens sampled from the log was examined and the relationship between them was evaluated. The relative permittivity (mean value of bottom and end of the log) measured at three points of the core material varied in each part of the heartwood, and a large difference was confirmed among sugi log individuals. The correlation coefficient between the relative dielectric constant of the log and the total dry matter moisture content of the core material sample was 0.824, and a high correlation was observed. The correlation coefficients between the phase differences of the logs and oven-dried moisture content of sapwood, heartwood, and sapwood + heartwood (whole log) by the disc specimens were 0.689, 0.527, 0.787, which was a significant correlation. It was also suggested that the moisture content distribution of the log can be esti-mated from the phase and attenuation fluctuations when the log moves between the antennas.

Keywords: Moisture content, electromagnetic wave, relative permittivity, phase difference, Japanese cedar

• Applying Discriminate Analysis and Acoustic Tool to Assign Loblolly Pine Families into Susceptibility Classes

Charles Essien, Brian Via, Thomas Gallagher, Timothy McDonald, Lori G. Eckhardt Loblolly pine is one of the most important tree species in the southeastern United States. However, root-feeding fungi continue to be one of the major challenges confronting pine production in this country. Little information exists on the use of rapid nondestructive wood quality assessment techniques to differentiate between families susceptible and tolerant to root-feeding fungi. In this study, we explore the possibility of using an acoustic tool and statistical techniques to differentiate between 17-year-old loblolly pine trees susceptible and tolerant to root-feeding fungi. Results indicate that the effects of root-feeding fungi on wood quality prop-erties differ widely between the families studied. The acoustic tool was successfully used to differentiate between the susceptible and tolerant families.

Keywords: Discriminate analysis, Root-feeding fungi, acoustic tools

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• Drill Bit Friction and Its Effect on Resistance Drilling Measurements in Logs

Evgenii Sharapov, Xiping Wang, Elena SmirnovaThe main objectives of this laboratory study were to determine the effect of drill bit friction on resistance drilling measurements conducted on green logs and to assess the potential of using relative resistance and feeding force to predict density and hardness of wood in logs, and ultimately in standing trees. Two freshly cut yellow birch (Betula alleghaniensis) logs, one with central rot and the other decay free, were used as test specimens. Drilling measurements were conducted on the logs using an IML-RESI PD 400 tool equipped with a standard spade needle drill bit. Following drilling measurements, nine 5.1-cm-thick disks were cut from the decayed log, one at each drilling location, and a 5.1-cm-wide strip was cut from each disk. A series of hardness tests was conducted on each strip based on a procedure modified from ASTM D 143-2012. Then each strip was cut into 1.8-cm segments to determine wood density using volumetric method. In addition, 195 drilling measurements were conducted on the decay-free log to specifically exam-ine the friction effect. Statistical analysis was conducted to determine friction vari-ations along the drilling path and develop density and hardness prediction models using measured resistance and feeding force as predictors.

Keywords: Drilling resistance, feeding force, Janka hardness, logs, wood density

• Use of Electric Resistance Tomography for Detection of Sapwood, Heartwood, and Decay in Commercial Forest Stands

Lothar GöckeThis poster presents measuring data of various applications of electric resistance tomography (ERT) in commercial forest stands. The data shows how ERT can be used to

• identify various stages of rot in picea, Douglas fir, and pine trees,

• detect wet wood in polar trees,

• detect fungus infections in grape wine trunks,

• measure the size of the valuable heartwood core in teak wood, and

• detect defects in veneer oak trees.

Keywords: Electric resistance tomography, decay detection, heartwood detection, sapwood measurement

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• High-Precision Tilt and Elastic Line Measurements of Trees or Poles under Load Using a Simple Smart Phone

Lothar GöckeLoad tests on trees have been used to measure both strength of the root system and breaking resistance of the stem. The anchorage strength of the root system is tested using inclinometers (based on accelerometer sensors) at the base of the tree. The stability of the trunk is measured by attaching strain gauges along the axis of the trunk and measuring fibre compression (strain) when a load (through a rope attached to the crown) is applied to the tree. The practical application of tilt measurement may suffer from noise that the accelerometer is naturally exposed to. Strain measurement on the trunk might be less accurate because the location the strain gauge attached to the trunk is not always exactly in the line of maximal force. This talk shows a method to precisely measure the inclination of the root plate and also the trunks curvature at multiple sections by using a common smart phone. The curvature is the result of all inhomogeneities of the trunk and can be translated into the overall modulus of elasticity (MOE) of a section of the trunk. The test setup allows for high accuracy of the tilt measurement (better than 1/100°) and also an accurate time-wise synchronization of all data points. The method can also be used to test the elastic line and/or “anchorage” of poles or other structures.

Keywords: Elastic line, load test, trees, poles

• Air-Coupled Ultrasound and Electrical Impedance Spectroscopy Applications for Wood

Markku Tiitta, Laura TomppoThe overall goal was to develop efficient methods to improve the quality assess-ment of wood. Air-coupled ultrasound and electrical impedance spectroscopy were the studied measurement methods. The ultrasound method is based on mechan-ical waves and is affected by the mechanical properties and defects of wood. Density affects both methods, and the electrical impedance method is especially affected by moisture content and the chemical properties of wood. The relations between the methods and the properties of several wood species were examined, both softwoods and hardwoods. Several studies were also conducted for modified wood. According to the results, electrical impedance spectroscopy, air-coupled ultrasound, and combined method are efficient nondestructive techniques for esti-mating quality properties of hardwood, softwood, and modified wood. Recently, industrial tests have also been conducted.

Keywords: Air-coupled ultrasound, electrical impedance spectroscopy, quality assessment

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• Determination of Modulus of Elasticity of Particleboard by Nondestructive and Destructive Testing Methods

Felipe Silva Bastos, Marcos Oliveira de Paula, Matheus Fernandes de Carvalho Reis, Vinícius Resende de CastroThe transverse vibration method offers great potential for nondestructive wood testing and evaluations due to the precision of the mathematical model associated with this method and the possibility of application in pieces of structural dimen-sions. However, there is a lack of study about the utilization in wood particleboard. Particleboards of Pinus caribaea were produced at Federal University of Viçosa, in the Mechanical Properties Laboratory, with density of 0.60 g cm–3 and final dimensions of 38 by 38 by 1 cm. Phenol-formaldehyde (PF) and sodium silicate (SS) adhesives were used with different proportions: 100% PF; 96% PF, 4% SS; 94% PF, 4% SS; 92% PF, 8% SS; 90% PF, 10% SS, for a total of five treatments. The particleboards were cut into samples for modulus of elasticity determination by a destructive method using a universal mechanical test machine and by the transverse vibra-tion method. This nondestructive testing was performed using a prototype with a microphone and the software Fast Fourier Transform Spectrum Analyzer to capture the mechanical wave vibration through each sample. Then the dynamic modulus of elasticity was calculated. The values obtained for modulus of elasticity using the transverse vibration method were equivalent to the destructive method, showing no significant difference. Therefore, such a tool is a potential alternative for wood particleboard mechanical characterization. It is necessary to emphasize the need to improve this technique, developing new equipment and creating models with adequate parameters and coefficients, so that this method can be more effectively used.

Keywords: Modulus of elasticity, mechanical testing, nondestructive method, particleboard, transverse vibration technique

• Plant Health Evaluation and Fall Risk in Urban Trees in the City of Belo Horizonte, Brazil

Aderbal Gomes da Silva, Luis Miguel MartinsThe objectives of this study were to evaluate the plant health and the risk of fall of 20 trees of four species frequent in Brazilian public roads. The evaluation was performed through visual inspection and the use of internal prospecting instru-ments. The trees were located on public roads in the city of Belo Horizonte, Minas Gerais, Brazil. Initially, dendrological characteristics were observed and dendro-metric parameters such as diameter at breast height (DBH), median canopy radius, total height, and height of the canopy base were evaluated. Visual inspection was carried out, evaluating the condition of the trees and local conditions, using as basis the VTA (visual tree assessment) method. In the diagnostic process, tools

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such as rubber hammer, binoculars, and internal prospecting instruments were also used. Five individuals were evaluated from each species: Jacaranda mimosaefolia, Ligustrum lucidum, Michelia champaca, and Poicianella pluviosa. The evaluated trees were older than 40 years, and had diameter at breast height greater than 45 cm and height between 10 and 16 m. At the end of the evaluation process, suppression was recommended for four individuals of Ligustrum lucidum, three of Jacaranda mimo-saefolia, and two of Poicianella pluviosa due to irreversible damages, characterizing low phytosanitary condition and high risk of fall. In general, it was observed that cavities, cancers, codominances, and biotic agents (fungi) affected the safety of the trees. The individuals of Michelia champaca evaluated presented medium phy-tosanitary quality with small necroses in the trunk, but without structural damages. The presence of the cochineal pest was also identified, but the species was tolerant.

Keywords: Hazard tree, risk assessment, plant health, visual inspection

• Nonconventional Approach to Evaluate the Quality of Heartwood and Sapwood

Sabrina Cherelli, Adriano BallarinThis study evaluated the quality of heartwood and sapwood from mature trees of two species (Corymbia citriodora and Eucalyptus tereticornis) by means of the qualification of their proportion, determination of basic and apparent density using nondestructive attenuation of gamma radiation technique, and calculation of the density uniformity index. The heartwood and sapwood were delimited by macroscopic analysis, and the calculations of areas and percentage of heartwood and sapwood were performed using digital image analysis. The uniformity index was calculated following methodology that numerically quantifies the dispersion of punctual density values of the wood around the mean density along the radius. The percentage of heartwood was higher than that of sapwood in all species studied. The density results showed no statistical difference between heartwood and sap-wood. In contrast, in all species studied there were statistical differences between uniformity indexes for heartwood and sapwood regions, making justifiable the inclusion of the density uniformity index as a quality parameter for Eucalyptus wood.

Keywords: Eucalyptus, density uniformity index, nonconventional approach

• Evaluation of Density Profile of Particleboard of Amazonian Wood Residues Using a Radiographic Method

Paula Surdi, Geraldo Bortoletto Júnior, Vinicius Resende de Castro, Mario Tommasiello Filho

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• Comparison between Eucalyptus and Oak Woods with a View to Application in Wooden Shims

Pedro Gutemberg de Alcântara Segundinho, Thais de Souza Marcchiori, Fabricio Gomes GonçalvesIt is remarkable how important the construction sector is in any country, along with sustainability in current times. In Brazil, wood material is not yet widely used in buildings, compared to countries in North America and Europe. Eucalyptus and oak woods were evaluate in this study to deepen the knowledge about them and to compare the two species of wood. The analysis was carried out by comparing physical and mechanical properties of the wood species; in almost all tests, the oak wood presented higher property values than eucalyptus wood. However, the euca-lyptus wood also shows suitability for the manufacture of wooden shims.

Keywords: Nondestructive tests, physical properties, mechanical properties, timber structures

• Characterization of the Dynamic MOE by Transverse Vibration Method in Glulam of Thermally Treated Eucalyptus grandis

César Polanco-Tapia, Diana Peña, Jose Nivaldo GarciaEucalyptus grandis species is recognized in Latin America because of its rapid growth and high mechanical resistance. Thermal treatment of biological materials is gaining importance in the scientific literature and in industrial processes to acquire advantages such as natural durability, waterproofness, dimensional stability, and color homogenization. Unfortunately, some authors found disadvantages in this process, especially regarding the loss of mechanical strength. The effect of heat treatment on the adhesive line stability is unknown. The present paper evaluated the effect in glulam of heat treatment in E. grandis through the transverse vibration nondestructive technique. It compared the obtained values of the dynamic mod-ulus of elasticity (MOE) in treated and untreated wood. The FFT Analyzer program was used to measure vibration frequencies; for the transformations, the USDA equations were followed. All the wood underwent bending test in three points (ASTM D 143) to determine static MOE. The pieces used had PRF (phenol resor-cinol formol) in the adhesive line localized in the thickness middle with 350 g m–2 of spread. Finally, we found differences for MOEs between treated and untreated wood, and between transverse vibration and bending static methods. In the case of the destructive tests, the failure did not occur on the adhesive line, and it can be anticipated that temperature conditions and time intervals used in the heat treat-ment did not cause serious damage to adhesive lines but rather to the wood.

Keywords: Glulam, heat treatment, transverse vibration, Fast Fourier Transform (FFT), bending test

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• Updating Numerical Models of Timber Bridges by Experimental Modal Analysis

Julio Vivas, Soledad Rodríguez, Juan Carlos Santos Fernández

• Comparison of Voltammetry and Digital Bridge Methods for Electrical Resistance Measurements in Wood

Shan Gao, Zhenyu Bao, Lihai Wang, Xiaoquan YueElectrical resistance of wood is closely related to moisture content, wood den-sity, and mobile ions and thus is used to determine the progressive discoloration and decay rates of standing trees and estimate transverse moisture distributions. Voltammetry and digital electric bridge are two common methods for wood resistance measurements in the laboratory. In this paper, factors influencing voltammetry, that is, current types (DC and AC), waveforms, voltages, frequency, and moisture content (MC), of Populus davidiana specimens were examined. Voltammetry and digital bridge methods were closely compared for accuracy and ease of operation. Results showed that current types, waveforms, voltages, and frequency had clearly different effects on the resistance values measured by voltam-metry. The measured DC resistance was considerably greater than AC impedance (about 50%) and decreased with increasing frequency at all measured MC levels. DC resistance presented a turning point at 8 V and was not sensitive to voltage change above 8 V, whereas AC impedance remained constant over the entire volt-age range. Effect of waveform on resistance was minor. No remarkable differences in resistances were found between the two methods in wood specimens with MC above fiber saturation point (FSP). Voltammetry was relatively stable compared to the bridge method when MC was below FSP. The relationships between MC and resistances of the two methods confirmed the previous reports from other scholars. Compared to the digital bridge, the voltammetry of AC with 1000-Hz sine waves was found to be a better method for measuring electrical resistance in wood.

Keywords: Electrical resistance; voltammetry; digital bridge; moisture content

• The Potential of Portable NIR Spectroscopy Devices for Rapid, Nondestructive Measurement of Basic Wood Density on Standing Trees

Esther Merlo Sánchez, Jean Paul Charpentier, Vincent Segura, Ines Bertoldi, Gonzalo Caballé, Oscar SantaclaraNear infrared (NIR) spectroscopy has been used quite successfully in measuring many wood properties. As a result, NIRS calibration has recently been devel-oped for wood basic density. To what extent can NIR spectroscopy be used as

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an alternative tool for estimating precisely defined wood microdensity variables? Recently, portable NIR devices have emerged on the market. Such devices offer the potential of acquiring NIR spectra on standing trees, but the way of collecting the spectra and the extent to which they compare with spectra collected in the lab-oratory remain to be explored. In this work, we explored and tested the potential of these devices for rapid, nondestructive measurement of basic wood density on standing trees. Measurements were carried out with a portable NIR device on two clonal eucalyptus tress in Spain, from which cores were previously extracted and basic density determined. Microdensity profiles were analyzed and NIR spectra were obtained in the laboratory.

Keywords: Near infrared spectroscopy, eucalyptus, calibration

• Dendrochronology Application: Potential of X-ray Microdensitometric and μ-EDXRF Techniques in Tree-Ring Physical and Chemical Analysis of Pinus taeda Wood

Daigard Ricardo Ortega Rodriguez, Elton E. Novais Alves, Pablo de Azevedo Rocha, Liovando Marciano da Costa, Mario Tomazello FilhoThe use of NDTE in dendrochronology is a novel alternative to assess wood properties and silvicultural metrics in a wide range of tree growing conditions. X-ray microdensitometric and microfluorescence (μ-EDXRF) techniques provide intra-annual ring data of physical and chemical availability. Our aim was to evaluate the potential use of X-ray microdensitometric and μ-EDXRF analysis to assess carbon accumulation and detect the presence of chemical elements in the wood of 17-year-old Pinus taeda. One radial sample at DHB were obtained from five P. taeda trees varying in their nutritional state (20, 40, 60, 80 and 100 ton/ha of cellulosic residues). Samples were analyzed in the QTRS-01X X-ray equipment for continuous radial scanned density of the wood. Radial density profiles were constructed and related to volume of growth to obtain annual carbon acumulation. X-ray transmis-sion intensity and microchemistry maps were obtained from twin radial samples in the μ-EDXRF spectrometer. Nutritional treatments had a significant effect on car-bon acumulation. The highest carbon acumulation in the wood was found for the sample with 80 ton/ha of cellulosic residues. The main chemical elements found were Na, Si, P, K, Ca, Cr, Mn, and Fe. This exploratory testing, using X-ray techniques in the P. taeda wood, show potential value for evaluating carbon acumulation and detecting chemical elements in wood. In addition, this NDTE may provide an interesting tool for interpreting the physical and chemical response of trees to their silvicultural growing conditions.

Keywords: X-ray fluorescence, densitometry, carbon accumulation, dendrochemistry

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• Methods for Evaluating Mechanical Properties of Wood–Plastic Composite Pallets

Zhanguo WeiWood–plastic composite (WPC) pallets are commonly used in logistic operations in developed countries. In China, the performance requirement and test methods have been developed for general purpose pallets. Because of the unique character-istics of WPC, the test methods developed for general purpose pallets cannot be adopted for the WPC pallets. This paper reports an ongoing study of developing new test methods for evaluating the mechanical performance of WPC pallets.

Keywords: Wood–plastic composite, pallet, test standard, standardization system

• Physical and Mechanical Characterization of Wood from Roots

Nina Cavalcanti, João Pedro Oliveira, Raquel GonçalvesTrees play an important role in urban areas because of their contribution to conserving energy, improving air quality, reducing flood risk, enhancing health, and adding charm and beauty to the cities. But weakening of trees due to human interference and poor planning can lead to accidents, affecting the safety of people and causing economic losses. A common cause of urban trees falling is weakness of the roots, but root properties are little studied. The purpose of this paper is to present some preliminary results of physical and acoustic characterization of wood from roots. The research was conducted in roots of six tree species. Samples were subjected to ultrasound using longitudinal waves in direct (parallel) and indirect (45° inclination) tests. Additionally, using an increment borer, a small cylinder was removed from each sample and used for basic density determination. The results showed that both direct and indirect longitudinal velocities vary with species, indi-cating the viability of sorting wood from roots by stiffness. This can be used in bio-mechanical analyses. The longitudinal velocity obtained using indirect and direct tests present statistical correlation, an important result for field trials where only indirect measurement is possible. Basic density has shown a moderate correlation with radial velocity. Even if preliminary, the results show the viability of physical and acoustical characterization of root wood and can provide an important tool for inspections considering tree risk analyses by biomechanical studies.

Keywords: Stiffness, basic density, acoustic properties, roots, urban trees

• Acoustic Characterization of Wood of BranchesGustavo Henrique Lopes Garcia, Monica Ruy, Rafael Gustavo Mansini Lorensani, Raquel GonçalvesWith the extreme events caused by climate change, there is significant growth in the number of breaking and falling branches in urban trees. When big branches

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fall in urban areas, there can be serious accidents. Branches have great importance in biomechanical analysis of tree behavior, but in general, their properties are not known. Wave propagation methods are used to determine mechanical properties of the stem wood of trees, and it’s believed that the technique may also be applied to the branches. The objective of this study was to present the methodology and preliminary results of acoustic characterization of wooden branches as well as to propose methodology for inspection applied directly on trees. Sections at different heights of the same branch of six species were collected and readings were taken longitudinally with direct measurements. Transducers were positioned on opposite faces of the branch section. With indirect measurements, transducers were posi-tioned at 45 degrees on the same face, because tree ends can’t be accessed during real-life inspection. Results showed that it’s possible to acoustically characterize wooden branches and that the speeds varied between species, indicating that stiff-ness variation is also being represented by this acoustic property. The results also allowed us to visualize correlations between direct and indirect velocity tests. This result is important to the use of the technology in live trees, which will be necessary for inspections aiming to analyze branch fall risk through biomechanical studies.

Keywords: Ultrasound testing, tree risk assessment, branches characterization, strength of branches

• Comparison among Velocities of Ultrasound Wave Propagations in Roots, Branches, and Stems

Cândida P. da Costa, Raquel Gonçalves, Nina M. O. Cavalcanti, Mariana N. Reis, Gustavo H. GarciaTrees are very important to urban welfare, but unfortunately, they can cause acci-dents. People want to preserve trees, but at the same time, safety is also necessary. Therefore, studies that have the objective to improve tree inspections are very important, and more scientific methods are needed to give inspectors more objec-tive information. Wave propagation methods are often used to determine elastic properties of wood, mainly the property of stiffness. At the same time, stiffness is a very important property related to the biomechanical behavior of trees. The objec-tive of this research was to determine and compare velocities of wave propagations obtained in roots, branches, and stems. The aim was to contribute to information about properties of wood from different parts of the tree and to support studies of tree risk assessment from biomechanics. The results, although preliminary, indi-cated that for wood from roots, branches, and stems, there are differences among velocities obtained in different species. Among the species tested, we did not find statistical differences between velocities obtained in wood from different parts of the tree.

Keywords: Wood stiffness, trees, tree risk assessment

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• Identification and Evaluation of Historic Timber Buildings in the Dominican Republic by Nondestructive Testing (NDT)

Virginia Flores Sasso, Raquel Carrera Rivery, Esteban Prieto ViciosoAll the Caribbean islands possess abundant wood architecture that are part of their cultural heritage and of the historical landscape of the region, most of them constructed between the 19th and 20th centuries, products of the commer-cial boom between the Greater Caribbean with the United States and Europe. Now, most of these buildings are in a poor condition and lacking maintenance, and Caribbean weather conditions accelerate the deterioration process. In the Dominican Republic, the timber buildings are not properly protected and there are no regulations or policies that control preservation, which results in inadequate interventions that affect their construction systems and historical value. The cause is a product of ignorance of the properties of the woods and absence of appro-priate methodology to evaluate and study it. The lack of a useful and consistent inspection method to detect damage and decayed parts of the timber structural elements, and the interest of saving the maximum amount of historic fabric, moti-vated this study. For that reason, the aim of the research is to characterize the type of wood and develop a methodology to evaluate the state of the historic timber fabric by nondestructive testing. A methodology was designed for in situ and laboratory evaluation. The intentions are to integrate research techniques and new processes with traditional methods. The methods used are visual inspection for quality, nondestructive testing, and a minimum of destructive testing (just to deter-mine a few parameters) to compare the mechanical characteristics of the structural elements with resistography readings and impulse tomography images.

Keywords: Historic timber, resistography, Arbotom impulse tomography, Caribbean timber

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20th International Nondestructive Testing and Evaluation ... NDTE Conference Gui… · Welcome 20th...

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