First Working Group 3 MeetingFirst Working Group 3...

Action FP0802

First Working Group 3 MeetingFirst Working Group 3 Meeting

Computational Modelling

May 13, 2009

Workshop “Experimental and computational methods in wood micromechanics” May 11-13, 2009

Tentative agendaTentative agenda

• Purpose of working group 3• Presentation of participantsPresentation of participants• Short-term scientific missions• Suggestions of future WG3 meetings• Multiscale modelling – bridging length scales• Multiscale modelling bridging length scales• Summary – decisions

Purpose of WG3Purpose of WG3

Simulations

WG3 Modellingg

Necessary input ValidationIteration

WG1 StructureMicroscopy

WG2 PropertiesExperimental characterizationpy p

Presentation of researchers and groups

‐ Name, affiliation, function‐ Competences and available techniques‐ Competences and available techniques

Michael Jarvis, Univ GlasgowKristofer Gamstedt KTHKristofer Gamstedt, KTHThomas Bader, TU WienTancrèdes Alméras, Univ MontpellierJan Bramming NTIJan Bramming, NTIParviz Navi, Bern Univ Applied SciencesJoão Fernandes, SuperwoodViivi Koivu, Univ JyväskyläViivi Koivu, Univ JyväskyläLoane Bigorgne, INSA de LyonMats Ekevad, Luleå Univ TechnolBrigitte Chabbert, FAREg ,

Others: oral presentations

Mike JarvisChemistry Department, Glasgow University, Scotland

Structure of wood and its relation to mechanicalStructure of wood and its relation to mechanical performanceTechniques available‐Techniques available

•FTIR microscopy with polarisation, deuteration and mechanical stretching

•Solid-state 13C and 1H NMR

•Diffuse fibre diffraction

•X-ray densitometry

Kristofer Gamstedt

KTH – Royal Institute of TechnologyDepartment of Fibre and Polymer TechnologyDivision of BiocompositesDivision of BiocompositesHead: Lars Berglund

Main activitiesCellulose‐based nanocompositesStructure‐property relations of wood

C d iCompetences and equipmentFEG‐SEMPreparation of MFC‐based materialsMe hani al testinMechanical testingMechanistic modelling

Potential collaboration partners Molecular dynamic simulationsWood science: morphology biological function archeological preservationWood science: morphology, biological function, archeological preservationImage analysis, x‐ray microtomography, microscopy

Institute for Mechanics of Materials and StructuresFaculty of Civil Engineering

Research interests - Thomas Bader et al.macroscopic mechanical and transport properties ofwood and wood based productsp- multi-scale micromechanical modeling- continuum micromechanics / unit cell theory

within the framework of poromechanics- within the framework of poromechanics- modeling on structural level (e.g. modeling of defects)- application of constitutive models to finite element methodsother research at the institute: micromechanical modeling of bone, skin, concrete, asphalt, a.o.

LaboratoryLaboratory for micro- and nanomechanics ofbiological and biomimetical materials

Laboratory

e.g. axial and torsional testing, nanointendation, ultrasonic equipment

Laboratory for macroscopic material testing

e g uniax/biax/triax testing machines creep testinge.g. uniax/biax/triax testing machines, creep testing

Instit tion CNRS U i M t lli (FRANCE)

Tancrède AlmérasInstitution: CNRS ‐ Univ. Montpellier (FRANCE)Laboratory of Mechanics and Civil Engineering = LMGCTeam:Tree and wood mechanics

Research interest: tree/wood biomechanics/micromechanics

Maturation stress in trees: mechanisms at stem level biomechanical• Maturation stress in trees: mechanisms at stem level, biomechanical and practical implications• Maturation stress in wood: generation mechanism at the cell-wall level, g ,consequences for wood behaviour• Properties of green wood: diversity (tropical woods, reaction woods), relation with structure at all scales biomechanical implicationsrelation with structure at all scales, biomechanical implications

At team level: + visco-elasticity, hygro-mechanical behaviourTechniques: microscopy AFM XRD mechanical tests (creep dynamic)


Techniques: microscopy, AFM, XRD, mechanical tests (creep, dynamic)

J B iJan Bramming

• Born and raised i Denmark, lived in Norway since 1991.

• Master's degree from UMB on Forestry –specialization in wood technology

• Employed at NTI since 2001.

• Formal position: Scientist.

Norsk Treteknisk Institutt (NTI)• Research & Development centre for Norwegian wood industry. 35 employees, 150 member companies• Leading edge competence: gluing, dryingLeading edge competence: gluing, drying and grading of wood• Laboratories for: Mechanical testing, Chemical analysis, glue test and approvals, wood drying surface treatment woodwood drying, surface treatment, wood autonomy.• Test fields: Life expectancy of impregnated wood and surface treatments• Information to member companies, engineers, architects, general public etc. • Quality documentation(EN CE TRADA JAS)(EN, CE, TRADA, JAS)• Quality control schemes (Construction wood, glulam, impregnated wood etc,)

Parviz Navi : Bern University of Applied SciencesPrevious works:‐ Homogenisation of viscoelastic materials using dispersion and damping relations‐ Application of Micromechanical approaches to model the wood axial tension, transient moisture effects on wood creep, wood cell damaging, and development of a 3D fracture model at fibre level.Current works:‐ Modelling the crack propagation and its stability in a panel under humidity, force and temperature variation.

B d d

Scale: boardDifferential

K‐type thermocouple• Based on data:

• directional permeabilities;• moisture content distribution;• wood mechanical properties;

pressure meter

p

• wood mechanical properties;

140

160Pressure in the vesselPressure inside board Exp Pressure inside board Sim

e, b

ar 100

120

C 50

60

70

Pres

sure

40

60

80

Tem

pera

ture

, ºC

30

40

50

T inlet vesselT outlet vesselT f f l

0

20

40

0 2000 4000 6000 8000 10000 12000 14000 16000 1800010

20

T tofpof vesselT surface wood boardT inside wood board

T sim inside board

Time, s

0 5000 10000 15000 20000

COST FP0802 Workshop, Vienna 2009COST FP0802 Workshop, Vienna 2009

Time, sec

João FernandesJoão Fernandes

Soft Condensed Matter and Statistical PhysicsDepartment of Physics, University of Jyväskylä

Laboratory facilities Research interestsLaboratory facilitiesX‐ray tomography‐ SkyScan 1172‐ X‐radia MicroCXT (18.5.2009 ‐>)

d ( )

X‐ray tomography‐Micro and nano‐scale materials analysis‐ Image analysisS l h i i i 3‐ X‐radia nanoCXT (8.6.2009 ‐>)

Microscopy‐ Scanning electron microscope (SEM)

‐ Structural characteristics in 3D

Microscopy‐Materials research in 2DScanning electron microscope (SEM)

‐ Transmission electron microscope (TEM)

Numerical fluid flow “simulator”LBM i l i f fl id bili

Materials research in 2D‐ Verification for tomographic reconstructions

Numerical fluid flow analysisFl id fl i h di‐ LBM simulations for fluid permeability

‐ Fluid imbibition/penetration inporous materials

‐ Fluid flow in porous heterogeneous media‐ Permeability, flow velocity, flow rate,flow paths, penetration rate etc.

“Home‐made” measurement devices‐Matrix‐diffusion‐ Fluid permeabilityO i l h

“Home‐made” measurements‐Materials research‐ Verification for numerical analysis resultsFl fil

Viivi KoivuUniversity of Jyväskylä

‐ Optical tomography‐ Pipe system for fluid / fibersuspension flows

‐ Flow profiles

WG3 COST Action FP0802Ki d f d liKind of modeling

INSA de Lyon , CNRS UMR 5259

Study at the macro and mesoscopic scaley p

Representation of softwood as cylindrically orthotropic material + linear stiffness variation along annual ringsy y p g g

Heterogeneous model : stiffness variation along each annual rings

1.E+07 El

Er

1.E+03

1.E+04

1.E+05

1.E+06

Mod

ule

[Mpa

]

Er

Et

Grt

1.E+01

1.E+02

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Position in an annual ring

http://sites.google.com/site/loanebigorgne/[email protected]

Mats EkevadAssociate ProfessorLuleå University of Technology, Division of Wood Science and Technology,Skellefteå, Sweden

Research interests:Finite element modelling of wood, in order to simulate production of sawn timber and alsosimulation of end‐use of wooden products. The length scale of the variations of the woodmaterial model varies much between different projects.

Examples: Si l ti f h i f t d d b id l th l f d d i ti i‐Simulations of mechanics of prestressed wooden bridges, length scale of wood description is large (say 0.5 m), focus here is on slip between members‐Simulations of influence of knots on stiffness, length scale say 10 mmSimulations of wood drying diffusion phenomena length scale say about the resolution of‐Simulations of wood drying, diffusion phenomena, length scale say about the resolution of CT scans, about 1 or a few mm.‐Most recent project: to model wood cutting, length scale, say 10 μm (tool edge radius), a difficult taskdifficult task

Laboratory equipment: CT (computed tomography) scanner, a new one installed this year. 512x512 pixels, resolution 1 mm, about 3000 levels/pixel, accuracy for one pixel is about +‐5512x512 pixels, resolution 1 mm, about 3000 levels/pixel, accuracy for one pixel is about + 5 kg/m3, 1 scan/s.

Interested in cooperation with other researchers with the same interests

h itFARE research unit(Fractionnement des Agro-Ressources et Environnement)

(Fractionnation of lignocellulosic ressourcesand Environment)

Head Bernard KUREK

Our object of interest:the lignocellulosic cell wallthe lignocellulosic cell wall

• Use schemes: fractionation followed by reconstructionfollowed by reconstruction

• Final properties of products and materials

• depend on bio-synthesis anddepend on bio synthesis and interactions with deconstruction and reconstruction processes

Global outputs of our research objectives: uses of renewable Carbon

• Uses of lignocellulosic biomass• Uses of lignocellulosic biomass…– energy, i.e. biofuels– biodegradable materials

b ilding blocks for chemistr– building blocks for chemistry– (Macro)-molecules for specialty chemistry

• … but achieving also sustainability of the systems… but achieving also sustainability of the systems– back to soil; N and C cycles

What are we doing?Fundamental

delineate key points of the multi scale building mechanisms of plantdelineate key points of the multi scale building mechanisms of plant cell wall

study the physical, chemical and biological transformations during processing as well as during soil decompositionprocessing as well as during soil decomposition

study some reconstruction mechanisms and processes with isolated polymers and fibres in (and for) new bio-based materials

Applied

dynamic description of lignocellulose properties at various scaledynamic description of lignocellulose properties at various scale levels:

- for substitution purposes for new functionalities- for new functionalities

How are we working: 4 teams COST FP0802Structure and Accessibility

of secondary plant cell wall

ctio

nFP0802

e pr

oduc

owle

dge

Physical and chemicaltransformations

Biological transformationsin complex media

Biotransformation in soil litters

Kno

nte

grat

ion

New fibrous materials Enzyme reactionsand fermentations C and N cycles

Int

about 55 people (incl. 35 permanent staff)

Structure and accessibility of plant cell wall

V Aguié - B ChabbertMultiscale studies of the cell wall cohesiveness and accessibility Locking point for destructuration (enzymatic, mechanical,, ...)

V. Aguié B . Chabbert

On model systems-macromolecular assemblies

Strategy: -system modulation ( i /d i ) ligninlignin--hemicellulose complexhemicellulose complex(construction /deconstruction)

-chemistry/cytochemistry/polymer interactions probing/ local probing

cellulose surfacescellulose surfaces

p g p g

On plant systems- genetic and environmental factors - various lignocelluloses:

fl h ( l U i Lill 1 S H ki )

Nanocristalsramie

Monolayer Multilayers(cellulose-hemicelluloses-

lignins-proteins)The image part with r elati…

The image part with r elati…





flax, hemp (col. Univ Lille1, S. Hawkins)grass (wheat, maize, miscanthus)wood (poplar, col. INRA Orléans, Nancy) 2 µm 2 µm



















Micro-cristauxde celHRGPPectineHRGPMcrocrsta Micro-cristauxde celHRGPPectineHRGPMcrocrsta Micro-cristauxde celHRGPPectineHRGPMcrocrsta Micro-cristauxde celHRGPPectineHRGPMcrocrsta Micro-cristauxde celHRGPPectineHRGPMcrocrsta Micro-cristauxde celHRGPPectineHRGPMcrocrsta Micro-cristauxde celluloseHRGPPectineHRGPMcrocrstauxde cellu Micro-cristauxde celluloseHRGPPectineHRGPMcrocrstauxde cellu

At nanometric scales

TopographyInterface(lignin)

Col. LMEN, Univ Reims

M. MolinariFiber

(cellulose)

M. Molinari

TEM/ AFM

Mechanical properties

TEM/ AFM

Mechanical properties« hard »

Ex: Hemp fibres

« soft »Resin

Physical and chemical transformations

J Beaugrand – B KurekMulti-scale studies for the determination of main cell wall properties involved during physicochemical processes

J. Beaugrand B. Kurek

three transformation typesthree transformation types fiber isolation; compounding; pressing

various lignocellulosesflax/hemp/wood/miscanthusflax/hemp/wood/miscanthus

Strategy: local probing to global assays (rheology; functional properties)(rheology; functional properties)

Short‐Term Scientific Mission ‐ STSM

• Aims to strengthen the existing network, especially for early stageg g , p y y gresearchers

• Funding to go to another institution or laboratory in another COST country to foster collaboration, learn new techniques, or to takemeasurements using instruments not available at home institution

l b tor laboratory.

• STSMs should last > 1 week, < 3 months

A l f /• Apply at www.cost.esf.org/stsm

• Application: Plan, CV, budget request to Action Chair and hostinstitutioninstitution

• Reviewed by WG leader, approved by management committee

All b li t d FP0802 h d i ti f i tit t• All members listed on FP0802 homepage: description of institutes, available infrastructure etc.

Action FP0802

Welcome WG 3 meeting

Your favourite modelling topic?Your favourite modelling topic?

Hosted by your institutions?

2010 – 2011 – 2012?2010 2011 2012?

WG 1‐3 meeting at INNVENTIAStockholm, November 4, 2009

Groom et al. (2002)

Si l fib t ti d d lliSingle fibre testing and modelling

Lennart Salmén

Stockholm in November?Stockholm in November?

WG3 meeting on modelling of wood in cultural heritage?

i d l• COST Action IE0601: WoodCultHerwww.woodculther.org

• Michal Lukomski, Cultural Heritage Research Group, Polish Academy of Sciences, Krakówp, y ,

• Dimensional stability with respect to flows of heat and moisture in the wood structuresheat and moisture in the wood structures using numerical simulations: FEM climate‐induced stress fields resulting structuralinduced stress fields, resulting structural deformations

COST ACTION IE0601Wood Science for Conservation

of Cultural Heritageof Cultural Heritage

General informationGeneral information

COST - European Cooperation in the fieldCOST - European Cooperation in the field of Scientific and Technical Research

- 35 member countries

- 9 scientific domains – our domain is ‘Materials physical and is Materials, physical and nanosciences’

- website: www.cost.esf.org

Information on the actionInformation on the action

- duration April 2007 – April 2011- duration April 2007 – April 2011

- 26 participating countries 26 participating countries (represented in the Management Committte)Committte)

- chair of the action: professor Luca pUzielli, University of Florence, e-mail: [email protected]: [email protected]

- website: www.woodculther.com

StructureStructure

3 working groups:3 working groups:

WG 1 d tiWG 1 - wood properties

WG 2 t d di iWG 2 - assessment and diagnosis

WG3 i d iWG3 - conservation and restoration

ActivitiesActivities

large meetings/conferences: - large meetings/conferences: Tervuren (Belgium) 2007, Florence 200 ( l) 20082007, Braga (Portugal) 2008, coming October 2009 in Hamburg g g

- focussed thematic workshopsp

- Short Term Scientific Missions

- training schoolsg


• Purpose of working group 3• Presentation of participantsPresentation of participants• Short-term scientific missions• Suggestions of future WG3 meetings• Multiscale modelling – bridging length• Multiscale modelling – bridging length

scales• Summary – decisions

Linking models of different length scales togetherlength scales together…

Multiscale modelling…

Missing data, weak links?

Multiscale modellingg

Output valuesOutput values

nks?

weaklin

Multi‐stephomogenization

re the

wWhe

rear

W

Hofstetter, Hellmich & Eberhardsteiner, 2005Input parameters

INPUT DATA

CONSTITUENT Cell wall layers CELL WALL

Neagu et al., 2006

CONSTITUENT Cell wall layers CELL WALL CelluloseHemicellulose

Homogenization

C H LE (GP ) 137 8 3 1

Lignin

H

L

Homogenization

AnalyticalE11 (GPa) 137 8 3.1

E22 (GPa) 18 3.4 3.1

G (GPa) 5 1 2 1 2

C

G12 (GPa) 5.1 2 1.2

ν12 (-) 0.38 0.3 0.3Volume fraction

C H LLayer MFA (°) Thickness

fractionS3 50 3ν 23 (-) 0.48 0.4 0.3

β11 (-) 0 0.6 0.4

β22 (-) 0 1.1 0.4

fractionS3, S2 0.44 0.32 0.24

S1 0.18 0.17 0.65

S3 -50 3

S2 +(0-50) 87

S1 -80 10

Sakurada et al. (1962)Cousins (1976,1978) Tashiro and Kobayashi (1991)

Persson (2000) Fengel and Stoll (1973)Brändström (2002)Brändström et al. (2003)

Nakamura et al. (2004)Cave (1978)

Abe et al. (1992)Bergander et al. (2002)

ELASTIC INPUT PARAMETERS (Neagu et al., 2006)Experimental Modelling Estimated

Cellulose

EL (GPa) 137[A], 138[B], 120-135[C], 90-140[H]

168[D], 113.5[E], 246[I] -The structural load 90 140[ ]

ET (GPa) - 17.7[D], 27.7[E], 18[F] -

GLT (GPa) - 5.1[D], 4.5[E] -

νLT (-) 0.38[G] 0.1[E], 0.005[D], 0.047[F] -

The structural load‐bearing component EL ≈ 140 GPa, ET ≈ 18‐30 GPa,

GLT ≈ 4‐5 GPa, υLT ≈ 0.1‐0.4, υTT ≈ 0.5LT ( ) , ,

νTT (-) - 0.52[D], 0.48[F]

Hemicelluloses

EL (GPa) 2.0[J], 8[K] - 14-18[N]

ET (GPa) - 3.4[F] 0.8[J], 1.4-3.5[L], 4.0[N]

GLT (GPa) - - 1.0[J], 1.8[L], 2.0[N]

νLT (-) - 0.3[F] 0.2[J], 0.1[N]

Coupling agent between the cellulose and the lignin

EL ≈ 2‐18 GPa, ET ≈ 1‐4 GPa, GLT ≈ 1‐2 GPa, υLT ≈ 0.1‐0.3, υTT ≈ 0.4

νTT (-) - 0.4[F] 0.4[N]

Lignin

EL (GPa) 3.1[M] - 2.0-3.5[N]

ET (GPa) - - 1.0[L]

GLT (GPa) 1.2[M] 0.8[E] 0.6[L]

νLT (-) - - 0.33[N]

Bulking agent making the cell wall rigid and preventing buckling

EL ≈ 2‐4 GPa, ET ≈ 1 GPa, GLT ≈ 0.5‐1.2 GPa, υLT ≈ 0.33, υTT ≈ 0.33

νTT (-) - - -

A) Sakurada (1962), B) Nishino (1995), C) Matsuo (1990), D) Tashiro (1991), E) Mark (1967), F) Cave (1978), G) Nakamura (2004), H) Ishikawa (1997), I) Mark (1980), J) Salmén (2004), K) Cousins (1978), L) Bergander (2002), M) Cousins (1976), N) Persson (2000)

Mike JarvisKey questionsKey questions ‐

•How to interface top-down and bottom-up models of deformation

•When we get to the nanoscale one microfibril beside another with•When we get to the nanoscale – one microfibril beside another, with polymers between – can we still talk of these components as ‘materials’ with definable moduli?

•Which hemicelluloses are where in softwoods?

•Where is the water and what does it do?

H d i d f ti ?•How does compression wood function?

Today: Numerical fluid flow analysis in porous media micro‐scale resolution –experimental verification

Background•Experimental sample size ~ 10 centimeters

Tomographic reconstruction

•Numerical sample size ~ few millimeters

•Representativeness: In order to compare numerical p pand experimental results, the small‐sized tomographic sample must have the same flow properties as the large experimental sample~ 2 mm large experimental sample

Solutions•Representative sampling for tomographic imaging•Representative sampling for tomographic imaging (average characteristics)•Sufficient (maximum) sample sizeS i i•Statistics•Other methods for picking representative simulation volumes (covariance, porosity etc.)~ 1 mm


Simulated (sub)volume

Tomorrow: Numerical fluid flow analysis in porous media nano‐scale resolution –>challenges!

Challenges:S l ti ll i 50

g

Tomographic reconstruction

•Sample preparation small size ~ 50 µm

•What do we see in the tomographic reconstructions?•How to cope with imaging noise?

~ 10 µm

•Is there any use for flow simulations in nano‐scale?•Is it possible to verify simulation results?Is it possible to verify simulation results?

All in all nano‐tomography will open a completely new world!

?completely new world!

Simulated (sub)volume


Tancrède Alméras – LMGC (CNRS / Univ. Montpellier, FRANCE)

Dimensional changePhysico-chemical changes

Modelling activity: generation of maturation stress in wood

Dimensional change in the constituents

Stiffness of the constituents

Physico chemical changes during maturation

Chemical iti

Embedded network modelMicrofibril network

structure

composition

Stiffness of each layer

Multilayer

Thickness and MFA of each layer

each layer

Stress induced in each layerMultilayer

cell model

Microscopic stress/strainsIn vivo boundary

Kinetics of layer formation

Macroscopic


stress/strainsIn vivo boundary conditions

Macroscopic stress/strains

WG3 COST Action FP0802Sh i ifi i iShort-term scientific mission


New crack iti

What we observe

31.5°apparition




New crack iti

What we observe

What we did Representation of softwood ascylindrically orthotropic material

31.5°apparition

y y p+ linear stiffness variation along annual rings




New crack iti

What we observe

What we did Representation of softwood ascylindrically orthotropic material

31.5°apparition

What we want to model

y y p+ linear stiffness variation along annual rings


Institute for Mechanics of Materials and StructuresFaculty of Civil Engineering

Input parameters for modelling

length scales physical propertieslength scales physical properties

- mm-scale: growth ring structure late-/earlywood content and densities

cellular structure shape of cell structure

data for model validation

- mm-scale: cell wall material orientation of cell. fibrils

l l i iff f l


- nm-scale: polymer matrix stiffness of polymers

strength of polymersdata for model validation

cellulose microfibrils stiffness/strength of cryst./paracryst. cellulose


more reliable data neededmissing data

Why is NTI in FP0802 ?• Educational

– Research work in general– Techniques and methodsq– Equipment

• NTI has been working with solid wood properties and fiber propertiesfiber properties. – Physical and mechanical properties in Norwegian spruce

and pine + ongoing project : Wood quality predicting

• NTI has also been working with several surface treatment projects

• Micro structural features of wood:• Micro structural features of wood: ‐ a natural step further on from the earlier projects – a microstructural explanation

• Hydro‐mechanical properties and modeling: ‐ interesting in connection with especially mechanical and physical wood properties, and the kiln drying process.p

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