Novel Sandwich Composite Structures for Blast Mitigation
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Arun Shukla, Nate Gardner Dynamic Photo Mechanics Laboratory , Dept. of Mechanical, Industrial and Systems Engineering The University of Rhode Island, Kingston RI 02881 Shuklaa @egr.uri.edu The dynamic behavior of various sandwich composites made of E-Glass Vinyl-Ester and Corecell A-series foam have been studied using a shock tube apparatus. For the polyurea investigation, the foam core was monotonically graded based on increasing wave impedance, and the influence of the polyurea location on the overall dynamic behavior was studied. For the CoreShell Rubber (CSR) vs Non-CSR toughened resin composite investigation, the core was homogeneous, and the influence of the coreshell rubber nano-particles on the overall dynamic behavior was studied. A high-speed side-view camera, along with a high-speed back-view 3-D Digital Image Correlation (DIC) system was utilized to capture the real timedeformation process as well as mechanisms of failure. Post mortem analysis was also carried out to evaluate the overall blast performance. Results will help in designing new and more efficient blast mitigating materials and structures. With an increased threat of damage to civilian and defense structures in the form of blast loading there has arisen a need to replace conventional structural materials with improved blast resistant material as well as generate new ideas to mitigate blast over- pressure. This material is based upon work supported by the U.S. Department of Homeland Security under Award Number 2008-ST-061-ED0001. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied of the U.S. Department of Homeland Security. N. Gardner, E. Wang, P. Kumar and A. Shukla, “Blast Mitigation in a Sandwich Composite using Graded Core with Polyurea interlayer” Experimental Mechanics, Accepted for Publication (2011) E. Wang, N Gardner and A. Shukla, “The blast resistance of sandwich composites with stepwise graded cores”, International Journal of Solid and Structures, 46, 3492-3502, 2009. E. Wang, N. Gardner and A. Shukla, “Experimental study on the performance of sandwich composites with stepwise graded cores subjected to a shock wave loading”, SEM Annual Conference and Exposition on Experimental and Applied Mechanics, Albuquerque, New Mexico , June 1-4, 2009. N. Gardner, “Blast performance of sandwich composites with discretely layered core”, SEM Annual Conference and Exposition on Experimental and Applied Mechanics, Student Paper Competition, Albuquerque, New Mexico , June 1-4, 2009. N. Gardner and A. Shukla, “The Blast Response of Sandwich Composites with a Functionally Graded Core”, SEM Annual Conference and Exposition, Indianapolis, Indiana, June 7-10, 2010. N. Gardner and A. Shukla, “The Blast Response of Sandwich Composites With a Functionally Graded Core and Polyurea Interlayer”, SEM Annual Conference and Exposition, Indianapolis, Indiana, June 7-10, 2010. N. Gardner and A. Shukla, “The Blast Resistance of Sandwich Composites with a Functionally Graded Core and Polyurea Interlayer”, IMPLAST 2010, SEM Fall Conference, Providence, October 12-14, 2010. Novel Sandwich Composite Structures for Blast Mitigation Technical Approach Abstract Relevance Accomplishments Through Current Year Future Work Publications Acknowledging DHS Support Opportunities for Transition to Customer Experimental Set-up and Procedure: Materials and Specimens: Configurations Specimens Configuration 1 Configuration 2 Polyurea Investigation CSR vs Non-CSR Toughened Composite Investigation Results: Blast loading on civilian structures Blast attack on USS Cole Blast attack on Army structures Consulting with Industry: 1. TPI Composites, Warren, RI 2. Specialty Products Inc.(SPI), Lakewood, Washington 3. Gurit SP Technology, Quebec, Canada New types of sandwich structures were designed and fabricated to withstand blast loadings and mitigate blast overpressures. Technical collaboration with TPI Composites, Specialty Products Inc., and Gurit SP Technology will help in fascilitating sample preparation. This effort also aligns with the mission of DHS to transition technology and allow for a unified effort to protect our homeland. Acknowledgements The authors kindly acknowledge the financial support provided by Department of Homeland Security (DHS) under Cooperative Agreement No. 2008-ST-061-ED0002, as well as the Office of Naval Research (ONR) under Grant No. N00014- 04-1-0268. Authors thank Gurit SP Technology and Specialty Products Incorporated (SPI) for providing the material as well as Dr. Stephen Nolet and TPI Composites for providing the facility for creating the composites used in this study. 1. The effect of equivalent core layer mass vs. equivalent core layer thickness in the blast response of sandwich structures A comprehensive series of shock tube experiments were conducted on sandwich panels consisting of composite facesheets and energy absorbing core materials in order to evaluate the overall blast response and mitigation capabilities Major Results 1. Polyurea Investigation: The application of polyurea behind foam core and in front of back facesheet (configuration 2) allows for stepwise compresison of core, reducing deflections, in-plane strains, back face velocities and overall damage 2. CSR vs Non-CSR Toughened Composite Investigation: The addition of nano-scale Coreshell Rubber (CSR) particles to the resin system of the sandwich structures, aids in dispersing the initial impulse of the shock wave, thus reducing deflections, in-plane strains, and back face velocites and overall damage Previously, the main focus of research in this area has been on the numerical and theoretical behavior of functionally graded materials. Experimental work on the dynamic response of composites with polyurea, as well as steel plates with polyurea has been investigated, but there has been no research regarding the dynamic response of sandwich composites with polyurea interlayer. Also, the addition of core shell rubber (CSR) to sandwich structures and their influence on blast loading is a relativley new application and investigation. Previously, only the impact response of core shell rubber (CSR) toughened composites has been studied. The Shock Tube Schematic of Shock Tube Detailed Dimensions of the Muzzle Real Pattern Back View 3-D DIC System Side View Camera Specimen Shock Tube High-speed photography set-up Core: Co-Polymer I designed for impact resistance Shell: Co-Polymer II designed to be compatible with thermosetting resins Microscopic View of Coreshell Rubber [www.kaneka.com] (a) Schematic (b) Real Secimen Specimen Configuration (a) Non-CSR (b) CSR Facehseet of Sandwich Structure Core cracking Delamination Core Compression Core cracking Delamination Core Compression (a) Non-CSR (b) CSR Post-mortem Images of CSR and Non-CSR Toughened Sandwich Composites Core Compression Delamination Core cracking Complete Core Collapse Core Compression Core cracking Delamination Core Compression Delamination Core cracking Configuration 1 Configuration 2 1.0 MPa 1.5 MPa Post-mortem Images of Both Configurations Indentation failure First Layer Compression Core Cracking Begins Skin Delamination Core Cracking Indentation failure Skin Delamination Core Cracking Begins Core Cracking First Layer Compression Configuration 1 Configuration 2 High Speed Images of Both Configurations In-plane strain for Both Configurations Out-of-plane velocity of CSR and Non-CSR Toughened Sandwich Composites Indentation failure Core Cracking Core Layer Delamination Skin Delamination Indentation failure Core Cracking Core Layer Delamination Non-CSR CSR High Speed Images of CSR and Non-CSR Toughened Sandwich Composites 0 μs 100 μs 400 μs 700 μs 1000 μs 1600 μs 0 μs 100 μs 400 μs 700 μs 1000 μs 1600 μs Full-field out-of-plane Deflection Non-CSR CSR 100 μs 400 μs 700 μs 1000 μs 1600 μs 100 μs 400 μs 700 μs 1000 μs 1600 μs Full-field in-plane Strain Non-CSR CSR 100 μs 400 μs 700 μs 1000 μs 1600 μs 100 μs 400 μs 700 μs 1000 μs 1600 μs 0 μs 150 μs 400 μs 650 μs 1150 μs 1800 μs 0 μs 150 μs 400 μs 550 μs 1150 μs 1800 μs Configuration 1 Configuration 2 Full-field out-of-plane Deflection 150 μs 400 μs 550 μs 1150 μs 1800 μs 150 μs 400 μs 650 μs 1150 μs 1800 μs Configuration 1 Configuration 2 Full-field out-of-plane Velocity 150 μs 400 μs 550 μs 1150 μs 1800 μs 150 μs 400 μs 650 μs 1150 μs 1800 μs Incident and Reflected pressure profiles Incident Pulse Reflected Pulse
Transcript of Novel Sandwich Composite Structures for Blast Mitigation
Arun Shukla, Nate GardnerDynamic Photo Mechanics Laboratory , Dept. of Mechanical, Industrial and Systems Engineering
The University of Rhode Island, Kingston RI 02881Shuklaa @egr.uri.edu
The dynamic behavior of various sandwichcomposites made of E-Glass Vinyl-Ester andCorecell A-series foam have been studied using ashock tube apparatus. For the polyureainvestigation, the foam core was monotonicallygraded based on increasing wave impedance, andthe influence of the polyurea location on theoverall dynamic behavior was studied. For theCoreShell Rubber (CSR) vs Non-CSR toughenedresin composite investigation, the core washomogeneous, and the influence of the coreshellrubber nano-particles on the overall dynamicbehavior was studied. A high-speed side-viewcamera, along with a high-speed back-view 3-DDigital Image Correlation (DIC) system was utilizedto capture the real timedeformation process aswell as mechanisms of failure. Post mortemanalysis was also carried out to evaluate the overallblast performance. Results will help in designingnew and more efficient blast mitigating materialsand structures.
With an increased threat of damage to civilian anddefense structures in the form of blast loading therehas arisen a need to replace conventional structuralmaterials with improved blast resistant material aswell as generate new ideas to mitigate blast over-pressure.
This material is based upon work supported by the U.S. Department of Homeland Security under Award Number 2008-ST-061-ED0001. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied of the U.S. Department of Homeland Security.
N. Gardner, E. Wang, P. Kumar and A. Shukla, “Blast Mitigation in aSandwich Composite using Graded Core with Polyurea interlayer”Experimental Mechanics, Accepted for Publication (2011) E. Wang, N Gardner and A. Shukla, “The blast resistance of sandwich
composites with stepwise graded cores”, International Journal of Solidand Structures, 46, 3492-3502, 2009. E. Wang, N. Gardner and A. Shukla, “Experimental study on the
performance of sandwich composites with stepwise graded coressubjected to a shock wave loading”, SEM Annual Conference andExposition on Experimental and Applied Mechanics, Albuquerque, NewMexico , June 1-4, 2009. N. Gardner, “Blast performance of sandwich composites with discretely
layered core”, SEM Annual Conference and Exposition on Experimentaland Applied Mechanics, Student Paper Competition, Albuquerque, NewMexico , June 1-4, 2009. N. Gardner and A. Shukla, “The Blast Response of Sandwich Composites
with a Functionally Graded Core”, SEM Annual Conference and Exposition,Indianapolis, Indiana, June 7-10, 2010. N. Gardner and A. Shukla, “The Blast Response of Sandwich Composites
With a Functionally Graded Core and Polyurea Interlayer”, SEM AnnualConference and Exposition, Indianapolis, Indiana, June 7-10, 2010. N. Gardner and A. Shukla, “The Blast Resistance of Sandwich Composites
with a Functionally Graded Core and Polyurea Interlayer”, IMPLAST 2010,SEM Fall Conference, Providence, October 12-14, 2010.
Novel Sandwich Composite Structures for Blast Mitigation
Technical ApproachAbstract
Relevance
Accomplishments Through Current Year
Future Work
Publications Acknowledging DHS SupportOpportunities for Transition to
Customer
Experimental Set-up and Procedure: Materials and Specimens:
Co
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Spec
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Configuration 1 Configuration 2
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Inve
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SR v
s N
on
-CSR
To
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Co
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Inve
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Results:
Blast loading on civilian structures
Blast attack on USS Cole Blast attack on Army structures
Consulting with Industry:
1. TPI Composites, Warren, RI2. Specialty Products Inc.(SPI), Lakewood, Washington3. Gurit SP Technology, Quebec, Canada
New types of sandwich structures were designed andfabricated to withstand blast loadings and mitigateblast overpressures. Technical collaboration with TPIComposites, Specialty Products Inc., and Gurit SPTechnology will help in fascilitating samplepreparation. This effort also aligns with the mission ofDHS to transition technology and allow for a unifiedeffort to protect our homeland.
Acknowledgements
The authors kindly acknowledge the financial supportprovided by Department of Homeland Security (DHS) underCooperative Agreement No. 2008-ST-061-ED0002, as well asthe Office of Naval Research (ONR) under Grant No. N00014-04-1-0268. Authors thank Gurit SP Technology and SpecialtyProducts Incorporated (SPI) for providing the material as wellas Dr. Stephen Nolet and TPI Composites for providing thefacility for creating the composites used in this study.
1. The effect of equivalent core layer mass vs. equivalent corelayer thickness in the blast response of sandwich structures
A comprehensive series of shock tube experiments wereconducted on sandwich panels consisting of compositefacesheets and energy absorbing core materials in order toevaluate the overall blast response and mitigation capabilities
Major Results
1. Polyurea Investigation: The application of polyurea behindfoam core and in front of back facesheet (configuration 2)allows for stepwise compresison of core, reducing deflections,in-plane strains, back face velocities and overall damage
2. CSR vs Non-CSR Toughened Composite Investigation: Theaddition of nano-scale Coreshell Rubber (CSR) particles to theresin system of the sandwich structures, aids in dispersing theinitial impulse of the shock wave, thus reducing deflections,in-plane strains, and back face velocites and overall damage
Previously, the main focus of research in this areahas been on the numerical and theoretical behaviorof functionally graded materials. Experimental workon the dynamic response of composites withpolyurea, as well as steel plates with polyurea hasbeen investigated, but there has been no researchregarding the dynamic response of sandwichcomposites with polyurea interlayer. Also, theaddition of core shell rubber (CSR) to sandwichstructures and their influence on blast loading is arelativley new application and investigation.Previously, only the impact response of core shellrubber (CSR) toughened composites has beenstudied.
The Shock Tube
Schematic of Shock Tube
Detailed Dimensions of the Muzzle
Real Pattern
Back View 3-D DIC System
Side View Camera
Specimen
Shock Tube
High-speed photography set-up
Core:
Co-Polymer I designed for
impact resistance
Shell:
Co-Polymer II designed to be
compatible with thermosetting
resinsMicroscopic View of Coreshell Rubber[www.kaneka.com]
(a) Schematic (b) Real SecimenSpecimen Configuration
(a) Non-CSR (b) CSRFacehseet of Sandwich Structure
Core cracking
DelaminationCore Compression
Core cracking
DelaminationCore Compression
(a) Non-CSR (b) CSRPost-mortem Images of CSR and Non-CSR
Toughened Sandwich Composites
Core Compression
Delamination
Core cracking
Complete Core CollapseCore Compression
Core cracking
Delamination
Core Compression
Delamination
Core cracking
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1.0 MPa 1.5 MPa
Post-mortem Images of Both Configurations
Indentation failure
First LayerCompression
Core CrackingBegins
SkinDelamination
Core Cracking
Indentation failure
SkinDelamination
Core CrackingBegins
Core Cracking
First LayerCompression
Configuration 1
Configuration 2
High Speed Images of Both Configurations
In-plane strain for Both Configurations
Out-of-plane velocity of CSR and Non-CSR
Toughened Sandwich Composites
Indentation failure
Core Cracking
Core LayerDelamination
SkinDelamination
Indentation failure
Core Cracking Core Layer
Delamination
No
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SRC
SR
High Speed Images of CSR and Non-CSR Toughened Sandwich Composites
0 μs 100 μs 400 μs 700 μs 1000 μs 1600 μs
0 μs 100 μs 400 μs 700 μs 1000 μs 1600 μs
Full-field out-of-plane Deflection
No
n-C
SRC
SR
100 μs 400 μs 700 μs 1000 μs 1600 μs
100 μs 400 μs 700 μs 1000 μs 1600 μs
Full-field in-plane Strain
No
n-C
SRC
SR
100 μs 400 μs 700 μs 1000 μs 1600 μs
100 μs 400 μs 700 μs 1000 μs 1600 μs
0 μs 150 μs 400 μs 650 μs 1150 μs 1800 μs
0 μs 150 μs 400 μs 550 μs 1150 μs 1800 μs
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Full-field out-of-plane Deflection
150 μs 400 μs 550 μs 1150 μs 1800 μs
150 μs 400 μs 650 μs 1150 μs 1800 μs
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Full-field out-of-plane Velocity
150 μs 400 μs 550 μs 1150 μs 1800 μs
150 μs 400 μs 650 μs 1150 μs 1800 μs
Incident and Reflected pressure profiles
Incident Pulse
Reflected Pulse
