Fracture behaviour and damage characterisation in composite impact panels by laboratory X-ray computed tomography
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The document presents a comprehensive study on the fracture behavior and damage characterization of composite impact panels using laboratory X-ray computed tomography (XCT). It details experimental procedures, materials used, and results regarding fracture toughness and impact damage across various matrix systems. Key findings indicate that XCT offers valuable insights into voids and damage, with certain toughening agents enhancing material properties more effectively than others.
![Outline
Introduction
Experimental procedures
Results
Conclusion
Manufacturing
Cure cycle optimisation and RFI
220
2 hours
200
Temperature (ºC)
• Cure cycle
– Optimised cure cycle based
on the degree of cure of the
neat resin
– Degree of cure > 95 %
200°C
180
2 hours
165°C
160
140
2 hours
130°C
120
100
0
• Resin Film Infusion (RFI)
50
100
150
200
250
Time (min)
300
350
400
Vacuum Bag
Mesh
Perforated Release Film
20 µm Release Film
Peel Ply
Fabric Stack
Mode-I sample
Vacuum
Outlet
Resin Film
Tacky Tape
Tool
Breather Fabric
Stacks [90, 0, 90, 0] of UD carbon fibre fabric, of 445 gm-2(Sigmatex, UK).
12k carbon tows bound by a fine glass fibre weft yarn at ≈ 6 mm intervals](https://image.slidesharecdn.com/wilkinson2013-140117131614-phpapp01/85/Fracture-behaviour-and-damage-characterisation-in-composite-impact-panels-by-laboratory-X-ray-computed-tomography-5-320.jpg)
Fracture behaviour and damage characterisation in composite impact panels by laboratory X-ray computed tomography
- 1. Fracture Behaviour and Damage Characterisation in Composite Impact Panels by Laboratory X-ray Computed Tomography Arthur Wilkinson1, Jasmin Stein1,2, Philip J. Withers2, and Fabien Léonard2 1Northwest Composite Centre, 2Henry Moseley X-ray Imaging Facility, School of Materials, The University of Manchester, UK Thermosets 2013 September 18th – 20th , Berlin NCCEF
- 2. Outline Introduction Experimental procedures Results Outline • Introduction – Overview • Experimental procedures – Materials – Manufacturing – Characterisation (SENB fracture, Mode-I ILFT, XCT) • Results – Plane-Strain Fracture Toughness of Matrices – XCT of As-prepared Panels – Mode I Interlaminar Fracture Toughness – Impact Behaviour – XCT of Impact Damage • Conclusions Conclusion
- 3. Outline Experimental procedures Introduction Results Conclusion Materials Base system • Base System – Formulated using Factorial Experiment Design (FED) based on; • Tg • Heat of reaction • Viscosity – Chemical structures; (a) TGAP (Araldite® MY0510, Huntsman) (b) TGDDM (Araldite® MY721, Huntsman) O O CH2 O CH2 CH O CH2 CH2 CH O CH CH2 CH2 N N CH2 CH CH2 CH2 CH CH2 (c) DDS (Aradure® 976-1, Huntsman) O O S NH2 N CH2 CH CH2 O O O CH2 CH2 CH NH2
- 4. Outline Experimental procedures Introduction Results Conclusion Materials Toughening agents • PES (a) Reactive high molecular weight (47k) - Virantage® VW10200 RFP, Solvay (b) Reactive low molecular weight (21k) - Virantage® VW10700 RFP , Solvay (c) Non-reactive medium molecular weight (36k) - Virantage® VW10300 FP , Solvay O O S O n • Tri-block copolymer (dimethylacrylamide-modified) MAM (a) Functional MAM -Nanostrength® M52N NP, Arkema PMMA/DMA PBuA PMMA/DMA
- 5. Outline Introduction Experimental procedures Results Conclusion Manufacturing Cure cycle optimisation and RFI 220 2 hours 200 Temperature (ºC) • Cure cycle – Optimised cure cycle based on the degree of cure of the neat resin – Degree of cure > 95 % 200°C 180 2 hours 165°C 160 140 2 hours 130°C 120 100 0 • Resin Film Infusion (RFI) 50 100 150 200 250 Time (min) 300 350 400 Vacuum Bag Mesh Perforated Release Film 20 µm Release Film Peel Ply Fabric Stack Mode-I sample Vacuum Outlet Resin Film Tacky Tape Tool Breather Fabric Stacks [90, 0, 90, 0] of UD carbon fibre fabric, of 445 gm-2(Sigmatex, UK). 12k carbon tows bound by a fine glass fibre weft yarn at ≈ 6 mm intervals
- 6. Outline Introduction Experimental procedures Results Conclusion Characterisation Techniques • XCT – Nikon Metrology 225/320 kV Custom Bay (see www.mxif.manchester.ac.uk ) • Impact • Acid digestion – void volume % – ASTM D3171 – Matrix digestion using sulfuric acid/ hydrogen peroxide – Specimen size ≈1 g – Instron Ceast 9350 Drop Tower – 89 mm x 55 mm, energies 5,10,15, 20 J • Plane-Strain Fracture Toughness -KIc – ASTM D5045 – 44 mm x 10 mm x 5 mm – at 10 mm/min crosshead speed • Mode I Interlaminar Fracture Toughness- GIc – ASTM D5528 – 125 mm x 25 mm x 5 mm – at 0.75 mm/min crosshead speed
- 7. Outline Introduction Experimental procedures Results Conclusion Results Composites Table 1: Acid digestion results of manufactured laminates. Laminates with Additive wt. % Fibre Content Vol. % Void Content Vol. % Neat Resin 0 68.4 ± 0.4 0.67 ± 0.10 RHMW PES 10 67.4 ± 2.0 1.23 ± 0.26 NRMMW PES 10 68.9 ± 0.1 1.35± 0.32 RBCP 5 69.6 ± 0.5 2.09 ± 0.05 X-Ray CT a) all labels b) Glass weft Yarns and voids c) Voids only Examples of segmentation: matrix (blue), yarn (yellow), and pores (red) (10 mm scale bar).
- 8. Outline Introduction Experimental procedures Results XCT statistical analysis of void positions Probability density - void to yarn distance Results Conclusion
- 10. Outline Introduction Experimental procedures Results Conclusion Comparative Rheology All 5% addition
- 11. Outline Introduction Experimental procedures Results Results Plane-Strain Fracture Toughness of Bulk Matrices -KIc Chosen as matrices •Molecular weight ↑ - toughening effect ↑ •Reactivity - toughening effect ↓ •Tri-block copolymer has the greatest effect Conclusion
- 12. Outline Introduction Results Mode I Interlaminar Fracture Experimental procedures Results Conclusion
- 13. Outline Introduction Experimental procedures Results Conclusion Results Mode I Interlaminar Fracture RHMW NRMMW Mode-I initiation GIC values Mean Mode-I propagation values FBCP
- 14. Outline Introduction Experimental procedures Results Conclusion Results Impact Cross-sectional orthoslice views (XZ, YZ) – unmodified resin system
- 15. Outline Introduction Experimental procedures Results Conclusion Results Impact 5J 15J 25J Interfacial damage area progression with impact energy. The numbers indicate the interlaminar regions below the impacted face – unmodified resin system
- 16. Outline Introduction Experimental procedures Results Conclusion Results Impact 15J Unmodified resin FBCP modified resin 15J
- 17. Outline Introduction Experimental procedures Results Conclusion Results Impact FBCP 15J 3-D view of impact damage; each interfacial damage is given a different colour
- 18. Outline Introduction Experimental procedures Results Conclusion Results Impact Damage volume vs. distance from impact face - unmodified resin 15J
- 19. Outline Introduction Experimental procedures Results Conclusion Results Impact Damage volume vs. distance from impact face - different matrices 15J
- 20. Outline Introduction Experimental procedures Results Conclusion Conclusions • XCT can provide extension information on voids in as-prepared composites and on damage in impacted composites. • In the bulk matrix systems, FBCP imparted superior toughness than PES. • In interlaminar fracture and impact testing differences due to matrix fracture toughness become less clear.
- 21. Outline Introduction Experimental procedures Results Conclusion Acknowledgements • EPSRC – funding • NWCC / NCCEF – facilities • Alan Nesbitt – technical support NCCEF – see www.nccef.co.uk • Huntsman, Solvay, Sigmatex, Arkema – supply of materials