Modares Mechanical Engineering

Modares Mechanical Engineering

Experimental Analysis of Impact Loading on Sandwich Panels with Glass/Epoxy Composite Faces and Cork Core

Document Type : Original Research

Authors
ahmad gerami 1
hadi vahidi 1
hamed ahmadi 2
gholamhossein liaghat 1
1 TARBIAT MODARES UNIVERCITY
2 Tarbiat Modares University
10.48311/mme.25.1.55
Abstract
This research experimentally investigates the effect of cork layer configuration on the Impact loading behavior of glass/epoxy hybrid composites. Three types of specimens were fabricated and subjected to a 9.32 g spherical projectile impact test: GE8 (8-layer glass/epoxy composite without cork), LSPC1 (with 1 mm thick cork layers alternating between glass fiber layers), and SPC (with a 3 mm thick cork layer in the center). The results showed that the LSPC1 specimen exhibited significantly higher ballistic resistance, with the highest ballistic limit velocity (135 m/s). Furthermore, this specimen demonstrated the lowest damage (including bulging, petaling, and delamination) and the highest energy absorption (84.9 J). This superior performance is attributed to the uniform distribution of thin cork layers, multi-stage energy absorption at multiple fiber/cork interfaces, plastic deformation of cork cells under buckling and crushing, and crack growth resistance. This study demonstrates that the use of thin and alternating cork layers is an effective strategy to significantly improve the ballistic resistance of glass/epoxy composites and highlights the importance of engineered layup design for achieving optimal impact performance. The findings of this research can be used in the design and manufacturing of lightweight and impact-resistant structures in the aerospace, automotive, and protective equipment industries
Keywords
Impact Loading
Sandwich panel
energy absorption
glass/epoxy composite
Cork

Subjects

1. Buitrago, B.L., S.K. García-Castillo, and E. Barbero, Influence of shear plugging in the energy absorbed by thin carbon-fibre laminates subjected to high-velocity impacts. Composites Part B: Engineering, 2013. 49: p. 86-92.
2. Abtew, M.A., et al., Ballistic impact mechanisms–a review on textiles and fibre-reinforced composites impact responses. Composite structures, 2019. 223: p. 110966.
3. Wang, J., A.M. Waas, and H. Wang, Experimental and numerical study on the low-velocity impact behavior of foam-core sandwich panels. Composite Structures, 2013. 96: p. 298-311.
4. Griškevičius, P., et al., Experimental and numerical study of impact energy absorption of safety important honeycomb core sandwich structures. Materials science, 2010. 16(2): p. 119-123.
5. Ivañez, I. and S. Sanchez-Saez, Numerical modelling of the low-velocity impact response of composite sandwich beams with honeycomb core. Composite Structures, 2013. 106: p. 716-723.
6. Feng, D. and F. Aymerich, Effect of core density on the low-velocity impact response of foam-based sandwich composites. Composite Structures, 2020. 239: p. 112040.
7. Andrew, J.J., et al., Parameters influencing the impact response of fiber-reinforced polymer matrix composite materials: A critical review. Composite Structures, 2019. 224: p. 111007.
8. Zenkert, D., et al., Damage tolerance assessment of composite sandwich panels with localised damage. Composites Science and Technology, 2005. 65(15-16): p. 2597-2611.
9. Sun, G., et al., High-velocity impact behaviour of aluminium honeycomb sandwich panels with different structural configurations. International Journal of Impact Engineering, 2018. 122: p. 119-136.
10. Khodadadi, A., et al., High velocity impact behavior of Kevlar/rubber and Kevlar/epoxy composites: a comparative study. Composite Structures, 2019. 216: p. 159-167.
11. Sarasini, F., et al., Static and dynamic characterization of agglomerated cork and related sandwich structures. Composite Structures, 2019. 212: p. 439-451.
12. Boria, S., et al., Green sandwich structures under impact: experimental vs numerical analysis. Procedia Structural Integrity, 2018. 12: p. 317-329.
13. Silva, F., M. De Moura, and A. Magalhães, Low velocity impact behaviour of a hybrid carbon‐epoxy/cork laminate. Strain, 2017. 53(6): p. e12241.
14. Castilho, T., L. Sutherland, and C.G. Soares, Impact resistance of marine sandwich composites. Maritime Technology and Engineering. London: Taylor & Francis Group, 2015: p. 607-618.
15. Ptak, M., et al., Assessing impact velocity and temperature effects on crashworthiness properties of cork material. International Journal of Impact Engineering, 2017. 106: p. 238-248.
16. Sánchez-Sáez, S., E. Barbero, and J. Cirne, Experimental study of agglomerated-cork-cored structures subjected to ballistic impacts. Materials Letters, 2011. 65(14): p. 2152-2154.
17. Amaro, A.M., et al., The high-velocity impact behaviour of kevlar composite laminates filled with cork powder. Applied Sciences, 2020. 10(17): p. 6108.
18. Ivañez, I., et al., High-velocity impact behaviour of damaged sandwich plates with agglomerated cork core. Composite Structures, 2020. 248: p. 112520.
19. Gomez, A., E. Barbero, and S. Sanchez-Saez, Modelling of carbon/epoxy sandwich panels with agglomerated cork core subjected to impact loads. International Journal of Impact Engineering, 2022. 159: p. 104047.
20. Gomez, A., S. Sanchez-Saez, and E. Barbero, Experimental analysis of the impact behaviour of sandwich panels with sustainable cores. Composites Part A: Applied Science and Manufacturing, 2023. 166: p. 107383.
21. Sutherland, L. and C.G. Soares, Impact resistance of cork-skinned marine PVC/GRP sandwich laminates. Thin-Walled Structures, 2022. 180: p. 109830.
22. Sergi, C., et al., Experimental and numerical analysis of the ballistic response of agglomerated cork and its bio-based sandwich structures. Engineering Failure Analysis, 2022. 131: p. 105904.
23. Gómez, A., S. Sanchez-Saez, and E. Barbero, Compression impact behaviour of agglomerated cork at intermediate strain rates. European Journal of Wood and Wood Products, 2021. 79(2): p. 381-396.
Modares Mechanical Engineering
Volume 25, Issue 1
January 2024
Pages 55-63