PSI - Issue 14

P Rama Subba Reddy et al. / Procedia Structural Integrity 14 (2019) 676–683 Author name / Structural Integrity Procedia 00 (2018) 000–000

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C-scan images and cross section photographs of 35 mm thick E-glass/phenolic and E-glass/epoxy laminates impacted close to ballistic limit velocity (630 & 610 ms -1 ) are shown in Fig.7. It was observed that close to ballistic limit, the projectile get arrested within the laminate. Shear cutting of fibres is seen at strike face whereas fiber bending and delaminations are spreaded in larger areas at rear side due to resistance offered by the laminate. E glass/phenolic laminate has shown more damage area by spreading the energy in lateral direcitons whereas E glass/epoxy has shown less damage area. However, depth of projectile penetration is found to be 17.5 mm and 21.5 mm for E-glass/phenolic and E-glass/epoxy laminates respectively. 5. Conclusions E-glass/epoxy laminate has shown higher mechanical and mode-1 fracture energy than E-glass/phenolic composite laminate. Energy absorption under ballistic impact has been studied against MS projectile and found that laminate having higher loss modulus, lower fracture energy and lower ILSS has shown higher energy absorption and higher ballistic limit. C-scan analysis on post impacted laminates shows that E-glass/phenolic has undergone more damage than E-glass/epoxy composite laminate. This is due to ease of undergoing delamination while interacting with projectile under ballistic impact conditions. Since delamination is major energy absorption mechanism, laminate having lower fracture energy support for higher energy absorption due to dissipation of energy in lateral directions. Acknowledgements Authors gratefully acknowledge Dr. Vikas Kumar, Director, Defence Metallurgical Research Laboratory (DMRL), Hyderabad for his encouragement to publish this work. The authors also acknowledge the support rendered by the staff of Armour Design and Development Division (ADDD). References Carrillo, J. G., Gambo, R. A., Flores-Johnson, E. A., Gonzalez-Chi, P. I., 2012. Ballistic performance of thermoplastic composite laminates made from aramid woven fabric and polypropylene matrix. Polymer Testing 31(4), 512-519. Gopinath, G., Zheg, J. Q., Batra, R. C., 2012. Effect of matrix on ballistic performance of soft body amour. Composite structures 94, 2690-2696. Griffin, C. F., 1987. Damage tolerance of toughened resin graphite composites. ASTM STP 937, 23-33. Jacobs, M.J.N., Van Dingenen, J.L.J., 2001. Ballistic protection mechanisms in personal armour. Journal of Materials Science 36(13), 3137-3142. Karthikeyan, K., Russell, B. P., Fleck, N. A., Wadley, H. N. G., Deshpande, V. S., 2013. The effect of shear strength on the ballistic response of laminated composite plates subjected to steel projectiles. European Journal of Mechanics A/Solids 42, 35-53. Laible, R.C., 1980. Ceramic composite armour in “ Ballistic materials and penetration mechanincs” , In: Laible, R.C. (Ed) Elsevier, Amsterdam, pp 135-143. Mackiewicz, J. F., Proulx, G., 1999. Effect of fiber-reinforced plastic strength properties on the ballistic performance of ceramic composite armor. Technical report. NATICK/TR-99/006. Madhu, V., Balakrishna Bhat, T., 2011. Armour protection and affordable protection for Futuristic combat vehicles. Defence Science Journal 61(4), 394-402. Morye, S.S., Hine, P.J., Duckett, R. A., Carr, D. J., Ward, I.M., 2000. Modeling of the energy absorption by polymer composites upon ballistic impact. Composite science and technology 60, 2631-2642. Nayak, N., Sivaraman, P., Banerjee, A., Madhu, V., Dutta, A.L., Mishra, V.S., Chakraborty, B.C., 2012. Effect of matrix on the ballistic impact of aramid fabric composite laminates by armor piercing projectiles. Polymer Composites 33, 443–450. Prasanth, C., Ravindranath, S., Samraj, A., Manikandan, T., 2014. Mode-I fracture analysis of thermally aged of glass and glass-carbon hybrid composites. International Journal of Innovative Technology and Exploring Engineering 3(10), 84-89. Rama Subba Reddy, P., Sreekantha Reddy, T., Madhu, V., Gogia, A. K., Venkateswara Rao, K., 2015. Behaviour of E-glass composite laminates under ballistic impact. Materials and Design 84, 79–86. Rama Subba Reddy, P., Sreekantha Reddy, T., Srikanth, I., Madhu, V., Gogia, A. K., Venkateswara Rao, K., 2016. Effect of viscoelastic behaviour of glass laminates on their energy absorption subjected to high velocity impact. Materials and Design 98, 272–279. Sevkat, E., Liaw, B., Delale, F., Raju, B.B., 2009. A combined experimental and numerical approach to study ballistic impact response of S2 glass fiber/toughened epoxy composite beams., Composite Science and Technology 69, 965–982. Wong, W., Horsfall, I., Champion, S. M., Watson, C. H., 2001. Effect of matrix type on the ballistic and mechanical performance of E-glass composite armour, 19 th international symposium of ballistics. Interlaken, Switzerland.