SIPS 2018

DETAILLED PROGRAM OVERVIEW

Dynamic Compressive Behavior of An E-Glass/Polyester Composite Material Subjected to Repeated Loads
Alper Tasdemirci¹; Mesut Bayhan¹; Semih Berk Seven¹; Ayda Ramyar¹; Mustafa Guden¹;
¹İZMIR INSTITUTE OF TECHNOLOGY, İzmir, Turkey;
PAPER: 124/Manufacturing/Regular (Oral)
SCHEDULED: 14:25/Mon./Sao Conrado (50/2nd)

ABSTRACT:
Composite materials are generally used as spall liner of the vehicle hull in military applications to protect the cabin crew from injuries [1]. In these applications, composite materials may be subjected to single or multiple impact loads. There are several studies on single loading impact events, but very few studies focused on repeated loadings. To determine the multi hit protection capability of materials using Split Hopkinson Pressure Bar (SHPB), Chen and Luo modified the conventional SHPB apparatus to deform ceramic specimen using two consecutive stress pulses [2]. Xia et al. performed an experimental study on OFHC Copper materials using stuffed strikers [3]. Rachel et al. conducted a study on copper and iron using a single striker bar formed two rods of dissimilar materials [4]. Bazle et al. carried out ballistic tests to obtain the multi hit capacity of S-2 glass/SC15 thick section composites [5]. In this study, multi-hit compressive behavior of a composite material was investigated both experimentally and numerically in the through-thickness direction. Repeated loading tests were carried out using the SHPB set-up, and LS-DYNA was used to simulate the tests numerically. To understand the failure mechanisms and damage progression, MAT_162 material model was selected. DYNAIN method was used to model the multiple impacts. This method allows to incorporate the damage attained in the specimen occurred during the first impact in the numerical model of the subsequent loadings. It was observed that delamination was occurred between the layers at regions particularly close to the specimen-incident bar interface. After the second hit, matrix damage propagated along the interfaces and the composite failed catastrophically. Experimental and numerical results showed close agreement in terms of failure mechanisms and damage initiation/progression. The numerical model can successfully predict the amount of strength decrease between the repeated loadings.

References:
[1] R. A. Ash, "9 - Vehicle armor A2 - Bhatnagar, Ashok," in Lightweight Ballistic Composites (Second Edition), ed: Woodhead Publishing, 2016, pp. 285-309.
[2] W. Chen and H. Luo, "Dynamic compressive responses of intact and damaged ceramics from a single split Hopkinson pressure bar experiment," Experimental Mechanics, vol. 44, pp. 295-299, Jun 2004.
[3] K. Xia, R. Chen, S. Huang, and S. N Luo, Controlled multipulse loading with a stuffed striker in classical split Hopkinson pressure bar testing vol. 79, 2008.
[4] R. E. Briggs, D. R. Drodge, D. M. Williamson, and W. G. Proud, "TWO-STEP LOADING IN A SPLIT HOPKINSON PRESSURE BAR," AIP Conference Proceedings, vol. 955, pp. 1173-1176, 2007.
[5] Z. H. Bazle, L. H. Jessica, and John W Gillespie, Jr., "Multi-hit ballistic impact on S-2 glass/SC15 thick-section composites: experiments," The Journal of Strain Analysis for Engineering Design, vol. 47, pp. 480-494, 2012/10/01 2012.