The effect of stacking sequence on the LVI damage of laminated composites; experiments and analysis

Results of a comprehensive experimental and computational low velocity impact (LVI) damage study are reported for T800s/3900-2B laminated composites with three stacking sequences. The stacking sequences studied are [0/45/0/90/0/- 45/0/45/0/- 45]s, [45/0/- 45/90]3s, and [45/-45/0/45/-45/90/45/-45/45/-45]s, which are [50/40/10], [25/50/25] and [10/80/10] where each number indicates the percentage of zero, 45 and 90 plies. For each layup, three impact energy levels have been examined. After the LVI tests, the induced damage has been characterized with ultrasound C-scanning and high-resolution micro computed tomography (micro-CT). Computational predictions have been conducted using the enhanced Schapery Theory (EST) model. The numerical results are accurate in terms of the impact load responses and induced damage. The physics of the LVI damage of the samples with various stacking sequences and as a function of impact energy has been resolved using the EST model. The damage predicted by the EST model and the revealed damage mechanisms contribute to understanding the physics of the LVI behavior of laminated composites.