Influence of plate vibration on delamination formation in composites under multiple impacts

Dynamic vibration is believed to be a basic property of the impacted composite laminates; however, its effect on delamination formation requires further investigation. This study proposes a numerical model in collaborating with ABAQUS, which was calibrated using experimental results, to investigate the effect of plate vibration on delamination formation in composite laminates subjected to two consecutive identical ice or steel projectile impacts with a fixed loading distance. The only variable parameter for the different simulations was the time interval between the two impacts. The loading condition considered in this study is an extreme case where the composite laminate was still vibrating after the first impact when the second impact occurred. The results showed that the delaminations that formed later were significantly affected by the time intervals of the two identical successive ice or steel projectiles. As the vibrated impact points travel from the minimum peak to the adjacent maximum peak during the first vibration period, the newly formed delamination areas monotonically increase with time and vice versa. The change in the maximum contact forces of two identical impacts induced by dynamic vibration is suggested to be a major reason for the discrepancy between the newly formed delamination and previous ones.