Experimental and numerical study on the dynamic response of rectangular plates under repeated impacts

This study provides a clear insight into the dynamic response of rectangular plates subjected to repeated impacts using experimental and numerical methods. Repeated impacts are performed on the mild steel plates with a length-to-width ratio of 3, which can be regarded as scaled-down ship plates. During the experiments, both fracture and pseudo-shakedown phenomena are observed, occurring under relatively high and low impact velocities, respectively. By thoroughly analysing various parameters related to the dynamic response, including the plate deformation, contact force, rebound velocity of the impactor, and dissipated energy ratio, among others, the study effectively characterizes the behaviour of plates under repeated impacts. Numerical simulations are conducted and a detailed comparison between the numerical and experimental results is carried out, accompanied by a careful analysis of the discrepancies between them. The numerical simulations exhibit a qualitative capability to predict the dynamic response of plates subjected to repeated impacts. The 'failure displacement' proposed by the authors is verified against the experimental results. Moreover, the threshold impact velocity for the pseudo-shakedown occurrence is unveiled by numerical simulations.