Analytical development on impact behaviour of composite sandwich laminates by differentiated loading regimes

Given the widespread usage of composite components in critical structures within the aerospace and automotive industries, it is deemed as an essential task to determine the effect of normal operation phenomena on its performance in impact. In particular, the present study aims for providing the developed analytical modelling techniques which are needed for describing the low velocity impact dynamic response of sandwich laminated structures. Alongside the analytical models, experimentally validated high-fidelity numerical models are used to check both the validity of the assumptions made as well as the accuracy of the analytical results in the different considered scenarios. An extensive analysis of the sandwich laminate impact performance has been studied, eventually resulting in a much improved, herein developed analytical formulation which is capable of accounting for the differentiated loading, unloading and reloading indentation regimes as well as for the lower facesheet local deflections. These considerations, which are normally neglected in equivalent studies, allow a precise capture of the energy absorption mechanisms.