Crashworthiness and failure analysis of steeple-triggered hat-shaped composite structure under the axial and oblique crushing load

Abstract

A clear understanding of failure mechanisms and coupling interaction of multiple failure modes greatly contributes to crashworthiness design of composite structure. Thus, the crashworthiness and failure of steeple-triggered hat-shaped composite structure (HSCS) is investigated based on finite element method. The stacked-shell model is adopted to capture both intra- and inter-laminar failure modes and validated with available experiments. The effect of oblique crushing on the crashworthiness of HSCS is predicted and analyzed. Further, to improve specific energy absorption (SEA), the HSCS as a sub-structure is used to design cellular structures including unit-cell, double-cell and four-cell structures. From the predicted results, failure process and complex coupling failure mechanisms of HSCS are revealed. It is found that the oblique crushing angle has a significant effect on the crashworthiness and there exists a critical angle. It is also revealed that the SEA increases with the increase of the cell number due to different splaying modes.