Energy Absorption Characteristics and Failure Mechanism of Fabric Composite Channel Section Structure under Axial Crushing Loading

A nonlinear progressive damage model was adopted to study the energy absorption mechanism of fabric composite channel section structures under axial quasi-static crushing loading. Based on continuous damage mechanics (CDM), intralayer and interlayer failure were initiated by the maximum stress and quadratic nominal stress criteria, respectively. The damage process of the material is described using the progressive damage evolution law based on the stiffness degradation method. The different failure modes exhibited by the composite channel section structure under different crushing displacements are analyzed in detail. The effects of geometric sizes and stacking sequences on the initial peak value, specific energy absorption (SEA), mean load, and failure mode are analyzed and discussed. The results show that thickness has a positive effect on the specific energy absorption and induces progressive failure of the structure. The initial peak force is a positive correlation function with respect to thickness and flange length. The flange length and stacking sequence have a significant effect on the crushing load response of the structure, and a reasonable stacking sequence can improve the crushing behavior of the structure.