Improving the crashworthiness of carbon fiber-reinforced composite channel section structure through controllable failure mechanisms

Abstract

To improve the crashworthiness of the composite channel section structure (CCSS), three external triggers including ditch plug trigger (DPT), trapezoidal groove trigger (TGT), and v-groove trigger (VGT) are proposed. A progressive damage model for CCSS is developed considering the damage initiation and evolution of intra- and inter-ply. Based on the model, the effects of the size of the external trigger and the friction coefficient between the external trigger and the structure on the axial energy absorption characteristics and failure modes of CCSS are investigated. The results show that the external trigger has a large influence on the failure process. The increase in ditch height of DPT is beneficial to improve the load-bearing capacity of the structure in the middle stage of crushing. Compared to DPT and TGT, VGT is more effective in decreasing the initial peak load and increasing the crushing load efficiency. The failure mechanisms of CCSS induced by the external trigger are revealed. The proposed external trigger can induce specific failure modes, and the structure tends to slide toward the middle after contact with TGT and VGT. The increase of the friction coefficient between CCSS and TGT or VGT can improve energy absorption. The results of the study can provide a reference for the design of external triggers for CCSS.