Axial energy absorption characteristics and trigger mechanism of C-channel CFRP thin-walled structures

To improve the crashworthiness of C-channel carbon fiber reinforced polymer (CFRP) thin-walled structures, the energy absorption characteristics and failure behavior of the structures under axial crushing load were studied. Considering the delamination effect, the progressive damage model of C-channel CFRP thin-walled structure was established. The quadratic stress failure and the nonlinear damage evolution criterion based on the mixed-mode energy method were used to predict the initial interlaminar failure and damage evolution, respectively. For this structure, the hybrid-angle chamfer trigger and steeple trigger were proposed, and the effects of different trigger configurations on the crashworthiness index and failure mode of C-channel CFRP thin-walled structures were compared and analyzed. The results show that the initial peak load corresponding to the hybrid-angle chamfer trigger decreases with the increase of the hybrid angle; The initial peak load can be effectively reduced by reducing the contact area between the hybrid-angle chamfer trigger and the loading plate at the initial crushing stage; The hybrid-angle steeple trigger can improve the failure process and has a positive effect on improving the crashworthiness of the structure.