Experimental and numerical investigation on crushing of metal-composite hybrid energy absorber under a quasi-static loading

In this paper, a parametric study on the effect of thickness and stacking sequence of composite layers in a hybrid energy absorber with an aluminum tube wrapped with glass/epoxy composite layers has been experimentally and numerically investigated. The samples were fabricated by vacuum assisted resin transfer molding (VARTM) and tested under a quasi-static crushing load. Specific absorbed energy was used as a criterion for evaluating. In addition, the type and mode of failure mechanisms during the crushing have been thoroughly investigated. The energy absorbers used by the multi-layered shell element is modeled in Ls-Dyna software and the effect of the trigger is considered with continuous reduction of the length of the shell layers relative to each other. The interlayer cracks are modeled according to the force-separation formulation and are used to eliminate the mesh size effects from the adhesion length criterion. Most of the mechanical properties required for modeling were also measured using standard tests. The results show an acceptable correlation between experimental data and numerical modeling. As the thickness increased, the maximum force, mean force, and absorbed energy (EA) increased. Aluminum Crash mode in aluminum tube compared to hybrid tube, it has been transformed from accordion to diamond. In addition, fiber collapse has been associated with the formation of outward bending layers.