Induced structure and its gradient design on energy absorption properties and failure behavior of aluminum/carbon fiber reinforced polypropylene super hybrid tube

Abstract The metal/fiber super hybrid tube is a mixture of pure metal and carbon fiber structure, featuring both stable energy dissipation of the metal and good energy absorption efficiency of the composite, with greatly improved lightweight. However, the failure mode of the hybrid tube is unstable and prone to Eulerian buckling, which affects its energy absorption performance. In this work, aluminum alloy/carbon fiber reinforced polypropylene super hybrid tube (Al/CFPP super hybrid tube) have been obtained through the addition of an induced structures, which aims at reducing the maximum peak load generated during collision. The effects of induced grooves and holes structure (number of holes, diameter and row number) on the damage and energy absorption were discussed. The results showed that the initial peak load can be effectively reduced by adding an induction groove structure. When the number of induction holes is 4, the diameter is 5 mm, and the number of rows is 1, the initial peak load decreases by 14.06%, and the total energy absorption is basically unchanged. Additionally, the gradient design of the hole diameter and spacing significantly helped guide the gradual failure of the structure, with the initial peak load decreased by 21.98% and the total absorption energy increased by 20.26%. Highlights Super hybrid structures were developed to improve crashworthiness. The effect of induced grooves energy absorption was analyzed. The effect of hole size and quantity energy absorption were analyzed. A gradient design of hole size and spacing was proposed. The combined of the induction hole and trigger angle was demonstrated.