Dynamic bending behavior of double-hat beams filled with alloy hierarchical structure

Abstract

Double-hat beams are widely used in vehicle body due to their light weight and high energy-absorbing properties. In this study, the dynamic three-point bending performance of the double-hat structure is improved by alloy hierarchical structure filling. The simulation model of the double-hat structure is established, and its accuracy is verified by experiments. Three different hierarchical structure models are proposed through the changes of structure and micro-element size. Compared with the traditional double-hat beam, the specific mean crushing force (SMCF) of triangular hierarchical structure (THS), parallelogram hierarchical structure (PHS) and hexagonal hierarchical structure (HHS) increased by 5.15, 4.35 and 3.92 kN/kg, and their deflections decreased by 180.56, 165.01 and 170.99 mm, respectively. The influence of geometric parameters of these three hierarchical models is studied. It is revealed that the increase in the number of microstructure columns significant enhanced the crashworthiness of the double-hat structure. It is also showed that the continuous expansion of the cell size affected the impact performance of different hierarchical structures. These results will make an important contribution to the crashworthiness design of double-hat beam and vehicle.