Lateral crushing and energy absorption behavior of hexagonal tubes with non-uniform thickness distributions

Abstract

To improve the energy absorption performance of hexagonal thin-walled energy absorbers, a space- and weight-efficient design method is proposed by rationally arranging the distribution of the thickness along walls. The plastic deformation characteristics and energy absorption behavior of the designed non-uniform hexagonal tubes subjected to lateral compression by two rigid plates are investigated. By properly adding the thickness at the regions near side corners, the plateau forces of the designed non-uniform hexagonal tubes are higher than that of the uniform hexagonal tube. Increasing the thickness of the horizontal walls can regulate the deformation mechanism of the hexagonal tubes and thus increase the effective stroke, which means that the lateral space is apt to be fully utilized. By simultaneously increasing the thicknesses at these regions, the stroke efficiency is significantly improved and the total energy absorptions of the non-uniform tubes can be 2.0–2.3 times that of the uniform hexagonal tube. In addition, compared with the corresponding uniform hexagonal tubes with the same weight, the rationally designed non-uniform hexagonal tubes can possess dramatic improvement in comprehensive energy absorption performance: the total energy absorption, stroke efficiency, and energy absorption efficiency can be improved by nearly 40%, 22%, and 30%, respectively.