Study on crushing behaviors of foam-filled thin-walled square tubes with different types and number of initiators under multiple angle loads

A finite element model of a thin-walled foam-filled square tube is developed for estimating its energy absorption characteristics. The crush behavior of the foam-filled tube is experimentally evaluated under axial loading and the measured force-deflection properties are used to examine validity of the model. The validated model is subsequently applied to study the effects of types and number of crush initiators on the energy absorption characteristics of the foam-filled thin-walled square tubes subjected to loading at different angles. It is shown that initiators can yield improved collision performance of the foam-filled thin-walled square tubes, when a reasonable number of crushing initiators are introduced. The energy absorption performances of the foam-filled structure with different types and quantities of crushing initiators are calculated and ranked. The results showed best performance when a set of four-corner-holes along the axial direction of the tubes is added. Based on the model results, a multi-objective optimization method is proposed for deriving an optimal design of the tube with a set of four-corner-holes for enhanced crashworthiness performance.