Energy absorption capability of multi-cell thin-walled tube under lateral loading

Abstract

Energy absorption performance of a structure is a vital aspect in modern transportation design to minimize human injuries during collision. To minimize impact energy, it is necessary to dissipate the energy generated from the collision by absorbing it through deformation of crashworthy structure. Thin-walled structures are widely used as energy absorbing systems due to their capability to efficiently absorb kinetic energy through plastic deformation. However, there are several accidents reported that involve collision between vehicles with toll booths, utility poles and flyover pillar that are lack of protective device. Most of the crashworthiness studies emphasized on the multi-cell structure with load applied axially. Therefore, the investigation on the multicell circular thin-walled tubes under lateral loading still gained less attention among the researchers. The primary objective of this thesis is to evaluate the crush response and energy absorption performance of multi-cell thin-walled tubes under quasi-static lateral loading. The compression test was performed under quasi-static lateral loading to evaluate the energy absorption performance of circular thin-walled tubes. Finite element models were developed and validated by comparing the crushing profile and load-displacement curve response of. A multi-cell configuration study was performed to identify the most optimal multi-cell configuration. Furthermore, the response surface method (RSM) for the design of experiment (DOE) was employed to identify the correlation between the geometrical variables parameters and the energy absorption responses. In addition, an investigation of geometrical factor of multi-cell structure was conducted by employing the multi-objective optimization design approach in order to establish the design guidelines of optimal geometrical configuration. Compression test result shows that a multi-cell thin-walled tube has superior energy absorption performance compared to a single thin-walled circular tube under lateral loading. It is evident that the specific energy absorption (SEA) of multicell thin-walled tube produces 28% and 76% greater than the single thin-walled circular tubes, SC-small and SC-large configurations, respectively. The outcomes of the study show that the energy absorption performance of multi-cell structure is significantly dependent on the number of tube cells and contact joint of the tube. Based on the multi-objective optimization study, it is evident that the optimal configuration of multi-cell thin-walled tube can be achieved with a smaller diameter and thicker circular tube. The main contribution of this thesis is the development of design guideline for the most optimal geometrical parameter of multi-cell thin-walled tube under lateral loading.