Structural crashworthiness analysis of a ladder frame chassis subjected to full frontal and pole side impacts

Automobile chassis is a major element of structural crashworthiness in road motor vehicles. Various chassis geometry and topology research studies have been conducted to improve crash energy absorption characteristics of the chassis. In side impacts, crashworthiness of an automobile body depends not only on the chassis geometry and topology, but also on the design and reliability of other structural members such as B-pillar and side panels. This study aims to contribute to the investigations on the effects of chassis geometry over crashworthiness, particularly focusing on the structure of a ladder frame chassis subjected to full frontal and pole side collisions. Preliminary work has been conducted to evaluate the behaviour of steel beam profiles under impact loading through finite element (FE) modelling, which helps understand the mechanics of the particular beams chosen as chassis elements. Another FE model is developed utilising a previously generated mesh of a pickup truck with a ladder frame chassis. The FE model is employed to simulate full frontal and pole side crash test scenarios on the isolated chassis as well as on the whole body of the vehicle. Crash energy absorption results and reaction forces are collected for different thicknesses and beam profile cross sections of the vehicle chassis to be utilised in several proposed design improvements aiming to enhance crashworthiness. Computational results exhibit good agreement with experimental findings.