Investigating the Effects of Materials, Geometric Properties and Modifications on the Crashworthiness of Bumper and Chassis System

Accidents are one of the main reasons of death for people across the globe, among which automobile accidents are a major portion resulting in fatalities and various injuries. Crashworthiness aims to affect the design of the structure of the vehicle so that it absorbs as much energy as it can which is sustained from an impact by plastically deforming in a controllable behaviour. The current trend in automobile design and manufacturing is to increase the number of lightweight and recycled components that forms the vehicle. However, using unconventional materials might affect the strength and energy absorption capabilities of the automobile chassis and body that may induce a change in the crashworthiness of the vehicle. This study aims to bring insight into the effects of various conventional as well as lightweight and recycled bumper-chassis systems on vehicle crashworthiness subjected to full-frontal impacts through computational modelling. Investigations are carried out for improving crashworthiness through the use of different materials, various profile thicknesses and modifications on the system geometry. Various finite element models embodying several bumper-chassis systems such as with crush zone, with hexagonal cross-section, with runner, and with range hood are generated and simulated to evaluate the design choices and modifications. Crush force efficiency and specific total strain energy absorbed are used as decisive parameters in assessing the systems. It is observed that some of the geometrical modifications have improved crash performance of the bumper and chassis system. The best alternative as a material is suggested to be “Recycled 7175 aluminium” with its light weight and considerably high impact energy absorption performance.