A finite element analysis of high-energy absorption cellular materials in enhancing passive safety of road vehicles in side-impact accidents

Abstract

In an effort to increase road vehicles' structural strength, cellular materials, such as foam, have been utilised and installed in vital parts of the vehicle. The limited structural crush zones in side-impact collisions, when compared to frontal impacts, have shown to cause higher deformation to the passenger compartments that will lead to severe injury to the vehicle occupants. Therefore, the need to further enhance road vehicles' passive safety system to protect the occupants during side-impact collisions is necessary. In addition to many passive safety features, cellular materials have been installed in current vehicles to serve as structural reinforcement by absorbing impact energy from transferring to the occupants. This study is aimed at investigating the effect of various cellular materials in enhancing vehicle crashworthiness such as side door's intrusion, interior door's acceleration and the internal energy of the cellular materials. To fulfil the objective of this paper, an existing finite element model of a sedan vehicle is modified to include a cellular material sandwiched in between the door panels. The cellular materials used for this study are IMPAXX, polyurethane foam, micro-agglomerated cork, DAX and CONFOR foams.The mechanical properties of the cellular materials utilised in the computational model are validated. Various dynamic responses of the vehicle structure with the inclusion of the five selected materials are numerically tested and compared against the vehicle structure without the cellular materials. Side-impact simulations in accordance to federal motor vehicle safety standard (FMVSS) No. 214 standard are used to replicate side-impact collisions. This study quantifies the energy absorption and side-door intrusion with different cellular padding. It also shows that the inclusion of cellular materials significantly reduces occupant compartment's intrusion and deceleration of the vehicle by at least 30%. Therefore, the inclusion of cellular materials has shown promising results in improving the crashworthiness of road vehicles.