Evaluation of new steel and composite beam designs for side impact protection of a sedan as per FMVSS 214, IIHS and side pole tests requirements

Abstract

Side impact crashes can be generally quite dangerous due to the limited space in the car door for large deformation and energy-dissipation in order to protect an occupant from the crash forces. The side impact collision is the second largest cause of death in United States after frontal crash. Day-by-day increase in the fuel cost and the emission of the smoke from the automobile industry are also the major concerns in the contemporary world. Hence the safety, fuel efficiency and emission gas regulation of the passenger cars are important issues in contemporary world. An ideal way to increase the fuel efficiency without sacrificing the safety is to employ composite materials in the body of the cars because the composite materials have higher specific strength than those of steel. The increase in the usage of composite material directly influences the decrease in the total weight of car and gas emission. In this research, carbon/epoxy AS4/3051-6 is used as composite material for a side impact beam design, which has adequate load carrying capacities and that it absorbs more strain energy than steel. The finite element (FE) models of a typical passenger car and the moving deformable barrier (MDB), as available in literature, have been utilized for the analysis in this thesis. The current side impact beam is removed from the car and the new beam, which is designed using CATIA, is merged on to the driver side of the front door of the car model. The total energy absorptions of the new beam with steel and composite material are compared with those of the current beam in three-point bending test simulations. The surface plots for mass (weight), specific energy, and intrusion are developed as design charts. The intrusions of the beam are then evaluated by using the full-vehicle models and as per regulatory FMVSS 214, IIHS and Side Pole impact safety methods. The new impact beam with composite material is shown to exhibit higher impact energy absorption capability, when compared to current beam and new beam with steel, with 62.5% reduction in weight.