Design of an aluminium-based vehicle platform for front impact safety

The current paper examines the design of an aluminium-intensive small car platform for desirable front impact safety performance. A space frame-type architecture comprised of extruded aluminium members with welded joints is considered for inherent structural rigidity, and low investment in terms of tooling. A finite element model of the vehicle is employed for crash analysis using the explicit code LS-DYNA. Confidence in analysis is established at the component level by benchmarking finite element models of welded joints against experimental data, and axial crushing of aluminium tubes against published numerical results and theoretical prediction. A numerical design of experiments is conducted for arriving at a front-end design that will yield desirable safety performance during impact against a rigid barrier at 30 mph (FMVSS 208 condition). For comparable new car assessment program performance at a higher speed of 35 mph, a lumped parameter idealization is used to identify the principal design changes that may be necessary. The current approach of component level testing combined with finite element and lumped parameter-based simulations can be regarded as an effective and time-saving procedure in the crash safety design of new vehicles.