A Study On Optimal Design of Longitudinal Shape For Improving Small-Overlap Performance

This paper presents a study on the optimal design of longitudinal shape for improving the small-overlap performance, based on a computer-based crash simulation model. The small-overlap frontal impact (SOFI) event was simulated using explicit finite element method. The models were developed for the simulation according to the Insurance Institute for Highway Safety IIHS real test conditions with the Flat 150 mm radius rigid barrier and 25% overlap. Several different cross sections of longitudinal members were subjected to dynamic compression load, which occurs in small overlap frontal impact. The different shapes of longitudinal structure were compared initially to obtain the cross section that fulfills the small overlap performance criteria. The evaluated performance parameters included the absorbed crash energy, crush force efficiency, ease of manufacture and cost. Once the cross section was selected, the design was further enhanced for better crashworthiness performances by investigating the effect of material characterization, increasing the wall thickness and by introducing a trigger mechanism. Real experiments were also performed for …. The results of this study showed that the multi edges profile with 2 mm wall thickness and steel material was a good candidate for energy absorption in SOFI condition.