Simulation of Frontal Barrier Offset Impacts and Comparison of Intrusions and Decelerations

The European safety regulation plan regarding frontal barrier offset impact calls for 30° angular impact protection in 1995 and a perpendicular 40% offset deformable barrier impact protection in the 1998 time frame. However, various other governmental and private agencies are looking at alternative test conditions. The Auto Motor and Sport Magazine and other insurance agencies have been conducting rigid barrier front impact tests at 40 and 50% offsets. In this study various test conditions were examined analytically. Detailed finite element models were developed to understand the implications of these impact conditions. The models provided insight into energy management mechanism, load transfer and vehicle deformation patterns due to offset impacts on to perpendicular and angular barriers. Several potential offset conditions were simulated using the FEA models. These were 50% offset perpendicular rigid barrier impact, 40% offset perpendicular rigid barrier impact, 40 and 50% offset perpendicular deformable barrier impact, and 30° angular impact with and without an anti-skid device on the rigid barrier. Dash and toe board intrusions, as well as vehicle deceleration pulses, were compared to identify the key considerations. Deformation patterns in the engine compartment and in body side structures were also examined. Model predictions were validated against prototype test data.

Details of NCAP and offset impacts, comparison of model results for various impact conditions and the correlations with test data are presented in this paper.