The proposed oblique impact test with a Research Moving Deformable Barrier (RMDB) by the National Highway Traffic Safety Administration (NHTSA) is designed to represent crashes involving partial longitudinal structural engagement between vehicles. The RMDB moves at a speed of 56mph (90kph), with a small overlap of 35% and an impact angle of 15°, into a stationary vehicle. In addition, the newly developed Test Device for Human Occupant Restraint (THOR) dummy and the Brain Injury Criterion (BrIC) are used to evaluate the injury risk. The implementation of these test modes and measurement techniques will raise the bar for performance of passive safety systems.

Meanwhile, the introduction of the Federal Motor Vehicle Safety Standard 226 (FMVSS 226) as a countermeasure for ejection mitigation during a rollover has increased the occupant protection area of side curtain airbags (SCAB). As a result, SCAB designs have incorporated increases in height, width, and depth, depending on the interaction of the airbag with the vehicle’s interior. This dimensional change in FMVSS 226 compliant SCAB, while yielding positive results in side impact and rollover crashes, may also play a critical role in the prevention of injury for the NHTSA oblique test mode. This study examines the effect of the expanded occupant protection coverage of FMVSS 226 compliant SCAB on BrIC results during an oblique impact. This study used publicly available oblique pulse data (published by NHTSA) in a Finite Element (FE) model with a Hybrid III 50th% dummy to perform an oblique impact test. The interior environment of the FE model was obtained by digitizing a generic buck and morphing available FE models from the National Crash Analysis Center (NCAC) database. The FE model was validated with a belted 35mph frontal impact test (FMVSS 208) and then used for the oblique impact analysis. This study examines three oblique FE models, each consisting of a different configuration of restraint systems. The first configuration did not utilize a SCAB;​ the second configuration had a non-FMVSS 226 compliant SCAB;​ and the third configuration had a FMVSS 226 compliant SCAB. In order to assess the effect of SCAB design, only the upper body results of the dummy were compared and analyzed. Differences in injury response were observed between the three configurations when evaluating the head acceleration, head rotation, and chest deflection. A significant improvement was observed in the BrIC result for the FMVSS 226 compliant SCAB when compared with the other two restraint system configurations tested. Though this study is design-specific, appropriate explanations are provided to support the study.