Investigation of the driver injury risks in small overlap impact with automatic emergency braking

Abstract The forward displacement caused by precrash braking may influence occupant injury risks in frontal impacts. However, the occupant injury mechanisms in the small overlap impact (SOI) with autonomous emergency braking (AEB) systems are not yet fully understood. This study aimed to investigate the driver injury mechanisms in SOI with AEB via finite element modelling using the THUMS occupant model and a validated vehicle model. Simulations were conducted under the braking-crash loadings which combined the simplified braking curves with representative SOI accelerations. Simulation results indicated a considerable increase in occupant thoracic compression owing to forward displacement induced by AEB, though the risk of brain injury remained uncertain. The presence of AEB in SOI changed occupant injury patterns, showing varied injury risk trends across different body regions. The main injury mechanisms under AEB crash load conditions were the reduced buffering effect of the restraint system and increased ride-down efficiency caused by AEB, contributing to greater uncertainty in overall occupant injury risk.