Occupant injury in full-vehicle offset frontal collision and restraint system effectiveness

Road traffic injuries constitute a leading cause of mortality worldwide, resulting in approximately 1.3 million fatalities annually. Conventional crash test anthropomorphic test devices (ATDs), such as the Hybrid III dummy, fundamentally lack the anatomical fidelity required to resolve tissue- and organ-level injuries. High-fidelity human body models (HBMs) such as the Total Human Model for Safety (THUMS) provide a validated computational alternative capable of predicting micro-level injury mechanisms. A comprehensive finite element (FE) framework was developed and validated to simulate a 60 km/h, 50% offset frontal impact of a full vehicle against an aluminium honeycomb Offset Deformable Barrier (ODB). The THUMS AM50 (50th-percentile adult male) human body model was positioned within a validated 2014 Honda Accord FE model incorporating an integrated three-point seatbelt and folded driver airbag. A restraint ablation study (both restraints, airbag only, seatbelt only, none) quantified individual and combined effects on head, spine, heart, and lungs. With both restraints, head acceleration reached 78 g (HIC36 = 605, <10% injury risk), and chest deflection was 42 mm, both within FMVSS 208 limits. The airbag reduced head acceleration by 32% and HIC36 by 45%, and the combined system lowered cardiac stress by 45% compared to the unrestrained case. Overall, the study characterizes existing restraint performance via ablation for head and thoracic protection and provides a reliable computational tool for vehicle safety design and injury prediction.