A Simulation-Based Study on the Influence of the Impact Velocity on the Structural Deformation, Stress, and Cabin Intrusion of Passenger Vehicles

The deformation and failure process of automobile components begins at the moment of impact. This complex physical phenomenon is influenced by numerous factors, many of which are random. This report presents a mathematical simulation of a moving vehicle colliding with a fixed barrier. The modeling process uses HyperMesh for preprocessing and Radioss for numerical computation to simulate the formation, deformation, and failure of vehicle components. The results of the numerical simulation are then compared with experimental data for analysis and evaluation. Recommendations are proposed to solve the problem of determining the vehicle's speed immediately before impact. These recommendations can serve as a reference for traffic accident investigations in Vietnam. The results show that as vehicle speed increases from 56 km/h to 80 km/h, the maximum displacement rises from 20 mm to over 120 mm and the maximum stress increases from 3,200 MPa to over 6,500 MPa, surpassing the material's strength limit. Contact energy increases nonlinearly, from 2.54×10⁶ Nm at 55 km/h to 9.00×10⁶ Nm at 80 km/h, reflecting the influence of plastic folding and strain rate effects. At speeds exceeding 70 km/h, the footwell, brake pedal area, and vehicle doors experience severe intrusion, which significantly reduces passenger protection capacity.