Investigating Deformation Behavior of Bus Frame Subjected to Side Impact: Experiment and Simulation

This study investigated the deformation behavior of a bus frame structure subjected to side-impact loading through a combined experimental and numerical approach. A side-impact test was conducted at the Automotive Research & Testing Center (ARTC), and a finite element (FE) model incorporating material nonlinearity and weld behavior was developed using LS-DYNA. The numerical framework was constructed to replicate the experimental configuration, including impact velocity and boundary conditions. During the experiments, the impact process was recorded using a high-speed camera, and strain histories were measured using strain gauges. After impact, the global deformation and intrusion of the frame were captured by 3D laser scanning. Results indicate that proposed FEA framework demonstrates good accuracy in predicting the global deformation of the bus frame and the frame intrusion obtained from simulation differs from the experimental measurement by 0.6%. For local deformation and strain responses, although the simulated strain histories reproduce the overall trends observed experimentally, the discrepancies in the peak strain values remain. These differences are mainly attributed to unavoidable manufacturing imperfections, variations in weld properties, and local structural complexities that are not fully captured in the numerical model.