Crash Analysis and Structural Optimization of Racing Car Chassis Based on LS-DYNA

Abstract

: This study investigates the crashworthiness and structural optimization of a racing car space-frame chassis under extreme off-road collision conditions. A three-dimensional chassis model was established in CATIA, and a frontal rigid-wall collision at 11.11 m/s was simulated using LS-DYNA. The results show that the chassis undergoes progressive plastic collapse, during which kinetic energy is rapidly converted into structural internal energy. The front longitudinal beams and diagonal braces are identified as the main energy-absorbing components, and deformation propagates from the front structure toward the rear while the occupant cabin remains largely intact. The peak contact force reaches approximately 1.68×10⁵ N, and stress concentration occurs mainly at the welded joints between the front cabin and the driver’s cabin. The maximum equivalent stress is about 131 MPa, while the peak plastic strain reaches 0.342, close to the material failure threshold of 0.35, indicating a critical weak region. The front bumper acceleration reaches about 13 g with a steep impact pulse. Based on these findings, local reinforcement and structural simplification were performed to improve safety and reduce mass. After optimization, the maximum plastic strain decreases from 0.342 to 0.148, and the peak front bumper acceleration decreases from 13 g to 8.6 g. The optimized chassis shows improved strain control, smoother energy absorption, and better crashworthiness, providing a useful reference for lightweight design and collision safety improvement of off-road racing car chassis.[1]