
Abstract: Crashworthiness is a crucial aspect of vehicle safety because it reduces structural damage and protects occupants during frontal collisions. Most previous studies have relied on Finite Element Method (FEM) simulations, which require high computational resources and complex geometric modelling, making them less efficient for early-stage design. To overcome this limitation, this study developed a four-mass dynamic model using a spring–damper system to simulate the crashworthiness of a vehicle's front-end structure under full frontal impact. The model represents the bumper beam, crash box, and chassis, and each is assigned specific values of mass, stiffness, and damping. Simulations were carried out using MATLAB Simulink under a frontal impact condition with an initial velocity of 15.6 m/s (56 km/h), an impact force of 72,000 N, and a duration of 0.2 seconds. Validation was performed based on previous studies that compared the Finite Element Method (FEM) and Lumped Parameter Model (LPM), showing that the displacement results of the present model were similar to those obtained by FEM. The simulation showed a maximum chassis displacement of 70 mm, followed by a rebound of 60 mm, stabilizing within 1.2 seconds. The peak velocity reached 2.5 m/s, and the maximum acceleration was 140 m/s², which decreased to 100 m/s² owing to damping and plastic deformation. These results indicate that the model can accurately and efficiently represent impact dynamics, offering a practical alternative for early crashworthiness evaluation and structural design optimization.
