Crashworthiness evaluation of a BEV front-end system based on equivalent static crash stiffness method

The structural crash stiffness analysis is an important part of crashworthiness evaluation for vehicle. However, the definition of the crash stiffness is confused, and the corresponding calculation methods are not uniform. In this study, a newly defined crash stiffness was proposed, and corresponding calculation (ESCS, equivalent static collision stiffness) method was developed. First, the basics of structural crashworthiness was explored. Second, a newly proposed crash stiffness calculation method and corresponding evaluation indicators were developed, which was based on the finite element method and energy principle. Meanwhile, the simple numerical example was performed to confirm its effectiveness. Finally, a finite element model of the BEV front-end system was established, and a physical crash test was conducted to evaluate the effectiveness of the crash model. Furthermore, the crashworthiness of the BEV front-end system was evaluated based on the analyses of crash force, crash energy, and crash stiffness. The results show that the proposed crash stiffness method can be used to evaluate structural crashworthiness, and the evaluation results were consistent with traditional crash force, crash energy, and other methods, which further verifies the effectiveness of the proposed crash stiffness evaluation method. This method also lays a foundation for further structural crashworthiness design improvements.