Equivalent Stiffness Modeling Method of a Battery System for Evaluating Vehicle Rear-End Collision Performance

The battery system of a vehicle is critical for its good operation, and in the event of vehicle collision, damage to the parts or displacement of the battery can significantly affect performance. Nonlinear characteristics must be considered when designing elastic parts for vehicle’s collision analysis, and nonlinear dynamic finite element analysis simulations should be used to derive dynamic responses through collision simulations. Existing models examine the overall behavior without specifically configuring each part, and therefore, we need a model that can derive dynamic responses through collision simulations at the part level. Thus, we propose an equivalent stiffness model for a battery system to evaluate the vehicle’s rear-end collision performance in the early design stage. The model showed errors of 7.54 % and 6.12 % in the peak-to-peak values for the x-axis and z-axis acceleration responses, respectively, on the upper part of the battery; the root mean square value was within the margin of error. Simulation results confirmed that the proposed model is as accurate as the real vehicle test and nonlinear dynamic finite element analysis model. Thus, it can be used in the early design stage to predict system performance for collision test in a system whose geometry has not been determined.