EVs on Road Ground-Impact Energy Evaluation Methodology: Dynamic of a Finite Element (FE)-Based Battery Pack Integrated into Full Vehicle Multi-Body Model on Abaqus 2022-01-0864

The present paper documents a comprehensive study on the ground-impact of battery packs in Electric Vehicles (EVs), a paramount concern for vehicle manufacturers. During an accidental crash, battery packs are usually exposed dangerously to possible intrusion of foreign objects (e.g., road debris). With the purpose of developing a generic methodology to evaluate the released energy content and due to high nonlinearities involved during the ground-impact maneuvers, a hybrid full vehicle model is needed. Hence, both FE-based battery case and virtual energy sensors have been integrated into the current Abaqus multi-body (MB) full vehicle model (suspensions, steering system, engine and a trimmed body). Energy peaks are estimated simulating a vehicle going over obstacles that a typical customer can encounter in daily-life (no off-normal situations) performed at different approaching speeds and obstacle sizes.

To evaluate the energy, the battery plate is divided as if it were a spaced grid of identical square-sized modules. Plate surface modularization is useful to install properly a certain amount of virtual sensors that store and measure the energy released during the impact. In addition, this strategic layout promotes the accuracy of the contact conditions between obstacles and the battery case.

The concept underlying the proposed multidisciplinary sequential procedure, based on three different phases (on road-impact energy evaluation, load cases definition and battery case/mechanical structure strength), ensures both to define specification for subsequent analyses (making iterations on the structure faster) and to possibly complete an effective design validation of the specific vehicle project under test. This methodology has been successfully applied transversally to several vehicle architectures (e.g., light commercial vehicles, sport/compact utility vehicles, supercars) and it shows the benefits of choosing the integration strategy over a typical co-simulation approach.