Abstract:
This study presents the development and validation of a finite element model (FEM) for crashworthiness analysis of the 1998 Audi A8, an all-aluminum passenger vehicle. The model was developed to simulate a 35 mph frontal impact against a rigid barrier as part of the NHTSA New Car Assessment Program (NCAP). To achieve a high-fidelity representation, the model was constructed using detailed mesh analysis, incorporating experimental measurements obtained through FaroArm 3D coordinate mapping and IGES surface digitization.
The model generation process involved defining structural geometry from a fully disassembled vehicle, with material properties characterized via uniaxial testing of metal coupons and load-deflection assessments of critical components, including the engine, suspension, transmission, and bumper support structures. TrueGrid was used to generate a precise finite element mesh, while LS-DYNA was employed for crash simulations, leveraging parallel computing resources at Oak Ridge National Laboratory.
A combination of single-surface and node-to-surface contact modeling strategies was implemented to address component interactions, ensuring accurate energy transfer and deformation predictions. The study highlights the importance of using multiple contact algorithms to minimize penetration errors and stabilize numerical behavior. Structural components such as the A-pillar, B-pillar, rocker panels, and engine cradle were modeled in detail to capture crash dynamics effectively.
Simulation results demonstrated strong correlation with full-scale crash test data, particularly in the deformation behavior of the front-end assembly and energy-absorbing bumper components. However, minor discrepancies in engine cradle deformation were attributed to limitations in surface mapping accuracy. Future improvements will focus on refining contact penalties, enhancing mesh resolution, and optimizing computational efficiency to further improve the predictive capability of the model for crash safety evaluations.
