These slides were presented at the NAFEMS World Congress 2025, held in Salzburg, Austria from May 19–22, 2025.

Abstract

The modern development of automotive products demands increasingly faster product development and design validation, reduced expensive physical testing, and a greater reliance on digital prototypes. Finite Element Analysis (FEA) has become an essential and powerful tool for predicting product behavior and validating designs. Automotive systems are subject to various types of mechanical loading, including random excitations that represent vibrations experienced throughout a product's lifetime. Linear FEA methods in the frequency domain are widely used in the industry to predict this behavior due to their efficiency. However, for certain complex Valeo products, a nonlinear time-domain approach offers higher accuracy by providing a more precise representation of product behavior, enabling improved predictions of failure modes, stress levels, and fatigue life. The main challenge in implementing nonlinear dynamic methods lies in the time-consuming preprocessing, post-processing, and significantly longer computation times. To address this issue Valeo has developed an automated process that allows it to convert models from a standard linear to nonlinear one, making nonlinear dynamic FEA feasible for large industrial FE models. The conversion process involves creating nonlinear contacts with the correct properties, changing the solver, implementing result post-processing, and automating the detection of common errors. Additionally, the objective is to maintain the current standard simulation workflow as closely as possible, enabling engineers to respond quickly to new design iterations and maintain a competitive edge through innovative solutions. The automated process for nonlinear dynamic FEA is demonstrated in a real case study involving a car Front Cooling Module (FCM) subjected to random vibration loadings. The FCM is a multi-component assembly comprising various types of heat exchangers. Historically, it was primarily responsible for cooling internal combustion engines in vehicles. However, with the electric vehicle revolution, the FCM has undergone a significant transformation. These changes have increased the need for detailed consideration of contact nonlinearities in acceptable simulation time.