Modern automotive customers are demanding for faster and faster product development, from initial response for quotation (RFQ) to serial production. Finite Element Analysis (FEA) is a powerful tool applied to design validation (DV). In Valeo, FEA and Reliability teams have been working together to establish a robust methodology based modern simulation tools to validate the desing of the components undergoing vibration fatigue validation tests.
Previous investigations had shown that “simple” DV simulations based on the material's ultimate tensile strength (UTS) rely on conservative criteria and basically target an infinite fatigue life endurance.
The present study aims at predicting the cumulative vibration damage of relatively complex systems (multi-materials components, prototype parts and representative system integration) in the high cyclic fatigue domain: the goal is to run representative FEA simulations as early as possible even before official nomination (RFQ phase).
In a numerical example, the fatigue damage simulations are calculated on a car Engine Cooling Module (ECM) undergoing vibration fatigue loadings. Various types of calculation methods are considered, which include modal linear and non-linear approaches and time domain methods.
We will illustrate the results as a comparative analysis between the presented methods. The objective of the study is to compare the vibration fatigue damage estimations obtained from the different approaches when applied to durability design validation of an automotive cooling system undergoing vibration fatigue loadings.