PSI - Issue 75

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia (2025) 000 – 000

ScienceDirect

www.elsevier.com/locate/procedia

Procedia Structural Integrity 75 (2025) 677–690

Fatigue Design 2025 (FatDes 2025) Probabilistic Fatigue Approach for Complex Vibration Signals. Case Study of Automotive components

Marco Bonato a , Karthikeyan Sridhar b , Manojkumar Lingareddy b and Anbalagan Dharmaraj b

a Valeo Power Division, La Verrière, France 78322, France b Valeo India Private Limited, Chennai 600119, India

Abstract Structural simulation is gaining momentum in the automotive industry, offering the potential to validate new component designs without lengthy and costly physical prototyping. Finite Element Analysis (FEA) techniques are powerful to simulate local stress concentrations and identify the weak zones – those locations prone to cumulative fatigue damage and failure. In the recent years, there have been numerous investigations concerning FEA simulations providing not only the stress level but also the quantification of local fatigue damage accumulation, allowing for the estimation of component durability and time to failure. Additional methods have been developed in order to overcome the limitations of “deterministic” approaches, by considering the variability associated with fatigue simulations, and introduce the concept of “Probabilistic Fatigue Simulations”, also known as “Stochastic Fatigue.” In this paper, we investigate Stochastic Fatigue techniques applied to automotive components undergoing mechanical vibration tests. The study focuses on the intrinsic challenges associated with a stochastic fatigue approach, i.e.: - the availability of the material characterization - the difficulty of correlating the simulation models - the choice of the input parameters to be considered for the Uncertainty Quantification (UQ) Proposed here is a concrete case study based on the simulation of a supporting bracket with known geometrical variations. The geometry is designed in such a way that it allows to consider: - multiple degrees-of-freedom systems - complex geometry that comes with various sources of variability The fatigue life of the part undergoing vibration stress from a complex vibration signal (a Sine Sweep On Random SSoR excitation) is initially stimulated via FEA-based fatigue and the fatigue life distribution determined by running multiple simulations by varying certain parameters (the geometry of the bracket, the strength coefficient, the Basquin fatigue exponent, the damping ratio and the surface roughness). Then, several specimens are vibrated until failure in a testing shaker, and the correlation results are discussed. By correlating the fatigue variability of FEA-based calculation, the aim of the study is to start from a relatively simple use case to further tackle the issues often encountered in automotive components, which have complex geometry, various

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Fatigue Design 2025 organizers

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of Dr Fabien Lefebvre with at least 2 reviewers per paper 10.1016/j.prostr.2025.11.069