Original Article

Green-FFT model for 3D contacts considering microstructure and defects

¹ Univ Lyon, INSA Lyon, CNRS, LaMCoS, UMR5259, 69621 Villeurbanne, France
² Univ Lyon, ECAM LaSalle, LabECAM, 69005 Lyon, France
³ Univ Lyon, INSA Lyon, CNRS, MATEIS, UMR5510, 69621 Villeurbanne, France

^* e-mail: jean-philippe.noyel@ecam.fr

Received: 24 July 2024
Accepted: 7 February 2025

Abstract

Physical phenomena at various scales are involved in energy dissipation and material degradation induced by mechanical contacts. Stress computation at the microstructural level is particularly valuable for the study of rolling contact fatigue or wear. For this purpose, a new efficient and versatile numerical model based on the Green-FFT method is proposed in this paper. Rough or dented surfaces can be modeled along with arbitrary material heterogeneities such as polycrystalline microstructure, inclusions or porosities. The novelty of this work lies in the efficiency of the Green-FFT method, which requires significantly lower computational cost than FEM for similar results. This enables detailed 3D analyses. The model entails three successive steps: contact pressure, stress distribution in a homogeneous material and stress distribution in a heterogeneous material computations. The periodization effect, which arises from the use of frequency domain, is mitigated by implementing zero-padding and buffer zones.