Modeling anisotropic low-cycle fatigue behavior based on a two-surface damage–plasticity framework

Computer Methods in Applied Mechanics and Engineering, vol. 461, pp. 119242

Abstract

Based on a two-surface damage–plasticity framework, this work develops a thermodynamically consistent anisotropic low-cycle fatigue model for ductile materials. The proposed formulation addresses a limitation of many existing phase-field fatigue models, where fatigue degradation may influence the regularization properties and consequently affect crack distributions. More specifically, a fatigue degradation function is introduced to progressively reduce the damage threshold, while the regularization properties are preserved as the damage gradient term remains unaffected by fatigue. To capture the tension–compression asymmetry observed under cyclic loading, the model combines the Drucker–Prager yield criterion with a star-convex energy decomposition, enabling asymmetric evolution of plasticity and damage. In addition, a second-order structural tensor is incorporated to describe the anisotropic damage evolution and preferred crack propagation directions. Numerical investigations demonstrate comparable regularization properties of the proposed model under monotonic and cyclic loading, as well as the predictive capability in capturing key fatigue behaviors. In particular, the predicted damage accumulation under various loading sequences is approximately consistent with the Palmgren–Miner rule, and the resulting fatigue lives follow the Coffin–Manson relation.

Authors 5

1. Jian Zhang Aachen Institute of Applied Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of Applied Mechanics, RWTH Aachen University, Mies-van-der-Rohe-Str. 1, Aachen, 52074, Germany

2. Hui Ruan corresponding

   University of Oxford

   Affiliation as printed

   Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, United Kingdom

3. Qinghua Zhang Aachen Institute of Applied Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of Applied Mechanics, RWTH Aachen University, Mies-van-der-Rohe-Str. 1, Aachen, 52074, Germany

4. Stefanie Reese

   University of Siegen

   Affiliation as printed

   University of Siegen, Adolf-Reichwein-Straße 2a, Siegen, 57076, Germany

5. Tim Brepols Aachen Institute of Applied Mechanics

   RWTH Aachen University

   Affiliation as printed

   Institute of Applied Mechanics, RWTH Aachen University, Mies-van-der-Rohe-Str. 1, Aachen, 52074, Germany