Peridynamics modelling on corrosion fatigue behaviours of an iron-based alloy considering mechanochemical effects

Abstract

The fatigue failure process is significantly accelerated in the presence of corrosion, a phenomenon widely observed in engineering practice. Accurately predicting the corrosion fatigue behaviours of materials remains challenging owing to the limited knowledge of the synergic effects of corrosion and fatigue loads. This paper proposes a new peridynamic simulation method to analyze corrosion fatigue problems based on authors' previous work, which considers mechanochemical effects to exhibit coupling between corrosion and material deformations. To validate the reasonability of the proposed method, corrosion fatigue tests on an iron-based (Fe-based) alloy are conducted to acquire experimental benchmarks. Then, numerical simulations based on the proposed method are conducted, whose results are compared with testing results, also simulation results obtained by previous simulation method. The proposed method not only provides accurate predictions on corrosion fatigue properties (the simulated fatigue limit is 249 MPa, the same with the tested one), but also increases accuracy on lifetime predictions by 66 % compared with authors’ previous work. The proposed method not only provides a unified simulation method in dealing with complex mechanical problems considering both continuity and discontinuity, such as corrosion fatigue, but also provides good accuracy in predictions of corrosion fatigue properties, making such method both theoretical-meaningful and engineering-practical.