Corrosion fatigue crack growth in stainless steels: A peridynamic study

Fatigue crack growth (FCG) behaviors are accelerated by corrosive environments, resulting in higher corrosion FCG (CFCG) rates and more rapid structural failure. Current local-theory-based numerical methods do not effectively capture the CFCG behaviors of metallic materials. Recently, peridynamic (PD) models, which are nonlocal-theory-based, have demonstrated good descriptive ability for discontinuous problems, making it promising to simulate CFCG via PD methods. In this paper, a peridynamics-based CFCG simulation framework is proposed and applied for the CFCG simulation of the stainless steel, Type-634. This framework provides explanations of corrosion-induced faster crack growth from the view of degradations of material properties. And the simulated results agree well with the experimental testing results, demonstrating the effectiveness of the proposed model. Moreover, the effects of corrosion-related degradation function parameters and loading frequencies on CFCG results are explored, and the results demonstrate the generalizability of the simulation method. With further development and embedding more accurate physical models, this simulation framework will effectively assist real CFCG tests.