Phase-field modeling for corrosion-fatigue degradation in metallic materials

Stress corrosion cracking (SCC) and fatigue are among the most critical degradation mechanisms in metallic structures, and their simultaneous action leads to highly accelerated and complex damage evolution. Cyclic loading in corrosive environments promotes pit formation, early crack initiation, and altered crack propagation paths, often resulting in premature failures. This coupled deterioration is especially relevant for offshore wind turbine foundations, nuclear piping, prestressed concrete bridges, marine structures, and aerospace components, where fluctuating stresses coincide with aggressive environments. Yet, current engineering tools still struggle to predict the combined effect of SCC and fatigue, as most design approaches treat them independently, yielding overly conservative or potentially unsafe lifetime estimates. Developing a reliable and mechanistically grounded predictive framework is therefore essential for accurate service-life assessment and the safe, cost-effective design of next-generation infrastructure.

In this project, we plan to develop a new corrosion–fatigue modeling framework capable of mechanistically describing dissolution-driven corrosion in metals, including processes such as pitting, stress corrosion cracking, and the pit-to-crack transition. The approach will couple mechanical straining with electrochemical kinetics and employ a phase-field formulation to represent the evolving metal–electrolyte interface, enabling the model to reproduce both activation-controlled and diffusion-controlled corrosion regimes. As part of this development, we will introduce an additional phase-field variable to represent fracture and fatigue, making it possible to simulate fatigue crack initiation and propagation under cyclic loading. Furthermore, a dedicated fatigue degradation mechanism will be formulated to capture cyclic damage accumulation, localized plasticity effects, and electrochemically assisted material weakening.
 
By coupling the corrosion and fatigue fields, the model will be able to capture how corrosion accelerates fatigue processes and how cyclic stresses, crack opening, and local plasticity further enhance dissolution. The framework is intended to be applicable to a broad range of metallic materials, including structural steels, aluminum alloys, and corrosion-resistant alloys used in offshore, energy, and transportation sectors. Through representative loading and environmental scenarios, the model will be calibrated and assessed to reproduce pit growth, pit-to-crack transition, and crack coalescence under simultaneous corrosion and fatigue conditions. Ultimately, the project aims to deliver a predictive, physics-based simulation tool for improved lifetime assessment and durability design of metallic structures exposed to aggressive environments and cyclic loading.