Numerical modeling of stress corrosion cracking in steel structures with phase field method

This study uses the phase field method to present a coupled mechano-electro-chemical formulation for predicting stress corrosion cracking (SCC) phenomena in steel structures. SCC constitutes an intricate damage process stemming from the interplay between mechanical loading and corrosion within an aggressive environment. The formulation presented herein introduces a phase-field parameter that aggregates the mechanical and electrochemical influences. To achieve this goal, the internal energies governing the SCC phenomenon are separated into elastic-damage strain energy, interfacial reaction energy, and energy resulting from changes in corrosion ion concentration. The Allen-Cahn equation is modified to include all energy contributions and calculate the phase-field parameter. Furthermore, a specific interfacial kinetic coefficient is introduced to the mechanical energy to consider corrosion current effects on mechanical properties. The Cahn-Hilliard equation is applied to model the corrosion ion concentration in the domain, and the mechanical state of the body is obtained by solving the equilibrium equations. Several numerical examples are presented to indicate the robustness and accuracy of the proposed formulation. In this respect, the method is applied to predict crack propagation resulting from SCC in two practical engineering problems, yielding promising results.