Multiphysics modeling framework for corrosion-fatigue degradation in reinforced concrete structures

Corrosion–fatigue interaction is a strongly coupled chemo-mechanical degradation process that critically affects the durability of reinforced concrete (RC) structures exposed to aggressive environments and cyclic loading. Although corrosion and fatigue are often treated separately, their simultaneous evolution leads to nonlinear and accelerated deterioration that existing sequential or decoupled approaches cannot capture. The complexity of reproducing concurrent chemical and mechanical degradation experimentally has contributed to significant knowledge gaps, reinforcing the need for a fully coupled, physics-based modeling framework.

In this project, we plan to develop a comprehensive multiphysics phase-field framework that simulates the full spectrum of processes governing corrosion–fatigue degradation in RC structures. The framework will incorporate chloride ingress, chloride binding, and carbonation-induced depassivation in concrete; reactive transport of corrosion products; pressure buildup and cracking caused by rust formation; corrosion diffusion and dissolution-driven weakening of steel; fatigue degradation in reinforcing steel; and fatigue crack propagation and splitting fracture in concrete. Degradation-dependent transport properties will be included to capture the bidirectional coupling between mechanical cracking and ionic transport, allowing corrosion, fracture, and fatigue to evolve simultaneously throughout the service life. The interaction between steel and concrete will further be modeled through corrosion- and fatigue-induced bond deterioration, enabling realistic simulation of slip, confinement loss, and load-transfer degradation.

To ensure physical fidelity, key chemo-mechanical and fatigue submodels will be calibrated and validated against targeted experimental tests, including studies focusing on the combined effect of corrosion and cyclic loading on bond strength. Selected aspects of the problem, such as rust formation at the steel interface, microstructural cracking, and bond-slip behavior, will be further investigated using multiscale modeling to resolve critical mechanisms that cannot be captured at the structural scale alone.

The anticipated outcome is a unified, predictive modeling framework capable of resolving how corrosion accelerates fatigue failure and how cyclic loading enhances corrosion progression. By enabling detailed 2D and 3D simulations under realistic environmental and mechanical conditions, the project aims to provide a robust tool for service-life assessment and the design of more durable RC structures exposed to aggressive environments and repeated loading.