Interpreting Concrete Fatigue Damage at the Mesoscale: Model Development and Parametric Analyses

This study presents a numerical framework for evaluating the fatigue damage behavior of concrete at the mesoscale. An equivalent stochastic mechanical model is introduced, accounting for inherent heterogeneity due to initial defects. The model is further enhanced by incorporating viscosity through linear damping elements within each element, and applying reasonable periodic boundary conditions. A practical numerical implementation strategy is developed within the framework of the ABAQUS finite element package for stress-controlled fatigue analysis, which incorporates the periodic boundary conditions. A series of fatigue numerical tests are performed under tensile loading conditions on representative random concrete specimens exhibiting varying degrees of heterogeneity. The results indicate that mesoscopic randomness significantly affects the progressive development of fatigue damage and ultimate failure patterns. The numerical model and implementation scheme serve as valuable tools for investigating fatigue mechanisms of concrete materials from a meso-mechanical perspective.