A novel micropolar peridynamic damage model for concrete components implemented in <scp>OpenSees</scp>

Abstract Concrete is widely used due to its high compressive strength; however, its brittleness and low tensile strength make it highly susceptible to cracking and fracture. Therefore, accurate modeling of its damage evolution is critical for ensuring structural safety. This paper proposes a novel micropolar peridynamic damage model integrated with Timoshenko beam theory. More importantly, the model introduces independent/coupled nonlinear damage criteria for tensile, compressive, shear, and torsional deformations by embedding the damage evolution criteria directly into the micropolar beam‐based formulation. The model is specifically designed to investigate the influence of microstructural interactions in concrete, with a particular focus on capturing complex damage mechanisms stemming from the Poisson effect, crack development, and shear failure. This model is integrated within the open‐source analysis platform OpenSees to leverage its extensive libraries of nonlinear solution algorithms and parallel computing capabilities. The proposed Timoshenko micropolar peridynamic (TMP) damage model is verified through two application examples: a uniaxial compression test of specimens with different Poisson's ratios and a pushover analysis of a reinforced concrete (RC) column. The results demonstrate that the TMP damage model, integrated into the OpenSees framework, can effectively capture the complex damage behaviors of RC components, including strength deterioration, stiffness degradation, and the Poisson effect at the macroscopic scale, as well as concrete crack development and rebar reinforcement behavior at the microscopic scale. This study provides a robust tool for better predicting and analyzing the multiscale damage behavior of RC components under complex loading conditions.