A coupled mechanical-diffusive peridynamics (PD) model is developed to simulate chloride penetration in saturated concrete under various loadings at meso-scale. PD is implemented in the architecture of finite element method (FEM) and truss elements are used to substitute for the PD bonds. In the coupled model, damage evolution and crack growth in concrete under loadings and chloride penetration into concrete with updated diffusivity caused by cracks can be investigated simultaneously. At each coupling step, the quasi-static mechanical analysis is conducted by solving the equilibrium equations, while the forward differencing method is adopted for chloride diffusion. Several numerical examples are carried out to validate the proposed PD models in terms of addressing mechanical-diffusive problems. The numerical results coincide with the test findings and clearly indicate that the width and depth of cracks can influence the chloride diffusivity when “threshold crack width” is reached. Additionally, the chloride diffusivity increases with the increase of stress level under high compressive, tensile and flexural stress levels.

建立了耦合的机械扩散扩散动力学（PD）模型，以模拟氯在中尺度下各种载荷下在饱和混凝土中的渗透。PD在有限元方法（FEM）的体系结构中实现，并使用桁架单元替代PD键。在耦合模型中，可以同时研究荷载作用下混凝土的损伤演化和裂纹扩展以及氯化物渗透到混凝土中的情况，这些新的扩散性是由裂缝引起的。在每个耦合步骤，通过求解平衡方程进行准静态力学分析，而氯离子扩散则采用正向微分法。在解决机械扩散问题方面，进行了几个数值示例来验证所提出的PD模型。数值结果与试验结果一致，清楚地表明，当达到“阈值裂纹宽度”时，裂纹的宽度和深度会影响氯化物的扩散率。另外，在高压缩，拉伸和弯曲应力水平下，氯化物扩散率随应力水平的增加而增加。