A multiscale micromechanics-based progressive damage model is developed to investigate the overall mechanical behavior and the interfacial microcrack evolutions of the cementitious composites featuring superabsorbent polymer (SAP) under uniaxial tension. Elastic properties, progressive damage process, and homogenization procedure of cementitious composites are systematically integrated in this model. The effective elastic moduli of the composites are determined based on a multiscale micromechanical framework. According to the small strain assumption, the total strain tensor and the elastic-damage compliance tensor are additively decomposed into elastic and damage-induced components. The damage-induced strains and compliances are then deduced from micromechanics. To characterize the progressive elastic-damage induced by microcracks, stages of microcrack propagation are identified from the interface contact stress and the matrix cleavage stress. The complex potentials and stress intensity factors for kinked interface cracks are derived from the distributed dislocations method. By implementing the homogenization process, the macroscopic mechanical behavior is obtained from the micro/mesoscale. The results indicate that the material parameters have clear mechanical significance. Different parameters, such as the SAP addition ratio, aggregate content, initial interfacial crack size, and initial interfacial crack location, are revealed to be influential in the overall mechanical behavior of the composites. The proposed model can be generalized to other particle-reinforced composites with different constituent properties, which can potentially contribute to the design and optimization of durable composites.

中文翻译：

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具有高吸水性聚合物 (SAP) 的水泥基复合材料的多尺度微机械渐进弹性损伤模型

开发了一种基于多尺度微观力学的渐进损伤模型，用于研究具有高吸水性聚合物（SAP）的水泥基复合材料在单轴拉伸下的整体力学行为和界面微裂纹演化。该模型系统地集成了水泥基复合材料的弹性性能、渐进损伤过程和均质化过程。复合材料的有效弹性模量是根据多尺度微机械框架确定的。根据小应变假设，将总应变张量和弹性损伤柔量张量相加分解为弹性分量和损伤诱发分量。然后从微观力学中推导出损伤引起的应变和柔量。为了表征微裂纹引起的渐进弹性损伤，根据界面接触应力和基体解理应力来识别微裂纹扩展的阶段。扭结界面裂纹的复势和应力强度因子是通过分布位错法推导出来的。通过实施均质化过程，从微观/介观尺度获得宏观力学行为。结果表明材料参数具有明确的力学意义。 SAP 添加比例、骨料含量、初始界面裂纹尺寸和初始界面裂纹位置等不同参数对复合材料的整体力学行为有影响。所提出的模型可以推广到具有不同成分特性的其他颗粒增强复合材料，这可能有助于耐用复合材料的设计和优化。