As two-dimensional numerical analysis is mostly used in concrete mesoscopic numerical analysis structures ,this paper puts forward one two-dimensional modeling approach of concrete aggregates with arbitrary shapes based on a pre-fabricated mesh .This approach effectively solves mesh quality problem of mesoscopic three-phase medium by using pre-fabricated mesh for aggregate mixing . The random concave and convex types of aggregates made a more realistic model ,avoiding inaccurate description of aggregate .The method ensures the randomness of embarking and the rationality of gradation distribution to achieve the aggregate rate reaching 75% .In the end ,this paper adopts concrete damage plasticity (CDP) to stimulate the mesoscopic corrosion cracking of concrete protection layer , analyzes crack initiation and expansion as well as the fracture of concrete .The numerical results are in good agreement with the experimental results .%基于目前混凝土细观数值分析多采用二维模型,提出了一种基于网格预先生成的二维随机凹凸型骨料的混凝土细观建模方法.该方法利用已生成的网格状态进行骨料投放,有效解决了在细观三相介质中的网格质量问题.采用随机凹凸型骨料使骨料模型更加接近真实形态,避免了该方法对骨料形貌描述不准确的问题.该方法可保证投放的随机性以及级配分布的合理性,二维投放骨料含量可达75%.最后,采用混凝土损伤塑性模型模拟了混凝土保护层锈胀开裂的细观断裂破坏过程,分析了混凝土裂纹萌生、扩展过程及破坏形态,数值结果与实验结果吻合良好.
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