In this paper a meso-concrete model is established by using cohesive element script and random aggregate procedure to investigate the influence of elastic modulus on the mesoscopic concrete properties, where the crack is simulated by the deletion of cohesive element. The meso-structure parameters of concrete specimen with homogeneous elastic modulus are investigated based on the model, such as aggregate shape, aggregate diameter and interfacial initial imperfection. The analysis results show that aggregate shape and diameter have an influence on the concrete behavior, and the decrease of aggregate diameter is recommended to improve the concrete strength. Interfacial initial imperfection has an obvious significance on concrete tension peak stress, and the tension strength declines by 67.9% when the interface between aggregate and mortar is all initial imperfection. Furthermore, a new method is proposed that mortar elements are randomly assigned in different elastic modulus sets for considering the non-uniformity of mortar. This method can contribute to promoting the feasibility from the ideal model to the real. Numerical examples are analyzed in order to verify the necessity of importing the non-uniformity, and a safety coefficient is recommended as 0.85 for considering the adverse effect of elastic modulus randomness of mortar.

本文通过内聚单元脚本和随机聚集过程建立了一个细观混凝土模型，研究了弹性模量对介观混凝土性能的影响，其中裂缝是通过删除内聚元素来模拟的。基于该模型，研究了均质弹性模量混凝土试件的细观结构参数，如骨料形状，骨料直径和界面初始缺陷。分析结果表明，骨料形状和直径对混凝土的性能有影响，建议减小骨料直径以提高混凝土强度。界面初始缺陷对混凝土的拉力峰值应力具有明显的意义，拉力强度降低了67。骨料和砂浆之间的界面都是初始缺陷时为9％。此外，提出了一种新方法，即考虑砂浆的不均匀性，将砂浆单元随机分配给不同的弹性模量集。这种方法有助于从理想模型到实际模型的可行性。为了验证输入不均匀性的必要性，分析了数值示例，考虑砂浆的弹性模量无规性的不利影响，建议安全系数为0.85。