单轴拉压状态下混凝土破坏的细观数值演化分析

在提出可同时满足级配曲线及指定骨料填充率的任意凹凸形骨料配置算法的基础上,建立了混凝土试件的细观随机骨料模型,并建立了空间应力环境下细观单元的弹性损伤本构关系;分别就工程中常采用的两种不同的混凝土强度,研究了混凝土试件的细观损伤演化过程及细观单元力学参数取值对混凝土试件宏观表征强度的影响。数值算例验证了模型的有效性,并揭示出混凝土试件破坏主要是由细观单元的拉伸损伤积累所导致的。

Mesoscopic Numerical Evolution Analysis of Concrete Damage Under Uniaxial Tension and Compression

An advanced method was presented to generate aggregates with random shapes and various sizes according to the given aggregate gradation curve and aggregate area fraction,and the elastic damage constitutive relations of mesoscopic elements were established in the three-dimension stress field.Numerical simulation tests were carried out to study the damage evolution on meso-level and the influences of parameters on macro-level strength of concrete specimen,in which two different kinds of concrete strengths were compared.The numerical results verify this mesoscopic model,and show that the failure of concrete is mostly due to the accumulation of tensile damage on mesoscopic level.