高强高性能混凝土损伤的细观数值演化
Meso-scale Numerical Analysis of Damage Evolution of High-strengthand High-performance Concrete

在细观层次上，混凝土可以被看作由水泥基、分散粒子和界面过渡层组成的三相复合材料。首先，基于骨料分布和形态的随机特性，将瓦拉文公式推广应用于确定二维混凝土试件截面凸多边形骨料分布，提出圆形骨料模型中以圆骨料的面积为控制参数，以圆内接多边形为基架的凸多边形随机骨料算法。进而以C80高强高性能混凝土为例，对数值试样进行单轴受压的数值模拟，得到相应的应力-应变曲线和损伤演化图。数值模拟结果与物理试验结果对比表明本文提出的数值模型合理可行。
On a meso-level, concrete can be seen as a three-phase composite material comprising a cement base, aggregate, and a transitional zone between the cement and aggregate. In this study, based on the random characteristics of the aggregate distribution and morphology, the Walraven formula is applied to determine the convex polygonal aggregate distribution of the two-dimensional concrete specimen's cross-section. Subsequently, an algorithm for the random convex polygon aggregate is proposed, in which an area of round aggregate is used as the control parameter and the inscribed polygon of the round aggregate is used as the framework. A numerical experiment is conducted on specimens under uniaxial compression by using the high-strength and high-performance concrete C80 as an example, and corresponding stress-strain curves and damage evolution pictures are drawn. A comparison between results of the numerical simulation and the physical test show that the numerical model proposed in this paper is both reasonable and feasible.