一种混凝土随机凸多边形骨料模型生成方法

A generating approach of random convex polygon aggregate model

混凝土的级配及骨料含量对其宏观力学特性有直接的影响,适当的随机骨料模型是进行混凝土细观力学数值模拟分析的前提和基础。本文首先讨论了瓦拉文公式的推导过程,分析了骨料分布和形态的随机特性,按照骨料切面几何图形面积等效的原则,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骨料分布。研究了点与多边形及多边形与多边形的贯穿和侵入的几何关系,编制了凸多边形生成程序和细观有限元剖分程序。全级配混凝土梁三分点加载弯曲数值试验显示了所编程序的正确性。

The mechanical behavior of concrete is directly related to its grade and aggregate content. A suitable random aggregate model is the precondition and basis for a successful simulation of concrete meso-mechanics. Geometric condition of Walraven formula was discussed in this paper. Based on the randomness and area equivalence of aggregates, a method of packing convex polygon aggregates is proposed based on the analysis on relationship between nodes and polygons, polygons and polygons, taking the actual aggregate content, grading, and aggregate shape into consideration. Further, the meshing codes are designed to automatically generate and instantaneously visualize the meso-scale structured grids of concrete. A numerical experiment is carried out to reveal validity of the method.