混凝土随机凸多面体骨料模型生成及细观有限元剖分

Approach to generation of random convex polyhedral aggregate model and plotting for concrete meso-mechanics

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。本文针对全级配大坝混凝土的高骨料含量的要求,给出了一种高效率生成随机球骨料模型的方法。并在随机球骨料模型的基础上,形成随机凸多面体骨料模型。同时,研究了细观单元属性判别方法,编制了对含有凸多面体骨料的细观区域进行结构性有限元网格剖分程序。本文给出的三维随机骨料模型算法不但考虑混凝土的骨料的实际级配和含量,而且计及了骨料的实际形态。

The mechanical behavior of concrete is directly related to its gradation and aggregate content. An appropriate random aggregate model is the basis for successfully simulating the meso-mechanical behaviors of concrete. A method for simulating full-graded aggregate concrete with high aggregate content, which can efficiently pack the spherical aggregates, is proposed. Based on this model, a 3-D random convex polyhedron aggregate model considering the actual aggregate content, gradation and shape of aggregate is established. Furthermore, the method for identifying the properties of the meso-elements is investigated and the meshing codes are designed to automatically generate the meso-scale structured grids of concrete.