基于四叉树网格加密技术的混凝土细观模型

Concrete Mesoscopic Model Based on Quadtree Mesh Refinement Technology

在建立混凝土细观模型常用的背景网格法基础上,基于平衡四叉树网格加密技术对混凝土的界面过渡区进行局部网格加密,给出了更为合理的反映界面过渡区组分的混凝土细观模型,并探讨了网格加密的程序化实施方案.所给出的混凝土细观模型可直接对界面单元赋予相对应的材料参数,改善了背景网格法中界面过渡区网格的锯齿状缺陷,能够更准确地反映界面过渡区的几何形态和材料性质.最后,通过数值算例证明了所提方法的合理性和可行性.

Based on the background mesh method commonly used in building concrete mesoscopic model,the mesh refinement technology of balanced quadtree was used to refine the local meshes of interfacial transition zone（ITZ）.The concrete mesoscopic model which is more reasonable for reflecting the constituent of ITZ is given,and the programmed implementation scheme of mesh refinement was studied.In the proposed concrete mesoscopic model,ITZ can be directly assigned as the corresponding material parameters,and the serrated imperfection of meshes of ITZ in the background mesh method is improved.Accordingly,the geometrical morphology and material property of ITZ are simulated much better and more truly.In the end,numerical example is presented to demonstrate the rationality and effectiveness of the proposed method.