混凝土骨料有限元模型自动生成方法

针对圆形、椭圆形、多边形三种剖面形状的骨料夹杂分别给出了混凝土的二维有限元建模方法，为细观结构研究提供了全自动的建模工具．提出了一种新的以面积为标度的任意两椭圆骨料侵入的判别准则，有效地克服了椭圆形骨料几何模型生成中的效率瓶颈问题；提出了综合考虑边数、形状、尺寸等随机特性的多边形骨料生成方法，并简单有效地保证了多边形骨料为凸的性质，使所建的随机几何模型能够更好地模拟人工骨料和再生骨料；对生成的几何模型，运用改进的推进波前法一次性生成所有骨料的有限元网格，为进一步的复合材料细观结构和宏观力学性能的多尺度计算打下了基础．最后用几个算例验证了算法的有效性。

Automatic generation of finite element model for concrete aggregate

The method of 2-D finite element modeling of concrete is presented respectively about round,oval and convex polygonal grain distributing randomly,and an automatic modeling tool is provided for the research on microstructure using FEM.A criterion of conflict overlap of any two oval aggregate is proposed based on an area-index that can solve the bottle-neck problem in geometry modeling.A method of generating convex polygonal aggregate considering the number of sides,shape and size simultaneously is proposed,ensuring the convex characteristics of all the polygonal aggregates,which can improve simulation of artificial or regenerated aggregates with the generated random geometry model.An improved advanced front technology(AFT) is employed to generate finite element meshes of the matrix and all aggregates at the same time.The research builds the foundation for the further multi-scale computation between the microstructure and the macro-mechanical performances of the multiphase composite.At last,some examples are given to demonstrate the validity of the method.