基于三维细观模型的全级配混凝土静态力学性能的数值模拟

摘要

According to the meso-structure and mechanical properties of fully-graded concrete, the 3D mesoscale model of convex polyhedron was generated to simulate the randomness of the aggregate in shape and spatial distribution. The static mechanical property of concrete under uniaxial, biaxial and triaxial loading conditions was simulated by the established 3D mesoscale model and the constitutive relations of its constituents. The 3D macro-meso analytical model of the three points bending concrete beam was established to investigate its deformation and crack development. Comparison between the ana- lytical results of the mesoscale model and the test data reveals a satisfactory agreement. It is demonstra- ted that the proposed mesoscale model has a high reliability in simulating static mechanical properties and failure mechanism of concrete under the complicated stress states.%根据混凝土材料的细观组成和力学特性，研究了骨料几何形状和空间分布规律，建立全级配混凝土三维凸多面体随机细观模型，引入了混凝土细观组份材料的本构模型，分别模拟了单轴、双轴和三轴状态下混凝土的静态力学性能，并建立混凝土梁的三维宏细观分析模型，研究了三点弯曲梁的变形及裂缝扩展情况。结果表明，本文建立的细观力学模型的计算结果与实验数据吻合较好，可以较好地模拟各种复杂应力条件下混凝土的静态力学性能和损伤破坏机理。