用细观单元等效化方法模拟混凝土细观破坏

Simulation of Concrete Meso-Failure Process with Meso Element Equivalent Method

从非连续介质力学角度出发,提出了1种能准确模拟混凝土断裂破坏过程的细观单元等效化方法,推导混凝土细观单元的等效力学行为并数值验证了其合理性。基于细观单元等效化模型,采用扩展有限元法对单轴拉伸条件下湿筛混凝土试件的裂纹扩展过程及宏观力学性能进行数值模拟,并与细观随机骨料模型结果进行对比。结果表明:与随机骨料模型相比,细观单元等效化模型大大减小了体系自由度,在较低计算量的情况下可以获得与之较吻合的裂纹扩展路径及宏观力学性能,充分展现了该力学模型的准确性和高效性。

Starting from the non-continuum mechanics, a meso element equivalent model was proposed to simulate the failure process of concrete. The equivalent mechanical behaviors of concrete meso element were deduced theoretically and verified by numerical simulation. Based on the meso element equivalent model, the failure process and macro mechanical properties of wet-screened concrete under uniaxial tensile were simulated with the extended-finite element method. And the results of meso element equivalent model were compared with those of random aggregate model. The results indicate that, compared with random aggregate model, the degrees of freedom of the structural system decrease greatly, and the crack propagation path and the macroscopic mechanical properties obtained from the meso element equivalent model are consistent with the random aggregate model, which reflects the accuracy and efficiency fully of the mechanical model.