基于细观损伤的混凝土破裂过程的三维数值模拟

3-D NUMERICAL SIMULATION OF CONCRETE FAILURE PROCESS BASED ON MESO-MECHANICS DAMAGE

在细观力学基础上将损伤力学和计算力学相结合来分析混凝土试件的变形、损伤和破坏过程。把混凝土简化成由骨料、砂浆及其二者之间的界面层所组成的三相复合材料,在已建立的混凝土骨料随机分布三维模型基础上用界面单元多次细分技术进行有限元网格划分,基于弹性损伤本构关系采用双折线损伤演化模型描述混凝土细观各相弹性损伤退化,用弹性模量的折减程度来反映混凝土试件在加载过程中的损伤程度。对混凝土圆柱体试件进行了数值模拟计算。进而通过损伤对混凝土材料裂纹的扩展、贯通以及最后破坏的过程进行研究。

Based on meso-mechanics,the distortion,damage and failure of concrete combined computati-on mechanics and damage-mechanics was researched.The concrete is simplified to be three-phase composites consisting of aggregate,mortar and bond.Based on 3-D random distribution of concrete aggregate FEM grid model,the bond element is meshed by multi-subdivision technology the decrease of elastic damage of concrete is described by the conduplicate-line damage evolvement model based on elastic damage constitutive relation,the degree of damage of concrete specimen is reflected by the degree of reduction of elastic-modulus.Then,3D numerical model of the cylinder specimen is calculated.So the crack propagation,coalescence and failure of concrete is researched by damage.