轻骨料混凝土断裂行为的细观数值模拟

Meso-scale Numerical Simulation on the Fracture Behavior of Lightweight Aggregate Concrete

基于细观尺度,将轻骨料混凝土看作由轻骨料、砂浆基质、两者之间的粘结界面层和气泡组成的四相复合材料。采用蒙特卡罗方法,随机生成轻骨料与气泡的位置和大小数据,在有限元计算软件ANSYS中建立二维的轻骨料随机分布数值模型,再将该模型导入ABAQUS中,在任意相连的两单元之间插入零厚度粘结单元,在单轴拉伸和压缩载荷作用下得到轻骨料混凝土数值试件的裂缝扩展路径及破坏形式。结果表明:通过该方法建立的数值模型,可模拟得出轻骨料混凝土试件的裂缝扩展路径,从而有助于在细观尺度上对轻骨料混凝土的力学性能进行深入研究。

Lightweight aggregate concrete can be considered as four phases composite material,which include lightweight aggregate,mortar matrix,bonding interface layer and bubble in meso-scale.The location and size of light aggregate and bubble in concrete were randomly generated using Monte Carlo method first,and a two dimensional random distribution numerical model of lightweight aggregate was established by a finite element calculation software ANSYS.A zero thickness bonding element was inserted between the two elements of an arbitrarily connected unit by importing the ANSYS model into another FEM software ABAQUS,and then the crack propagation path and failure mode of lightweight aggregate concrete under uniaxial tension and compression loads were obtained.The experimental results show that the crack propagation path of lightweight aggregate concrete specimen can be simulated by the numerical model established by this method,which is helpful to the further research of lightweight aggregate concrete in meso-scale.