Meso-scale Numerical Simulation For Lightweight Aggregate Concrete

Based on the meso-scale,lightweight aggregate concrete is considered as four phase composite material which include lightweight aggregate,mortar matrix,interface layer and bubble.The mechanical properties and constitutive relations of the material of each phase composition affect the macro mechanical properties,fracture behavior and crack propagation law of lightweight aggregate concrete.At present,the research on lightweight aggregate concrete is mostly based on the experiment,and the results and data of the test will be affected by many factors.In addition,with the development of the computer speed,the meso-scale of lightweight aggregate concrete specimens by numerical simulation become the corresponding disadvantages of test and supplement of the test results is an important research method based on.In this paper,the numerical simulation of the fracture behavior and mechanical properties of lightweight aggregate concrete is carried out based on the meso-scale.(1)This paper based on the lightweight aggregate concrete corresponding specimen size,using Monte Carlo method,the location and size of the randomly generated light aggregate with bubble,the establishment of lightweight aggregate random distribution model,and the corresponding output data.(2)According to the data,a two-dimensional numerical model is established in ANSYS,and the mesh is divided to generate the elements of each phase component.Then the model is imported into ABAQUS,through the preparation of the corresponding script in Python,insert the zero thickness bonding element between two arbitrary units connected,get the lightweight aggregate concrete specimens of two-dimensional numerical model.(3)The material parameters of each phase composition of lightweight aggregate concrete are given.According to the research object of this paper and referring to the relevant literature to determine the material constitutive relation curve,and the failure criterion of the element is determined.(4)The numerical simulation results show that the mechanical properties of the specimens,the propagation path and the failure modes of the specimens under uniaxial tension and compression load and the three point bending load are obtained.The results show that the difference between failure modes of lightweight aggregate concrete and ordinary concrete,the failure form and the crack propagation path is not the same,there are some influence of lightweight aggregate and interfacial layer on the crack propagation path.At the same time,the results show that the numerical model established by this method,can be more reasonable and effective to simulate the light aggregate concrete specimens of the crack propagation path is helpful for further study of lightweight aggregate concrete.