Numerical Simulation Of Meso-level Structure Of Concrete

As a heterogeneous material, concrete is used a great deal and widely, and the investigation on its mechanical properties and fracture process is of a vital importance to mining engineering, underground engineering and structural engineering. In-depth studies are going on. It's developed from large-scale objective model experiment to reduced scale model experiment; form simple mechanics device to various advanced detecting device; and the theory is developed from elastic mechanics, plastic mechanics to fracture mechanics and damage mechanics. The study of concrete fracture has also developed from macro-level to meso-level.The classic macroscopic mechanical models, which characterize the concrete as a continuum at macroscopic level and consider the test results of laboratory scale specimen as the mechanical properties of the material, could analyze the mechanical response of structures with greater size. In reality, the test results of laboratory that are generally called physical and mechanical parameters of material are average responses of a heterogeneous specimen with a certain size. This kind of homogenization is very important to the investigation of concrete structures and numerical analysis of engineering. But it is difficult to use these models to study the complete failure process caused by the initiation, propagation and coalescence of cracks when subjected external loading.In this paper, a mesoscopic numerical concrete model is constructed on its meso-structures. In order to reflect the heterogeneity of concrete at mesoscopic level, the concrete is firstly assumed to be a two-phase composite composed of matrix, aggregate, holes, and cracks. Then a random aggregate numerical model is constructed with Monte Carlo method. And additionally Delaunay triangulation is constructed by Finite Element Method. During the numerical simulation, the heterogeneity is achieved by specifying corresponding parameters to the mesoscopic elements that represent the different phases of concrete.