Microstrcture Simulation And Property Analysis Of Three-Dimensional Polycrystalline Composite Materials

Computer simulation plays a very important role in deep investigation of properties of three-dimensional polycrystalline composite materials. In consideration of some existing problems in computer simulation of polycrystalline composite materials, our research mainly focuses on three aspects, they are:1. An effective computer numerical method, including a precise stereological equation and a numerical algorithm, is developed to determine the continuous numerical empirical probability density function of the three-dimensional size distribution of spherical second-phase particles. Within the numerical method, a self-adaptive grouping technique is proposed to solve the negative value problem in former methods. The errors between the computed and actual parameters of the 2-DSD are analysed,and the findings indicate that the method can simulate the PDF of the 2-DSD accurately.2. An effective method is put forward for modeling of microstructure of three-dimensional two-phase polycrystalline composite materials. The modeling method includes two procedures. First, Random Close Packing Of Spheres (RCPS) is generated with two groups of spheres and each group has its own volume distribution. Then Laguerre Voronoi diagram is performed basing on the sphere packing to generate the grains of two phases, thus the model of two phase polycrystalline composite materials is obtained. Because the model is based on the RCPS, the grain volume distributions of the two phases are easily controlled by changing the volume distributions of two groups of spheres in RCPS. Various geometrical and topological characterizations of the model are computed and analysed, and the results demonstrate that This modeling method can be utilized in deep investigation of structure–property relations in two-phase polycrystalline composite materials.3. We develop a three-dimensional finite element method (FEM) to calculate the macroscopic dielectric constants of three-dimensional model of two-phase polycrystalline composite materials. We computed the macroscopic dielectric constants of all the models in different dielectric ratio of super dielectric phase to low dielectric phase by our FEM and analyze the results.