Simulation & Computation Of Composite Microstructures

With the in-depth study of micro-scale problems for material, scientists give great interest and concern for intrinsic link between material microstructure and the corre-sponding material properties, in particular, the local combination of geometrical shape and the orientation of material composition on the impact of combined effects of ma-terial properties. In recent years, many scholars at home and abroad make computer technology to apply to material science successfully by means of computer simulation and numerical calculation, digital simulation and numerical calculation of material microstructure is achieved by using various algorithms, but most of these studies only focused on a certain kinds of material or a certain microstructure in the numerical calculation process of micro-theory while ignoring the application of computer tech-nology in material science in the basic platform construction.In the field of "Digital Material" technology, technological processes is designed by computer simulation to build a series of composite material microstructure model, using Visual C++programming language developed simulation software ProDesign three-dimensional version, emphatically explains how to result in a meet special re-quired microstructure by change, control, combine geometric entity builded by the computer, the use of OpenGL visualization technique shows a variety of microstructure model, the software users can obtain a complex composite material microstructure by combining different kinds of basic module. Specific research includes three aspects:In order to achieve visual simulation of microstructure of multicrystal body in plane state, Out-of-core incremental algorithm is designed for two-dimensional Laguerre (L) model, to the algorithm as the core, the software ProDesign two-dimensional version is upgraded. As the L model grain size distribution is con-trollable, Simulative microstructure model to be closer to the actual material micro-structure, Meanwhile, the restriction of computer memory is avoided during L model building in the "mass" spherical particles collection, the upgraded version of software test on the person computer for fast simulations, two-dimensional microstructure of multicrystal body which compose of hundreds of thousands grains can be simulated.In the simulation of three-dimensional microstructure of multicrystal body, Out-of-core incremental algorithm of three-dimensional L model based on computer hard disk file for operation and storage was designed which using simple and reason- able spatial data organization, the construction of the "mass" of 3D microstructures of multi-crystal body is achieved in the appoint "representative volume element" district, Meanwhile, the corresponding visualization techniques is developed for show con-structed L model and the corresponding weighted balls collection, it can facilitate the results evaluation of simulation. The interior structure study of multi-crystal body in-terested by scientist, arbitrary planar subdivision method is designed, that achieve the purpose for the demonstration of the interior structure of multi-crystal.Through the simulation of second phase components embed in the multi-crystal body, A simulation technology is developed which can be systematic, modular "pro-duce" of the various components enhanced composite material microstructure "sample". At the construction process of the simulation algorithm:From the perspective of computational geometry, the issue which judging arbitrary multi-ellipsoids whether mutually intersection or separation or inclusion is solved; also, the issue which judging arbitrary multi-polyhedra whether mutually intersection or separation or inclusion is solved; the issue which judging arbitrary ellipsoid and polyhedron whether mutually intersection or separation or inclusion is solved; area calculation module is designed for arbitrarily shaped convex polygon, in the same way, calculation module of volume of any shaped convex polyhedron is designed too. Through a complex rotation, trans-lation transformation of the geometric model, any size, shape, orientation, spatial dis-tribution of ellipsoidal components simulation is implemented, which can according to user-specified or random manner. the simulation of polyhedral particles through "same one split method" or "other one splid method", the former obtain polyhedral particles from "representative volume element" itself, the latter obtain polyhedral particles from another "representative volume element". All types of composite material microstruc-ture use OpenGL visualization technique designs of the entity and three surface visu-alization display program.Meanwhile, simulation software ProDesign three-dimensional version is devel-oped for simulate three-dimensional composite material microstructure, which based on L algorithm and simulation of second phase components. "mass" scale of composite material microstructure model which simulated by ProDesign can meet the engineering application requirements, and the location, shape, average size, distribution method, volume share, spatial orientation of second phase composition can be setted and as-sembled Arbitrarily in accordance with the pre-designated requirements, and gets all relevant geometric information data. The software is able to simulate geometric details of microstructure from an auto-forming, and can construct wide variety of complex composite microstructure model by different combinations of the basic modules. The development of software set up a "communication" bridge among "material micro-structure-visual simulation-finite element analysis", and provide the basis simulation tools for the calculation of microstructure of composite material.In the field of "Numerical Material" technology, based on APDL scripting lan-guage and the platform of commercial finite element analysis software ANSYS, the whole process which automated build, definition, calculation of material "representa-tive volume element" technology is builded, and the material microstructure calcula-tion software CMMC is developed. based on material microstructure model con-structed by ProDesign three-dimensional version, in the ANSYS, software CMMC can automatically achieve geometric model construction; material, boundary conditions and load definition; finite element mesh division; solution type and load step settings; output of the calculation; automatic extraction and preservation of images and anima-tion; and so on. In the end, this study basically achieved the goal of building an inte-grative software platform for simulation and calculation composite material micro-structure.