3-D SIMULATION OF INTERPENETRATING PHASE COMPOSITES USING FEM/EFGM

Abstract

Interpenetrating Phase Composites (IPCs) are multiphase composites where each phases is interconnected three- dimensionally. The lighter, stilThr stronger and tougher material is called metal phase and the other as reinforcement. They have unique geometry which oftrs improved mechanical and physical properties. According to the occurrence of the of the interpenetration at dil'fercnt length scales, IPCs can be categorised as molecular, micro or meso composites. This project provides a modelling and simulation of alumina- copper based IPC. The computational used to model and simulate the IPC is based on Flement Free Galerkin Method ( FFGM) using MAFLAB. Oving to complexity in microstructure & randomness of IPCs. the modelling of these materials have not been etTectivelv studied yet. Two models have been proposed by the author one in two - dimension and another one in three- dimension. They are Unit- cell model vhicli is based on the geometry Of the sub-cell. A sub-cell is a collection of randomly generated quarter circle placed in the corner of' a square in two- dimension and randomly generated cuboids placed in the corners of' a cube in three- dimension. Many sub-cells are arranged together making a unit-cell. l)egree of penetration is introduced which controls the geometry of' the models between interpenetrating and particulate. Other parameters such as volume liaction. interpenetrating geometry have been incorporated into the model. In this thesis two types of analysis is carried out on both the models. The elastic analysis includes finding out the equivalent elastic properties of the IPCs like Young's modulus. Shear modulus and Poisson's ratio. For this effective medium approximation technique has been used. In this technique the strain energy of the IPC is equated to that of the equivalent homogeneous medium. The elastic properties at certain volume fractions are found out and are validated with the experimental results and others available in the literatures. The elasto-plastic analysis for large values of' starin is carried out to lnd the equivalent stress- strain curve of the lPC. The results are found to be within the limits and comparable to the results avai fable in the literatures.