Utility of microstructure modeling for simulation of micro-mechanical response of composites containing non-uniformly distributed fibers

Composite microstructures often contain non-uniformly distributed fibers having different sizes. Therefore. in finite-element (FE)-based simulations of the mechanical response of composites, the non-uniform spatial arrangement of fiber centers and distribution of fiber sizes need to be incorporated. In this contribution, a unique combination of digital image processing. microstructure modeling, and FE-based simulations is used to develop a methodology for modeling the micro-mechanical response of composites having non-uniform spatial arrangement of fibers. The methodology is developed via modeling of the micro-mechanical response of a ceramic matrix composite (CMC) containing unidirectional aligned Nicalon (SIC) fibers that are non-uniformly distributed in a glass ceramic matrix. For comparison, the micromechanical response of typical digital images of the composite microstructure and a simple microstructure model having periodic arrangement of fibers are also simulated. It is shown that the computer simulated microstructure model that accounts for non-uniform spatial arrangement of fibers having a range of sizes can be used for realistic parametric studies on the micro-mechanical response of the composite. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.