Microstructure sensitive design: A tool for exploiting material anisotropy in mechanical design.

摘要

A new mathematical framework called Microstructure Sensitive Design (MSD) was recently developed to facilitate solutions to inverse problems in microstructure design where the goal is to identify the complete set of relevant microstructures that are predicted to satisfy a set of designer specified criteria for effective properties or performance. In this work, MSD has been successfully applied to a few design case studies involving polycrystalline metals and continuous fiber reinforced composites (CFRC). The solutions obtained are, as expected, strongly influenced by the selected homogenization theories. In the case studies presented here, elementary first-order theories are used for both the polycrystalline metals and the continuous fiber reinforced composites. In the composite case, elementary first-order theories spanning two length scales have been selected to obtain effective properties of continuous fiber reinforced composite material systems. Having selected these first-order theories, we proceeded to demonstrate the viability of applying the MSD framework to designing optimal orientation distributions in both polycrystalline metals and continuous fiber reinforced composites for the selected mechanical design problems. Specifically, the mechanical design case study used in this work involved maximizing the load carrying capacity of an orthotropic plate with a circular hole and loaded in in-plane tension. MSD results for this case study show a potential improvement of 27% in nickel polycrystals and 267% improvement in AS4-Epoxy composites investigated in this study. Additionally the mechanical design of a pressure vessel containing a partially through axial flaw is examined; the potential improvement in energy dissipated during crack growth is 31%.