A new approach to multi-criteria material selection in engineering design

Abstract

The selection of a material to meet given design requirements generally requires that a compromise be struck between several, usually conflicting, objectives. The problem is complicated because the decision-space is large, it is discrete rather than continuous, and the relative value to be placed on each objective is imprecisely known. Here we explore the ways in which multi-objective optimisation methods can be adapted to address this problem. We find that trade-off surfaces give a way of visualizing the alternative compromises, and that "utility" functions (or "value" functions) identify the part of the surface on which optimal solutions lie. Implementing this for two objectives is straightforward, but doing so for more then two requires new visualization tools. Here we develop a tool and illustrate its use.