Supporting design decision-making when applying materials in combination

The importance of materials selection in engineering design is well recognised. There are already plenty of formalised methods to support selection of individual materials, where the requirements on the materials are, respectively, known. Practical design problems, however, often involve materials in combination – the multiple materials jointly contribute to the performance of the system to produce optimal design metrics; and the selection of materials is often coupled with the determination or design of structural components and their configuration. To address these problems, this paper recommends a multiple-mapping strategy and an inter-level behavioural modelling strategy. The former can simultaneously consider both structural and materials solutions in supporting design decision-making at the early design stage; while the latter can provide a platform for the designer to work out the couplings among the properties of the materials and their corresponding components, thus supporting design decision-making in selecting materials when they are applied in combination, which is generally at the downstream design stage. The paper also discusses the implications and difficulties in providing optimal solutions to the addressed problems; and based on this, to propose some prospects of future work to further improve these design strategies.