Case Studies in Concept Exploration and Selection with s-Pareto Frontiers

This paper investigates three disparate design cases where the newly developed s-Pareto frontier based concept selection paradigm is used to compare competing design concepts under a multiobjective optimization framework. The new paradigm, which was recently introduced by the authors, is based on the principle of Pareto optimality – a principle that defines an important class of optimal solutions to multiobjective optimization problems. These solutions, termed Pareto solutions, are optimal in the sense that improvement in one objective can only occur with the worsening of at least one other. The set of Pareto solutions comprises the Pareto frontier – a frontier that is particularly useful in engineering design because it characterizes the tradeoffs between the design objectives. Under the newly developed paradigm, a so-called s-Pareto frontier is used to characterize the tradeoffs between conflicting design objectives and the tradeoffs between competing design concepts. As such, the s-Pareto frontier holds significant potential for the important activity of concept selection. In this paper, the usefulness of the s-Pareto frontier for concept evaluation and selection is explored through examining three real-world case studies. As such, the present paper takes a needed and notable step beyond the simple two and three bar truss examples provided by the authors in previous archival publications on the s-Pareto topic. The first case study considers the design of a battery contact for a mobile phone; the second case involves the design of a compliant bicycle derailleur; the third involves the design of a rigidified inflatable structure. Each case provides a unique perspective on the s-Pareto frontier based concept selection paradigm.