Set-Based Design Method for the Early Phase Design of Structures With Uncertainties

Abstract

Since an early phase of design intrinsically contains uncertainties from various sources of variations, design performances are fluctuating or reflect uncertainty caused by uncertain design variables. Analysis tool such as finite element method (FEM) is useful for structural analysis. However, using unique point solution does not express information about uncertainties. Designers need to figure out an outline of the structural feature and have to obtain a design idea under some uncertain design information in a structural design at the early phase of design. We have proposed a preference set-based design (PSD) method that generates a ranged set of design solutions that satisfy sets of performance requirements. This study proposes a structural design method for the early phase of design based on the PSD method that is possible to analyze structure with design uncertainty by elastic FEM and obtain a ranged set of design solutions. That is, a design method for analyzing structures and obtaining a ranged set of design solutions with uncertainties of material property and dimension of structure (coordinates of geometry) under fluctuating distribution of performance characteristics of stress and displacement is proposed. In order to illustrate the availability of our approach, design problem of 3-dimensional truss structure is solved.