Manufacturing tolerances and multiple loading conditions in structural configuration optimization

Most structures, during their service life, are subjected to several loading conditions; moreover, during their assembly, some or all of the assumed design variables are varied due to manufacturing imperfections. In the case of an optimum structure this can be especially dangerous. The problem of imperfections is a random one and its possible solution is not easily applicable due to its complexity. There is thus a need to give designers a tool that will enable them to incorporate the manufacturing tolerances in a relatively simple way. The proposed approach is deterministic, giving approximate minimum weight design with a safety margin. This is because limits of constraints are reduced by products of sensitivities multiplied by given tolerances. This paper is illustrated with two minimum weight designs of truss con gurations, under three loading conditions each