Optimal Design of Arches Using the Complex Method

Optimal designs of arches under multiple load cases using an automated design routine are presented. The design variables consist of geometric (arch shape) as well as member sizing variables (cross-sectional dimensions). The members are sized on the basis of working stress design procedure, and all the relevant provisions of the AISC specifications are met. The optimal arch shapes produced by the present method for a uniformly distributed load case show a good agreement with the theoretical results. The optimal designs under two and three load cases are also obtained. Under two load cases, the optimal shapes are not very different than a parabolic curve passing through the supports and crown of the arch.