摘要

In this paper, the optimum design procedure based on colliding bodies optimization method and its enhanced version are applied to optimal design of two commonly used configurations of double-layer grids, and optimum span-depth ratios are determined. Two ranges of spans as small and large sizes with certain bays of equal lengths in two directions and different types of element groupings are considered for each type of square grids. These algorithms obtain minimum weight grid through appropriate selection of tube sections available in AISC load and resistance factor design (LRFD). Strength constraints of AISC-LRFD specifications and displacement constraints are imposed on these grids. The comparison is aimed at finding the depth at which each of the different configurations shows its advantages. Finally, the effect of support locations on the weight of the double-layer grids is investigated. The results are graphically presented from which the optimum depth can easily be estimated for each type, while the influence of element grouping can also be realized at the same time.

  • 出版日期2017-6