Optimal configuration of tapered steel gable frames based on total installed costs using the Enhanced Crystal Structure Algorithm

Abstract

Steel gable frames are the structural system of choice for industrial buildings and warehouses. As the frame span length and column height increase, prismatic members become economically infeasible, whereas tapered members can be optimized to provide the highest material usage efficiency and the least possible cost. The objective of this study is to compare the optimal design of four different practical configurations of tapered steel gable frames against the case of using prismatic members. Therefore, the optimal configuration for each span length, column height, and loading condition can be determined. Five distinct loading conditions are considered including high wind loads, high seismic loads, and low, medium, and high snow loads. The study results led to developing decision support charts to determine the optimal configuration based on the ratio of the material cost to the total installed costs, including material, fabrication, and erection costs. In addition, higher material savings can be achieved by using tapered members with a larger number of member divisions and design variables by about 14% up to 25.3% compared to using only prismatic members.