Optimum Design of Steel Structures in Accordance with AISC 2010 Specification Using Heuristic Algorithm

This paper proposes a heuristic algorithm (HA) for the optimum design of steel structures in accordance with all three methods specified in the ANSI/AISC 360-10 “Specification for Structural Steel Buildings”. These methods include the direct analysis method (DAM), and two alternative methods, namely, the first-order analysis method (FAM), and the effective length method (ELM). The objective of the design algorithm is to obtain the least weight for the designed steel sections. The optimum design combines the SAP2000 structural analysis program and the heuristic algorithm that is written in Microsoft Visual Basic program. The rigorous second-order analysis was performed in both DAM and ELM, while the first-order analysis was used in the FAM. Three design examples of planar steel frames are used to illustrate the application. Among the three design methods, the FAM results in lower bound solutions, while the EFM results in upper bound solutions.