Optimum design of steel structures via differential evolution algorithm and application programming interface of SAP2000

Thesis Type: Postgraduate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Civil Engineering, Turkey

Approval Date: 2012




The objective of this study is to investigate the use and efficiency of Differential Evolution (DE) method on structural optimization. The solution algorithm developed with DE is computerized into software called SOP2011 using VB.NET. SOP2011 is automated to achieve size optimum design of steel structures consisting of 1-D elements such as trusses and frames subjected to design provisions according to ASD-AISC (2010) and LRFD-AISC (2010). SOP2011 works simultaneously with the structural analysis and design software SAP2000 in order to find the global or near optimum designs for real size truss and frame structures in which the optimization problem is classified as constrained, discrete size optimization. Software interacts with SAP2000 through the Open Application Programming Interface (OAPI), which provides an access to information of SAP2000 inputs and outputs. It is programmed for finding reasonable and optimized results for truss and frame steel structures by choosing appropriate ready sections for structural members considering the minimum weight via DE technique. Based on the comparison of the obtained results with the literature, DE algorithm with penalty function implementation is proved to be an efficient optimization technique amongst several major methods used for discrete constrained size optimization of real size steel structures. Also, it has been shown that by using optimized designs obtained by DE, weight of the structures can be reduced up to 67.9% for steel truss structures and 41.7% for steel frame structures compared to SAP2000 auto design procedure, hence resulting a significant saving of materials, cost, work hours and energy required for the project.