Minimum weight design of truss roof systems under corrosion effect by ant colony and butterfly optimization algorithm methods

Optimum design is the sum of the processes that ensure the most efficient use of the obtained resources and the most robust way to reach the target-oriented works. With the optimum design of the structures, it is aimed to obtain the minimum weight among the structures with sufficient strength. On the other hand, its behavior under loads affecting the structural system designed in line with the targeted purpose should also remain within acceptable limits. Thus, obtaining the structure that provides the design constraints and has a minimum weight constitutes the optimum design problem. Optimization techniques based on artificial intelligence, which is one of the solution methods of building systems, are used in optimum design. In this thesis, the effect of corrosion on steel structural elements used in space truss roof systems will be examined. The minimum weight design will be carried out with the determined algorithm methods, including and excluding the corrosion effect of the plane truss and space truss roof systems. Ant Colony Optimization (ACO), one of the oldest algorithm methods based on swarm intelligence, and Butterfly Optimization Algorithm (BOA), one of the new algorithm methods developed in recent years, were used. MATLAB programming language was used to make the necessary calculations in order to perform the minimum weight desing in a short time. First of all, two separate analysis programs were written, in which plane and space truss systems were analyzed by Finite Element Method (FEM). The stress, slenderness and displacement conditions specified in the American Institute of Steel Construction-Allowable Strength Design (AISC-ASD) (1989) standard are included in the program. The proposed ACO and BOA algorithms were included in the analysis program created by coding in the MATLAB programming language in plane and space lattice system design examples. Finally, considering the corrosion effect, the changes in the minimum weight of the structure were determined and presented. The analysis results obtained were compared among themselves and with the existing results in the literature. In the analysis results, it was seen that the proposed ACO and BOA methods were very close to the results of other algorithm methods in the solution of plane and space truss systems. Thus, by proving the acceptability of the methodology used in this study, it was investigated how the corrosion effect affects the minimum weight of the structure. When different truss roof problems under the influence of corrosion are examined, the geometry of the structure, the number of elements, the type of loading, etc. It is presented in comparison with the tables determined in the results of the analysis, where the structure becomes a little heavier depending on the factors. Keywords: Minimum weight design, ant colony optimization, butterfly optimization algorithm, truss systems, MATLAB, corrosion.