OPTIMIZATION OF TRUSS STRUCTURES USING HARMONY SEARCH ALGORITHM

Abstract

The design of many engineering systems can be a complex process, which means many possibilities and factors must be considered during problem formulation. The process of searching for a design that meets both performance and safety standards with reliable impact is the goal of structural optimization. Structural optimization is an approach whereby the structural design is subjected to being optimized in terms of weight while maintaining all design constraints such as stress, strain, and stability. Structural design optimization problems involve searching for the minimum of the stated objective function, usually the weight of the structure and constructability. Trusses are triangular frame works in which the members are subjected to essentially axial forces due to externally applied load at the joints only. Truss structures can be optimized by varying the structure’s size, shape, and topology. Although combining these three prototypes of optimization can ultimately a yield better result, the underlying mathematical model becomes complicated. Over the last decade, new optimization strategies based on metaheuristic algorithms have been devised to obtain the optimal design for structural systems. Harmony search (HS) is a metaheuristic algorithm proposed by Geem et al., inspired by the observation that the aim of music is to search for a perfect state of harmony. In this research, the implementation of HS algorithm has been applied to optimize the size of truss structures that results in the weight reduction of the truss members. The results obtained with HS were compared to those obtained from the original sizes before optimization, to verify the influence on the optimal design of truss structures subjected to stresses, deflections, vertical and lateral displacements, and buckling constrains.