Simultaneously multi-material layout, and connectivity optimization of truss structures via an Enriched Firefly Algorithm

In this paper, the multi-material layout and connectivity (topology) optimization problems are considered simultaneously for two- and three- dimensional truss structures. To obtain more appropriate solutions, a new enriched version of the firefly algorithm is proposed. Its performance has been investigated by optimizing mathematical benchmark functions and engineering problems. The mathematical test functions include unimodal, high dimensional multimodal, and fixed-dimensional multimodal problems. Their corresponding results are compared with those other well-known meta-heuristic algorithms. Also, three types of truss structures, either two or three dimensional, are optimized according to the concepts of the basic layout optimization problem. Finally, the details of the multi-material layout and connectivity (topology) optimization are introduced, and the Enriched Firefly Algorithm (EFA) has been applied to obtain their optimum structural design.