Member sizing optimization of large scale steel space trusses using a symbiotic organisms search algorithm

A systematic approach of optimization is needed to achieve an optimal design of large and complex truss structures. In the last three decades, many researchers have developed and applied various metaheuristic optimization methods to the design of truss structures. This paper investigates a new metaheuristic algorithm called symbiotic organisms search (SOS) for member sizing optimization of relatively large steel trusses. The case studies include a 120-bar dome truss, a 160-bar pyramid truss, and a 942-bar tower truss. The structural analyses are carried out using the standard finite element method. The profile of the members is circular hollow structural sections selected from a set of the AISC standard profiles. The design results using the SOS are then compared to those obtained using other metaheuristic methods, namely the particle swarm optimization, differential evolution, and teaching-learning-based optimization. The comparison shows the superior performance of the SOS in terms of both the optimal solution and consistency. Thus, the SOS is a good alternative for optimizing the design of steel truss structures in real engineering practice