جامعة نوتنغهام2024-12-102024-12-10https://dspace.academy.edu.ly/handle/123456789/754Undoubtedly, the best design of any structure aims at the most economical and environmentally balanced solution without impairing its function and structural integrity. To achieve this, structural designers often engaged in design optimisation. In this study, single and multi-objective stochastic search methods are proposed for optimum design of two and three-dimensional multi-story structures with three, six, and nine stories. The optimality objectives are the structure weight and embodied energy as well as calculating the cost and embodied carbon of the resulting optimum options. Three optimality algorithms developed in MATLAB, namely, Genetic Algorithms (GA), Particle Swarm Optimisation (PSO) and Harmony Search Algorithm (HSA), were used for structural optimisation to compare the effectiveness of the algorithms. Two life cycle stages were considered, production and construction stages which include three boundaries: materials, transportation, and erection. In the formulation of the optimum design problem, 107 universal beams “UKB” and 64 columns “UKC” sections were considered for the discrete design variables. The imposed behavioural constraints in the optimum design process were set according to the provision of EC3.Undoubtedly, the best design of any structure aims at the most economical and environmentally balanced solution without impairing its function and structural integrity. To achieve this, structural designers often engaged in design optimisation. In this study, single and multi-objective stochastic search methods are proposed for optimum design of two and three-dimensional multi-story structures with three, six, and nine stories. The optimality objectives are the structure weight and embodied energy as well as calculating the cost and embodied carbon of the resulting optimum options. Three optimality algorithms developed in MATLAB, namely, Genetic Algorithms (GA), Particle Swarm Optimisation (PSO) and Harmony Search Algorithm (HSA), were used for structural optimisation to compare the effectiveness of the algorithms. Two life cycle stages were considered, production and construction stages which include three boundaries: materials, transportation, and erection. In the formulation of the optimum design problem, 107 universal beams “UKB” and 64 columns “UKC” sections were considered for the discrete design variables. The imposed behavioural constraints in the optimum design process were set according to the provision of EC3.DESIGN OPTIMISATION OF MULTI-STORY STEEL STRUCTURES WITH SINGLE AND MULTI-OBJECTIVE FUNCTIONS USING THREE OPTIMISATION TECHNIQUES