Study On Optimization Of Roof Truss Structure Of A Terminal Building

With the development of economy,large-span buildings are emerging.Steel structure is widely used in large-span buildings because of its high strength and strong resistance to deformation.Due to the emergence of various kinds of complex projects,traditional optimization methods have been difficult to adapt to the solution of complex structural optimization problems,and the development of optimization algorithm provides a new and efficient solution for structural optimization design.This dissertation improves the gravitational search algorithm.In the first stage of the improved gravitational search algorithm,the population is divided into several sub-groups,and each sub-group is evaluated independently by the particle swarm gravitational search hybrid algorithm.Feasibility-based rules are used to compare and update particles in multiple sub-populations.As a result,the particles move faster to the feasible region,and the convergence speed of the gravitational search algorithm is effectively accelerated.In the second stage of improving gravitational search algorithm,orthogonal crossover operator based on orthogonal design is used to improve the best position in all particles.Five truss models are optimized by improved gravitational search algorithm and standard gravitational search algorithm.The results show that compared with other algorithms,the number of iterations of the improved gravitational search algorithm to get the optimal value is significantly reduced,and the optimal solution obtained by the improved gravitational search algorithm is obviously superior to the general algorithm.Taking an airport terminal as an example,under the premise of meeting the design criterion of steel structure,the improved gravitational search algorithm and standard gravitational search algorithm are used to optimize the section size of the roof steel truss.The section area and weight of the optimized steel truss are compared with the original data.The finite element software ANSYS is used to model and analyze the reliability,deformation characteristics and mechanical performance of the truss structure before and after optimization.From the analysis results,it can be concluded that the optimization design can not only meet the needs of the project,but also improve the performance of the original structure system in some aspects and effectively save costs,which verifies the necessity and effectiveness of theoptimization design and provides reference value for the optimization of other similar projects.