Optimum Design And Study Of Large-cantilever Steel Tube Truss Structure

Space truss structure has the advantages of light weight, low cost and simple construction etc. However, the conventional design method is to assume the member sections of rods, and then checking the strength, rigidity, stability and so on, to get a better economic indicators mainly by the experience of the designer. So, optimum design and study of space truss structure has the vital significance.The study make the structure to satisfy the requirement of standard and the specific conditions to maximize the saving material, reducing cost.This article take the sculpture in East City Economic Development Center Square of Nanchang as the object of study. The sculpture is a large-cantilever steel tube truss.I will combine both the theory and the optimization design and take finite element analysis to the structure, so as to achieve the purpose of optimization design.(1) Establish a three-dimensional model of the large cantilever truss structure by AutoCAD, using Etabs finite element software for analyzed, and using MIDAS software for calculation,design and analysis process is given in various condition of the load combination, and get the section of size of the large cantilever truss structure, by comparing the internal forces of rod, reducing cross section to simple optimizae the truss structure.(2) Introduc the optimization design principle and process of optimization design in the finite element analysis software of ANSYS.(3) Combine with structure optimization theory and ANSYS software,with ANSYS software, the optimization design modular, to the actual large cantilever steel truss structure as an example, put forward two kinds of Scheme mode of the structure and to optimize the design, in order to research the application of the optimization design theory in the large cantilever steel truss structural optimization analysis..In the process of optimization, with satisfy the intensity, stability, stiffness as constraint condition, the steel pipe outer radius and wall thickness as the design variables, the truss structure of all steel volume as objective function. With optimization algorithm in the ANSYS software to get the optimum design of truss structures. Finally, compare the optimal design result with the traditional structure design optimization results and preliminary results to verify the optimization results.(4) Take the before and after optimization scheme of the cantilever truss in the first scheme as model, calculation of the natural frequency of vibration, observation of the structural vibration, observe the effects of optimization on the natural frequency. Then enter the El-Centro wave on the structure to make time-history analysis of seismic reflection, observation and comparison of seismic performance of structure before and after optimization.