Optimization Design And Parameter Analysis Of Light-Weight Steel Structure With Small Span Non-Uniform Gabled Frames

In lightweight steel housing system, portal frames have the obvious advantages in construction cycle, structural applicability compared with traditional architecture. Portal frames have been widely used for less steel weight of structures which have become the leading form of structure lighter, especially in non-uniform portal frames, so proper structural dimensions have an important significance for such building structures.This paper systematically discusses the characteristics of lightweight steel structure, details on the structure of the design methodology. On the basis of the principles of finite element analysis with the soft ware ANSYS for the structural optimization design with the objective function of steel weight to be used least, while it should meet the specifications with overall stability, local stability, strength, rigidity and cross-section geometrical size these constraint conditions to optimize the cross-section size of structure. Educed the connections among optimization times, optimization methods, structural steel weight and the cross-section size, compared the optimization results with the general design in order to the make carrying capacity of each members approaching its full stress aimed at minimum steel weight of structures, and make some reasonable proposals based on the above analysis.According to precise finite element theory, put forward fourteen comprehensive optimization design parameters of non-uniform portal frame,viz. web depth, web thickness, flange width and flange thickness, beam gradient, column height, frame span and column space. Using self-programming structure optimization procedure to discuss the stress conditions of portal frames with permanent load and variable load, analyze different gradients, different column depths, different spans and different space-column of frame structures to select the optimum structural forms which is in better target of deflection and steel weight. Large calculating examples are presented to draw conclusions about structural forms optimization and the connections between various design parameters, and conclude regression equation about steel weight on the basis of large calculating data for the reference of similar project application.