The Structure Design And Optimization Research On Large Span Steel Truss

This article embarks from the large span steel truss structure. STS module ofPKPM software is used and relevant specification is combined with. Thestructure is modeled, analyzed and optimized.This paper starts from the actual cases. Firstly, the roof frame selection andsupport system is designed. A truss is modeled, analyzed and nodes checked byusing the software. Then four optimization schemes are proposed. Shorten theinternodes length of the lower chord, increase and decrease the ratio of the endheight and span of the truss in limit experience, turn the member bar of the roofinto square steel tube. Model and analyze the structure with the software again.The following conclusions are reached through comparisons.(1) The lower chord internodes length changes from6m to5m. The nodeload is decreased. But the section of the member bar isn’t reduced effectively. Theinternal force of the structure is increased. The vertical displacement of thestructure is also increased. The total amount of steel is increased. With thenumber of rod and node increased, it’s inconvenience on construction.(2) The vertical stiffness of the structure will be improved by increasing theend height. But the section of the bar is bigger than the original design. Theinternal force of the structure and the total amount of steel is bigger. With the endheight increased, the size of part structural members is increased. It’sinconvenience to produce, transport and install the rods.(3) The vertical stiffness of the structure is reduced and the internal force ofthe structure is increased after reducing the end height. The section of the bar isthe same with the original design. But the section of the inclined rod of thestructure and vertical rod which connects the vertical support are effectivelyreduced. The total amount of steel is increased greatly. It’s convenient forconstruction by reducing the end height. Thus it’s a feasible optimization schemefor the traditional steel roof truss with double angle form through reducing theend height. (4) Square steel pipe truss is better than traditional steel truss on stress,construction and the total amount of steel.