Calculating Method Study For Composite Steel-Concrete Truss Based On FEA

Because of the best mechanical and applicable qualities, the composite steel-concrete trusses possess extensive application foreground and eminent economic benefit in the field of bridge engineer and high-rise building. In this paper, the researches and developments of composite beams were introduced in detail first at home and abroad, then the advanced development and practical value of composite steel-concrete trusses were described and analyzed at large. The analysis model of three-dimensional finite element is established on the basis of experimentation done before. The results from FEA analysis show that the FEM result is greatly coincident with the experimental result. Subsequently, the shear-lag effect of concrete flange was researched based on the former FE. Model, and variable possible influencing factors as different loading cases, width-span ratio, span-height ratio etc which will decide the value of effective width of concrete flange are ticked off, then compares theoretical results with the criterion.Following this work, the working mechanism of composite truss is expounded, and then nails down the influence extent of all kinds of factors upon the member's stiffness through the FE method, and a simple displacement formula is proposed in the end. Whereafter, the mode analysis of composite truss is finished; the modal results can easily reflect the dynamic character and possible damage form of composite truss. At last the conclusions were summarized and the questions, which needed to be experimental investigation and to be analyzed, were listed.