Steel - Concrete Composite Truss Force Performance Tests And Finite Element Analysis

Steel-concrete composite truss was a new kind of composite structure, which had some advantages including lighter self-weight, greater rigidity, lower fabrication cost, and its entirety and carrying capacity were better. At present, it possesses extensive application in the field of bridge engineer and high-rise building. But because the research of composite truss in our country developed relatively lately, it hadn't examination and applications leading to limit the type of bridge application at home. Therefore, researching of composite truss node must be valuable to the engineering applications.Experimental research on static behavior of three full-scale steel-concrete composite truss node model tests was presented. Through the full-scale model test, the dissertation discusses the behavior, failure mechanism and deformation of composite truss node. According to the experimental test data, the load-displacement curves, load-strain curves, strain distribution in concrete, steel-legs, steel-plate were analyzed from the static experiment of three model tests.The analysis model of composite truss node was conducted on finite element method by software ABAQUS. Factors including analysis program and element, material constitutive model,boundary conditions, load mode, nonlinear problem as well as iterate way were investigated to study their effects on the composite truss node capacity. There were two kinds of modeling to simulate the node in the monotonous load bearing performance, and then choose the better scheme.Comparison between the FEM analysis results and results obtained by tests was investigated, which verified the rationality of the numerical method. On this base, the load-displacement curve of concrete chord, steel legs, counteracting force and distribution of stress on the componets when the composite truss node was destroyed. The paper showed that the FEM analysis value and experimental results were in good agreement in elastic period. After the experiment yield, the finite element analysis of the displacement value and the strain value were higher than the experimental results, but it still was allowable. And then the ultimate load-carrying capacity of the composite truss node was in investigated and compared with experimental results.The conclusions were summarized and the questions, which needed to be experimental investigation and to be analyzed, were listed.