Large Span Steel - Concrete Composite Truss Static Performance Test

With the wide development of steel-concrete composite structure systems in the civil construction, it has great theoretical significance and obvious value for the mechanical properties and failure researches of composite truss joints. This paper focuses on one type joint about steel-concrete composite truss, which is composed of concrete and steel tube. To study the influence factors of joint, both theoretical analyses and experimental researches method are used. The main achievements can be summarized as follows:(1) Experimental tests on three steel-concrete composite truss joints with monotonous static force were carried out and the bearing capacity was discussed. Based on current test results, the above joint has adequate bearing capacity.(2) Nonlinear finite element analysis was carried out on the steel-concrete composite truss joint by applying the finite element analysis programe Abaqus. The analysis was mostly concentrated on the mechanical character and failure process of this structure by the numerical simulation with elastoplastic damage constitutive model for concrete of Abaqus. By analysis and comparison between the results, the calculated results by Abaqus agree well with experimental results. It demonstrates that the numerical analysis is reliable in predicting the load versus deformation relationship.(3) According to experimental tests and finite element analysis, we can reveal the mechanism and the process of destruction and the micromechanism of stress distribution for its composition components. Then the ultimate bearing capacity of the joint was determined.(4) Up to now, there is no experimental test based on this type of joint in the country. This paper will offer some reference to the further experimental tests and rational design of this structure. In addition, it will be helpful for practical applications in the future.