Steel - Concrete Composite Truss Plate Auricular Node Experimental Study And Theoretical Analysis

Steel-concrete composite truss structure is a new type of structure that is consist of the steel-concrete composite chords and the steal web member. The node of steel-concrete composite truss studied in this thesis is not only the assembly areas where the upper chord and the web member meet and interact with each other, but also the core point of force transferring in this structure. The mechanical performance of the node exerts great influences on the working performace of truss structure. In order to study the working performance of ear-plate node specimens under horizontal loading, the static loading test and general software ABAQUS are employed. The following are the researching contents and major achievements:1) Two experiments on the ear-plate node specimens that ratios one to three are carried out during the process. The working performance of composite joints are analyzed according to the strain and displacement as well as the failure characteristics of steel leg yielding and concrete cracking during the experiment. Experiment has indicated that the carrying capacity of the node specimen is good. However, buckling failure occurred at the steel legs in the two experienment, so the bearing capacity of ear-plate depends mainly upon strength and sectional properties of steel legs..2) General software ABAQUS is employed to do numerical simulation on the ear-plate node. And then the data are compared with that worked out by the experiment. By doing so, the accuracy of the software ABAQUS and brief design of the node is tested. It turns out that this model is reliable in calculation and can reflect the real working state of the node of steel-concrete composite truss. Detailed analysis of the data shows that the malfunction of the node is because of chord crack and steel legs buckling. Therefore, the strength of chord,and the strength and sectional properties of steel legs exerts great influence on the ultimate bearing capacity of the node. At the same time, the mechanical performance of PBL is analyzed.3) Parameter analysis is carried out to composite truss ear-plate node with different intensity of steel-concrete, thickness of steel legs and intensifies and shape of shear connector. And the influence of different parameters to the maximum displacement and the maximum stress of the node are made clear. Research shows that bearing capacity of the ear-plate node can be obviously improved by upgrading the quality of steel-concrete and increasing the thickness of steel legs. The change of reinforcement ratio of Longitudinal and stirrup ones as well as the size and intensity of PBL have little influences on the ultimate bearing capacity of the node.