| The application of hybrid structure in bridge engineering is becoming more and more extensive.Due to the complexity of the force and the particularity of the structure,it is often necessary to carry out targeted research.Based on the engineering background of Xiangshan Bridge,this paper conducts research on the force characteristics and force transmission mechanism of exposed steel-concrete joints and embedded steel-concrete joints through finite element simulation analysis and model tests.The work content is as follows:(1)Summarize the structural characteristics and mechanical characteristics of different connection forms of steel-concrete joints;Xiangshan Bridge,analyze the structural characteristics of steel truss arch-concrete V-frame composite bridge joints,and classify them as "exposed joints" And "embedded nodes";the force characteristics of the two types of nodes are analyzed through the full bridge finite element analysis.(2)Aiming at the "exposed joints",ABAQUS was used to establish a nonlinear finite element analysis model to study the characteristics of the joints;a 1:5 scale model of the joints was designed and loaded under the most unfavorable conditions.Comparing the results of the scaled model test and the refined finite element model,the reliability of the structure is verified,and the force transmission mechanism of this type of node is analyzed.(3)Aiming at the "embedded node",ABAQUS was used to establish a nonlinear finite element analysis model to study the force characteristics of the node;a 1:5 scale model of the node was designed and loaded under the most unfavorable conditions.Comparing the results of the scaled model test and the refined finite element model,the reliability of the structure is verified,and the force transmission mechanism of this type of node is analyzed.(4)According to the force transmission mechanism of the two types of joints,the main influencing factors of the mechanical behavior of the steel-concrete joints are determined,and the structural parameters of the two types of joints are studied through the finite element analysis method.For the exposed steel-concrete joints,the main parameters are consistent.Plate thickness,shear nail length,anchor prestress and PBL structure form;for embedded steel-concrete joints,the main parameters are the length of the built-in concrete of the steel box and the thickness of the outer concrete.The optimization suggestions for the two types of steel-concrete joints are given through parameters. |
