Research On Mechanical Behavior And Structural Optimization Of Steel-concrete Composite Section Of Hybrid Beam Cable-stayed Bridge

Hybrid beam cable-stayed bridge is a kind of bridge structure rising in recent years.The steel-concrete composite section is the key structural part of this type of bridge.The stress and structure are complex.The detailed analysis and structural optimization of the steel-concrete composite section is an important engineering design task.On the basis of DONGPING bridge,the stress performance and structural optimization of the steel-concrete composite section of the bridge are studied,which has a good reference value for similar projects.The main work of this paper are as follows:(1)The whole bridge model of DONGPING bridge is established by using Midas analysis software.The internal force change and its law of the steel-concrete joint section are analyzed in the process of bridge construction and operation,and the most unfavorable working condition for the analysis and optimization of the steel-concrete joint section is further determined.(2)The refined finite element model of the steel-concrete joint section is established by using ABAQUS,and the stress distribution of each component in the steel-concrete joint section is studied in detail;the causes of the steel-concrete joint section void are analyzed and the corresponding solutions are put forward;on this basis,the mechanical properties of the steel cell under the condition of 5%of the bottom plate void are discussed,and the most sensitive design parameters is determined in steel cell.(3)The length of the steel-concrete joint,the form of composite stiffeners in the transition section and the thickness of the top and bottom plates of PBL connectors are analyzed,and the most reasonable structural form of stress is determined,which provides general suggestions for the design of the steel-concrete joint section.