Research on structural behavior of steel–concrete joint in hybrid girder under long-term loads

In order to explore the mechanical performance of the steel–concrete joint of hybrid girder under long-term loads, a detailed 3-D finite element model was established. Four long-term loads including creep, concrete shrinkage, temperature rising and temperature decreasing were considered. The magnitude and distribution of stress in the steel components and the infilled concrete were analyzed, and the forces of the shear connectors were investigated. The results show that the stress of the steel plates in the composite joint increases with the impact of creep, concrete shrinkage and temperature decreasing. The maximum stress of the web increases by 40 MPa, 23 MPa and 58 MPa, respectively. The area of the infilled concrete that is in tension grows taking the concrete shrinkage and temperature decreasing into account. The maximum uplift forces of the stud connectors respectively increase by 12 kN and 26 kN with the effects of concrete shrinkage and temperature decreasing. Considering the effects of shrinkage, temperature rising and decreasing, the shear forces of the perfobond connectors on the steel web increase by 16 kN, 19 kN and 36 kN.