Numerical Simulation Of The Interfacial Behavior Of Uhpfrc Orthotropic Steel Composite Deck

In recent years,the use of ultra-high performance fiber reinforced concrete(UHPFRC)as an overlay on orthotropic steel deck(OSD)systems has demonstrated to be an effective solution to cope with fatigue problems and wearing surface delamination that OSD systems are frequently prone to.However,the contribution of UHPFRC to the reduction in fatigue stresses of OSDs depends on the composite action between the two materials,as a poor interaction will lead to poor composite action,consequently to less contribution of UHPFRC.Thus the mechanical behavior of the contacting interface between UHPFRC overlay and steel deck plays a significant role in the structural behavior of the composite deck.(1)The numerical simulation analysis of steel-UHPFRC composite plate is carried out using three interface types.The interface types considered in the simulation include,UHPFRC and steel natural bond interface,the interface with welded headed stud and the interface with cold bonded corrugated steel plate shear connectors.Through the finite element analysis,the influence of the three interface types on the composite stiffness,interface slip and UHPFRC cracking was analyzed.For the simulation,the interface and UHPFRC were modeled based on the cohesive zone model approach and by the combination of the concrete damage plasticity and the extended finite element method,respectively.The results of finite element analysis showed that the shear stiffness of the interface between UHPFRC and steel plate increased,the interface slip rate decreased,and the cracking of UHPFRC was delayed.In addition,compared to the welded stud shear connector,cold bonded corrugated steel plate shear connectors can effectively improve the composite action of UHPFRC steel composite plate.(2)The quasi-static numerical simulation of UHPFRC-OSD composite deck was carried out.UHPFRC and steel natural bond interface,the interface with welded headed stud and the interface with cold bonded corrugated steel plate shear connectors were used,and their effects on the composite behavior of UHPFRC-OSD composite deck were compared.Through the finite element analysis,the influence of the three interface types on the composite stiffness,interface slip and UHPFRC cracking was analyzed.The results showed cold bonded corrugated steel plate shear connectors are better compared to welded headed stud shear connectors,as they contribute significantly in the increase of the composite stiffness of UHPFRC-OSD composite deck,they reduce stresses in UHPFRC and steel plate,and provide better interfacial shear strength.