Study On The Interface Shear Performance Of Corrugated Steel-UHPC Composite Bridge Deck

As the part of bridge that directly supports the load of vehicle,the working state of bridge deck is critical to the safety and durability of bridge.In order to improve the overall performance of bridge,a corrugated steel-UHPC composite bridge deck with light weight and high bearing capacity is proposed.In order to study the interface shear performance of corrugated steelUHPC composite bridge deck,the shear capacity of stud shear connectors and PBL shear connectors is calculated,and the main factors of the interface shear performance of corrugated steel-UHPC composite bridge deck are studied through theoretical analysis and non-linear numerical simulation.The main contents of the paper are as follows.(1)Non-linear element simulation of stud shear connectors in steel-UHPC composite bridge deck.Based on the theory of beam on elastic foundation and the stress mode of shear stud in UHPC,the deflection differential equation of shear stud is established.And the theoretical calculation expression of load displacement curve of stud is obtained through mathematical solution.Through ABAQUS,a non-linear finite element analysis of the push-out test of stud shear connectors was carried out to study the failure mode of stud in UHPC,and analyse the influence of the studs’ number,studs’ height,studs’ diameter,the shape of steel plate and the strength of concrete on the shear performance of stud shear connectors.The results of nonlinear finite element analysis show that the failure mode of studs in UHPC is the shear failure of its root;the studs welded on the corrugated steel plate have greater shear capacity;the shear capacity of stud shear connectors in UHPC is linearly related to its number;the shear capacity of stud shear connectors in UHPC has nothing to do with its height,but it increases with the increase of its diameter;the theoretical calculation results of load displacement curve of stud are in good agreement with the finite element results,but there still remains errors in some parts;the reference specification of composite structures at home and abroad are not suitable for directly calculating the shear capacity of stud connectors in UHPC.(2)Non-linear Finite element simulation of PBL shear connectors in steel-UHPC composite bridge deck.Through ABAQUS,a non-linear finite element analysis of the push-out test of PBL shear connectors was carried out to study the failure mode of PBL shear connectors in UHPC,and analyse the influence of hole shape,hole numbers,hole diameter,rebar and the strength of concrete on the shear performance of PBL shear connectors.The results show that the failure mode of the PBL shear connector in UHPC is the shear compression failure of the concrete tenon in the hole;the hole shape has a significant effect on the shear resistance of PBL shear connectors;The shear capacity of PBL shear connectors will increase with the increase of hole diameter,hole numbers and the performance of the concrete;the reference composite structure codes at home and abroad are not suitable for directly calculating the shear capacity of PBL shear connectors in UHPC;the calculation error between finite element model and the formula obtained by numerical fitting is less than 5%.(3)The design methods of shear connectors of corrugated steel-UHPC composite bridge deck.The elastic method is proposed to design the shear connectors of corrugated steel-UHPC composite bridge deck.And through the elastic and plastic method,the design of stud shear connectors and PBL shear connectors in corrugated steel-UHPC composite bridge decks were carried out.The results show that the plastic design method is more suitable for the design of stud shear connectors,while the elastic design method is more suitable for design of PBL connectors.Through the maximum horizontal shear flow,the elastic design method can ensure the safety of the interface of corrugated steel-UHPC composite bridge deck.