| In the 21st century,ultra-high performance concrete(UHPC)is used in various aspects such as wet joints,maintenance reinforcement and profiled steel-UHPC combined bridge decks due to its excellent durability and mechanical properties.This paper focuses on the flexural performance of profiled steel-UHPC combined beams.The finite element software was used to simulate the steel-UHPC push-out test with bolt shear keys and the four-point bending test of the steel-UHPC combination beam,mainly to study the connection performance and load-bearing capacity of the interface of the steel-UHPC combination beam under stress,to explore the influence of various variables on the experimental results through parametric analysis,and to derive the formula for calculating the bending load capacity of the positive section under different neutral axis positions,this paper The following research work was mainly done.(1)ABAQUS was used to numerically simulate the Roll-out tests with different diameter stud,and the effects of stud diameter,stud strength,stud length and concrete strength on the bearing capacity,damage mode,ductility and stiffness of the specimens were investigated.The existing empirical equations for load-slip are summarized and new empirical equations are fitted.(2)ABAQUS was used to numerically simulate the four-point bending test of the combination beam,and the load-displacement curves obtained from the numerical simulation were compared with the test results to prove the correctness of the numerical simulation results.Then parametric analysis was used to study the effects of section strength,section profile size,upper reinforcement cross-sectional area,stud specification,upper concrete slab height,concrete slab width and concrete strength on the load carrying capacity and energy loss of the combined beam.(3)By reviewing related literature,two types of section bending forms of composite beams are summarized,and the formulae for calculating the bending load capacity of composite beams in specific cases are proposed;the applicability of the formulae is proved by comparing the calculation results with the simulation results. |
