Analysis On Mechanical Properties Of New Shear Connectors By Bonding

The steel-concrete composite beam can give full play to the advantages of two materials,such as steel and concrete.It has good overall performance and significant cost benefit.It has been widely used in practical engineering.However,traditional steel-concrete composite are cast-in-place mostly and they aren't suitable for prefabricated construction and cannot be erected quickly.The traditional shear connectors are mostly metal joint keys arranged in a certain distance,resulting in problems such as stress concentration and discontinuity of transmission force.In view of the problem,this paper puts forward three new shear connectors:(1)Cemented shear connector of epoxy mortar,(2)Epoxy mortar mixed stud shear connector outsourcing,(3)The bolt shear bond with high strength friction.At the same time,in order to study the mechanical properties of three kinds of shear connectors,the test and finite element analysis are carried out on the push out specimens using such shear connectors.The main work of this article is:(1)Introduced the purpose of test,the method of test,design basis and design idea of the three kinds of new shear connectors.In order to obtain the mechanical index of the material used in the test,the material property test was carried out.(2)According to the experimental study of the pure cemented shear connector,the failure process and failure form of the cemented shear bond are described in detail,and the failure of the specimen isn't found in the cemented layer.The shear strength of this kind of connection is analyzed by the load-slip curve and the ultimate shear capacity.The shear strength of this shear connector can reach the engineering requirements.At the same time,the finite element analysis is carried out by using the spring element to simulate the cemented layer,and the simulation data are compared with the actual experimental data,and the influence formula of the cementation thickness to the shear strength of the cemented shear bond is fitted.(3)For the post cast stud shear connection key,the experimental study was carried out.from the three aspects of the failure form,the load slip curve and the ultimate shear capacity,the two shear bonds of the mixed cementation and the precast cementation were compared and analyzed.The effects of the reserved pore size of the concrete slab on the shear bearing capacity of the specimens were found.Combined with many codes,shear strength formula are given when bond epoxy mortar wrapped stud.(4)The experimental study on the shear bond of high strength friction bolt is carried out,and the mechanical properties and sliding trend of the specimens under this connection are studied by changing the concrete reserve diameter,the diameter of the bolt rod and the pretension force.The test results show that the pre-tightening force has an obvious effect on the overall mechanical properties of the specimen,while increasing the bolt diameter has no obvious effect on the bearing capacity of the specimen.The model was simulated by finite element software,and the finite element simulation value was compared with the actual test data.In this paper,a new type of shear connector used for rapid assembly is studied and analyzed in detail.The series of conclusions and design formulas will further enrich the research content of the assembled steel concrete composite structure bridge,and provide a theoretical reference for the follow-up research.