| Steel concrete composite girder bridges consist of steel girders,concrete bridge decks and shear studs.This structure is widely used in engineer projects because of the combined structure make best use of the concrete that it has high compressive strength and avoid that the steel is easy to yield under pressure.In this paper,the structural form of steel concrete composite beams is introduced in detail,described the theory,experiment and numerical simulation of shear studs,introduced the calculation method and design theory of shear stiffness and tensile stiffness of the shear studs.Shear studs are the key elements in steel concrete composite beams,its performance directly affects the bearing capacity and the performance of the composite beams.Because the shear studs are flexible shear connectors,the slip strain and the vertical tension compression strain will be produced under the action of the load,performance by slip and lift on Macroscopic.The slip effect and lift effect will reduce the bearing capacity of the bridge,increase of bridge deflection,reduce the service life of composite beam,the mutual coupling between the interface slip and lift effect,make the problem more complicated.Most of the previous literature just study about slip or lift effect,few studies of the coupling effect between the two sides.This paper mainly researches the effect of the steel-concrete composite beam interface slip and lift by using numerical simulation method,The main contents and results of the research are as follows:(1)Through the introduction of ANSYS numerical experiments simulated obtains the load-shear displacement curve of the nail,analysis of shear stress between the parameters and the contact state between the nail and surrounding concrete.(2)Analyze and compare the interface slip effect of simply supported and continuous composite beams under different type of loads.(3)Study the interface slip effect of composite beams with uniform arrangement and sectional uniform arrangement of shear studs..(4)Analysis and compare the interface lift effect between simple supported beam and continuous composite beam under eccentric load.(5)Study on the mutual influence between the slip effect and the lift effect at the end of simply supported bridge.(6)Study the influence that the slip effect bring to the lift effect,analysis the slip effect at the end of continuous supported bridge and the place that supported except theend about the continuous composite beam(7)Establish the model contains construction stage of the Hong Kong-Zhuhai-Macao Bridge,analyze the influence of the system transformation and the construction technology of the lift and fall on the interface slip and lift off effect.The main conclusions are as follows:(1)Shear stud push-out tests in tension side and surrounding concrete,range of shear studs on the surface of the root and middle lower surface.Shear load bearing capacity of 114.46 k N,China Construction steel structure standard calculation value116.12 k N,the difference between the two 1.4%.(2)With the increase of shear stiffness of shear studs,the slip is gradually reduced.The maximum value is at the end of the beam.The shear distribution is more uniform,the smaller the end of the beam.The sectional arrangement of shear studs can reduce slip at the end of bridge.(3)With the shear stud tensile stiffness increase on the far side of the interface from tension to compression,proximal interface pressure slightly reduced;in the longitudinal direction of the bridge proximal end beam and the intermediate support near the compression range increases far by the side of the pull weakened.Combined beam horizontal and vertical combination of the degree of improvement.(4)The interface tension of void increases slip effect,reduce the compression of interface slip effect;slip effect increases lift effect.(5)The roof falling beam technology has played a role in the peak of the transfer of the peak of the Hong Kong-Zhuhai-Macao Bridge.The effect of the lift off effect in the construction process is negligible. |
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