Spatial Force Analysis Of Steel-concrete Composite Beam Based On Slip Effect

Steel-concrete composite girder bridge is a kind of bridge structure developed since the 1920s,which has the characteristics of both steel and concrete structures and has been widely used in the field of bridge engineering.The development of steel-concrete combination girders in China is slow,and most of the research directions are for steel box girders and section concrete,but there are few studies for steel-concrete combination girders.Therefore,futher theoretical and finite element analysis of steel-concrete composite beams is not only of great practical significance for the development of composite structures,but also has a broader prospect for its application in the field of bridges.In this paper,the following research work is carried out on the factors affecting the bond-slip of steel-concrete composite beams.(1)The theoretical equations are derived separately for the slip of steel-concrete combined linear and curved beams.For the steel-concrete combined linear beam,the pins can be considered as "elastic foundation beam" and the differential equations are established;for the steel-concrete combined curved beam,the Goodman elastic sandwich assumption is applied to study the nonlinearity of the combined interface of the steel-concrete combined curved beam,and the angle of the steel-concrete combined curved beam is introduced.For the steel-concrete combination curve beam,Goodman’s elastic sandwich assumption is applied to study the nonlinearity of the steel-concrete combination curve beam interface,and the angle of rotation of the steel-concrete combination curve beam is introduced to study the relationship between the slip and load of the steel-concrete combination beam.(2)The finite element simulations were carried out by using large finite element software Midas Civil and ANSYS to derive the slip amounts of steel-concrete combined curved beams and linear beams under external loads,and to compare them with the values of the derived load slip theory calculation equations,and to analyze the slip effects of steel-concrete combined beams and their influencing factors.The finite element simulations are carried out to study the stresses of the steel-concrete composite girders under the influence of bonded slip effect with the parameters of radius of curvature,steel girder strength grade,steel girder web thickness,steel girder height,concrete slab thickness and concrete strength grade respectively,and the slip variation law of the steel-concrete composite girder bridge under the influence of different parameters is also derived and compared with the calculated equation values in the theoretical analysis to investigate the effect of different The results are compared with the values of calculation equations in the theoretical analysis to investigate the influence of different factors on the slip effect of steel-concrete composite girders,and to suggest reasonable cross-sectional dimensions of curved steel-concrete composite girders.(3)The correctness of the theoretical formulae and the correctness of the finite element modeling are analyzed from the available test results and engineering examples.The correctness of the theoretical formulae is verified by comparing the experimental values with the theoretical formulae;the correctness of the finite element modeling is verified by comparing the experimental values with the finite element values;and finally,the feasibility of applying the formulae to engineering practice is verified by comparing the engineering example values with the theoretical formulae.