Analysis On The Deflection Of Steel-Concrete Composite Beams Under Shear Deformation Interlayer Slip And Long -Term Load Effect

In this paper,the research object is mainly based on the composite beams and continuous composite beams of the i-steel and concrete beams.The analytical methods are combined with the theoretical analysis and the spatial finite element analysis and the measured values.The shear deformation effect,interlayer slip effect and long-term load effect of the composite beams of the two systems are studied in depth.The main work and research results are as follows.(1)In view of the structural steel and concrete composite beams,through flexible interlayer assumption,based on the principle of energy variation method,established the theory is applicable to arbitrary cross section in the form of composite beams considering shear deformation,interlayer sliding control differential equation.The formulas for calculating the slip displacement and deflection of the simple supported composite beams under uniformly distributed load and inter-span concentrated load and of the two-span continuous beams under uniform load.Through the comparison and analysis with the finite element value and the measured value,Anastomosis is in good agreement of the three.The deviation is small and the correctness of the theory is verified.In addition,the shear deformation and slippage effect on the steel-concrete composite beam and continuous beam are analyzed.(2)Based on the verified theory of computation of two-span continuous composite beams,With the influence factors such as high span ratio,shear stiffness of stud,the material grade of concrete wing plate and the thickness of steel girder webs and the width of concrete wing slab under the same height span,The influence of shear deformation and interlayer slip effect on the slip displacement and deflection of two continuous I-steel-concrete composite beams under uniformly distributed load is analyzed.The influence factors of slip displacement and shear deformation and interlayer slip effect on total deflection are summarized.(3)Based on the age-adjusted effective modulus method to consider the effect of creep,considering the concrete shrinkage and creep effect,using the energy variational method,the differential equations of considering shear deformation,interlayer slip and creep effect are established.The general solution of sliding displacement and deflection of composite beams is derived.The calculated value of deflection under uniformly distributed load is compared with the measured value,and the rationality of the method of shrinkage creep and the correctness of the calculation formula are verified.In addition the influence of creep and shrinkage on the deflection of steel-concrete composite beams was analyzed.