Research On Deformation And Lateral Distribution Of Simple Supported Composite Curved â… -Beam

The application of steel-concrete curved composite beam increases gradually with the development of bridge structures and materials. As important parts of bridge design, it is of great significance to study the deformation and lateral distribution of this type bridge.The interface slip between steel and concrete reduces the stiffness of composite beam and increases its deformation under load. At present, the research on the deformation of composite beam is mainly concentrated in the deflection calculation of composite straight beam, therefore most research on composite beam is about flexural property, and less is about torsional property. The composite curved beam will produce torsional angle under vertical load because of the bending-torsion coupling, so it is necessary to study the torsional stiffness of composite beam. The interface slip not only affects the deformation of composite beam, but also changes its lateral load distribution. Studying the lateral distribution variation of composite curved beam with combination degree, and deducing corresponding calculation formula, which can be used to guide the design of this type bridge.This paper is based on the research project of transportation science and technology plan in jilin province, whose name is Research on Static and Dynamic Characteristics, Anti-Overturning Stability and Design Method of Steel-Concrete Composite Beam, and the following work is carried out on simple supported composite curved â… -beam.(1) The method of effective stiffness is used to calculate the deformation of composite beam, which is got by interpolation between free composite stiffness and completely composite stiffness. The relationships between the stiffness of composite beam and variables are studied using ANSYS model, such as central argle, stud stiffness, and so on. Then the expression of torsional stiffness interpolation function is obtained by curve fitting.(2) The composite curved beam is divided into completely composite and additional deformation sub-structures according to the deformation, both of which satisfy the assumption of rigidity crossbeam, then the formulas for calculating the lateral load distribution of composite curved beam is obtained including slip effect. The lateral distribution of load is not the same as that of internal force or deformation for curved beam due to the bending-torsional coupling. The influence lines of lateral moment distribution are obtained according to the relationship between internal force and external load of curved beam, and the lateral distribution coefficients are got after the most unfavorable lateral loading on the influence lines.(3) A modal analysis is carried out on the composite curved beam, whose lateral deformation distribution is obtained with modal frequency and modal shape, then the lateral load distribution and lateral moment distribution are got according to the relationship between deformation, internal force and load of curved beam. The numerical examples show that the calculation results of modal parameter method and finite element static analysis are in good agreement, which has verified the applicability of this method to the lateral distribution calculation of composite curved beam.(4) The influence of some variables on the lateral distribution of composite curved beam are studied by finite element static analysis method and direct substitution method, including shear connector stiffness, radius of curvature, main girder spacing, and so on, to further understand the load distribution characteristics of this type bridge, and provide a reference for its design.