Closed-form solution for shear lag effects of steel-concrete composite box beams considering shear deformation and slip  

作　　者：周旺保 蒋丽忠 刘志杰 刘小洁 

机构地区：[1]School of Civil Engineering,Central South University [2]National Engineering Laboratory for High Speed Railway Construction

出　　处：《Journal of Central South University》2012年第10期2976-2982,共7页中南大学学报（英文版）

基　　金：Projects(51078355,50938008) supported by the National Natural Science Foundation of China;Project(094801020) supported by the Academic Scholarship for Doctoral Candidates of the Ministry of Education,China;Project(CX2011B093) supported by the Doctoral Candidate Research Innovation Project of Hunan Province, China;Project(20117Q008) supported by the Central University Basic Scientific Research Business Expenses Special Fund of China

摘　　要：Based on the consideration of longitudinal warp caused by shear lag effects on concrete slabs and bottom plates of steel beams,shear deformation of steel beams and interface slip between steel beams and concrete slabs,the governing differential equations and boundary conditions of the steel-concrete composite box beams under lateral loading were derived using energy-variational method.The closed-form solutions for stress,deflection and slip of box beams under lateral loading were obtained,and the comparison of the analytical results and the experimental results for steel-concrete composite box beams under concentrated loading or uniform loading verifies the closed-form solution.The investigation of the parameters of load effects on composite box beams shows that:1) Slip stiffness has considerable impact on mid-span deflection and end slip when it is comparatively small;the mid-span deflection and end slip decrease significantly with the increase of slip stiffness,but when the slip stiffness reaches a certain value,its impact on mid-span deflection and end slip decreases to be negligible.2) The shear deformation has certain influence on mid-span deflection,and the larger the load is,the greater the influence is.3) The impact of shear deformation on end slip can be neglected.4) The strain of bottom plate of steel beam decreases with the increase of slip stiffness,while the shear lag effect becomes more significant.Based on the consideration of longitudinal warp caused by shear lag effects on concrete slabs and bottom plates of steel beams, shear deformation of steel beams and interface slip between steel beams and concrete slabs, the governing differential equations and boundary conditions of the steel-concrete composite box beams under lateral loading were derived using energy-variational method. The closed-form solutions for stress, deflection and slip of box beams under lateral loading were obtained, and the comparison of the analytical results and the experimental results for steel-concrete composite box beams under concentrated loading or uniform loading verifies the closed-form solution. The investigation of the parameters of load effects on composite box beams shows that： 1） Slip stiffness has considerable impact on mid-span deflection and end slip when it is comparatively small; the mid-span deflection and end slip decrease significantly with the increase of slip stiffness, but when the slip stiffness reaches a certain value, its impact on mid-span deflection and end slip decreases to be negligible. 2） The shear deformation has certain influence on mid-span deflection, and the larger the load is, the greater the influence is. 3） The impact of shear deformation on end slip can be neglected. 4） The strain of bottom plate of steel beam decreases with the increase of slip stiffness, while the shear lag effect becomes more significant.

关 键 词：steel-concrete composite box beam shear lag effect shear deformation SLIP closed-form solution 

分 类 号：TU398.9[建筑科学—结构工程]