Analysis on Shear Lag Warping Stress of Thin-walled Box Girders with Boundary Constraint Effect

In order to reflect objectively the shear lag warping stress distribution of box girders, the solid model of box girders were established with the help of finite element software and the transverse distribution of the warping stresses was drawn on the cross section. The warping displacement mode of each plates were refined by the transverse distribution, the reflection of warping stress self-balancing condition and the boundary constraint correction coefficient of cantilever plates were introduced for the box section. The additional deflection induced by shear lag effect was chosen as generalized displacement. The governing differential equations for reflecting additional deflection and the boundary condition were established by applying energy variation method. The analytical solution to the additional deflection and warping stress for shear lag of simply supported and two-span continuous box girder were derived. The boundary constraint correction coefficient can be 1.4, which combined with the spatial element method results. Example shows that the calculated stresses in the flanges by the proposed method agree well with those by the spatial finite element method. © 2019, The Editorial Board of Journal of Basic Science and Engineering. All right reserved.