Abstract
In this paper, two analysis models for the coupled torsional-bending responses of thin-walled beam with discontinuously variable cross-sections are presented. These models are based on a thin-walled beam theory which takes into account shear deformation by the 2D or 3D shear warping function. A C1 continuous finite element with boundary contraction technique is used for the discretization. The compatibility condition of warping, which is automatically satisfied in the 3D shear warping model, is satisfied approximately in the 2D shear warping model by use of warping error minimization technique. By an example of box girder with open section, the accuracy and efficiency of present models are shown.
