A modified finite segment method for thin-walled single-cell box girders with shear lag

This paper presents a modified finite segment method for shear-lag analysis of thin-walled box girders. The method is based on the hypothesis that the warping displacement of a flange plate is governed by a third-order parabolic curve. Based on the principle of minimum potential energy, the governing differential equations with two unknown displacement functions are derived. The homogeneous solutions of the differential equations are used to represent the displacement functions of the finite element. By mean of the variational principle, the element stiffness equation is developed and the normal longitudinal stresses taking into account the shear lag are obtained. To verify the accuracy of the proposed method, three experiments are conducted so that the present results are compared with those obtained by the model tests and other methods.