A beam element for shear lag analysis of beams with arbitrary cross section

In wide box girder bridges or multi-girder bridges with wide girder spacing, the bending strain on the flange or slab is not uniform in the direction perpendicular to the bridge axis due to the shear lag effect. For the analysis of shear lag, an analytical method with the assumption of displacement distribution due to shear lag has been proposed, then it has been developed into the method in which displacement is expressed by series expansion. Authors have proposed semi-analytical approach to solve the shear lag problem with the help of the homogenized beam theory. In this paper, we propose a beam element that can take into account the distribution of shear lag displacement from numerical analysis of the homogenized beam. A simple box girder and a continuous box girder are analyzed by the present element and these results show agreement with the analytical solution and ordinary three-dimensional finite element analysis. © 2018 by the Japan Society for Computational Engineering and Science.