ABSTRACT
An efficient modeling technique has been proposed to predict the behavior of thin-walled steel box-girders subjected to dynamic loading. In the proposed technique the general three-dimensional (3D) equations used for accurate representation of the structural deformation of these complex beam-like slender structures are decoupled into a two-dimensional (2D) cross-sectional problem and a one-dimensional (1D) beam problem through decomposition of the 3D strain field. The 2D cross-sectional problem is solved by a 2D finite element analysis considering in-plane as well as out-of-plane warping displacements of the beam section. The 1D beam problem is solved by a 1D beam finite element analysis and the results obtained are utilized to recover 3D stress, strain and displacement fields accurately. Numerical examples of thin walled box girders are solved using the proposed approach to show its performance. The comparison between the results obtained by the proposed method and detailed 3D finite element analyses highlights the accuracy as well as computational efficiency of the proposed method.
