Shear flow in thin-walled cellular sections

Frequently flexural members are made of single or multiple cellular sections due to a variety of reasons. Clearly, the superb torsional capacity of such sections is a major attraction for girders in horizontally curved alignments. However, the ease of maintenance and esthetic considerations favor the choice of such girders.The determination of the shear stress at any point along the boundary of an open section can be made by the evaluation of the shear flow integration from a free edge or zero surface to any surface. In the instance of a closed cell, there is no free surface and thus the problem becomes indeterminate and the integration cannot be evaluated to determine the shear flow.Although a general methodology to overcome this difficulty is available in the literature, a simple digital computer program has been created to evaluate the bending shear flow of any multiply-connected cellular sections. Several examples are solved and showed the unreasonableness of the frequently used approximate solutions.