Abstract

This study used the finite element method to analyse a single panel with stiffeners along all four edges subjected to imposed shear displacements.

The analysis clarifies the stress distribution from initial buckling until the failure load, and shows that although the theories used in the design of plate girders under shear loading may give satisfactory values, the model used if very far from the real behaviour. For plate girders used in structural engineering the capacity is reached when first yield in shear in the tension corners occurs, without any of the diagonal tension assumed in most of the theories.

The ultimate load capacity of shear webs in a plate girder is modelled as the sum of the shear strength of the web and the bending strength of the flanges. After initial buckling the web provides an increasing shear resistance, without any contribution from flange blending until the first shear yielding occurs in the tension corners. After this yielding occurs, the flanges bend and the capacity of the web may be further increased as a result of the normal force at the boundary created by the bending rigidity in the flange.

In this study a new simple equation is developed to predict the ultimate shear force for rectangular panels.