Shear strength of end web panels

In most classical theories for post-buckled web panels under shear, it was assumed that tension-field action was anchored by flanges and adjacent web panels. Such an assumption led to the conclusion that post-buckling strength can only develop in intermediate web panels. Accordingly, the AISC specifications do not account for post-buckling strength in end web panels. In this paper, more than sixty full-scale plate girders were modelled and analyzed by the finite element method to assess the shear strength of end web panels. An objective of this nonlinear large deflection numerical study was to clarify the effect of geometric properties of end web panels on their shear strength in the elastic and inelastic buckling ranges. Numerical results were verified by comparison to classical web buckling theory and experimental results published in literature. Unlike most post-buckling theories, it was shown that end web panels possessed post-buckling strength where diagonal tension stresses were equilibrated by compressive stresses in end-bearing stiffeners and portions of the web stiffened by flanges and stiffeners. Numerical results were used to establish new design rules for shear strength of end web panels including tension field action.

► Stiffened end web panels possessed post-buckling strength.
► Diagonal tension in end web panels was balanced by compression in web and stiffeners after buckling.
► Post-buckling strength of end web panels increased when thick flanges and/or slender webs were used.
► Shear strength of end web panels decreased when spacing between transverse stiffeners increased.
► Long end web panels with aspect ratio greater than 3 possessed post-buckling strength.