Ultimate strength of plate girder panels with initial imperfection under bending and shear

The ultimate strength of plate girder panels with initial imperfection (deflection) of the web was analyzed using the finite element method. Loading combinations consisting of bending moment and shear were analyzed. The behavior of the panels was examined and found to agree well with those observed in experiments conducted by others.; The results of analysis confirmed the previously observed condition that there would be no sudden buckling when there was initial deflection of the web. The magnitude of web deflection generally increased with the increase of load magnitude.; The primary parameters which affected the strength of plate girder panels were the web slenderness ratio, the panel aspect ratio, and the ratio of compression zone of the web. Strength interaction diagrams of bending moment and shear were constructed from the results of the analysis assuming the maximum permissible initial deflection. Strength equations were formulated for these diagrams.; The ultimate loads of girder panels tested by others were compared with the corresponding strength from the strength equation. With an assumed maximum permissible initial deflection of the web, the computed strength was on the conservative side.; Comparison of the bending and shear strength equations with provisions of the current design rules gave good results. The is no provision for the interaction of bending and shear. Consideration of adoption of the interaction equation developed in this study is recommended.