Analysis and Design of Steel Frames Considering Panel Joint Deformations

This paper provides insight to the background of the development and requirements for panel-zone design in the 1986 AISC LRFD specifications. In particular, two criteria for the design of beam-column panel zones are discussed; the first method is based on the von Mises first-yield criterion for the panel-zone web, and the other utilizes the postyield shear resistance of the panel derived from the flexural resistance of boundary elements surrounding the panel-zone joint. The nonlinear behavior of a moment-resisting frame with panel-zone joints designed according to these two requirements is studied. Lui's 1985 rigorous second-order elastic-plastic hinge analysis is used to assess the performance of a frame considering panel-zone deformations. An advanced analysis technique based on a notional-load plastic-hinge approach is introduced. This advanced analysis technique is used to evaluate the proper design criteria for panel-zone joints in moment-resisting frames, and to study the influence of panel-zone deformations on the frame's limit of resistance. From these studies, the effects of the panel-zone deformations on the overall frame resistance can then be summarized and discussed.