Shear Behavior of Steel Frame Joints

The load-deformational response of beam-column joints in moment resisting steel frames subjected to severe lateral actions has been studied experimentally and analytically. The investigation showed that joints per se are elements with large energy dissipation capacity, exhibiting a high reserve strength beyond first yielding, large ductility, and stable hysteretic behavior. A tri-linear mathematical model is proposed for the joint response that compares well with the experimental results. Design recommendations are given based on strength and stiffness considerations. The effects of axial loads on the columns and shear stiffeners are investigated and included in the mathematical models and design recommendations. It is hoped that the results of the reported investigation will contribute to a better prediction of the static and dynamic characteristics of frames. These characteristics are strongly affected by the joint response, and joints need to be included as finite deformable elements in a realistic frame analysis.