Abstract
Energy absorption capacity of frames under severe earthquakes is required for a current design of low-rise steel frames. In this paper, the superior elasto-plastic behavior of beam-to-column connections without shear stiffening is employed for the frame energy absorption to avoid (1) damage concentration in a story of the frame during severe earthquakes, (2) member instability caused by lateral or local buckling which is apt to develop in plastic range. The effect of plastic deformation of the connections in an aseismic design of the frame is theoretically investigated herein. Some results are : (1) The energy absorption of a frame with no-shear stiffening connections corresponds to one with shear stiffening connections by giving only 1.3〜1.5 times story displacement. (2) At that story displacement, the plastic deformation of the connections without shear stiffening remains within stable region in the restoring force characteristics. (3) The aseismic design of frames depended on the energy absorption capacity of connections, that is, panelcollapse design of frames with elastic members is possible.
