Effects of panel zone deformations on seismic response

Abstract This paper shows that joint panel zone shear deformations may have a significant effect on the structure strength and stiffness and on the distribution of inelastic deformations in a frame structure subjected to earthquake excitations. If panel zones are strong in shear, frame behavior is as predicted from conventional rigid frame analysis with inelastic deformations concentrated in plastic hinge regions in beams or columns. If panel zones are weak in shear, the joints are weak links in which inelastic deformations are concentrated and the beams and columns will not develop their bending strength under lateral loading. As a consequence the structure strength and stiffness may be reduced considerably. Since designs with weak joints are becoming the rule rather than the exception, due consideration should be given to the effects of joint shear deformations on frame behavior.