Abstract
Prager's hardening rule modified by Ziegler is discussed in terms of generalized force-displacement expression to obtain the constitutive relations between forces and displacements of the beam element which may have plastic hinges at both ends. The present theory well explains Baushinger's effect in the cyclic behavior of the plane steel frame with columns subjected to alternately repeated bending moments under high axial forces as experimented by Dr. Wakabayashi et. al.
