Improved refined plastic-hinge analysis accounting for local buckling

In this paper, a refined plastic-hinge analysis is improved to account for the effect of local buckling. This analysis accounts for material and geome tric nonlinearities of the structural system and its component members. Mor eover, the problem associated with conventional refined plastic-hinge analy ses in that no consideration is given to the degradation of the flexural st rength caused by the local buckling is overcome. Efficient ways of assessin g steel frame behavior including gradual yielding associated with residual stresses and flexure, second-order effect, and geometric imperfections are presented. In this study, a model consisting of the width-thickness ratio i s used to account far the local buckling. The proposed analysis is verified by the comparison of the plastic-zone, LRFD, and experimental results. Cas e studies show that local buckling is a very crucial element to be consider ed in refined plastic hinge analysis. The proposed analysis is shown to be an efficient, reliable tool ready to be implemented into design practice. ( C) 2001 Elsevier Science Ltd. All rights reserved.