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 geometric nonlinearities of the structural system and its component members. Moreover, the problem associated with conventional refined plastic-hinge analyses in that no consideration is given to the degradation of the flexural strength caused by the local buckling is overcome. Efficient ways of assessing 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 is used to account far the local buckling. The proposed analysis is verified by the comparison of the plastic-zone, LRFD, and experimental results. Case studies show that local buckling is a very crucial element to be considered 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.