A second-order inelastic model for steel frames of tapered members with slender web

Jin-Jun Li^a, Guo-Qiang Li^b, Siu-Lai Chan^c

^a R&D Department, Shanghai Maglev Transportation Development Company, 2520 Longyang Road, Shanghai, 201204, China

^b College of Civil Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China

^c Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China

Received 22 June 2002, Revised 29 January 2003, Accepted 29 January 2003

ABSTRACT:

A concentrated plasticity model is proposed for second-order inelastic analysis of the steel frames of tapered members with a slender web. Such significant effects as residual stresses, initial geometric imperfection, gradual section yielding at the element ends, distributed plasticity within the element and local web buckling are considered in this model. Numerical examples on tapered compact columns, prismatic beam-columns with local buckling, a prismatic frame with local buckling and a tapered frame with local buckling are studied in this paper to verify the accuracy and efficiency of the proposed analytical model. As an application, the column curves of tapered steel columns are obtained with the proposed analytical model, both excluding and including the local buckling effects of slender webs. Some meaningful conclusions are drawn in the end of this paper.

Keywords:

Second-order inelastic analysis; Concentrated plasticity model; Steel frames; Tapered members; Slender web