This paper is a sequel to recent publications in which a novel method to allow for the P-delta effect of steel sway frames designed by ultimate limit state approaches was proposed. In this paper the new P-delta method is examined by way of a wider parametric study covering various sub-assemblages and also a full framework. The method does not require the calculation of the effective column lengths and in principle would remain valid where fully plastic analysis is adopted by design codes. It is concluded that this extremely simple method can lead to savings in materials as well as in design time compared with conventional effective length-based procedures.
There are a confusing number of beam-column approaches in present steel and concrete design codes. This paper critically compares uniaxial beam-column design provisions in limit state approaches coupled with an elastic structural analysis. Such analysis and design are the most popular in design offices. The aspects of lateral-torsional buckling and local stability (web and flange buckling) are excluded from this study. The object of this paper is to make practising engineers aware of the many divergent presentations of such beam-column design provisions in current design specifications and to encourage the use of alternative design methods, instead of the common effective length-based approaches. One such alternative method, recently developed by myself, is included in this paper for comparison purposes.