Recent research advances in cold-formed steel structures

Recent developments in the practical utilisation of cold-formed sections in building construction have taken place on three related fronts. There have been significant developments in the technology which result in more complex shapes with a higher yield stress so that cold-formed sections represent a particularly high-tech form of constructional steelwork. Developments in technology would be of little consequence unless there were parallel developments in practical applications and this is illustrated by the continual increase in the market share of cold-formed sections. This, in turn, makes demands on design procedures and requires parallel development in calculation models and design codes. In particular, sections have tended to become more highly stiffened and this necessitates a more sophisticated treatment of local buckling, distortional buckling and the interactions between them. The latest trend is to move from simplified design models to design procedures based on "whole section" analysis. In this paper, recent developments in technology and application are outlined and this is followed by more detailed consideration of the related design procedures. (C) 2000 Elsevier Science Ltd. All rights reserved.