Chapter 1 - Introduction

Abstract

This chapter provides an introduction on cold-formed tubular sections. Cold-formed structural members are being used more widely in routine structural design as the world steel industry moves from the production of hot-rolled section and plate to coil and strip, often with galvanized and painted coatings. Steel in this form is more easily delivered from the steel mill to the manufacturing plant where it is usually cold-rolled into open and closed section members. The usual process of manufacture is to form hot or cold-rolled steel strip to a circular shape, then to join the abutting edges by an electric resistance weld (ERW) or submerged arc weld before final forming to the design shapes, usually circular hollow sections (CHS), square hollow sections (SHS) or rectangular hollow sections (RHS). In some applications of tubular members, the sections are in-line galvanized with a subsequent enhancement of the tensile properties. Cold-formed tubular sections are widely used as structural members in steel construction, in the transportation industry, for agricultural equipment, for highway equipment, for mechanical members and for recreational structures. This chapter concludes the research performed to date on cold-formed tubular members and connections, but also provides design examples in accordance with both the Australian Standard AS 4100 and the British Standard BS 5950.