Developments in connections in cold-formed building structures and design specifications

For all building structures national and international Codes are important in the design process. This is also true for connections in cold-formed building structures. Lightweight construction has developed rapidly in this field, but the Codes, by their very nature are far slower in their development. For this reason a number of connection types are not fully covered, or not covered at all, by the existing Codes. Designers thus face a different situation with respect to connections than for usual steel buildings. This paper describes the relation between traditional connection systems and existing Codes. The ideal situation should be that the development of connection systems and their treatment in Codes (fastener and structural codes) should be well balanced for appropriate application in the building industry. But, because of the comparatively slow development of the Codes, new developments (clinching, air driven pins and adhesive bonding) require guidance on how to proceed in design. For selection of a connection system the important structural and non-structural parameters are surveyed. With the use of these parameters it should be possible to choose system, a fit for purpose i.e. a reliable (safe and durable) and economical system.