Strength of Flare-Bevel and Flare-Vee Welded Connections in G450 Sheet Steels (No. R806)

Abstract

This paper investigates the reliability of the existing design equations specified in AS/NZS 4600:1996 for flare-bevel and flare-vee welded connections in cold-reduced high-strength G450 sheet steels. The existing design equations are adapted from the AWS D1.3 Structural Welding Code, which is based on the testing results on flare-bevel welded connections only in mainly mild sheet steels. In the present work, flare-bevel and flare-vee welded connections in 1.5-mm and 3.0-mm sheet steels were fabricated using different GMAW procedures and tested to failure. All the transverse flare-bevel welded connections failed in the HAZs of the parent material. The longitudinal flare-bevel and flare-vee welded connections in 1.5-mm sheet steel also failed in the HAZs of the parent material, while those in 3.0-mm sheet steel failed in the weld metal. Nevertheless, it was found that the existing design rules may be applied conservatively to transverse and longitudinal flare-bevel welded connections in G450 sheet steels provided the weld quality is comparable to that produced in-house. On the other hand, it was found that the existing equations overestimate the capacity of flare-vee welded connections in G450 sheet steels. Ideally, flare-bevel and flare-vee welded connections in 3.0-mm G450 sheet steel are design in accordance with AS 4100. A survey of arc welded connections produced by industry fabricators suggested that the quality of in-house welded connections is unlikely to be matched in practice.