Project Description

Dr. Jeffrey A. Packer
Department of Civil Engineering, University of Toronto

Effective Weld Properties for Connections of Round HSS

Currently, the design of welds in round HSS-to-HSS connections is invariably performed using a design philosophy whereby welds are proportioned to develop the capacity of the connected branch member walls, which could lead to inefficient and costly connections.

The goal of this research project is to determine the effective lengths of fillet welds in round-to-round HSS T-, Y- and X-connections under branch axial loading. A set of fillet-welded, isolated connection tests – designed to be weld-critical – will be performed, with variations in the principal influential parameters: the weld size, the branch-to-chord width ratio (β), and the chord member wall slenderness (D/t). This experimental program will be highly indicative of many other truss-type connections, it will evaluate the utility of existing AWS D1.1 guidance, and it will enable calibration of the proposed fillet weld design procedure to currently expected safety index levels.

The long term objective of this research is to generate general design procedures for welds to round HSS chord (or “through”) members, based on actual branch forces (rather than member or connection capacity) and using specific effective lengths (or effective properties), in a similar manner to that done for welds to rectangular HSS.


Dr. Jeff Packer is a Bahen/Tanenbaum Professor of Civil Engineering at the University of Toronto. He graduated from the University of Adelaide, Australia, then subsequently received his Master’s degree from the University of Manchester (1975) and Ph.D. from the University of Nottingham (1978), in the U.K. Since his initial appointment at the University of Toronto in 1980 he has undertaken research, development and consulting work primarily on tubular steel structures. He has published extensively on this topic, including several co-authored CIDECT Design Guide books (published in four languages) and two Design Guides for the Canadian Institute of Steel Construction (CISC). He currently serves on technical committees for the American Welding Society (AWS D1), the American Institute of Steel Construction (AISC), the Comité International pour le Développement et l’Étude de la Construction Tubulaire (CIDECT), the American Society of Civil Engineers (ASCE), Canadian Standards Association (CSA) and the International Institute of Welding (IIW), where he is also on the Board of Directors. He is a licensed Professional Engineer, a Fellow of the American Society of Civil Engineers, a Fellow of the Institution of Civil Engineers (U.K.) and has served on the Editorial Boards of several journals. His recent awards include: Kurobane Lecture Award (ISTS, 2003), American Institute of Steel Construction Special Achievement Award (2005), Houdremont Award (International Institute of Welding, 2006), and a Doctor of Science degree from the University of Nottingham (2006)

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