Table of Contents
Journal of Structures
Volume 2016, Article ID 4856059, 11 pages
Research Article

An Alternative Stiffening Method for Rigid CHS L-Joints

School of Civil and Structural Engineering, Dublin Institute of Technology, Bolton Street, Dublin 1, Ireland

Received 17 May 2016; Revised 8 June 2016; Accepted 12 June 2016

Academic Editor: Lucio Nobile

Copyright © 2016 Niall Holmes et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The paper presents a new method of stiffening CHS L-joints and compares it against current stiffened and unstiffened moment connections. The method is derived from studying the failure modes of existing methods, typically local buckling and ovalisation of the section. Unstiffened right-angled CHS connections have been shown to be weak due to local buckling and ovalisation. Stiffing plates placed across the joint can increase the moment capacity of the section by preventing ovalisation of the section but is architecturally unsightly. An alternative approach, where a stiffening plate welded vertically inside both the column and beam, outperformed the unstiffened frame plate in terms of reduced ovalisation and increased load capacity. It was also found to perform better than the stiffened connection in terms of both vertical and horizontal deflection. However, more research is required to ensure a fully restrained connection to satisfy codes of practice and constructible.