Advanced Steel Construction

Vol. 5, No. 4, pp. 481-499 (2009)




C.K. Lee *, S.P. Chiew, S.T. Lie, T. Sopha and T.B.N. Nguyen

School of Civil and Environmental Engineering, Nanyang Technological University

50, Nanyang Avenue, Singapore 639798

*(Corresponding author: E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.)

Received: 14 May 2008; Revised: 9 July 2008; Accepted: 29 July 2008




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This paper describes the testing results of two full-scale partially overlapped circular hollow section (CHS) K-joints. The two specimens were designed in such a way that partially overlapping is inevitable in order to eliminate the eccentricity of the resulted joints. Experimental studies were carried out by applying static loadings at the end of the through braces of the joints. The stress distributions of the partially overlapped CHS K-joints tested under the three basic loading cases (axial (AX), in-plane (IPB) and out-of-plane bending (OPB)) and their combinations were carefully recorded during the test. For each specimen, experimental study was carried out to investigate the stress concentration factor (SCF) and the hotspot stress (HSS) distributions along the brace-chord intersections. The experimental results obtained show that even for a simple combination of AX and IPB loading cases, the maximum HSS could be located either on the brace side or the chord side of the joints. The SCFs obtained from the experimental studies are compared with the SCF formulae suggested by Efthymiou and Durkin [1] and those from finite element analyses. It is observed that Efthymiou’s formulae may not be completely suitable for the design of partially overlapped CHS K-joints.



Partially overlapped circular hollow section K-joint, stress concentration factor, hot spot stress, fatigue assessments


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