Static Strength of Axially Loaded Tubular K-Joints. I: Behavior
Publication: Journal of Structural Engineering
Volume 125, Issue 2
Abstract
This paper reports the results of an extensive finite-element study into the static behavior of axially loaded tubular K-joints. The emphasis of the study was on the effects of the geometric parameters and the overlap amount on the behavior of overlap joints. The results of some K-joints with small gaps were also included for comparative purposes. The study reveals new insight into how the behavior of axially loaded overlap K-joints varies across the practical range of geometric parameters. Certain overlap geometries were seen to be 100% efficient, with the joints reaching the brace member squash load capacity. Other failure modes of chord bending, brace local buckling, and in particular, combined chord bending and brace local buckling were evident. Examination of the load-deformation characteristics for the sharp falls in the postpeak load—reflecting sudden joint failures, which have been a suggested cause for concern in the past—has revealed that relatively few overlap geometries exhibit such behavior. The ultimate capacity results, and their significance in the light of available design guidance, are examined in a companion paper.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
ABAQUS users' manuals I and II . (1995). Hibbit, Karlsson, and Sorensen Inc., Pawtucket, R.I.
2.
API RP 2A: planning, designing and constructing fixed offshore platforms . (1993). 20th Ed., American Petroleum Institute, Washington, D.C.
3.
Bjornoy, O. H. ( 1993). “Static strength of tubular joints II: Analyses and tests of gap and overlap K-joints.” Veritec Rep. No. 91-3393, A. S. Veritec, Van Nuys, Calif.
4.
Bolt, H. M., Seyed-Kebari, H., and Ward, J. K. ( 1992). “The influence of chord length and boundary conditions on K joint capacity.” Proc., 2nd Int. Offshore and Polar Engrg. Conf., Vol. 4, International Society of Offshore and Polar Engineers, Golden, Colo., 347–354.
5.
“Capacity of overlapping K and YT joints.” (1993). Offshore Res. Focus No. 94, Health and Safety Executive, London.
6.
Connelly, L. M., and Zettlemoyer, N. ( 1989). “Frame behaviour effects on tubular joint capacity.” Proc., 3rd Int. Symp. on Tubular Struct., Lappeenranta, Finland, 81–89.
7.
Design guide for circular hollow section (CHS) joints under predominantly static loading . (1991). Comité International pour le Developpement et l'Étude de la Construction Tubulaire (CIDECT), Paris, France.
8.
Dexter, E. M. ( 1996). “Effects of overlap on behaviour and strength of steel circular hollow section joints,” PhD thesis, University of Wales, Swansea, U.K.
9.
Dexter E. M., and Lee, M. M. K. (1999). “Static strength of axially loaded tubular K-joints. II: Ultimate capacity.”J. Struct. Engrg., ASCE, 125(2), 202–210.
10.
Dexter E. M., Lee, M. M. K., and Kirkwood, M. G. ( 1994). “Effect of overlap on strength of K joints in CHS tubular members.” Proc., 6th Int. Symp. on Tubular Struct., Melbourne, Australia, 581–589.
11.
Dexter E. M., Lee, M. M. K., and Kirkwood, M. G. ( 1996). “Overlap K joints in circular hollow sections under axial loading (an investigation of the factors affecting static strength using numerical modelling).” J. Offshore Mech. and Arctic Engrg., 118, 53–61.
12.
Healy, B. E. ( 1994). “A numerical investigation into the capacity of overlap circular K-joints.” Proc., 6th Int. Symp. on Tubular Struct., Melbourne, Australia, 563–571.
13.
“Joint industry funded research programme: analytical and experimental investigation of the behaviour of tubular frames, phase II.” (1992). Vol. 1, BOMEL, Maidenhead, U.K.
14.
Kurobane, Y., Makino, Y., and Ochi, K. (1984). “Ultimate resistance of unstiffened tubular joints.”J. Struct. Engrg., ASCE, 110(2), 385–400.
15.
Kurobane, Y., Ogawa, K., Ochi, K., and Makino, Y. ( 1986). “Local buckling of braces in tubular K-joints.” Thin-Walled Struct., 23–40.
16.
Lalani, M. ( 1992). “Developments in tubular joints technology for offshore structures.” Proc., 2nd Int. Offshore and Polar Engrg. Conf., Vol. 4, International Society of Offshore and Polar Engineers, Golden, Colo., 260–274.
17.
Ochi, K., Makino, Y., and Kurobane, Y. ( 1984). “Basis for design of unstiffened tubular joints under axial brace loading.” IIW Annual Assembly, Doc. XV-561-84, International Institute of Welding, Cambridge, U.K.
18.
Offshore installations: guidance on design, construction and certification . (1990). 4th Ed., Health and Safety Executive, London.
19.
Tizani, W. M. K., Yusuf K. O., Davies, G., and Smith, N. J. ( 1996). “A knowledge based system to support joint fabrication decision making at the design stage—case studies for CHS trusses.” 7th Int. Symp. on Tubular Struct., Miskolc, Hungary, 483–489.
20.
van der Valk, C. A. C. ( 1991). “New aspects related to the ultimate strength of tubular K- and X-joints.” Proc., Offshore Mech. and Arctic Engrg. Conf., Vol. 3-B, Stavanger, Norway, 417–422.
21.
Yura, J. A., Zettlemoyer, N., and Edwards, I. F. ( 1980). “Ultimate capacity equations for tubular joints.” Offshore Technology Conf. 3690, Offshore Technology Conference, Houston, Tex.
22.
Zettlemoyer, N. ( 1988). “Developments in ultimate strength technology for simple tubular joints.” Proc., Offshore Tubular Joints Conf., Surrey, U.K.
Information & Authors
Information
Published In
History
Received: Aug 6, 1998
Published online: Feb 1, 1999
Published in print: Feb 1999
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.