The Continuum of Connection Rigidity in Timber Structures
Keywords:
Frames, semi-rigid connections, deformed shapes, timber, rigid connections, pinned connections, computer modelingAbstract
The use of timber in rigid frames has been hampered by the debate surrounding the rigidity of the moment connections. Joint stiffness is a function of beam flexural stiffness, as well as of the rotational stiffness of the connection. The level of joint rigidity, which is predictable from joint stiffness, significantly affects the bending moments and forces that are transferred through the connection. We used joint-test data from the literature and computer models to assess the effect of various parameters on joint stiffness. There is a continuum of joint stiffness for moment-resisting connections where the deformed shapes of the beams in beam-to-column connections are described by pinned, semi-rigid, and rigid behavior. Engineers can assess the level of joint rigidity during the design process so that the resulting connections and frames meet performance expectations. It seems unlikely that a fully rigid joint can be designed for use in timber portal frames because of stiffness orthotropy. However, moment-resisting joints that are less than 50% rigid can be used in timber frames to develop frame-like behavior.References
Batchelar, M. L., and R. D. Hunt. 1991. Composite plywood and steel gusset plates for moment resisting joints in timber frames. Pages 3.104-3.109 in Proc. 1991 International Timber Engineering Conference, vol. 3. Timber Research and Development Association, High Wycombe, UK.nCheng, J. J. R. 1996. Moment resisting glulam rivet joints. Pages 2.161-2.168 in Proc. International Wood Engineering Conference '96, vol. 2. 1996 International Wood Engineering Conference, New Orleans, LA.nCost (European Cooperation In The Field of Scientific and Technical Research). 1998. The COST/cl Action: Control of semi-rigid behavior of civil engineering connections http://www.vtt.fi/rtc7/costc1.html'>http://www.vtt.fi/rtc7/costc1.htmlnDhillon, B. S., and J. W. O'Malley, III. 1999. Interactive design of semirigid steel frames. J. Struct. Eng. 125(5):556-564.nHyde, R. A. 1996. Innovative timber construction: A study of portal frame prototype development for housing. Limited distribution report, Department of Architecture, The University of Queensland, Brisbane, Australia.nInayami, M., and I. Sakamoto. 1989. Development research of new wooden rigid frame structure. Pages 19-23 in Proc. Second Pacific Timber Engineering Conference 1989, vol. 2. University of Auckland, Auckland, NZ.nKikuchi, S. 1991. Stresses and deformations of timber frames with semi-rigid joints. Pages 2.383-2.390 in Proc. 1991 International Timber Engineering Conference. Timber Research and Development Association, High Wycombe, UK.nKomatsu, K. 1989. Performance of timber moment-resisting joints. Pages 25-30 in Proc. Second Pacific Timber Engineering Conference, 1989, vol. 2. University of Auckland, Auckland, NZ.nKomatsu, K., N. Kawamoto, K. Horie, and M. Harada. 1991. Modified glulam moment-resisting joints. Pages 3.111-3.118 in Proc. 1991 International Timber Engineering Conference, vol. 3. Timber Research and Development Association, High Wycombe, UK.nLeichti, R. J. 1998. Structural analysis of rigid timber ladders and towers for commercial-scale architecture. Limited distribution report, Department of Architecture, The University of Queensland, Brisbane, Australia.nMalhotra, S. K., and Y. Jin. 1989. Behavior of mortise and tenon joints used in traditional Chinese timber frame construction. Pages 31-36 in Proc. Second Pacific Timber Engineering Conference 1989, vol. 2. University of Auckland, Auckland, NZ.nMcGuire, J. 1995. Notes on semi-rigid connections. Goddard Space Flight Center, NASA. Greenbelt, MD. 7 pp.n
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