An energy-based method is presented for the prediction of the elastic-plastic force-displacement and/or moment-rotation responses of tubular joints for arbitrary radial loading paths under the action of up to four combined forces and moments. The method is based on the results of a sample of load paths obtained from computational models or measured from experimental tests. The work is important in the context of the elastic-plastic behaviour of structures in general and in particular as a basis for the development of single elastic-plastic tubular joint elements. The method employs normality of the generalized displacement vector to level hypersurfaces of total (elastic-plastic) complementary work.
BanonH.BeaR. G.BruenF. J.CornellC. A.KriegerW. F.StewartD. A.Assessing the fitness for purpose of offshore platforms. I: Analytical methods and inspectionsJ. Struct. Engng, Am. Soc. Civ. Engrs, 1994, 120 (12), 3595–3612.
2.
BeaR. G.Nonlinear performance of offshore platforms in extreme storm wavesJ. Waterway, Port, Coastal and Ocean Engng, Am. Soc. Civ. Engrs, 1996, 122 (2), 68–74.
3.
BroughtonP.SilvaL.Design of the Judy steel piled jacket structureProc. Instn Civil Engrs Structs Buildings, February 1996, 116, 1–18.
4.
LalaniM.Post-yield and post-peak behaviour of tubular joints in offshore structures. In Proceedings of Fifth Interna tional Symposium onTubular Structures, Nottingham, 1993, pp. 446–454.
5.
BillingtonC. J.BoltH. M.WardJ. K.Reserve, residual and ultimate strength analysis of offshore structures: state of the art review. In Proceedings of the Third Interna tional Offshore and Polar Engineering Conference, Singapore, 6–11 June 1993, pp. 125–133.
6.
FesslerH.MockfordB. H.WebsterJ. J.Parametric equations for the flexibility matrices of multi-brace tubular joints in offshore structuresProc. Instn Civ. Engrs, December 1986, 81 (2), 675–696.
7.
SouissiR.Flexibility of tubular joints. In Proceedings of the Third International Symposium onTubular Structures (Eds NiemiE.MäkeläinenP.), Lappeenranta, Finland, 1989, 1990, pp. 137–146 (Elsevier Applied Science, London).
8.
ChenB.HuY.Local flexibility of tubular joints of offshore platforms In Fatigue in Offshore Structures (Eds DoverW. D.Madhava RaoA. G.), Vol. 1, 1996, pp. 155–193 (Oxford and IBH Publishing, New Delhi).
9.
BouwkampJ. G.HollingsJ. P.MalsonB. F.RowD. G.The effects of joint flexibility on the response of offshore towers. In Proceedings of the Offshore Technology Conference, OTC 3901, 1980.
10.
Underwater Engineering Group Node Flexibility and Its Effect on Jacket Structures—A Pilot Study on Two-dimensional Frames, 1984 (UEG Publishing, UR22, London).
11.
UedaY.RashedS. M.H.NakachoK.An improved joint model and equations for flexibility of tubular jointsTrans. ASME- OMAE, J. Offshore Mechanics Arctic Engng, May 1990, 112, 157–168.
12.
HydeT. H.LeenS. B.Prediction of elastic-plastic displacements of tubular joints under combined loading using an energy-based approachJ. Strain Analysis, 1997, 32 (6), 435–454.
13.
HydeT. H.LeenS. B.Elastic-plastic moment-rotation characterisation of tubular YT-joint using an energy method for response prediction. In Proceedings of the Eighth International Offshore and Polar Engineering Conference, Montreal, Canada, 24–29 May 1998, Vol. IV, pp. 56–63.
14.
LeenS. B.HydeT. H.Prediction of elastic-plastic generalised force-displacement responses of tubular joints for three different loading modesJ. IASS, April 1999, 40 (1), 43–55.
15.
HydeT. H.OuH.LeenS. B.Experimental and finite element investigations on the static strength of a plane tubular framework structure. In Proceedings of the Ninth International Offshore and Polar Engineering Conference, Brest, France, May 1999, Vol. IV, pp. 63–70.
FesslerH.HassellW.A model technique for static strength of tubular jointsSteel Construction Today, 1990, 4, 104–112.
18.
FesslerH.HassellW.HydeT. H.A model technique for bending strength of tubular jointsJ. Strain Analysis, 1992, 27 (4), 197–210.
19.
ABAQUS User's and Theory Manuals, Version 5.5, 1995 (Hibbit, Karlsson and Sorensen, Pawtucket, Rhode Island).
20.
CrisfieldM. A.Non-linear Finite Element Analysis of Solids and Structures, 1991 (John Wiley, Chichester, West Sussex).
21.
LeenS. B.HydeT. H.An experimental and finite element study on the non-linear force—displacement charac teristics of tubular YT-joints under combined axial loadingJ. Strain Analysis, May 1999, 34 (3), 183–207.
22.
LeenS. B.Elastic-plastic generalised load-displacement prediction for tubular joints. PhD thesis, University of Nottingham, May 1999.
23.
ConnellyL. M.ZettlemoyerN.Frame behaviour effects on tubular joint capacity. In Proceedings of the Third International Symposium onTubular Structures (Eds NiemiE.MäkeläinenP.), Lappeenranta, Finland, 1989, 1990, pp. 81–89 (Elsevier Applied Science, London).
