Write your message


Volume 5 - Winter and Spring 2016                   ijmt 2016, 5 - Winter and Spring 2016: 27-35 | Back to browse issues page

XML Print


Download citation:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:

Ahmadi H, Ziaei Nejad A. Stress Concentration Factors in Uniplanar Tubular KT-Joints of Jacket Structures Subjected to In-Plane Bending Loads. ijmt 2016; 5 :27-35
URL: http://ijmt.ir/article-1-461-en.html
1- University of Tabriz
Abstract:   (9808 Views)

In the present research, data extracted from the stress analysis of 46 finite element models, verified using test results obtained from an experimental investigation, were used to study the effect of geometrical parameters on the chord-side stress concentration factors (SCFs) of central and outer braces in uniplanar tubular KT-joints of offshore structures subjected to four different types of in-plane bending (IPB) loads. Parametric study was followed by a set of the nonlinear regression analyses to develop SCF parametric equations for the fatigue analysis and design of uniplanar tubular KT-joints under IPB loadings.

Full-Text [PDF 1137 kb]   (5451 Downloads)    
Type of Study: Research Paper | Subject: Offshore Structure
Received: 2016/01/10 | Accepted: 2016/03/15

References
1. Kuang, J.G., Potvin, A.B. and Leick, R.D., (1975), Stress concentration in tubular joints, Proceedings of the Offshore Technology Conference, Paper OTC 2205, Houston (TX), US.
2. Wordsworth, A.C. and Smedley, G.P., (1978), Stress concentrations at unstiffened tubular joints, Proceedings of the European Offshore Steels Research Seminar, Paper 31, Cambridge, UK.
3. Wordsworth, A.C., (1981), Stress concentration factors at K and KT tubular joint, Proceedings of the Conference on Fatigue of Offshore Structural Steels, p. 59-69.
4. Efthymiou, M. and Durkin, S., (1985), Stress concentrations in T/Y and gap/overlap K-joints, Proceedings of the Conference on Behavior of Offshore Structures, Delft, the Netherlands, p. 429-440.
5. Efthymiou, M., (1988), Development of SCF formulae and generalized influence functions for use in fatigue analysis, OTJ 88, Surrey, UK.
6. Hellier, A.K., Connolly, M. and Dover, W.D., (1990), Stress concentration factors for tubular Y and T-joints. International Journal of Fatigue, Vol. 12, p. 13-23.
7. Smedley, P. and Fisher, P., (1991), Stress concentration factors for simple tubular joints, Proceedings of the International Offshore and Polar Engineering Conference (ISOPE), Edinburgh, p. 475-483.
8. UK Health and Safety Executive, (1997), OTH 354: stress concentration factors for simple tubular joints-assessment of existing and development of new parametric formulae, Prepared by Lloyd’s Register of Shipping, UK.
9. Karamanos, S.A., Romeijn, A., Wardenier, J., (2000), Stress concentrations in tubular gap K-joints: mechanics and fatigue design, Engineering Structures, Vol. 22, p. 4-14.
10. Gho, W.M. and Gao, F., (2004), Parametric equations for stress concentration factors in completely overlapped tubular K(N)-joints, Journal of Constructional Steel Research, Vol. 60, p. 1761-1782.
11. Gao, F., (2006), Stress and strain concentrations of completely overlapped tubular joints under lap brace OPB load. Thin-Walled Structures, Vol. 44, p. 861-871.
12. Gao, F., Shao, Y.B. and Gho, W.M., (2007), Stress and strain concentration factors of completely overlapped tubular joints under lap brace IPB load. Journal of Constructional Steel Research, Vol. 63, p. 305-316.
13. Morgan, M.R. and Lee, M.M.K., (1998), Parametric equations for distributions of stress concentration factors in tubular K-joints under out-of-plane moment loading, International Journal of Fatigue, Vol. 20, p. 449-461.
14. Morgan, M.R. and Lee, M.M.K., (1998), Prediction of stress concentrations and degrees of bending in axially loaded tubular K-joints, Journal of Constructional Steel Research, Vol. 45, pp. 67-97.
15. Chang, E. and Dover, W.D., (1999), Prediction of stress distributions along the intersection of tubular Y and T-joints, International Journal of Fatigue, Vol. 21, p. 361-381.
16. Chang, E. and Dover, W.D., (1999), Parametric equations to predict stress distributions along the intersection of tubular X and DT-joints, International Journal of Fatigue, Vol. 21, p. 619-635.
17. Shao, Y.B., (2004), Proposed equations of stress concentration factor (SCF) for gap tubular K-joints subjected to bending load, International Journal of Space Structures, Vol. 19, 137-147.
18. Shao, Y.B., (2007), Geometrical effect on the stress distribution along weld toe for tubular T- and K-joints under axial loading, Journal of Constructional Steel Research, Vol. 63, p. 1351-1360.
19. Shao, Y.B., Du, Z.F. and Lie, S.T., (2009), Prediction of hot spot stress distribution for tubular K-joints under basic loadings, Journal of Constructional Steel Research, Vol. 65, p. 2011-2026.
20. Lotfollahi-Yaghin, M.A. and Ahmadi, H., (2010), Effect of geometrical parameters on SCF distribution along the weld toe of tubular KT-joints under balanced axial loads, International Journal of Fatigue, Vol. 32, p. 703-719.
21. Ahmadi, H., Lotfollahi-Yaghin, M.A. and Aminfar, M.H., (2011), Geometrical effect on SCF distribution in uni-planar tubular DKT-joints under axial loads, Journal of Constructional Steel Research, Vol. 67, 1282-1291.
22. Karamanos, S.A. Romeijn, A. and Wardenier, J., (1999), Stress concentrations in multi-planar welded CHS XX-connections, Journal of Constructional Steel Research, Vol. 50, p. 259-282.
23. Chiew, S.P., Soh, C.K. and Wu, N.W., (2000), General SCF design equations for steel multiplanar tubular XX-joints, International Journal of Fatigue, Vol. 22, p. 283-293.
24. Wingerde, A.M., Packer, J.A. and Wardenier, J., (2001), Simplified SCF formulae and graphs for CHS and RHS K- and KK-connections. Journal of Constructional Steel Research, Vol. 57, 221-252.
25. Karamanos, S.A., Romeijn, A. and Wardenier, J., (2002), SCF equations in multi-planar welded tubular DT-joints including bending effects, Marine Structures, Vol. 15, p. 157-173.
26. Lotfollahi-Yaghin, M.A. and Ahmadi, H., (2011), Geometric stress distribution along the weld toe of the outer brace in two-planar tubular DKT-joints: parametric study and deriving the SCF design equations, Marine Structures, Vol. 24, p. 239-260.
27. Ahmadi, H., Lotfollahi-Yaghin, M.A. and Aminfar, M.H., (2011), Distribution of weld toe stress concentration factors on the central brace in two-planar CHS DKT-connections of steel offshore structures, Thin-Walled Structures, Vol. 49, p. 1225-1236.
28. Ahmadi, H., Lotfollahi-Yaghin, M.A. and Aminfar, M.H., (2012), The development of fatigue design formulas for the outer brace SCFs in offshore three-planar tubular KT-joints, Thin-Walled Structures, Vol. 58, p. 67-78.
29. Ahmadi, H., Lotfollahi-Yaghin, M.A., (2012), Geometrically parametric study of central brace SCFs in offshore three-planar tubular KT-joints, Journal of Constructional Steel Research, Vol. 71, p. 149-161.
30. Dharmavasan, S. and Aaghaakouchak, A.A., (1988), Stress concentrations in tubular joints stiffened by internal ring stiffeners, Proceedings of the Seventh International Conference on Offshore Mechanics and Arctic Engineering, Houston (TX), US, p. 141-148.
31. Aaghaakouchak, A.A. and Dharmavasan, S., (1990), Stress analysis of unstiffened and stiffened tubular joints using improved finite element model of intersection, Proceedings of the Ninth International Conference on Offshore Mechanics and Arctic Engineering, Vol. III, Part A, Houston (TX), US, p. 321-328.
32. Ramachandra Murthy, D.S., Madhava Rao, A.G., Ghandi, P. and Pant, P.K. (1992), Structural efficiency of internally ring stiffened steel tubular joints, Journal of Structural Engineering, Vol. 118, 3016-3035.
33. Nwosu, D.I., Swamidas, A.S.J. and Munaswamy, K., (1995), Numerical stress analysis of internal ring-stiffened tubular T-joints, Journal of Offshore Mechanics and Arctic Engineering, Vol. 117, p. 113-125.
34. Ramachandra, D.S., Gandhi, P., Raghava, G. and Madhava Rao, A.G., (2000), Fatigue crack growth in stiffened steel tubular joints in seawater environment, Engineering Structures, Vol. 22, p. 1390-1401.
35. Hoon, K.H., Wong, L.K. and Soh, A.K. (2001), Experimental investigation of a doubler-plate reinforced tubular T-joint subjected to combined loadings, Journal of Constructional Steel Research, Vol. 57, p. 1015-1039.
36. Myers, P.T., Brennan, F.P. and Dover, W.D., (2001), The effect of rack/rib plate on the stress concentration factors in jack-up chords, Marine Structures, Vol. 14, p. 485-505.
37. Woghiren, C.O. and Brennan, F.P., (2009), Weld toe stress concentrations in multi planar stiffened tubular KK Joints, International Journal of Fatigue, Vol. 31, p. 164-172.
38. Ahmadi, H., Lotfollahi-Yaghin, M.A., Shao, Y.B. and Aminfar, M.H., (2012), Parametric study and formulation of outer-brace geometric stress concentration factors in internally ring-stiffened tubular KT-joints of offshore structures, Applied Ocean Research, Vol. 38, p. 74-91.
39. Ahmadi, H., Lotfollahi-Yaghin, M.A. and Shao, Y.B., (2013), Chord-side SCF distribution of central brace in internally ring-stiffened tubular KT-joints: A geometrically parametric study, Thin-Walled Structures, Vol. 70, 93-105.
40. Ahmadi, H. and Lotfollahi-Yaghin, M.A., (2015), Stress concentration due to in-plane bending (IPB) loads in ring-stiffened tubular KT-joints of offshore structures: Parametric study and design formulation, Applied Ocean Research, Vol. 51, p. 54-66.
41. Ahmadi, H. and Zavvar, E., (2015), Stress concentration factors induced by out-of-plane bending loads in ring-stiffened tubular KT-joints of jacket structures, Thin-Walled Structures, Vol. 91, p. 82-95.
42. Ahmadi, H., Lotfollahi-Yaghin, M.A. and Aminfar, M.H., (2011), Effect of stress concentration factors on the structural integrity assessment of multi-planar offshore tubular DKT-joints based on the fracture mechanics fatigue reliability approach, Ocean Engineering, Vol. 38, p. 1883-1893.
43. Ahmadi, H. and Lotfollahi-Yaghin, M.A., (2012), A probability distribution model for stress concentration factors in multi-planar tubular DKT-joints of steel offshore structures, Applied Ocean Research, Vol. 34, 21-32.
44. Ahmadi, H. and Lotfollahi-Yaghin, M.A., (2013), Effect of SCFs on S–N based fatigue reliability of multi-planar tubular DKT-joints of offshore jacket-type structures, Ships and Offshore Structures, Vol. 8, p. 55-72.
45. Dallyn, P., El-Hamalawi, A., Palmeri, A. and Knight, R., (2015), Experimental testing of grouted connections for offshore substructures: A critical review, Structures, Vol. 3, p. 90-108.
46. Ahmadi, H., Mohammadi, A.H. and Yeganeh, A., (2015), Probability density functions of SCFs in internally ring-stiffened tubular KT-joints of offshore structures subjected to axial load, Thin-Walled Structures, 2015, Vol. 94, p. 485-499.
47. Ahmadi, H., Mohammadi, A.H., Yeganeh, A. and Zavvar, E., (2016), Probabilistic analysis of stress concentration factors in tubular KT-joints reinforced with internal ring stiffeners under in-plane bending loads, Thin-Walled Structures, Vol. 99, p. 58-75.
48. UK Department of Energy, (1983), Background notes to the fatigue guidance of offshore tubular joints, London, UK.
49. American Welding Society (AWS), (2002), Structural welding code: AWS D 1.1, Miami (FL), US.
50. N’Diaye, A., Hariri, S., Pluvinage, G. and Azari, Z., (2007), Stress concentration factor analysis for notched welded tubular T-joints, International Journal of Fatigue, Vol. 29, p. 1554-1570.
51. IIW-XV-E, (1999), Recommended fatigue design procedure for welded hollow section joints, IIW Docs, XV-1035-99/XIII-1804-99, International Institute of Welding, France.
52. Bomel Consulting Engineers, (1994), Assessment of SCF equations using Shell/KSEPL finite element data, C5970R02.01 REV C.

Send email to the article author


Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

Creative Commons License
International Journal of Maritime Technology is licensed under a

Creative Commons Attribution-NonCommercial 4.0 International License.