Safety Assessment of Damaged Multi-planar Square Hollow Section Welded Joints Using the New BS 910:2013+A1:2015
Advances in Applied Sciences
Volume 4, Issue 1, February 2019, Pages: 11-22
Received: Mar. 19, 2019;
Accepted: Apr. 26, 2019;
Published: May 17, 2019
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Seng Tjhen Lie, School of Civil and Environmental Engineering, Nanyang Technological University, Singapore
Vipin Sukumara-Pillai, School of Civil and Environmental Engineering, Nanyang Technological University, Singapore
The safety assessment procedure in the new BS 7910:2013+A1:2015 guide is based on the failure assessment diagram (FAD) method. This paper aims to validate the above procedure for complex geometries such as damaged multi-planar square hollow section (SHS) welded joints and to recommend optimal solutions if necessary. FAD curves are constructed for cracked multi-planar SHS TT-, YT- and KT-joints for the first time and are compared with the Option 1 curve of the BS guide. A robust novel automatic finite element (FE) mesh generator, which is validated using the full-scale experimental test results, is used in this study. The new FE mesh generator addresses the issue of non-convergence by using a key-hole for the modelling the crack tip in elastic-plastic analyses. The new FE mesh generator is capable to model cracks and geometries of arbitrary dimensions and is able to achieve convergence of solutions even at a high plastic deformation. It is shown to be aiding in speedy generation of cracked FE mesh models which is otherwise time consuming to generate using commercial software packages. The results show that the Option 1 curve does not always guarantee safe solutions for multi-planar SHS welded joints. Hence, a penalty factor of 1.1 is recommended to be used to calculate the plastic collapse load. The use of proposed penalty factor gives optimal solutions for cracked multi-planar SHS TT-, YT- and KT-joints.
Seng Tjhen Lie,
Safety Assessment of Damaged Multi-planar Square Hollow Section Welded Joints Using the New BS 910:2013+A1:2015, Advances in Applied Sciences.
Vol. 4, No. 1,
2019, pp. 11-22.
BS 7910:2013+A1:2015, “Guide to methods for assessing the acceptability of flaws in metallic structures”, British Standards Institution, London, 2015.
Burdekin, F. M. and Yang, G. J., “Failure assessment diagrams for mixed mode loading and cracked tubular joints”, Proceedings of 9th International Conference on Fracture, ICF9, Sydney, 1997, pp. 27-37.
Zerbst, U., Ainsworth, R. A. and Schwalbe, K. H., “Basic principles of analytical flaw assessment methods”, International Journal of Pressure Vessels and Piping, 2000, 77, pp. 855–867.
Milne, I., Ainsworth, R. A., Dowling, A. R. and Stewart, A. T., “Assessment of the integrity of structures containing defects”, International Journal of Pressure Vessels and Piping, 1988, 32, pp. 3–104.
Lo, S. H. and Lee, C. K., “Solving crack problems by an adaptive refinement procedure”, Engineering Fracture Mechanics, 1992, 43, pp. 147–163.
Vipin, S. P., “Safety and risk assessment of damaged multi-planar square hollow section (SHS) TT-, YT- and KT-joints”, Ph.D. thesis, Nanyang Technological University, Singapore, 2015.
API RP579, “Fitness-for-service”, American Petroleum Institute, Washington, 2007.
Packer, J. A., Wardenier, J., Zhao, X. L., van der Vegte, G. J. and Kurobane, Y., “Design guide for rectangular hollow section (RHS) joints under predominantly static loading”, 2nd ed. CIDECT 3, Geneva, 2009.
IIW, “Static design procedure for welded hollow section joints – recommendations”, International Institute of Welding, IIW Doc. XV-1329-09, IIW Doc. XV-E-09-400, 2005.
Lie, S. T., Vipin, S. P. and Li, T., “New reduction factor for cracked square hollow section T-joints under axial loading”, Journal of Constructional Steel Research, 2015, 112, pp. 221-227.
Lie, S. T., Vipin, S. P. and Li, T., “New weld toe magnification factors for semi-elliptical cracks in double-sided T-butt joints and cruciform X-joints”, International Journal of Fatigue, 2015, 80, pp. 178-191.
Lie, S. T., Li, T. and Shao, Y. B., “Stress intensity factors of tubular T/Y-joints subjected to three basic loading”, Advanced Steel Construction, 2016, 12(2), pp. 109-133.
Lie, S. T., Vipin, S. P. and Li, T., “New reduction factor for cracked square hollow section multi-planar TT-, YT- and KT-joints”, Engineering Structures, 2017, 139, pp. 108–119.
Vipin, S. P., Kolios, A., Lie, S. T. and Wang, L., “New reduction factor for cracked square hollow section K-joints”, Journal of Constructional Steel Research, 2018, 144, pp. 166-175.
Lie, S. T., Yang, Z. M. and Gho, W. M., “Validation of BS7910:2005 failure assessment diagram for cracked square hollow section T-, Y- and K-joints”, International Journal of Pressure Vessels and Piping, 2009, 86, pp. 335–344.
Stacey, A., Sharp, J. V. and Nichols, N. W., “The influence of cracks on the static strength of tubular joints”, Proceedings of 15th International Conference on Offshore Mechanics and Arctic Engineering, Florence, 1996, pp. 435–450.
ABAQUS, “Standard user’s manual”, Version 6.11, Hibbett, Karlsson & Sorensen, Inc., Rhode Island, 2011.
Aliabadi, M. H. and Rooke, D. P., “Numerical fracture mechanics”, Kluwer Academic Publishers, Dordrecht, 1991.
FEACrackTM, “User’s manual”, Version 3.2, Quest Integrity Group LLC., Seattle, 2010.
Stacey, A., Sharp, J. V. and Nichols, N. W., “Static strength assessment of cracked tubular joints”, Proceedings of 15th International Conference on Offshore Mechanics and Arctic Engineering, Florence, 1996, pp. 211–224.
Muscat, M., Mackenzie, D. and Hamilton, R., “A work criterion for plastic collapse”, International Journal of Pressure Vessels and Piping, 2003, 80, pp. 49–58.
ASME VIII Division 2, “Rules for construction of pressure vessels”, American Society of Mechanical Engineers, New York, 1998.