Abstract
Coupled dynamic analyses of a deep-water Semi-submersible platform, in the South China Sea region, is carried out under postulated damage of the restraining system for both 10 and 100-years return period events. Under the combined action of wind, wave, and current loads, motion responses of Semi-submersible at 1500 and 2000 m water depths are analyzed in time-domain. Dynamic tension variations in the mooring lines are investigated for a fatigue failure using the S–N curve approach. Inclusion of a submerged buoy in the mooring system resulted in a marginal increase of the response due to a reduction in the restoration force of the mooring lines; submerged buoy also resulted in additional damping. The results of numerical studies showed an increase in tension in the mooring lines, which are adjacent to the damaged ones, causing reduced fatigue life. With the inclusion of submerged buoy in the mooring system, there is a considerable decrease in tension variation in mooring lines, increasing fatigue life. Failure of a mooring line causes an increase in tension of the adjacent mooring line, but not valid under all circumstances. It is seen from the studies that despite the postulated failure induced in a mooring, the adjoining line remains unaffected due to a steady coupling motion of the platform.
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References
Berthelsen, P. A., Baarholm, R., Stansberg, C. T., Hassan, A., Downie, M., & Incecik, A. (2009). Viscous drift forces and responses on a semi-submersible platform in high waves. In ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering (pp. 469–478). American Society of Mechanical Engineers Digital Collection.
Chandrasekaran, S. (2015). Dynamic analysis and design of ocean structures. Springer, India. ISBN: 978-81-322-2276-7.
Chandrasekaran, S., & Jain, A. K. (2016). Ocean structures, Construction, Materials, and Operations. CRC Press, Florida.ISBN: 978-149-87-9742-9
Chandrasekaran, S. (2017, a). Dynamic analysis and design of ocean structures. Springer, 2nd Edition, Singapore. ISBN: 978-81-322-2276-7.
Chandrasekaran, S., & Gaurav S (2017). Design aids for offshore structures under special environmental loads, including fire resistance. Springer, Singapore. ISBN: 978-981-322-10-7608-7
Chandrasekaran, S., & Nagavinothini, R. (2019). Offshore triceratops under impact forces in ultra-deep arctic waters. International Journal of Steel Structures. https://doi.org/10.1007/s13296-019-00297-1.
Chandrasekaran, S., & Uddin, S. A. (2020). Postulated failure analyses of a spread-moored semi-submersible. Innovative Infrastructures Solutions, 5(2), 1–16. https://doi.org/10.1007/s41062-020-0284-2.
Chen, P., Chai, S., Ma, J., (2011). Performance evaluations of taut-wire mooring systems for the deep-water Semi-submersible platform. In ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering, 207–2015, https://doi.org/10.1115/OMAE2011-49281
Clauss, G., Schmittner, C., & Stutz, K. (2002). Time-domain investigation of a semi-submersible in rogue waves. In ASME 2002 21st International Conference on Offshore Mechanics and Arctic Engineering (pp. 509–516). American Society of Mechanical Engineers Digital Collection, https://doi.org/10.1115/OMAE2002-28450
Dev, A. K., & Pinkster, J. A. (1995). Viscous mean drift forces on moored Semi-submersibles. In The Fifth International Offshore and Polar Engineering Conference. International Society of Offshore and Polar Engineers.
DNV-OS-E301, 2008. Position mooring, 33–34.
DNV-RP-C203, 2005. Fatigue design of offshore steel structures, 14–16.
DNV-RP-F205, 2010. Global Performance Analysis of Deepwater Floating Structures.
Garza-Rios, L. O., Bernitsas, M. M., Nishimoto, K., & Matsuura, J. O. P. J. (2000). Dynamics of spread mooring systems with hybrid mooring lines. Journal of Offshore Mechanics and Arctic Engineering, 122(4), 274–281. https://doi.org/10.1115/1.1315591.
Gottlieb, O., & Yim, S. C. (1992). Nonlinear oscillations, bifurcations, and chaos in a multi-point mooring system with a geometric nonlinearity. Applied Ocean Research, 14(4), 241–257. https://doi.org/10.1016/0141-1187(92)90029-J.
Hassan, A., Downie, M. J., Incecik, A., Baarholm, R., Berthelsen, P. A., Pakozdi, C., & Stansberg, C. T. (2009). Contribution of the mooring system to the low-frequency motions of a semi-submersible in combined wave and current. In ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering (pp. 55–62). American Society of Mechanical Engineers Digital Collection, https://doi.org/10.1115/OMAE2009-79074
Hussain, A., Nah, E., Fu, R., & Gupta, A. (2009). Motion comparison between a conventional deep draft Semi-submersible and a dry tree Semi-submersible. In ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering (pp. 785–792). American Society of Mechanical Engineers Digital Collection, https://doi.org/10.1115/OMAE2009-80006
Jang, B. S., Kim, J. D., Park, T. Y., & Jeon, S. B. (2019). FEA based optimization of Semi-submersible floater considering buckling and yield strength. International Journal of Naval Architecture and Ocean Engineering, 11(1), 82–96. https://doi.org/10.1016/j.ijnaoe.2018.02.010.
Kim, Y., Kim, K. H., Kim, J. H., Kim, T., Seo, M. G., & Kim, Y. (2011). Time-domain analysis of nonlinear motion responses and structural loads on ships and offshore structures: development of WISH programs. International Journal of Naval Architecture and Ocean Engineering, 3(1), 37–52. https://doi.org/10.2478/IJNAOE-2013-0044.
Lee, Y., Incecik, A., & Chan, H. S. (2005). Prediction of Global Loads and Structural Response Analysis on A Multi-Purpose Semi-submersible. In ASME 2005 24th International Conference on Offshore Mechanics and Arctic Engineering (pp. 3–13). American Society of Mechanical Engineers Digital Collection, https://doi.org/10.1115/OMAE2005-67003
Mao, H., & Yang, H. (2016). Parametric pitch instability investigation of Deep Draft Semi-submersible platform in irregular waves. International Journal of Naval Architecture and Ocean Engineering, 8(1), 13–21. https://doi.org/10.1016/j.ijnaoe.2015.09.001.
Mavrakos, S. A., Papazoglou, V. J., Triantafyllou, M. S., & Hatjigeorgiou, J. (1996). Deep-water mooring dynamics. Marine Structures, 9(2), 181–209. https://doi.org/10.1016/0951-8339(94)00019-O.
Mavrakos, S. A., & Chatjigeorgiou, J. (1997). Dynamic behavior of deep-water mooring lines with submerged buoys. Computers and Structures, 64(1–4), 819–835. https://doi.org/10.1016/S0045-7949(96)00169-1.
Odijie, A. C., Wang, F., & Ye, J. (2017). A review of floating semi-submersible hull systems: Column stabilized unit. Ocean Engineering, 144, 191–202. https://doi.org/10.1016/j.oceaneng.2017.08.020.
Ormberg, H., & Larsen, K. (1998). Coupled analysis of floater motion and mooring dynamics for a turret-moored ship. Applied Ocean Research, 20(1–2), 55–67. https://doi.org/10.1016/S0141-1187(98)00012-1.
Qiao, D., & Ou, J. (2013). Global responses analysis of a Semi-submersible platform with different mooring models in the South China Sea. Ships and Offshore Structures, 8(5), 441–456. https://doi.org/10.1080/17445302.2012.718971.
Stansberg, C. T. (2008). Current effects on a moored floating platform in a sea state. In ASME 2008 27th International Conference on Offshore Mechanics and Arctic Engineering. American Society of Mechanical Engineers Digital Collection. 433–444, https://doi.org/10.1115/OMAE2008-57621
Sunil, D. K., & Mukhopadhyay, M. (1995). Free vibration of semi-submersibles: A parametric study. Ocean Engineering, 22(5), 489–502. https://doi.org/10.1016/0029-8018(94)00012-V.
Umar, A., Ahmad, S., & Datta, T. K. (2004). Stability analysis of a moored vessel. Journal of Offshore Mechanics and Arctic Engineering, 126(2), 164–174. https://doi.org/10.1115/1.1710873.
Wang, K., Er, G. K., & Iu, V. P. (2018). Nonlinear vibrations of offshore floating structures moored by cables. Ocean Engineering, 156, 479–488. https://doi.org/10.1016/j.oceaneng.2018.03.023.
Xu, S., Ji, C. Y., & Soares, C. G. (2018). Experimental and numerical investigation a semi-submersible moored by hybrid mooring systems. Ocean Engineering, 163, 641–678. https://doi.org/10.1016/j.oceaneng.2018.05.006.
Xue, X., Chen, N. Z., Wu, Y., Xiong, Y., & Guo, Y. (2018). Mooring system fatigue analysis for a Semi-submersible. Ocean Engineering, 156, 550–563. https://doi.org/10.1016/j.oceaneng.2018.03.022.
Yan, J., Qiao, D., & Ou, J. (2018). Optimal design and hydrodynamic response analysis of deep-water mooring systems with submerged buoys. Ships and Offshore Structures, 13(5), 476–487. https://doi.org/10.1080/17445302.2018.1426282.
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Chandrasekaran, S., Uddin, S.A. & Wahab, M. Dynamic Analysis of Semi-submersible Under the Postulated Failure of Restraining System with Buoy. Int J Steel Struct 21, 118–131 (2021). https://doi.org/10.1007/s13296-020-00420-7
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DOI: https://doi.org/10.1007/s13296-020-00420-7