Browse > Article
http://dx.doi.org/10.3744/SNAK.2010.47.3.447

A Study on the Design Sea-state Determination Using the IFOSM Method  

Lee, Jae-Ohk (Hyundai Maritime Research Institute, Hyundai Heavy Industries)
Rho, Jun-Bumn (Hyundai Maritime Research Institute, Hyundai Heavy Industries)
Publication Information
Journal of the Society of Naval Architects of Korea / v.47, no.3, 2010 , pp. 447-453 More about this Journal
Abstract
Response-based approach is getting more preferred in determining the design sea-state for offshore structures because traditional environment-based approach is known to yield a much conservative design condition. This paper introduces the inverse first-order second-moment (IFOSM) method as a response-based approach, which is expected to give a more feasible design condition at the cost of reasonable number of motion analyses. The IFOSM method is based on the theory of probability and adopts an optimization scheme to determine the design point. Both the design maximum response and design sea state can be obtained straightforwardly from the optimum. The IFOSM method has been applied to a turret-moored FPSO's design problem and showed its effectiveness in practical use.
Keywords
Design sea-state; Design return period; First-order second-moment method; Inverse FOSM method;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Hohenbichler, M. and Rackwitz, R., 1981,“Non-normal dependent vectors in structuralsafety,” Journal of the Engineering MechanicsDivision, Vol.107, No.EM6, pp.1227-1238.
2 Lee, J.O., 2001, Probabilistic structural optimizationbased on target performance approach,Ph.D. thesis, Seoul National University.
3 Lee, J.O., Yang, Y.S. and Ruy, W.S., 2002, “Acomparative study on reliability-index andtarget-performance-based probabilistic structuraldesign optimization,” Computers andStructures, Vol.80, No.3-4, pp.257-269.   DOI   ScienceOn
4 Prior-Jones, R.L., Bole, J.B., and O'Connor, P., 1983, "Environmental force studies for the Inde and Leman fields in the Southern North Sea," E&P Forum, Joint Probability Workshop.
5 Winterstein, S.R., Ude, T.C., Cornell, CA, Bjerager, P. and Haver, S., 1994, "Environmental parameters for extreme response: Inverse form with omission factors," Structural Safety & Reliability, Schueller, Shinozuka and Yao (eds), Balkema, Rotterdam.
6 Yang, Y.S., Suh, Y.S. and Lee, J.O., 1999, Structural reliability engineering, Seoul national university press, Seoul.
7 Hasofer, A.M. and Lind, L.C., 1974, “Exact andinvariant second moment code format,” Journalof the Engineering Mechanics Division, Vol.100,No.1, pp.111-121.
8 Det Norske Veritas, 2005, Sesam user manual,WADAM.