Background: The present paper regards the concerted action of wind and wave loads on offshore wind turbines in the extreme storm event. The load combination problem involves the definition of the characteristic loads and safety factors. In wind engineering and offshore engineering well established practices for the definition of characteristic values and safety factors for wind and wave loads separately exist. The aim is to investigate the possibility of making a simple merger of these existing practices into a possibly conservative design rule. Method of Approach: The paper applies a simplified probabilistic approach giving an understanding of how the merging can possibly be established and finally gives first guidance on the choice of characteristic values and safety factors. Results and conclusions: Under the assumptions made herein, it is made probable that a simple combination rule can be established.

“Petroleum and Natural Gas Industries—Fixed Steel Offshore Structures,” 2003, ISO/CD 19902, ISO Central Secretariat, Geneva.
“Component-Based Calibration of North West European Annex Environmental Load Factor to ISO Fixed Steel Offshore Structures Code 19902,” 2002, Bomel Ltd, Maidenhead, UK.
Tarp-Johansen, N. J., Madsen, P. H., and Frandsen S. T., 2004, “Partial Safety Factors for Extreme Load Effects in Wind Turbines,” Risø Report No. R-1319(EN), Risø National Laboratory, Roskilde.
Tarp-Johansen, N. J., Madsen, P. H., and Frandsen, S. T., 2003, “Calibration of Partial Safety Factors for Extreme Loads on Wind Turbines,” Proceedings CD-ROM of the European Wind Energy Conference and Exhibition 2003.
Sverre, H., Gran, T. M., and Sagil, G., 1998, “Long Term Response Analysis of Fixed and Floating Structures,” Report No. 98s97*4715, STATOIL, Norway.
“Actions and Action Effects, draft 2 for revision 2,” NORSOK standard N-003, 2004, Standards Norway, Lysaker, Norway,
Tarp-Johansen, N. J., 2004, “Storm Profiles for Wind Loads,” Note for IEC WG03, Risø National Laboratory, Roskilde, Denmark.
Tromans, P., 2000, “Extreme Environmental Load Statistics in UK Waters,” Offshore Technology Report No. 2000/066, Health and Safety Executive, UK, ISBN 0 7176 2061 1.
Ersdal G., Sørensen, J. D., and Langen, I., 2003, “Updating of structural failure probability based on experienced wave loading,” Paper No. JSC-386, Proceedings of the 13th International Offshore and Polar Engineering Conference and Exhibition, ISOPE 2003.
Ditlevsen, O., and Madsen, H. O., 1996, Structural Reliability Methods, Wiley, Chichester, Chap. 6.
You do not currently have access to this content.