DNV-OS-J103: Design of Floating Wind Turbine Structures

1 OFFSHORE STANDARD. DNV-OS-J103. Design of Floating wind Turbine Structures JUNE 2013. The electronic pdf version of this document found through is the officially binding version DET NORSKE VERITAS AS. FOREWORD. DNV is a global provider of knowledge for managing risk. Today, safe and responsible business conduct is both a license to operate and a competitive advantage. Our core competence is to identify, assess, and advise on risk management. From our leading position in certification, classification, verification, and training, we develop and apply standards and best practices.

2 This helps our customers safely and responsibly improve their business performance. DNV is an independent organisation with dedicated risk professionals in more than 100 countries, with the purpose of safeguarding life, property and the environment. DNV service documents consist of among others the following types of documents: Service Specifications. Procedural requirements. Standards. Technical requirements. Recommended Practices. Guidance. The Standards and Recommended Practices are offered within the following areas: A) Qualification, Quality and Safety Methodology B) Materials Technology C) Structures D) Systems E) Special Facilities F) Pipelines and Risers G) Asset Operation H) Marine Operations J) Cleaner Energy O) Subsea Systems U) Unconventional Oil & Gas Det Norske Veritas AS June 2013.

3 Any comments may be sent by e-mail to This service document has been prepared based on available knowledge, technology and/or information at the time of issuance of this document, and is believed to reflect the best of contemporary technology. The use of this document by others than DNV is at the user's sole risk. DNV does not accept any liability or responsibility for loss or damages resulting from any use of this document. Offshore Standard DNV-OS-J103, June 2013. Changes Page 3. CHANGES CURRENT.

4 General This is a new document. Acknowledgments The development of this offshore standard was carried out under a Joint Industry Project supported by the following companies: Statoil ASA, Norway Nippon Steel & Sumitomo Metal Corporation, Japan Sasebo Heavy Industries Co., Ltd., Japan STX Offshore & Shipbuilding Co., Ltd., Korea Navantia, , Spain Gamesa, Spain Iberdrola Renovables Energ a , Spain Alstom wind , Spain The Glosten Associates, Inc., Principle Power Inc., This support is gratefully acknowledged.

5 DET NORSKE VERITAS AS. Offshore Standard DNV-OS-J103, June 2013. Contents Page 4. CONTENTS. SEC. 1 INTRODUCTION .. 10. 1 10. Objectives .. 10. Scope and application .. 11. Non-DNV codes .. 11. Equivalence and future developments .. 11. Hierarchy of DNV Offshore Publications .. 12. 2 12. 3 Verbal forms .. 14. Terms .. 14. 4 Acronyms, Abbreviations and Acronyms and abbreviations .. 16. Symbols .. 17. 5 Typical Floaters and Boundary Conditions ..19. 19. SEC. 2 SAFETY PHILOSOPHY AND Design PRINCIPLES.

6 21. 1 21. Application .. 21. 2 Safety Philosophy ..21. Safety class methodology .. 21. Target safety .. 22. Robustness .. 22. 3 Design Principles and Design Conditions ..22. Methods for structural Design .. 22. Aim of the 22. Design conditions .. 22. 4 Limit 23. 5 Design by the Partial Safety Factor Method ..23. 23. The partial safety factor format .. 24. Characteristic load effect .. 26. Characteristic resistance .. 26. Load and resistance 26. 6 Design Assisted by Testing ..26. 26. Model 26. Full-scale testing and observation of performance of existing Structures .

7 26. 7 Probability-Based Design ..27. 27. SEC. 3 ENVIRONMENTAL 28. 1 28. 2 wind , Waves and Current ..29. 29. wind .. 29. Waves .. 31. Current .. 32. 3 Water Depth and Water Water 32. Water 32. 4 Seismicity ..33. 33. 5 Soil Conditions ..33. 33. DET NORSKE VERITAS AS. Offshore Standard DNV-OS-J103, June 2013. Contents Page 5. 6 Regional Environmental Data for Definition of Environmental 34. 7 Other Site Conditions ..35. 35. 35. Marine growth .. 35. SEC. 4 LOADS AND LOAD EFFECTS .. 36. 1 36. Extreme loads.

8 36. Fatigue 36. Transportation loads .. 36. wind Turbine 36. Wake-induced 36. 2 Response 37. Deep-draught floaters (DDFs) .. 37. Semisubmersibles .. 37. Tension-leg platforms (TLPs).. 37. Monohull Structures .. 37. 3 Basis for Definition of Characteristic Loads ..38. Load categorization .. 38. Definition of characteristic 38. 4 Permanent Loads (G) ..40. 40. Floater-specific 40. 5 Variable Functional Loads (Q) ..40. 40. Ship impacts and collisions .. 40. 6 Environmental Loads (E) ..41. 41. Floater-specific 41.

9 Design load 42. Ice loads .. 42. Fatigue 42. 7 Accidental Loads (A) ..42. 42. 8 Deformation Loads (D)..43. 43. 9 Pressure Loads on Hull ..43. 43. Tank pressures .. 43. Sea pressures for the 45. Combination of tank pressures and sea 46. Superimposition of responses .. 46. Wave slamming .. 47. SEC. 5 LOAD FACTORS AND MATERIAL 48. 1 Load Load factors for the ULS and the ALS .. 48. Load factor for the FLS .. 48. Load factor for the SLS .. 49. 2 Material Material factors for the 49. Material factors for the FLS.

10 49. Material factors for the ALS and the SLS .. 49. SEC. 6 50. 1 50. 2 Selection of Metallic Materials ..50. 50. Structural steel and aluminium .. 50. Bolting 50. DET NORSKE VERITAS AS. Offshore Standard DNV-OS-J103, June 2013. Contents Page 6. 3 Selection of Concrete 50. 4 Selection of Grout Materials ..51. 51. 5 Selection of Composite Materials ..51. 51. 6 Selection of Materials for Chains, Wires and 51. Chains .. 51. Steel 51. Fibre ropes .. 51. 7 Selection of Materials for Electrical Cables.