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Part  B  -  Certificates  and  approval  requirements

•  With  regard  to  certifying  the  fatigue  strength  of  reinforced  concrete  and  reinforced  concrete  components, ­
  refer  to  the  DASt  publication  439  „CEB-FIP  Model  Code  1990“  (Berlin  1994)  f151.
•  With  regard  to  the  structural  design  of  solid  structures,  refer  to  the  current  version  of  the  Offshore
Standard  DNV-OS-C502  „Offshore  concrete  structures“  £16].
•  With  regard  to  the  structural  design  of  grouted  joint  connections,  refer  to  the  DNV  publication  „Structural ­
  Design  of  Grouted  Connection  in  Offshore  Steel  Monopile  Foundations“  (Global  Windpower,
2004)  f  171  as  well  as  the  GL  Guideline  for  the  Certification  of  Offshore  Wind  Turbines  [6],  chapter
5.4.4  „Grouted  connections“.
•  With  regard  to  certificates  using  the  finite  element  method,  refer  to  the  GL  Guideline  for  the  Certification ­
  of  Offshore  Wind  Turbines  [6],  chapter  5.A  „Strength  Analysis  with  the  Finite  Element  Method“.

3.2.3.3  Required  certificates
•  Certificates  of  dynamic  properties:
Natural  frequencies  of  the  overall  system  comprising  turbine,  tower  and  substructure  including
the  foundation  elements
Testing  compliance  of  natural  frequencies  in  the  load  simulation  with  the  natural  frequencies
calculated  based  on  the  support  structure  data
Checking  of  vibration  amplitudes  and  vibration  speeds  as  well  as  accelerations  with  regard  to
the  functions  of  the  offshore  wind  turbine
•  Certificates  in  the  ultimate  limit  state  (ULS):
Strength  certificates
Stability  certificates
Certificates  of  force  applications  and  connections
•  Certificates  in  the  fatigue  limit  state  (FLS):
Certificate  against  fatigue  (operational  stability)
•  Certificates  in  the  serviceability  limit  state  (SLS):
Limitation  of  deformation
Limitation  of  concrete  compressive  stresses,  steel  stresses  and  decompression
Limitation  of  crack  widths
•  Certificates  of  durability:
Certificate  of  the  corrosion  protection  concept:
Cathodic  corrosion  protection  with  sacrificial  anodes  or  by  impressed-current  systems  and
coatings
•  Certificates  in  the  accidental  limit  state  (ALS)  if  such  are  provided.
•  Evaluation  of  hull-retaining  properties  of  the  support  structure:
Estimate  of  the  potential  damage  to  a  ship's  hull  on  collision  between  unmanoeuvrable  ships
and  support  structures  of  the  offshore  wind  turbine
Evaluation  of  the  positional  security  of  the  components  of  the  offshore  wind  turbine  (nacelle)
under  short-time  effect  of  collision  loads
•  Representation  of  the  noise  emissions  from  the  support  structure,  in  particular  the  substructure:
Noise  emissions  during  the  construction  phase  and
Noise  emissions  during  the  operation  phase
•  Representation  of  the  planned  inspection  of  the  support  structure  by  a  condition  inspection  system
(CMS)  for  at  least  1/10  of  the  offshore  wind  turbines