Long-term performance of offshore wind turbines supported on monopiles and suction caissons

Domenico Lombardi, James A. Cox, Subhamoy Bhattacharya

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


Offshore wind turbines are relatively new technology with limited prior long-term performance experiencetherefore research is required to investigate the effect of the prolonged cyclic loading on the dynamic response of these verydynamic sensitive systems. This paper describes typical experimental results gained from a series of 1-g testing carried out on awind turbine scale model. Three different soil profiles are considered: dry sand, saturated sand and soft clay. The tests werecarried out on wind turbine model supported by two types of foundation, namely monopile and suction caisson. Theexperimental results show that the change in natural frequency of the model is strongly dependent on the soil conditions.Specifically in sandy soils (both dry and saturated) the frequency increases with number of cycles, possibly due to adensification of the soil next to the pile. However, tests with suction caisson show a more complex behavior. Contrastingly, testsperformed in soft clay show decreasing in natural frequency of the turbine with the cycles possibly due to a softening soilbehavior.
Original languageEnglish
Title of host publicationProceedings of the 8th international conference on structural dynamics
Subtitle of host publicationEURODYN 2011
Place of PublicationLeuven, Belgium
PublisherUniversity of Leuven
Number of pages5
ISBN (Print)9789076019314
Publication statusPublished - 2011
Event8th International Conference on Structural Dynamics - Leuven, Belgium
Duration: 4 Jun 20116 Jun 2011
Conference number: 116680


Conference8th International Conference on Structural Dynamics
Abbreviated titleEURODYN 2011


  • Offshore
  • Wind turbines
  • Cyclic loading
  • Physical modeling
  • Natural frequency
  • Suction caisson
  • Monopile


Dive into the research topics of 'Long-term performance of offshore wind turbines supported on monopiles and suction caissons'. Together they form a unique fingerprint.

Cite this