Dynamic response of jackettype offshore wind turbine foundation


CAI Jie fa1, ZHONG Shun cong1,2, ZHONG Jian feng1, FU Xi bin3

(1.Laboratory of Optics, Terahertz and Nondestructive Testing, School of Mechanical Engineering and Automation, 
Fuzhou University, Fuzhou 350108, China；2.Fujian Key Laboratory of Medical Instrument and Pharmaceutical 
Technology, Fuzhou 350000, China；3.Xiamen Special Equipment Inspection Institute, Xiamen 361000, China)


Abstract: In order to ensure the safety of wind turbine，aiming at the problem that jackettype offshore wind turbine foundation was easy to generate damage because of the harsh marine environment when it was in the process of service, a technique for monitoring the health status of jackettype offshore wind turbine foundation by single point measurement was proposed. Based on the linear Morison equation and random wave theory, the random wave load model was built. By using the Gumbel probability distribution, the wave height of the extreme wave load was predicted. A finite element model for the foundation of 5 MW offshore wind turbine was established. The dynamic responses of the damaged and intact offshore wind turbine foundation excited by the random wave load were computed. The first three order natural frequencies of the turbine foundation could be obtained by applying the fast fourier transform to the dynamic response data. The difference of natural frequencies of intact and damaged offshore wind turbine foundations were compared; also, the effects of damage on dynamic response was achieved. The results indicate that this method can analyze the health condition of the foundation and provides a feasible reference plan to monitor the health status of offshore wind turbine foundation.

Key words: offshore wind turbine foundation; random wave load; dynamic response; natural frequency