Application of Lagrange's equation of motion to estimate natural frequencies of monopile foundations

Feng Chien Su, Chih Yin Chung, Sheng Yan Chiu, Ming Ju Wu, Yu Shu Kuo

Research output: Contribution to conferencePaper

Abstract

Determination of natural frequencies is essential to design offshore wind turbine foundations and is relevant to the stability of supporting structure. When the natural frequencies offshore wind turbine foundations are close to the external loading frequencies, excess deformations may occur due to resonance and lead to collapse of supporting structures. The natural frequencies of supporting structure change with foundation geometries, soil properties and structure stiffness. In the existing offshore wind farm in Europe, in most cases monopile foundations have been built as support structures for the wind turbine. To evaluate the natural frequencies and vibration responses of monopile foundation in the preliminary design of offshore wind turbine, a simplified method considered the pile-soil stiffness and deformation responses of supporting structure is presented in this study. The kinetic and strain energies of a structure system are applied to Lagrange's equation of motion to determine the natural frequency of monopile foundation. The natural frequencies of monopile foundation installed in soil with different properties can be determined quickly.

Original languageEnglish
Pages671-679
Number of pages9
Publication statusPublished - 2012 Jan 1
Event6th Chinese-German Joint Symposium on Hydraulic and Ocean Engineering, CGJOINT 2012 - Keelung, Taiwan
Duration: 2012 Sep 232012 Sep 29

Other

Other6th Chinese-German Joint Symposium on Hydraulic and Ocean Engineering, CGJOINT 2012
CountryTaiwan
CityKeelung
Period12-09-2312-09-29

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All Science Journal Classification (ASJC) codes

  • Ocean Engineering
  • Water Science and Technology

Cite this

Su, F. C., Chung, C. Y., Chiu, S. Y., Wu, M. J., & Kuo, Y. S. (2012). Application of Lagrange's equation of motion to estimate natural frequencies of monopile foundations. 671-679. Paper presented at 6th Chinese-German Joint Symposium on Hydraulic and Ocean Engineering, CGJOINT 2012, Keelung, Taiwan.