Fragility reduction of offshore wind turbines using tuned liquid column dampers

Arash Hemti, Erkan Oterkus, Nigel Barltrop

Research output: Contribution to journal › Article

Abstract

High flexibility of offshore wind turbines (OWTs) makes them vulnerable to excessive vibrations. This paper studies vibration control of offshore wind turbines induced by multi-hazard excitations. A model consisting of entire offshore wind turbine foundation and tower controlled by tuned liquid column dampers(TLCD) considering nonlinear soil pile interaction is established. The model is subjected to wave, wind, and seismic loading. The effect of severity of earthquake on the performance of the structural control device is investigated. A fragility analysis based on acceleration capacity thresholds is performed to estimate reliability improvement using the structural control devices. The fitted fragility functions based on multiple stripes analysis are constructed and compared with the empirical cumulative distribution curves. The results suggest that the use of an optimal TLCD with a mass ratio of 2.5% reduces the fragility of the system by as much as 6% and 12% for operational and parked conditions, respectively.
LanguageEnglish
JournalSoil Dynamics and Earthquake Engineering
Publication statusAccepted/In press - 28 May 2019

Fingerprint

Offshore wind turbines
wind turbine
structural control
vibration
liquid
liquids
Liquids
cumulative distribution
wind wave
Vibration control
earthquakes
seismic wave
Towers
Vibrations (mechanical)
Piles
Earthquakes
Hazards
pile
hazard
Soils

Keywords

  • offshore wind turbine
  • fragility analysis
  • vibration control
  • tuned liquid column damper

Cite this

Hemti, Arash ; Oterkus, Erkan ; Barltrop, Nigel. / Fragility reduction of offshore wind turbines using tuned liquid column dampers. In: Soil Dynamics and Earthquake Engineering. 2019.
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abstract = "High flexibility of offshore wind turbines (OWTs) makes them vulnerable to excessive vibrations. This paper studies vibration control of offshore wind turbines induced by multi-hazard excitations. A model consisting of entire offshore wind turbine foundation and tower controlled by tuned liquid column dampers(TLCD) considering nonlinear soil pile interaction is established. The model is subjected to wave, wind, and seismic loading. The effect of severity of earthquake on the performance of the structural control device is investigated. A fragility analysis based on acceleration capacity thresholds is performed to estimate reliability improvement using the structural control devices. The fitted fragility functions based on multiple stripes analysis are constructed and compared with the empirical cumulative distribution curves. The results suggest that the use of an optimal TLCD with a mass ratio of 2.5{\%} reduces the fragility of the system by as much as 6{\%} and 12{\%} for operational and parked conditions, respectively.",
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Hemti, A, Oterkus, E & Barltrop, N 2019, 'Fragility reduction of offshore wind turbines using tuned liquid column dampers' Soil Dynamics and Earthquake Engineering.

Fragility reduction of offshore wind turbines using tuned liquid column dampers. / Hemti, Arash; Oterkus, Erkan; Barltrop, Nigel.

In: Soil Dynamics and Earthquake Engineering, 28.05.2019.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Fragility reduction of offshore wind turbines using tuned liquid column dampers

AU - Hemti, Arash

AU - Oterkus, Erkan

AU - Barltrop, Nigel

PY - 2019/5/28

Y1 - 2019/5/28

N2 - High flexibility of offshore wind turbines (OWTs) makes them vulnerable to excessive vibrations. This paper studies vibration control of offshore wind turbines induced by multi-hazard excitations. A model consisting of entire offshore wind turbine foundation and tower controlled by tuned liquid column dampers(TLCD) considering nonlinear soil pile interaction is established. The model is subjected to wave, wind, and seismic loading. The effect of severity of earthquake on the performance of the structural control device is investigated. A fragility analysis based on acceleration capacity thresholds is performed to estimate reliability improvement using the structural control devices. The fitted fragility functions based on multiple stripes analysis are constructed and compared with the empirical cumulative distribution curves. The results suggest that the use of an optimal TLCD with a mass ratio of 2.5% reduces the fragility of the system by as much as 6% and 12% for operational and parked conditions, respectively.

AB - High flexibility of offshore wind turbines (OWTs) makes them vulnerable to excessive vibrations. This paper studies vibration control of offshore wind turbines induced by multi-hazard excitations. A model consisting of entire offshore wind turbine foundation and tower controlled by tuned liquid column dampers(TLCD) considering nonlinear soil pile interaction is established. The model is subjected to wave, wind, and seismic loading. The effect of severity of earthquake on the performance of the structural control device is investigated. A fragility analysis based on acceleration capacity thresholds is performed to estimate reliability improvement using the structural control devices. The fitted fragility functions based on multiple stripes analysis are constructed and compared with the empirical cumulative distribution curves. The results suggest that the use of an optimal TLCD with a mass ratio of 2.5% reduces the fragility of the system by as much as 6% and 12% for operational and parked conditions, respectively.

KW - offshore wind turbine

KW - fragility analysis

KW - vibration control

KW - tuned liquid column damper

UR - https://www.sciencedirect.com/journal/soil-dynamics-and-earthquake-engineering

M3 - Article

JO - Soil Dynamics and Earthquake Engineering

T2 - Soil Dynamics and Earthquake Engineering

JF - Soil Dynamics and Earthquake Engineering

SN - 0267-7261

ER -

Hemti A, Oterkus E, Barltrop N. Fragility reduction of offshore wind turbines using tuned liquid column dampers. Soil Dynamics and Earthquake Engineering. 2019 May 28.

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