Effect of scour on the natural frequency responses of the meteorological mast in the Taiwan strait

Wei Chen Tseng, Yu Shu Kuo, Kung Chun Lu, Jing-Wen Chen, Chiou Fong Chung, Ruey Chyi Chen

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The meteorological mast (met mast) for the Taiwan Power Company's offshore wind farm is located in Taiwan Strait near Changhua County. The p-y curve method recommended in the current offshore foundation design codes does not account for the local scour around the pile foundation; it overestimates the lateral pile deformation and underestimates the foundation stiffness. This paper presents a method to correct the initial modulus of subgrade reaction and modify the ultimate lateral resistance caused by the local scour. The natural frequency of the met mast structure is also determined by a numerical model and verified with the measured data in situ. A comprehensive parameter study is performed to analyze the effect of scour on the dynamic responses of the met mast. Two types of foundation model, a coupled-springs foundation model and a distributed-springs foundation model, are considered in the dynamic analysis of the met mast. The results demonstrate that using a distributed-springs foundation model provides a relatively accurate estimate of the natural frequencies of the met mast structure. Furthermore, the scour exerted significant effects on certain modes of the vibration responses. The natural frequencies of the met mast structure can be reduced by approximately 14% due to scour, particularly in the horizontal bending modes. This paper also provides a preliminary strategy for structural monitoring and analysis to detect scour damage on offshore wind turbines with monopile foundations.

Original languageEnglish
Article number823
JournalEnergies
Volume11
Issue number4
DOIs
Publication statusPublished - 2018 Apr 1

Fingerprint

Scour
Taiwan
Frequency Response
Natural Frequency
Frequency response
Natural frequencies
Lateral
Wind Turbine
Dynamic Response
Dynamic Analysis
Model
Stiffness
Modulus
Horizontal
Damage
Offshore wind turbines
Vibration
Offshore wind farms
Pile foundations
Monitoring

All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment
  • Energy Engineering and Power Technology
  • Energy (miscellaneous)
  • Control and Optimization
  • Electrical and Electronic Engineering

Cite this

Tseng, Wei Chen ; Kuo, Yu Shu ; Lu, Kung Chun ; Chen, Jing-Wen ; Chung, Chiou Fong ; Chen, Ruey Chyi. / Effect of scour on the natural frequency responses of the meteorological mast in the Taiwan strait. In: Energies. 2018 ; Vol. 11, No. 4.
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abstract = "The meteorological mast (met mast) for the Taiwan Power Company's offshore wind farm is located in Taiwan Strait near Changhua County. The p-y curve method recommended in the current offshore foundation design codes does not account for the local scour around the pile foundation; it overestimates the lateral pile deformation and underestimates the foundation stiffness. This paper presents a method to correct the initial modulus of subgrade reaction and modify the ultimate lateral resistance caused by the local scour. The natural frequency of the met mast structure is also determined by a numerical model and verified with the measured data in situ. A comprehensive parameter study is performed to analyze the effect of scour on the dynamic responses of the met mast. Two types of foundation model, a coupled-springs foundation model and a distributed-springs foundation model, are considered in the dynamic analysis of the met mast. The results demonstrate that using a distributed-springs foundation model provides a relatively accurate estimate of the natural frequencies of the met mast structure. Furthermore, the scour exerted significant effects on certain modes of the vibration responses. The natural frequencies of the met mast structure can be reduced by approximately 14{\%} due to scour, particularly in the horizontal bending modes. This paper also provides a preliminary strategy for structural monitoring and analysis to detect scour damage on offshore wind turbines with monopile foundations.",
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Effect of scour on the natural frequency responses of the meteorological mast in the Taiwan strait. / Tseng, Wei Chen; Kuo, Yu Shu; Lu, Kung Chun; Chen, Jing-Wen; Chung, Chiou Fong; Chen, Ruey Chyi.

In: Energies, Vol. 11, No. 4, 823, 01.04.2018.

Research output: Contribution to journalArticle

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