Axial Dynamic Stiffness of Tubular Piles in Viscoelastic Soil

Mehdi Bayat, Lars Vabbersgaard Andersen, Lars Bo Ibsen

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

Large offshore wind turbines are f0W1ded on jacket structures. In this study, an elastic full-space jacket structure foundation in an elastic and viscoelastic medium is investigated by using boundary integral equations. The jacket structure foundation is modeled as a hollow, long circular cylinder when the dynamic vertical excitation is applied. The smooth surface along the entire interface is considered. The Betti reciprocal theorem along with Somigliana's identity and Green's function are employed to drive the dynamic stiffness of jacket structures. Modes of the resonance and anti-resonance are presented .in series of Bessel's function. Important responses, such as dynamic stiffness and phase angle, are compared for different values of the loss factor as the material damping, Y0W1g's modulus and Poisson's ratio in a viscoelastic soil. Results are verified. with known results reported in the literature. It is observed that the dynamic stiffness fluctuates with the loss factor, and the turning point is independent of the loss factor while the turning point increases with load frequency. It is seen that the non-dimensional dynamic stiffness is dependent on Young's modulus and Poisson's ratio, whilst the phase angle is independent of the properties of the soil. It is shown that the non-dimensional dynamic stiffness changes linearly with high-frequency load. The conclusion from the results of this study is that the material properties of soil are significant parameters in the dynamic stiffness of jacket structures, and the presented approach can unfold the behavior of soil and give an approachable physical meaning for wave propagation.
OriginalsprogEngelsk
TidsskriftEnergies
Vol/bind9
Udgave nummer9
Sider (fra-til)734
Antal sider17
ISSN1996-1073
DOI
StatusUdgivet - 2016

Fingerprint

Piles
Soil
Stiffness
Soils
Poisson's Ratio
Turning Point
Poisson ratio
Identity function
Offshore wind turbines
Angle
Bessel functions
Boundary integral equations
Wind Turbine
Young's Modulus
Smooth surface
Bessel Functions
Circular Cylinder
Boundary Integral Equations
Circular cylinders
Green's function

Bibliografisk note

This article belongs to the collection Wind Turbines

Emneord

  • Offshore foundation
  • Mathematical model
  • Boundary integral
  • Damping in viscoelastic media
  • Resonance

Citer dette

Bayat, Mehdi ; Andersen, Lars Vabbersgaard ; Ibsen, Lars Bo. / Axial Dynamic Stiffness of Tubular Piles in Viscoelastic Soil. I: Energies. 2016 ; Bind 9, Nr. 9. s. 734.
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abstract = "Large offshore wind turbines are f0W1ded on jacket structures. In this study, an elastic full-space jacket structure foundation in an elastic and viscoelastic medium is investigated by using boundary integral equations. The jacket structure foundation is modeled as a hollow, long circular cylinder when the dynamic vertical excitation is applied. The smooth surface along the entire interface is considered. The Betti reciprocal theorem along with Somigliana's identity and Green's function are employed to drive the dynamic stiffness of jacket structures. Modes of the resonance and anti-resonance are presented .in series of Bessel's function. Important responses, such as dynamic stiffness and phase angle, are compared for different values of the loss factor as the material damping, Y0W1g's modulus and Poisson's ratio in a viscoelastic soil. Results are verified. with known results reported in the literature. It is observed that the dynamic stiffness fluctuates with the loss factor, and the turning point is independent of the loss factor while the turning point increases with load frequency. It is seen that the non-dimensional dynamic stiffness is dependent on Young's modulus and Poisson's ratio, whilst the phase angle is independent of the properties of the soil. It is shown that the non-dimensional dynamic stiffness changes linearly with high-frequency load. The conclusion from the results of this study is that the material properties of soil are significant parameters in the dynamic stiffness of jacket structures, and the presented approach can unfold the behavior of soil and give an approachable physical meaning for wave propagation.",
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Axial Dynamic Stiffness of Tubular Piles in Viscoelastic Soil. / Bayat, Mehdi; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo.

I: Energies, Bind 9, Nr. 9, 2016, s. 734.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Axial Dynamic Stiffness of Tubular Piles in Viscoelastic Soil

AU - Bayat, Mehdi

AU - Andersen, Lars Vabbersgaard

AU - Ibsen, Lars Bo

N1 - This article belongs to the collection Wind Turbines

PY - 2016

Y1 - 2016

N2 - Large offshore wind turbines are f0W1ded on jacket structures. In this study, an elastic full-space jacket structure foundation in an elastic and viscoelastic medium is investigated by using boundary integral equations. The jacket structure foundation is modeled as a hollow, long circular cylinder when the dynamic vertical excitation is applied. The smooth surface along the entire interface is considered. The Betti reciprocal theorem along with Somigliana's identity and Green's function are employed to drive the dynamic stiffness of jacket structures. Modes of the resonance and anti-resonance are presented .in series of Bessel's function. Important responses, such as dynamic stiffness and phase angle, are compared for different values of the loss factor as the material damping, Y0W1g's modulus and Poisson's ratio in a viscoelastic soil. Results are verified. with known results reported in the literature. It is observed that the dynamic stiffness fluctuates with the loss factor, and the turning point is independent of the loss factor while the turning point increases with load frequency. It is seen that the non-dimensional dynamic stiffness is dependent on Young's modulus and Poisson's ratio, whilst the phase angle is independent of the properties of the soil. It is shown that the non-dimensional dynamic stiffness changes linearly with high-frequency load. The conclusion from the results of this study is that the material properties of soil are significant parameters in the dynamic stiffness of jacket structures, and the presented approach can unfold the behavior of soil and give an approachable physical meaning for wave propagation.

AB - Large offshore wind turbines are f0W1ded on jacket structures. In this study, an elastic full-space jacket structure foundation in an elastic and viscoelastic medium is investigated by using boundary integral equations. The jacket structure foundation is modeled as a hollow, long circular cylinder when the dynamic vertical excitation is applied. The smooth surface along the entire interface is considered. The Betti reciprocal theorem along with Somigliana's identity and Green's function are employed to drive the dynamic stiffness of jacket structures. Modes of the resonance and anti-resonance are presented .in series of Bessel's function. Important responses, such as dynamic stiffness and phase angle, are compared for different values of the loss factor as the material damping, Y0W1g's modulus and Poisson's ratio in a viscoelastic soil. Results are verified. with known results reported in the literature. It is observed that the dynamic stiffness fluctuates with the loss factor, and the turning point is independent of the loss factor while the turning point increases with load frequency. It is seen that the non-dimensional dynamic stiffness is dependent on Young's modulus and Poisson's ratio, whilst the phase angle is independent of the properties of the soil. It is shown that the non-dimensional dynamic stiffness changes linearly with high-frequency load. The conclusion from the results of this study is that the material properties of soil are significant parameters in the dynamic stiffness of jacket structures, and the presented approach can unfold the behavior of soil and give an approachable physical meaning for wave propagation.

KW - Offshore foundation

KW - Mathematical model

KW - Boundary integral

KW - Damping in viscoelastic media

KW - Resonance

KW - Offshore foundation

KW - Mathematical model

KW - Boundary integral

KW - Damping in viscoelastic media

KW - Resonance

U2 - 10.3390/en9090734

DO - 10.3390/en9090734

M3 - Journal article

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SP - 734

JO - Energies

JF - Energies

SN - 1996-1073

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ER -