Centrifuge modeling to evaluate natural frequency and seismic behavior of offshore wind turbine considering<scp>SFSI</scp>

Seong, Juntae; Ha, Jeong‐Gon; Kim, Jae Hyun; Park, Heon-Joon; Kim, Dong-Soo

doi:10.1002/we.2127

Cited by 11 publications

(3 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on this method, the dimensions of the scaled model were further scaled without increasing the centrifugal acceleration. The details of the model simplification can be found in Seong et al [41]. The scaling ratio of 50:1 was selected in order to minimize the rigid container boundary effect.…”

Section: Modelling Of Monopilementioning

confidence: 99%

Evaluation of Soil–Foundation–Structure Interaction for Large Diameter Monopile Foundation Focusing on Lateral Cyclic Loading

Kim

Jeong

et al. 2023

JMSE

View full text Add to dashboard Cite

In this study, the monotonic and cyclic behavior of an offshore wind turbine with a monopile foundation installed in a sand layer were evaluated in the centrifuge. A simplified offshore wind turbine was modeled, and the lateral load was applied to the tower under displacement control. The monotonic loading test evaluated ultimate lateral load capacity and bending moment profiles under different loading levels. During cyclic loading, variations of moment-rotation responses, cyclic stiffness, and bending moments along the pile were observed. The initial rotational stiffness of the monopile decreased as the loading level increased. In the fatigue limit state (FLS) and service limit state (SLS) loading conditions, no noticeable variation in stiffness was observed with the number of cycles. However, in the ultimate limit state (ULS), the stiffness of the monopile increased during the first few cycles, followed by a decreasing rate of increase, and reached a certain value. The loading rate had a weakening effect on the monopile–soil interaction, which was supported by the bending moments induced in the monopile.

show abstract

Section: Modelling Of Monopilementioning

confidence: 99%

Evaluation of Soil–Foundation–Structure Interaction for Large Diameter Monopile Foundation Focusing on Lateral Cyclic Loading

Kim

Jeong

et al. 2023

JMSE

View full text Add to dashboard Cite

show abstract

“…Alati et al [25] directly treated the bottom constraint of the turbine as a fixed base without considering the soil and foundation, which is commonly adopted by structural engineers. However, ignoring the SSI effect greatly overestimates the natural frequency of the turbine [26], leading to significant errors in the seismic design of OWTs. Therefore, soil-structure interactions must be considered in simplified dynamic analysis methods to balance accuracy and computational efficiency.…”

Section: Introductionmentioning

confidence: 99%

Combined Seismic and Scoured Numerical Model for Bucket-Supported Offshore Wind Turbines

Jia,

Liang,

Shen

et al. 2024

JMSE

View full text Add to dashboard Cite

Numerous offshore wind turbines (OWTs) with bucket foundations have been installed in seismic regions. Compared to the relative development of monopiles (widely installed), seismic design guidelines for bucket-supported OWTs still need to be developed. Moreover, scour around bucket foundations induced by water–current actions also creates more challenges for the seismic design of OWTs. In this study, a simplified seismic analysis method is proposed that incorporates the soil–structure interaction (SSI) for the preliminary design of scoured bucket-supported OWTs, aiming to balance accuracy and efficiency. The dynamic SSI effects are represented using lumped parameter models (LPMs), which are developed by fitting impedance functions of the soil–bucket foundation obtained from the four-spring Winkler model. The water–structure interaction is also considered by the added mass in seismic analysis. Based on the OpenSees 3.3.0 platform, an integral model is established and validated using the three-dimensional finite element method. The results indicate that the bucket-supported OWT demonstrates greater dynamic impedance and first-order natural frequency compared to the monopile-supported OWT, which has an increased seismic response. Seismic spectral characteristics and intensities also play an important role in the responses. Additionally, scour can change the bucket impedance functions and the frequency characteristics of the OWT system, leading to a significant alteration in the seismic response. Scour effects may be advantageous or disadvantageous, depending on the spectral characteristics of seismic excitations. These findings provide insights into the seismic response of bucket-supported OWTs under scoured conditions.

show abstract

“…Early dynamic centrifuge tests were carried out by Yu et al (2015) and Wang et al (2020) looking at uniform deposits of sand with OWTs supported on bucket foundations. Seong et al (2017) and Seong and Kim (2019) investigated the dynamic response of different offshore foundations using dynamic centrifuge modelling. However, this research was on dry uniform soil beds.…”

Section: Introductionmentioning

confidence: 99%

Dynamic and monotonic response of Monopile Foundations for Offshore wind turbines using centrifuge testing

Seong

Abadie

Madabhushi

et al. 2022

Bull Earthquake Eng

View full text Add to dashboard Cite

The seismic response of monopile foundations is a growing area of research as the offshore wind industry expands worldwide, including in earthquake prone regions of the world. This paper presents dynamic centrifuge tests aimed at investigating the dynamic response of monopiles in both dry and saturated sandy soils. The latter case includes soil liquefaction under strong input motions, with measured excess pore pressures indicating liquefaction. The natural frequency of the monopile-soil system is experimentally determined by measuring the response to a sine sweep motion. Strong earthquakes are then applied at this frequency and its harmonics. This paper discusses the response of the monopile in terms of the peak accelerations observed in the dry and saturated tests, as well as using response spectra and amplification ratios. The dynamic bending moments along the pile are also measured to infer the bending moment profile with depth. Finally, two identical monopiles are pushed-over in each of the centrifuge tests to establish the pre and post-earthquake monotonic response, including the lateral stiffness and capacity, which are compared for the dry model tests and the saturated case.

show abstract

Centrifuge modeling to evaluate natural frequency and seismic behavior of offshore wind turbine consideringSFSI

Cited by 11 publications

References 19 publications

Evaluation of Soil–Foundation–Structure Interaction for Large Diameter Monopile Foundation Focusing on Lateral Cyclic Loading

Evaluation of Soil–Foundation–Structure Interaction for Large Diameter Monopile Foundation Focusing on Lateral Cyclic Loading

Combined Seismic and Scoured Numerical Model for Bucket-Supported Offshore Wind Turbines

Dynamic and monotonic response of Monopile Foundations for Offshore wind turbines using centrifuge testing

Contact Info

Product

Resources

About