Control of wind/wave-induced vibrations of jacket-type offshore wind turbines through tuned liquid column gas dampers

Dezvareh, Reza; Bargi, Khosrow; Mousavi, Seyed Amin

doi:10.1080/15732479.2015.1011169

Cited by 24 publications

(11 citation statements)

References 16 publications

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“…Excessive motions of the main structure are significantly suppressed by the gravitational restoring forces and moments acting on the displaced liquid in the horizontal and vertical columns. Lee et al (2006), Roderick (2012), Mousavi et al (2012), and Dezvareh et al (2015) proved the effectiveness of the TLCD at mitigating the responses of fixed or floating offshore platforms. However, the influence of the TLCD on the fatigue behavior of mooring lines for floating structures has not been studied.…”

Section: Tuned Liquid Column Dampermentioning

confidence: 97%

“…The tuned liquid column damper (TLCD) has features like compatibility with the surrounding environment and easy maintenance requirements and costs that make it an appropriate choice for offshore structures. Colwell and Basu (2009), Dezvareh et al (2015), Bargi et al (2016), and Hemmati et al (2019) proved that the TLCD is capable of suppressing the response of fixed offshore wind turbines to wind and wave loadings. TLCDs were also found to greatly increase the fatigue life of structural elements.…”

Section: Introductionmentioning

confidence: 95%

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Enhancement the Fatigue Life of Floating Breakwater Mooring System Using Tuned Liquid Column Damper

Shahrabi

Bargi

2019

Lat. Am. j. solids struct.

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Safety is a key design criterion for floating structures. A high rate of mooring accidents has been reported over the past decades. Preventing mooring line failure is a key design objective for floating breakwater systems. The mooring system comprises sets of mooring lines anchored to the seabed. These components are exposed to highly cyclic nonlinear load fluctuations induced by an irregular wave climate during their service life. DNVGL-OS-E301 classifies the mooring lines for floating breakwaters as long-term elements that should be evaluated according to the fatigue limit state. Fatigue of mooring lines needs to be monitored and evaluated to warrant the station keeping and integrity of overall system. Applying an additional control device to a floating breakwater mitigates the structural response and hence mobilized tension in mooring system. The focus of present study was to examine the effect of an additional control device on fatigue life of mooring lines for floating breakwaters. To evaluate the effect of a control device on the fatigue behavior of mooring lines, a floating breakwater was simulated with a tuned liquid column damper (TLCD) attached. A time-dependent approach based on S-N curves in conjunction with the Palmgren-Miner rule was employed to evaluate the mooring line fatigue. This paper presents a further parametric study focused on the effect of TLCD on fairlead point displacement, mobilized tension, damage rate, and fatigue life of mooring lines. The results showed that TLCD increased the fatigue life of mooring line and thus dramatically decreased the likelihood of the mooring system being damaged by fatigue. This would reduce the maintenance costs and increase the lifetime and operational safety of floating breakwater. In addition, the presented case study showed that failure probability of mooring lines against fatigue damage was also reduced and was acceptable for the safety factor defined in DNVGL-OS-E301. This proposed approach of applying a TLCD is a practical tool for designing the components of a floating breakwater more efficiently. Keywords floating breakwater (FB); tuned liquid column damper (TLCD); fatigue assessment; mooring system; S-N curves; structural control Enhancement the Fatigue Life of Floating Breakwater Mooring System Using Tuned Liquid Column Damper Mostafa Shahrabi et al.

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Section: Tuned Liquid Column Dampermentioning

confidence: 97%

Section: Introductionmentioning

confidence: 95%

Enhancement the Fatigue Life of Floating Breakwater Mooring System Using Tuned Liquid Column Damper

Shahrabi

Bargi

2019

Lat. Am. j. solids struct.

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“…These studies have examined a variety of tuned dampers, including the tuned mass damper (TMD), the tuned liquid dampers (TLD), the tuned liquid column dampers (TLCD) and the active mass dampers (AMD) for two types of single-pile and floating wind turbines. Since, among the marine conditions, the load caused by the wave have a higherlasting o effect on the marine structures, the offshore wind turbines were controlled under the simultaneous stimulations of wave and wind in the latest research by the TLCGD damper and its vibrations decreased [9]. Then, the effect of this damper on the reduction of forces caused by the earthquake was evaluated in the offshore wind turbine with the template support platform [10].…”

Section: Introductionmentioning

confidence: 99%

Application of Soft Computing in the Design and Optimization of Tuned Liquid Column–Gas Damper for Use in Offshore Wind Turbines

Dezvareh

2019

ijcoe

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Tuned liquid column gas damper is a new type of energy absorber that can mitigate the vibrations of structures if their frequency and mass parameters are well tuned. Since this damper has recently been introduced and its behaviour in certain structures such as offshore oil platforms and wind turbines has already been tested, a suitable and accurate method is required to identify these optimal parameters. Therefore, considering the complexity of loads exerted on wind turbines in seas (wave and wind loads), in present study attempts are made to use a new artificial neural network approach to obtain optimal tuned liquid column-gas damper (TLCGD) parameters for mitigation of wind turbine vibrations. First fixed offshore wind turbines at various depths are designed in the MATLAB coding environment. After obtaining the stiffness, damping and mass matrices of the structures, the program enters the Simulink, and the wind turbine structure along with the TLCGD is exposed to different wave-wind load combinations within reasonable range of damper parameters. The neural network training is launched based on available statistical data of the offshore wind turbine with different heights as well as different frequency and mass ratios of the damper. According to this method, the percentage of errors found in the neural network outputs was negligible compared to the actual results obtained from the analysis in Simulink (even for inputs that stood outside the training range of the neural network). The mean error percentage, the standard deviation and the effective value of the neural network with actual values are below 10% for all three types of the structure. Finally, the method presented in this study can be used to obtain optimal parameters of the TLCGD for all kinds of offshore wind turbines at different depths of the sea, which leads to the optimal design of this damper to reduce the vibrations of wind turbines under wave and wind load pressures.

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“…Bargi et al too have been able to reduce the vibrations of the offshore wind turbine using tuned liquid column gas damper. Their research is all-inclusive because they controlled the vibrations under the simultaneous effects of wind, wave, and earthquake forces [4] [5]. Patil and Jungid [6], analyzed three jacket structures equipped with friction dampers, viscose dampers, and viscoelastic dampers under the action of wave forces.…”

Section: Introductionmentioning

confidence: 99%

Optimized SMA Dampers in Vibration Control of Jacket-type Offshore Structures (Regular Waves)

Ghasemi

Shabakhty

Enferadi

2019

ijcoe

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Undesired oscillations of jacket platform may influence the structural functionality and sometimes fatigue occurs. The main objective of this research is to control wave-induced vibrations of fixed jacket platforms with the use of optimized shape memory alloys dampers. To model the hysteretic behavior of SMA elements and performing dynamic analysis an efficient isothermal idealized constitutive model is developed in this research and direct integration time history analysis is carried out. Dynamic responses of multidegree of freedom system of jacket platform, with 90 m height and equipped with SMA dampers, is estimated and compared with the bare jacket. Furthermore, an optimization algorithm such as Ideal Gas Molecules Movements (IGMM) is implemented in this research to improve the efficiency of the dampers and minimize the deck displacements under the action of extreme wave. The results show that the optimized SMA dampers can improve the structural response by decreasing 47.5 percent of deck displacement, 56.5 percent of deck acceleration and finally 28 percent of base shear. In an SMA damper-equipped platform, reduced wave intensity will reduce the damper efficiency.

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Control of wind/wave-induced vibrations of jacket-type offshore wind turbines through tuned liquid column gas dampers

Cited by 24 publications

References 16 publications

Enhancement the Fatigue Life of Floating Breakwater Mooring System Using Tuned Liquid Column Damper

Enhancement the Fatigue Life of Floating Breakwater Mooring System Using Tuned Liquid Column Damper

Application of Soft Computing in the Design and Optimization of Tuned Liquid Column–Gas Damper for Use in Offshore Wind Turbines

Optimized SMA Dampers in Vibration Control of Jacket-type Offshore Structures (Regular Waves)

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