An integrated FEA-CFD simulation of offshore wind turbines with vibration control systems

Kampitsis, A. E.; Kapasakalis, Konstantinos A.; Via-Estrem, Lluís

doi:10.1016/j.engstruct.2022.113859

Cited by 44 publications

(10 citation statements)

References 46 publications

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“…A conceptual design with additional implementation details and constraints is presented in Section 4.3 of this study. Based on previous indicative designs of the EKD concept with pre‐compressed springs by Kampitsis et al, 33 the NS element may reach a realistic absolute upper value of −130 kN/m per 1 tn of total superstructure mass. The damping coefficient limits should be selected based on the common viscous damping device limitations, available in the market. The NS element stroke (

U_{NS}

), namely, the absolute relative displacement of the terminals of

K_{N}

is set as a constraint with an upper limit of 5 cm, based on the details and limitations of the conceptual design presented in Section 4.3.…”

Section: Design and Optimization Of The Ekd‐r Parametersmentioning

confidence: 98%

“…A conceptual design with additional implementation details and constraints is presented in Section 4.3 of this study. Based on previous indicative designs of the EKD concept with pre-compressed springs by Kampitsis et al, 33 the NS element may reach a realistic absolute upper value of À130 kN/m per 1 tn of total superstructure mass. 3.…”

Section: Optimization Process Constraints and Limitationsmentioning

confidence: 99%

“…Among others, special mechanical designs involving conventional positive stiffness prestressed elastic mechanical elements, such as post‐buckled beams, plates, shells, and pre‐compressed springs, arranged in appropriate geometrical configurations can generate controlled NS with the desired magnitude. In this work, the mechanism proposed by Kampitsis et al 33 is used, and the schematic presentation of this configuration is presented in Figure 7.…”

Section: Numerical Test Casementioning

confidence: 99%

“…[27][28][29] In addition, the proper allocation of the stiffness-mass elements of the device leads to a system that is both statically and dynamically stable; the properties of the KDamper can be designed in order to maintain the initial/static stiffness of the structure and, hence, avoid potential instabilities. This vibration control system has been examined for the protection of bridges 30,31 wind turbines, 32,33 and structural systems, [34][35][36] achieving reduction of the displacement demand at the base level. Specifically, Kapasakalis et al 34 introduced the extended version of the KDamper concept as a vibration absorber for low-rise buildings; the system was applied supplementary to conventional base isolation for a typical RC structure.…”

Section: Introduction and Scopementioning

confidence: 99%

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A negative stiffness dynamic base absorber for seismic retrofitting of residential buildings

Mantakas

Kapasakalis

Alvertos

et al. 2022

Structural Contr & Hlth

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In this study, a negative stiffness-based passive vibration absorber is developed and implemented as a seismic retrofitting measure for typical reinforced concrete (RC) residential buildings. The device, namely, the extended KDamper for retrofitting (EKD-R), is introduced at the base of the structure, between the foundation level and the first story of the building. The design of the EKD-R device and the selection of its properties are undertaken by incorporating a harmony search (HS) algorithm that provides optimized parameters for the mechanism, following constraints and limitations imposed by the examined structural system. Nonlinearities due to the plastic behavior of the structural members and soil-structure interaction (SSI) effects are modeled and taken into consideration during the process. Subsequently, a realistic case study of a benchmark three-story RC building is examined, and the performance of the EKD-R system is assessed. The building superstructure is designed according to Eurocodes. The structure-foundation system, along with the EKD-R, is explicitly modeled using finite elements (FE) that may realistically capture structural nonlinearities and SSI effects. The HS algorithm is employed, and optimized EKD-R components are obtained and implemented in the benchmark structure. Finally, a series of recorded real ground motions are selected, and nonlinear time-history dynamic analyses are conducted aiming to assess the behavior of the controlled system. Results indicate the beneficial role of the novel dynamic absorber, hence rendering the concept a compelling seismic retrofitting technology.

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U_{NS}

), namely, the absolute relative displacement of the terminals of

K_{N}

is set as a constraint with an upper limit of 5 cm, based on the details and limitations of the conceptual design presented in Section 4.3.…”

Section: Design and Optimization Of The Ekd‐r Parametersmentioning

confidence: 98%

“…A conceptual design with additional implementation details and constraints is presented in Section 4.3 of this study. Based on previous indicative designs of the EKD concept with pre-compressed springs by Kampitsis et al, 33 the NS element may reach a realistic absolute upper value of À130 kN/m per 1 tn of total superstructure mass. 3.…”

Section: Optimization Process Constraints and Limitationsmentioning

confidence: 99%

Section: Numerical Test Casementioning

confidence: 99%

Section: Introduction and Scopementioning

confidence: 99%

See 2 more Smart Citations

A negative stiffness dynamic base absorber for seismic retrofitting of residential buildings

Mantakas

Kapasakalis

Alvertos

et al. 2022

Structural Contr & Hlth

Self Cite

View full text Add to dashboard Cite

show abstract

“…The TMD system is more robust to variations in damping ratio and frequency ratio with a larger mass ratio, while a larger TMD damping results in a smaller TMD stroke [17]. An extended KDamper enhances its vibration reduction capacity by introducing negativestiffness elements, while avoiding adding additional mass [18]. The conventional linear TMDs are limited in their scope of application due to their relatively large masses.…”

Section: Introductionmentioning

confidence: 99%

Optimal Tuned Inerter Dampers for Vibration Control Performance of Adjacent Building Structures

Kang

Tang

et al. 2023

Buildings

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Under the effect of strong earthquakes, collisions or excessive inter-story displacements may occur between adjacent building structures to the extent that the building structure is damaged. The traditional seismic measures for these structures can no longer meet the needs in practical engineering. In this paper, we propose the application of parallel and serial TID-based control systems in adjacent buildings as an example of a single-story adjacent building, and use it to form a new adjacent building seismic reduction structure. In this paper, the dynamic characteristics and design parameter optimization of the vibration control system are investigated by means of the Monte Carlo pattern search method and H2 norm theory. The results show that the introduction of serial and parallel TID in adjacent building structures can effectively improve the seismic resistance of adjacent buildings. The problem of vibration amplification caused by resonance is obviously improved, which is especially evident in the adjacent building structure vibration control system based on parallel TID. The vibration control system of adjacent building structures based on parallel TID is more robust. When optimizing the right building, the damping requirement of the TID decreases for the vibration control system based on parallel TID as the adjacent building mass ratio increases, while the damping requirement of the TID increases for the vibration control system based on serial TID. In both vibration control systems, the difference in the optimal inertial mass ratio is small. In practice, a moderate increase in the difference between adjacent building masses can have a positive effect on the vibration control performance of the systems. The main contribution of this paper is to fill the research gap in parallel and serial TID applications for adjacent building vibration reduction.

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Concise analytical solutions to negative‐stiffness inerter‐based DVAs for seismic and wind hazards considering multi‐target responses

Su,

Chen,

Zeng

et al. 2024

Earthq Engng Struct Dyn

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Practical engineering structures are subjected to hazardous seismic‐ and wind‐ induced vibrations during their lifetime. They should be designed based on capacity and serviceability targets. Similarly, the design of dynamic vibration absorbers (DVAs) should also meet multiple requirements. However, most current analytical approaches are based on a single‐target response and may lead to cumbersome expressions for complicated scenarios. To address these issues, concise solutions to negative‐stiffness inerter‐based DVAs are proposed in this paper. Firstly, a generic analytical optimization approach for H‐norm solutions considering different response targets of displacement, velocity, acceleration, and transmissibility, is established. Subsequently, the concise solutions are derived based on Taylor's expansion of these analytical solutions by ignoring higher‐order items of the equivalent mass ratio. Finally, the application scope and effectiveness of the proposed concise solutions are discussed. Consequently, the resulting concise solutions are proved to be located close to the pareto fronts of multi‐target optimization results. They have shown superior performances than conventional solutions in controlling the structural capacity and serviceability indicators of a practical five‐story steel frame case under dynamic wind and seismic hazards. Conclusively, the proposed concise solutions are simple in expression and reveal excellent multi‐target performances, which can provide guidance and insights for the optimal design of DVAs.

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An integrated FEA-CFD simulation of offshore wind turbines with vibration control systems

Cited by 44 publications

References 46 publications

A negative stiffness dynamic base absorber for seismic retrofitting of residential buildings

A negative stiffness dynamic base absorber for seismic retrofitting of residential buildings

Optimal Tuned Inerter Dampers for Vibration Control Performance of Adjacent Building Structures

Concise analytical solutions to negative‐stiffness inerter‐based DVAs for seismic and wind hazards considering multi‐target responses

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