Article
Engineering, Marine
Xinqi Liu, Jun Xu, Guangling He, Chao Chen
Summary: This paper presents a spring pendulum pounding tuned mass damper (SPPTMD) to mitigate the lateral vibration of monopile offshore wind turbines (MOWT). Mathematical modeling, parameter optimization, and verification demonstrate that the SPPTMD has better control effects in the low frequency detuning region.
Article
Engineering, Civil
Gino Bertollucci Colherinhas, Marcus Vinicius Girao de Morais, Marcela Rodrigues Machado
Summary: This paper presents a monopile wind turbine designed using the spectral element method and genetic algorithm technique, and demonstrates its performance under random excitation.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2022)
Article
Green & Sustainable Science & Technology
Zili Zhang
Summary: This paper investigates the use of electromagnetic shunt tuned mass damper (EMSTMD) to suppress in-plane vibrations of a floating offshore wind turbine (FOWT). The EMSTMD improves the performance and durability of the damper by replacing the dashpot with a shunted electromagnetic (EM) transducer. The study establishes a 17-degree-of-freedom (17-DOF) model for FOWT and compares the performance of the optimized EMSTMD with the classic TMD in both frequency and time domains. The results show that the EMSTMD consistently outperforms the TMD in reducing tower side-side vibrations of FOWT.
Article
Engineering, Marine
J. W. Zhang, X. Liang, L. Z. Wang, B. X. Wang, L. L. Wang
Summary: This paper investigates the influence of passive tuned mass dampers (TMDs) on the dynamical responses of offshore wind turbines (OWTs) under different wind-wave loadings. The results show that TMDs have an excellent vibration reduction effect when the OWT is parked. The optimal designs for the TMD are further conducted and the research results show that the vibration reduction performance of the TMD is enhanced when the OWT is parked. This work provides technical support for optimal design of the TMD under the wind-wave environments.
Article
Engineering, Civil
V. Jahangiri, C. Sun, F. Kong
Summary: A novel three-dimensional pounding pendulum tuned mass damper (3d-PPTMD) is developed to reduce vibrations of offshore wind turbines caused by misaligned wind and wave loading. The 3d-PPTMD is found to be more effective and compact compared to traditional damping systems, providing better mitigation performance under different loading scenarios and off-tuning effects.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Marine
Gwanghee Park, Ki-Yong Oh, Woochul Nam
Summary: This study introduces a bilinear TMD to address the issue of poor performance of linear TMDs in strong wind conditions, optimizing its parameters for various operational wind conditions. The bilinear TMD outperforms previous TMDs by 10%-15% in every evaluated wind condition.
Article
Energy & Fuels
Gino Bertollucci Colherinhas, Francesco Petrini, Marcus Vinicius Girao de Morais, Franco Bontempi
Summary: This paper presents an optimal design procedure for a pendulum tuned mass damper (PTMD) to mitigate the global structural vibrations of offshore wind turbines (OWTs) using MATLAB program and ANSYS 3D finite element model to calculate and evaluate. The parameters of the PTMD are optimized using a genetic algorithm to minimize the peak response of the primary structure, and the performance of the PTMD is examined on a 3D global FE model.
Article
Engineering, Civil
Hao Ding, Okyay Altay, Jin-Ting Wang
Summary: This study investigates the efficiency of toroidal tuned liquid column dampers (TTLCDs) in controlling the lateral vibration of monopile supported offshore wind turbines. The TTLCDs are capable of simultaneously matching the natural frequencies of the wind turbines in both fore-aft and side-side directions. A mathematical model of the TTLCDs inside the nacelle is derived and a simulation interface between MATLAB/Simulink and FAST is established. A design procedure for TTLCDs in monopile wind turbines is provided. Numerical calculations are performed considering different wind velocities, wave-wind misalignment angles and working conditions, taking into account fatigue and ultimate load cases. A parametric analysis is conducted on the flow resistance coefficient of TTLCDs. The results demonstrate that TTLCDs can effectively control lateral vibrations and improve the structural performance of monopile wind turbines against wind and wave loads.
ENGINEERING STRUCTURES
(2023)
Article
Engineering, Marine
V Jahangiri, C. Sun
Summary: This paper proposes a novel three-dimensional non-linear tuned mass damper (3d-NTMD) to effectively mitigate three-dimensional structural responses. A numerical search approach is adopted to determine the optimum design, and the 3d-NTMD has the potential to mitigate three-dimensional vibrations of a large set of civil/mechanical systems.
Article
Engineering, Marine
Dingxin Leng, Yi Yang, Kai Xu, Yancheng Li, Guijie Liu, Xiaojie Tian, Yingchun Xie
Summary: A semi-active variable-stiffness tuned mass damper using magnetorheological elastomer materials is proposed to mitigate undesired dynamic responses of offshore wind turbines. The effectiveness of the design is demonstrated with a jacket supported offshore wind turbine with MRE-TMD installed at the top of the tower.
Article
Engineering, Marine
Zili Zhang, Christian Hoeg
Summary: This paper investigates the use of an inerter-enhanced vibration absorber, the rotational inertia double tuned mass damper (RIDTMD), for damping in-plane vibrations of a floating offshore wind turbine (FOWT). It compares the performance of RIDTMD and TMD in both frequency domain (FD) and time domain (TD), showing that RIDTMD consistently outperforms TMD in suppressing tower side-side vibrations with the cost of slightly larger damper stroke. Both dampers positively influence spar roll motion and blade edgewise vibration.
Article
Engineering, Marine
Dongzhe Lu, Wenhua Wang, Xin Li
Summary: By conducting a fully coupled dynamic model test, we studied the vibration control effect of a TMD on a jacket OWT under wind and wave conditions. We designed and manufactured a TMD model and evaluated its vibration-mitigation performance in the experiment.
Article
Engineering, Marine
Valentina Laface, Gioacchino Alotta, Giuseppe Failla, Carlo Ruzzo, Felice Arena
Summary: This paper presents a new approach to mitigate the motion of floating spar supports for offshore wind turbines using a two-degree-of-freedom tuned mass damper device. Extensive numerical simulations prove its effectiveness compared to a standard single-degree-of-freedom tuned mass damper, and design parameters are identified.
Article
Green & Sustainable Science & Technology
Tianyi Zhang, Wenhua Wang, Xin Li, Bin Wang
Summary: This study proposes the application of a tuned mass damper inerter (TMDI) to mitigate vibrations in offshore wind turbines (OWTs) under combined wind-wave-earthquake loads. The optimized TMDI outperforms the TMD in suppressing the coupled wind-wave-earthquake responses by considering smaller attached mass. This superiority can be attributed to the multi-frequency and enhanced fundamental frequency suppression capabilities of the TMDI, resulting from the higher-mode damping effect and mass amplification effect of the inerter device.
Article
Engineering, Marine
Hang Zhang, Binrong Wen, Xinliang Tian, Xin Li, Yehong Dong, Manchang Wang, Zhike Peng
Summary: This paper presents an experimental study on the dynamic response mitigation of a floating offshore wind turbine (FOWT) under complex environmental loads. A highly adaptive Tuned Mass Damper (TMD) is designed and constructed to effectively reduce the vibration of the FOWT. The results verify the effectiveness of TMD and provide a foundation for experimental techniques on advanced FOWT controllers.
Article
Engineering, Civil
Vahid Jahangiri, Hadi Mirab, Reza Fathi, Mohammad Ettefagh
LATIN AMERICAN JOURNAL OF SOLIDS AND STRUCTURES
(2016)
Article
Engineering, Civil
Vahid Jahangiri, Mir Mohammad Ettefagh
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2018)
Article
Engineering, Mechanical
C. Sun, V. Jahangiri
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2018)
Article
Engineering, Civil
Chao Sun, Vahid Jahangiri
ENGINEERING STRUCTURES
(2019)
Article
Engineering, Marine
V Jahangiri, C. Sun
Article
Engineering, Marine
V Jahangiri, C. Sun
Article
Engineering, Civil
Mousa Rezaee, Reza Fathi, Vahid Jahangiri, Mir Mohammad Ettefagh, Aysan Jamalkia, Morteza H. Sadeghi
Summary: This paper presents an applicable method of damage detection and structural health monitoring for floating wind turbines based on the ARMA model and fuzzy classification. The proposed method is able to identify the damage location and severity of mooring lines with acceptable success rate in the presence of noise.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2021)
Article
Engineering, Civil
V. Jahangiri, C. Sun, F. Kong
Summary: A novel three-dimensional pounding pendulum tuned mass damper (3d-PPTMD) is developed to reduce vibrations of offshore wind turbines caused by misaligned wind and wave loading. The 3d-PPTMD is found to be more effective and compact compared to traditional damping systems, providing better mitigation performance under different loading scenarios and off-tuning effects.
ENGINEERING STRUCTURES
(2021)
Article
Construction & Building Technology
C. Sun, V. Jahangiri, H. Sun
Summary: The study introduces a three-dimensional adaptive pendulum tuned mass damper (3D-APTMD) to control excessive vibration of offshore wind turbines. Through an adaptive tuning algorithm, the damper adjusts its natural frequency and damping properties in real-time to match the wind turbine dominant frequency, showing promising effectiveness in maintaining performance during damage and offering improved reduction effects compared to traditional dampers.
STRUCTURAL CONTROL & HEALTH MONITORING
(2021)
Article
Construction & Building Technology
Zhiming Zhang, Chao Sun, Vahid Jahangiri
Summary: This study proposes a two-step strategy for damage identification of offshore wind turbines via Finite Element (FE) model updating. The first step identifies the damaged component(s), while the second step focuses on exact damage localization and quantification. Results indicate that the proposed methodology can correctly identify most structural damage using operational data.
STRUCTURAL CONTROL & HEALTH MONITORING
(2022)
Article
Engineering, Marine
V Jahangiri, C. Sun
Summary: This paper proposes a novel three-dimensional non-linear tuned mass damper (3d-NTMD) to effectively mitigate three-dimensional structural responses. A numerical search approach is adopted to determine the optimum design, and the 3d-NTMD has the potential to mitigate three-dimensional vibrations of a large set of civil/mechanical systems.
Article
Engineering, Marine
Chao Sun, Wei Song, Vahid Jahangiri
Summary: This study proposes a real-time hybrid simulation (RTHS) framework to study the structural performance of floating offshore wind turbines (FOWTs) under wind-wave loading. The delays in sensors and actuators have a significant influence on the performance of the RTHS framework. Sensitivity analyses quantified the errors caused by delays and noises. The results provide important information for future implementation and further development of RTHS technology for similar marine structures.
Article
Construction & Building Technology
Wei Song, Chao Sun, Yanhui Zuo, Vahid Jahangiri, Yan Lu, Qinghua Han
FRONTIERS IN BUILT ENVIRONMENT
(2020)
Article
Engineering, Civil
Chao Sun, Vahid Jahangiri, Hui Sun
SMART STRUCTURES AND SYSTEMS
(2019)
Article
Engineering, Marine
Alba Ricondo, Laura Cagigal, Beatriz Perez-Diaz, Fernando J. Mendez
Summary: This research presents a site-specific metamodel based on the SWASH numerical model simulations, which can predict coastal hydrodynamic variables in a fast and efficient manner. The metamodel uses downscaled and dimensionality reduced synthetic database to accurately reproduce wave setup, wave heights associated with different frequency bands, and wave runup. This method has great potential in coastal risk assessments, early warning systems, and climate change projections.
Article
Engineering, Marine
Xiao Yu, Wangjun Ren, Bukui Zhou, Li Chen, Xiangyun Xu, Genmao Ren
Summary: This study investigated and compared the compression responses and energy absorption capacities of coral sand and silica sand at a strain rate of approximately 1000 s-1. The results showed that coral sand had significantly higher energy absorption capacity than silica sand due to its higher compressibility. The study findings suggest that using poorly graded coral sand can improve its energy absorption capacity.
Article
Engineering, Marine
Jingxi Zhang, Junmin Mou, Linying Chen, Pengfei Chen, Mengxia Li
Summary: This paper proposes a cooperative control scheme for ship formation tracking based on Model Predictive Control. A predictive observer is designed to estimate the current motion states of the leader ship using delayed motion information. Comparative simulations demonstrate the effectiveness and robustness of the proposed controller.
Article
Engineering, Marine
Yu Yao, Danni Zhong, Qijia Shi, Ji Wu, Jiangxia Li
Summary: This study proposes a 2DH numerical model based on Boussinesq equations to investigate the impact of dredging reef-flat sand on wave characteristics and wave-driven current. The model is verified through wave flume experiments and wave basin experiments, and the influences of incident wave conditions and pit morphological features on wave characteristics are examined.
Article
Engineering, Marine
Jayanta Shounda, Krishnendu Barman, Koustuv Debnath
Summary: This study investigates the double-average turbulence characteristics of combined wave-current flow over a rough bed with different spacing arrangements. The results show that a spacing ratio of p/r=4 offers the highest resistance to the flow, and the double-average Reynolds stress decreases throughout the flow depth. The advection of momentum-flux of normal stress shows an increase at the outer layer and a decrease near the bed region after wave imposition. Maximum turbulence kinetic energy production and diffusion occur at different layers. The turbulence structure is strongly anisotropic at the bottom region and near the outer layer, with a decrease in anisotropy observed with an increase in roughness spacing.
Article
Engineering, Marine
Meng Zhang, Lianghui Sun, Yaoguo Xie
Summary: The research proposes a method for online identification of wave bending and torsional moment in hull structures. For structures without large openings, the method optimizes sensor positions and establishes a mathematical model to improve accuracy. For structures with large openings, a joint dual-section monitoring method is proposed to simultaneously identify bending and torsional moments in multiple key cross sections.
Article
Engineering, Marine
Longming Chen, Shutao Li, Yeqing Chen, Dong Guo, Wanli Wei, Qiushi Yan
Summary: This study investigated the dynamic response characteristics and damage modes of pile wharves subjected to underwater explosions. The results showed that the main damaged components of the pile wharf were the piles, and inclined piles had a higher probability of moderate or more significant damage compared to vertical piles. The study also suggested that replacing inclined piles with alternative optimized structures benefits the blast resistance of pile wharves.
Article
Engineering, Marine
I. -C Kim, G. Ducrozet, V. Leroy, F. Bonnefoy, Y. Perignon, S. Bourguignon
Summary: Previous research focused on the accuracy and efficiency of short-term wave fields in specific prediction zones, while we developed algorithms for continuous wave prediction based on the practical prediction zone and discussed important time factors and strategies to reduce computational costs.
Article
Engineering, Marine
Hang Xie, Xianglin Dai, Fang Liu, Xinyu Liu
Summary: This study investigates the load characteristics of a three-dimensional stern model with pitch angle through a drop test, and reveals complex characteristics of pressure distribution near the stern shaft. The study also shows that the vibration characteristics of the load are influenced by the drop height and pitch angle, with the drop height having a greater effect on the high-frequency components.
Article
Engineering, Marine
Hangyuan Zhang, Wanli Yang, Dewen Liu, Xiaokun Geng, Wangyu Dai, Yuzhi Zhang
Summary: The deep-water bridge is more vulnerable to earthquake damage than the bridge standing in air. The larger blocking ratio has a significant impact on the added mass coefficient, which requires further comprehensive study. The generation mechanism of block effect is analyzed using numerical simulation software ANSYS Fluent. The results show that the recirculation zone with focus reduces the pressure on the back surface of the cylinder, resulting in the peak value of in-line force not occurring synchronously with the peak value of acceleration. The change in position and intensity of the recirculation zone with focus, as well as the change in water flow around the cylinder surface, are identified as the generation mechanism of the block effect, which has a 10% influence on the hydrodynamic force. The changing rule of the added mass coefficient with blocking ratio is discussed in detail, and a modification approach to the current added mass coefficient calculation method is suggested. Physical experiments are conducted to validate the modification approach, and the results show that it is accurate and can be used in further study and real practice.
Article
Engineering, Marine
Golnesa Karimi-Zindashti, Ozgur Kurc
Summary: This study examines the performance of an in-house code utilizing a deterministic vortex method on the rotation of circular and square cylinders. The results show that rotational motion reduces drag forces, suppresses fluctuating forces, and increases lift forces. The code accurately predicts vortex shedding suppression and identifies the emergence of near-field wakes in the flow over rotating square cylinders.
Article
Engineering, Marine
George Dafermos, George Zaraphonitis
Summary: The survivability of damaged ships is of great importance and the regulatory framework is constantly updated. The introduction of the probabilistic damage stability framework has rationalized the assessment procedure. Flooding simulation tools can be used to investigate the dynamic response of damaged ships.
Article
Engineering, Marine
Xuyue Chen, Xu Du, Chengkai Weng, Jin Yang, Deli Gao, Dongyu Su, Gan Wang
Summary: This paper proposes a real-time drilling parameters optimization method for offshore large-scale cluster extended reach drilling based on intelligent optimization algorithm and machine learning. By establishing a ROP model with long short-term memory neurons, and combining genetic algorithm, differential evolution algorithm, and particle swarm algorithm, the method achieves real-time optimization of drilling parameters and significantly improves the ROP.
Article
Engineering, Marine
Sung-Jae Kim, Chungkuk Jin, MooHyun Kim
Summary: This study investigates the dynamic behavior of a moored submerged floating tunnel (SFT) under tsunami-like waves through numerical simulations and sensitivity tests. The results show that design parameters significantly affect the dynamics of the SFT system and mooring tensions, with shorter-duration and higher-elevation tsunamis having a greater impact.
Article
Engineering, Marine
G. Clarindo, C. Guedes Soares
Summary: Environmental contours are constructed using the Inverse-First Order Reliability Method based on return periods. The paper proposes the use of the Burr distribution to model the marginal distribution of long-term significant wave heights. The newly implemented scheme results in different environmental contours compared to the reference approach.