Experimental study of improved modal strain energy method for damage localisation in jacket-type offshore wind turbines

Liu, Fushun; Li, Huajun; Li, Wei; Wang, Bin

doi:10.1016/j.renene.2014.07.007

Cited by 59 publications

(24 citation statements)

References 12 publications

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“…Modal Strain Energy is a method, which can be used in the model updating technique. There are certain advantages for using the modal strain energy for model updating, and some researches have been studied this topic (Liu, Li, H., Li, W., & Wang, 2014;Yan Ren, & Huang, 2012).…”

Section: Introductionmentioning

confidence: 99%

Damage Detection of Truss Structures by Reduction of Degrees of Freedom Using the Serep Method

Arefi

Gholizad

2020

BJRBE

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Damage detection of bridge structures during their operating lifetime is essential. In this paper, two approaches, All Degrees of Freedom and Reduction of the Degrees of Freedom methods, are used to detect the damages in structures. The first method considers All Degrees of Freedom of the structure and the second method, Reduction of the Degrees of Freedom. Since the sensors are installed only on a few degrees of freedom, the responses are available for some of them. The Degrees of Freedom must be reduced and System Equivalent Reduction Expansion Process method is one of the most efficient ways to solve the problem. This research aimed to identify the damage of structures using the Modal Strain Energy method by reducing the structural degree of freedom. Two standard examples are used and the results compared to different damage cases to examine the efficiency of the mentioned method. The results illustrated the proper performance of the Reduction of the Degrees of Freedom method to identify the damage in truss structures. By increasing the number of modes, Reduction of the Degrees of Freedom method detects considerably more accurate the damaged elements, especially when the noise is considered. Also, based on the outcomes to identify damaged elements, it is possible to consider more modes instead of more sensors.

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Section: Introductionmentioning

confidence: 99%

Damage Detection of Truss Structures by Reduction of Degrees of Freedom Using the Serep Method

Arefi

Gholizad

2020

BJRBE

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“…Therefore, the present research is limited, but in agreement with the assumptions considered in this study. Further investigations can be performed in a future work such as tubular joint design [22] and fatigue assessment [23,24]. The influence of a different wind turbine such as vertical axis wind turbines [25] and wind turbines in other environments [26,27] is also worth investigating.…”

Section: Introductionmentioning

confidence: 99%

Initial Design Phase and Tender Designs of a Jacket Structure Converted into a Retrofitted Offshore Wind Turbine

2019

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Jackets are the most common structures in the Adriatic Sea for extracting natural gas. These structural typologies are suitable for relative low water depths and flat sandy sea floors. Most of them have been built in the last 50 years. When the underground source finishes, these structures should be moved to another location or removed if they have reached their design life. Nevertheless, another solution might be considered: change the future working life of these platforms by involving renewable energy and transforming them into offshore wind towers. The present research proposal aims to investigate the possibility of converting actual structures for gas extraction into offshore platforms for wind turbine towers. This simplified analysis is useful for initial design phases and tender design, or generally when available information is limited. The model proposed is a new simplified tool used to study the structural analysis of the jacket structure, developed and summarized in 10 steps, firstly adopted to study the behavior of the oil and gas structure and then for the retrofitted wind tower configuration.

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“…Offshore wind energy provides better wind conditions with less turbulence than onshore wind and has no visual or auditory annoyances (Liu et al, 2014). Thus, it has become an attractive source of renewable energy.…”

Section: Introductionmentioning

confidence: 99%

Numerical and experimental investigation of modal-energy-based damage localization for offshore wind turbine structures

Zhang

Yang

2018

Advances in Structural Engineering

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Offshore wind turbine structures are prone to deterioration and damage during their service life in harsh marine environment. To explore highly efficient and robust damage detection methods for offshore wind turbine structures, three well-known modal strain energy indices are reviewed first and then a new index named total modal energy method is proposed. The innovation of the new index is the simultaneous use of modal strain energy and modal kinetic energy. To investigate the feasibility and robustness of the four modal-energy-based methods, numerical and experimental studies are conducted on a tripod-type offshore wind turbine structure with simulated and measured data. It is indicated that all the four modal-energy-based methods work well with limited incomplete modal data, especially for the single-damage cases. While for the cases of multiple damage locations, the new total modal energy index significantly outperforms the traditional modal strain energy indices. Moreover, high robustness is shown for the indices, when the measured mode shapes of undamaged and damaged structures are polluted with the same noise level. However, when their noise levels have some difference, two of the modal strain energy indices turn invalid, but the new total modal energy index still shows stronger robustness. As frequencies are also used in the total modal energy index, its robustness to the noise in modal frequencies is also studied. It is shown that the results are slightly affected by the measurement noise in modal frequencies. Besides, the influence of finite element modeling errors is also investigated with both simulated and experimental data. Results show that all the four modal-energybased methods are all very stable and insensitive to certain modeling errors. So, finite element model updating is not necessary in the test structure herein.

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Experimental study of improved modal strain energy method for damage localisation in jacket-type offshore wind turbines

Cited by 59 publications

References 12 publications

Damage Detection of Truss Structures by Reduction of Degrees of Freedom Using the Serep Method

Damage Detection of Truss Structures by Reduction of Degrees of Freedom Using the Serep Method

Initial Design Phase and Tender Designs of a Jacket Structure Converted into a Retrofitted Offshore Wind Turbine

Numerical and experimental investigation of modal-energy-based damage localization for offshore wind turbine structures

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