Article
Engineering, Marine
Eduard Lotovskyi, Angelo P. Teixeira, Carlos Guedes Soares
Summary: This paper examines the production availability and maintenance costs of an offshore wind turbine with a horizontal axis configuration using Petri Nets modelling and Monte Carlo Simulation. It evaluates the reliability and maintainability of the components, as well as the logistics of production and maintenance operations. The study aims to optimize age-based preventive maintenance parameters to reduce costs and increase operating income.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Green & Sustainable Science & Technology
F. Fallahi, I. Bakir, M. Yildirim, Z. Ye
Summary: This paper proposes a condition-based maintenance and operations scheduling approach that utilizes real-time sensor data and considers dependencies and uncertainties in wind farm operations. Experimental results demonstrate significant improvements in asset availability, market revenue, and maintenance costs.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)
Article
Engineering, Industrial
Rundong Yan, Sarah Dunnett, Lisa Jackson
Summary: This study examines the effectiveness and cost-efficiency of condition monitoring (CM) methods for operating offshore wind turbines (OWTs). Petri Net (PN) simulation models are used to evaluate the OWT availability and operation and maintenance (O & M) costs. The research suggests that combining purpose-designed CM with less frequent advanced service is the most cost-effective approach to achieve high turbine availability. Additionally, the use of a purpose-designed CM is crucial for the economical operation of OWTs and cannot be replaced by the current wind farm SCADA system.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2023)
Review
Green & Sustainable Science & Technology
Zhengru Ren, Amrit Shankar Verma, Ye Li, Julie J. E. Teuwen, Zhiyu Jiang
Summary: Operations and maintenance of offshore wind turbines (OWTs) are essential for the development of offshore wind farms. Maintenance, in particular, plays a crucial role in the overall cost of energy due to practical constraints and high costs associated with offshore operations. The impact of maintenance on the life cycle of offshore wind farms is complex and uncertain, with maintenance strategies significantly affecting efficiency, profitability, safety, and sustainability. Onsite maintenance involves intricate marine operations that rely on practical factors for efficiency and safety, while potential negative environmental impacts also need to be considered.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Engineering, Marine
Xiaosen Xu, Fang Wang, Oleg Gaidai, Arvid Naess, Yihan Xing, Junlei Wang
Summary: This study presents an efficient Monte Carlo based method to study bivariate extreme dynamic response statistics in the context of FOWT design. The ACER2D method enables accurate and efficient predictions of extreme return period contours, which can help optimize FOWT design values and reduce structural production costs.
Article
Engineering, Industrial
Yifei Wang, Rui He, Zhigang Tian
Summary: A condition-based maintenance (CBM) policy is proposed for electrical distribution systems (EDS) to achieve maintenance decision-making with minimum costs. The proposed method takes into account the inspection states of EDS and incorporates opportunistic maintenance. It also mitigates invalid failure data in EDS and considers the influence of structural dependencies.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2023)
Review
Energy & Fuels
Omer Khalid, Guangbo Hao, Cian Desmond, Hamish Macdonald, Fiona Devoy McAuliffe, Gerard Dooly, Weifei Hu
Summary: The cost of transferring technicians and equipment in marine operations is a significant part of offshore wind power. Considering the characteristics of sites for floating offshore wind farms, such as being further from the shore and in harsh environments, the cost evaluation needs to take into account maintenance requirements and restricted weather windows. There is an urgent need to explore the potential use of robotic systems in the operation and maintenance of wind farms to reduce expensive manned visits. Robotic systems are crucial not only in replacing repetitive tasks and reducing the cost of energy but also in reducing health and safety risks by assisting human operators in inspections. This paper provides a review of the current state of robotics applications in the operation and maintenance of floating offshore wind farms, highlighting emerging technology trends, challenges, opportunities, and future research agendas.
Article
Energy & Fuels
Cuong D. Dao, Behzad Kazemtabrizi, Christopher J. Crabtree, Peter J. Tavner
Summary: This paper models various maintenance activities and their impacts on offshore wind turbine components, proposing an integrated maintenance strategy that reduces costs, improves energy generation, and balances the trade-off between condition-based maintenance and other activities. Simulation results demonstrate the effectiveness of the proposed strategy in optimizing maintenance for offshore wind turbines.
Article
Engineering, Environmental
Leonardo Leoni, Ahmad BahooToroody, Mohammad Mahdi Abaei, Filippo De Carlo, Nicola Paltrinieri, Fabio Sgarbossa
Summary: Improving safety in engineering processes, especially in Oil & Gas operations, has been a key focus in recent decades. Risk remediation programs are essential to minimize failure risks and reduce associated costs. Comprehensive tools, such as Risk-Based Maintenance methodology, are crucial to address uncertainties and prioritize maintenance operations.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2021)
Article
Engineering, Civil
Jonas P. P. Falcao, Jose L. V. de Brito, Suzana M. M. Avila, Marcus V. G. de Morais
Summary: This paper describes a method for controlling the vibrations of floating offshore wind turbines (FOWTs) using a proposed tuned mass damper with an inverted pendulum (TMD-IP). The results show that the TMD-IP can effectively reduce tower rotation and barge translation, achieving reductions of approximately 95% and 70% respectively under harmonic excitation and random wind loading.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2023)
Article
Energy & Fuels
Ravi Pandit, Davide Astolfi, Anh Minh Tang, David Infield
Summary: Offshore wind turbines have gained popularity worldwide in recent years due to their ability to generate a large amount of electrical power. However, they are vulnerable to damage from high-speed winds, making accurate weather forecasting crucial for optimizing their operation and maintenance. This paper proposes three sequential data-driven techniques for long-term weather forecasting and compares their strengths and weaknesses. The study results suggest that the proposed technique can generate realistic and reliable weather forecasts and respond well to seasonality.
Article
Engineering, Marine
Jianda Cheng, Yan Liu, Wei Li, Tianyun Li
Summary: This paper proposes a deep reinforcement learning framework to explore the cost-optimal condition-based maintenance (CBM) policy for offshore wind turbines. By optimizing four policies, the framework demonstrates the impact of CBM policies on economic performance and highlights the interrelationship between maintenance policy and economic performance.
Article
Thermodynamics
Eirik Ogner Jastad, Torjus Folsland Bolkesjo
Summary: Offshore wind capacity in North Sea countries is expected to grow significantly in the next decade. This study analyzes the market value and economic potential of offshore wind developments using the Norwegian continental shelf as a case. Uncertain economic and political developments are incorporated through Monte Carlo simulations. The highest market values are obtained for wind parks with 3 GW installed capacity allowed to flexibly transmit electricity to several markets.
Article
Green & Sustainable Science & Technology
Li Yang, Gaoyang Li, Zihan Zhang, Xiaobing Ma, Yu Zhao
Summary: This article introduces a novel weather-centered O&M framework for wind turbines, considering the impacts of wind on energy production and maintenance plans. By quantifying both positive and negative effects of wind conditions, a flexible maintenance resource allocation policy is developed to improve overall revenue.
IEEE TRANSACTIONS ON SUSTAINABLE ENERGY
(2021)
Article
Engineering, Civil
Agnieszka Blokus-Dziula, Joanna Soszynska-Budny
Summary: This paper presents an availability analysis of a multistate infrastructure in the case of regular inspections and renewals, considering a wind farm infrastructure as a case study. The paper identifies and predicts the reliability of the infrastructure, distinguishing three reliability states and assuming Weibull reliability functions for its components. The multistate approach is applied to analyze the maintenance and availability of the infrastructure, distinguishing between early, random, and wear-out failures. The results show that the reliability structures of the infrastructure significantly affect its output power, highlighting the importance of determining the minimum number of operating wind turbines for ensuring its sufficient efficiency.
JOURNAL OF INFRASTRUCTURE SYSTEMS
(2022)
Article
Energy & Fuels
Shaikha Al-Sanad, Jafarali Parol, Lin Wang, Athanasios Kolios
Summary: An integrated structural optimization framework for onshore wind turbine towers was developed in this study, combining a parametric finite element analysis model with a genetic algorithm to minimize tower mass while meeting design requirements. The framework was validated and applied to a representative 2.0 MW onshore wind turbine tower, demonstrating significant mass reduction potential.
INTERNATIONAL JOURNAL OF SUSTAINABLE ENERGY
(2022)
Article
Engineering, Marine
Abdulhakim Adeoye Shittu, Ali Mehmanparast, Peyman Amirafshari, Phil Hart, Athanasios Kolios
Summary: This study presents a sensitivity analysis of offshore wind turbine support structures and emphasizes the importance of a probabilistic design approach. The results highlight the significant role of wind speed uncertainty in driving structural design, with hydrodynamic load effects being secondary. Additionally, considering the correlation between variables has a notable impact on structural reliability in ultimate limit state design.
INTERNATIONAL JOURNAL OF NAVAL ARCHITECTURE AND OCEAN ENGINEERING
(2022)
Article
Engineering, Multidisciplinary
D. Cevasco, J. Tautz-Weinert, M. Richmond, A. Sobey, A. J. Kolios
Summary: This study aims to investigate the feasibility of detecting and locating anomalies in the jacket support structure of an offshore wind turbine. A monitoring scheme is proposed based on a database of simulated modal properties, and a supervised Fisher's linear discriminant analysis is used to transform modal indicators for anomaly identification. A fuzzy clustering algorithm is trained to predict the membership of new data. A case study demonstrates the effectiveness of the global monitoring in detecting and locating simulated scenarios.
ASCE-ASME JOURNAL OF RISK AND UNCERTAINTY IN ENGINEERING SYSTEMS PART B-MECHANICAL ENGINEERING
(2022)
Article
Engineering, Mechanical
Peyman Amirafshari, Athanasios Kolios
Summary: Estimation of probability detection curves for non-destructive evaluation (NDE) can be time-consuming and costly. This study proposes a method based on Bayesian theorem to estimate POD curves, and validates its applicability using an existing database. The study finds that the predictions of the Bayesian model are consistent with the commonly used hit/miss model.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Review
Green & Sustainable Science & Technology
L. Wang, A. Kolios, X. Liu, D. Venetsanos, C. Rui
Summary: This paper presents a state-of-the-art reliability assessment of offshore wind turbine (OWT) support structures, highlighting the importance of considering uncertainties in soil properties and environmental loads. It provides a comprehensive review on structural reliability, reliability-based calibration of codes, fatigue reliability, and the implementation of reliability assessment. The paper also discusses current and future developments in reliability assessment, such as reliability-based design optimization, multi-hazard reliability analysis, and risk-based inspection.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)
Article
Engineering, Industrial
Guang Zou, Athanasios Kolios
Summary: With the development of technology, the benefits of informed structural maintenance decision-making based on systematic decision analysis have been increasingly recognized and required. This study investigates the potential benefits of negative outcomes to maintenance costs, failure risk, and reliability through developing a probabilistic VoI computational method. The influences of maintenance effect modeling on VoI computation are also studied.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2022)
Article
Energy & Fuels
Javier Contreras Lopez, Athanasios Kolios
Summary: Blades, as crucial components of wind turbines, have significant impact on both capital and operational costs. However, the failure modes and processes of the composite materials used in the blades are not well understood. Therefore, conducting a systematic study to analyze the failure modes and their criticalities is essential for reducing operational and maintenance costs. The results of this study can provide insights into maintenance strategies and risk mitigation techniques, contributing to the development of dynamic decision support systems.
Article
Green & Sustainable Science & Technology
Javier Contreras Lopez, Athanasios Kolios, Lin Wang, Manuel Chiachio
Summary: Blades are crucial and costly components of wind turbines. This study presents a framework for estimating leading edge erosion and energy production degradation over time. It utilizes synthetic wind and rain data, erosion protection coatings, and aerodynamic polar curves to simulate erosion and calculate energy losses. Applying this framework to a case study of a 5MW wind turbine in the North Sea, it was found that the maximum annual energy production losses range from 1.6% to 1.75% and the first erosion failure occurs between years 2 and 6.
Article
Engineering, Industrial
Ali Saleh, Manuel Chiachio, Juan Fernandez Salas, Athanasios Kolios
Summary: With the emergence of monitoring technologies, condition-based maintenance has become a reality in the wind energy industry. This is crucial in avoiding unnecessary maintenance actions and reducing costs associated with operation and downtime. An intelligent Petri net algorithm has been developed to model and optimize offshore wind turbines' operation and maintenance, combining advanced Petri net modelling with Reinforcement Learning. The results show that this method can achieve optimal condition-based maintenance policy while considering maximum availability and minimal operational costs.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2023)
Review
Energy & Fuels
Kelvin Palhares Bastos Sathler, Konstantinos Salonitis, Athanasios Kolios
Summary: In order to become more competitive and attract investors, wind energy systems need to reduce their final cost of energy. This can be achieved by either reducing costs or increasing production, using the metric of Overall Equipment Effectiveness (OEE) to measure and improve operational losses. The introduction of this metric can enable a comparison between different wind energy assets and provide an integrated indicator linking production and losses.
INTERNATIONAL JOURNAL OF SUSTAINABLE ENERGY
(2023)
Article
Engineering, Marine
A. Kolios, M. Richmond, S. Koukoura, B. Yeter
Summary: To meet the growing demand for offshore wind energy and reduce the cost of energy, it is important to improve the effectiveness of operation and maintenance activities. This can be achieved by accurately modeling these activities, which requires more accurate weather forecasting algorithms.
Article
Engineering, Marine
Baran Yeter, Yordan Garbatov, Feargal Brennan, Athanasios Kolios
Summary: The present study develops a risk model for analysing offshore wind projects based on operational and macroeconomic data. The study investigates the parameters defining the project-specific risk premium attached to these projects and conducts a probabilistic financial analysis using Monte Carlo Simulation. The model takes into account both the operational characteristics and macroeconomic factors to estimate the project-related risk and validate the cost of capital calculations. The developed model is demonstrated on a fictitious ageing offshore wind farm under different economic circumstances, considering critical project-specific parameters.
Article
Energy & Fuels
Shaikha Al-Sanad, Jafarali Parol, Lin Wang, Athanasios Kolios
Summary: Having an optimal design of the wind turbine tower is essential for economic and safe design. The commonly used partial safety factors (PSFs) are not tailored for specific designs. By calibrating the PSFs based on reliability, using information from the condition monitoring system, precise engineering of wind turbine tower structures can be achieved. This study develops a structural optimization model for wind turbine towers using a parametric finite element analysis model and a genetic algorithm. The optimized design of the tower with calibrated PSFs achieved a 2.9% reduction in mass compared to the design with un-calibrated PSFs.
Article
Energy & Fuels
Julia Walgern, Katharina Fischer, Paul Hentschel, Athanasios Kolios
Summary: The pitch system is a critical subsystem of wind turbines, playing a key role in maximizing wind capture while protecting the turbine from excessive loads. This study analyzes the failure rates of electrical and hydraulic pitch systems based on a large population of onshore assets. The results show high failure rates for both types of pitch systems, with hydraulic systems performing slightly better. Additionally, the study identifies variations in failure rates among different turbine manufacturers and a tendency for higher failure rates in larger turbines.
Article
Green & Sustainable Science & Technology
Mareike Leimeister, Maurizio Collu, Athanasios Kolios
Summary: This paper focuses on the optimization design of spar-type platforms for floating offshore wind turbines. In situ aero-hydro-servo-elastic simulations are used to support conceptual design optimization, considering transient and non-linear loads. The results show significant cost reduction potential when alternative structural and manufacturing strategies are considered.
WIND ENERGY SCIENCE
(2022)
Article
Engineering, Industrial
Mateusz Oszczypala, Jakub Konwerski, Jaroslaw Ziolkowski, Jerzy Malachowski
Summary: This article discusses the issues related to the redundancy of k-out-of-n structures and proposes a probabilistic and simulation-based optimization method. The method was applied to real transport systems, demonstrating its effectiveness in reducing costs and improving system availability and performance.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Wencheng Huang, Haoran Li, Yanhui Yin, Zhi Zhang, Anhao Xie, Yin Zhang, Guo Cheng
Summary: Inspired by the theory of degree entropy, this study proposes a new node identification approach called Adjacency Information Entropy (AIE) to identify the importance of nodes in urban rail transit networks (URTN). Through numerical and real-world case studies, it is found that AIE can effectively identify important nodes and facilitate connections among non-adjacent nodes.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Hongyan Dui, Yaohui Lu, Liwei Chen
Summary: This paper discusses the four phases of the system life cycle and the different costs associated with each phase. It proposes an improvement importance method to optimize system reliability and analyzes the process of failure risk under limited resources.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Xian Zhao, Chen Wang, Siqi Wang
Summary: This paper proposes a new rebalancing strategy for balanced systems by switching standby components. Different switching rules are provided based on different balance conditions. The system reliability is derived using the finite Markov chain imbedding approach, and numerical examples and sensitivity analysis are presented for validation.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Fengyuan Jiang, Sheng Dong
Summary: Corrosion defects are the primary causes of pipeline burst failures. The traditional methodologies ignore the effects of random morphologies on failure behaviors, leading to deviations in remaining strength estimation and reliability analysis. To address this issue, an integrated methodology combining random field, non-linear finite element analysis, and Monte-Carlo Simulation was developed to describe the failure behaviors of pipelines with random defects.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Guoqing Cheng, Jiayi Shen, Fang Wang, Ling Li, Nan Yang
Summary: This paper investigates the optimal joint inspection and mission abort policies for a multi-component system with failure interaction. The proportional hazards model is used to characterize the effect of one component's deterioration on other components' hazard rates. The optimal policy is studied to minimize the expected total cost, and some structural properties of the optimal policy are obtained.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Hongyan Dui, Yaohui Lu, Shaomin Wu
Summary: A new resilience model is proposed in this paper for systems under competing risks, and related indices are introduced for evaluating the system's resilience. The model takes into account the degradation process, external shocks, and maintenance interactions of the system, and its effectiveness is demonstrated through a case study.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Yang Li, Jun Xu
Summary: This paper proposes a translation model based on neural network for simulating non-Gaussian stochastic processes. By converting the target non-Gaussian power spectrum to the underlying Gaussian power spectrum, non-Gaussian samples can be generated.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Yanyan Liu, Keping Li, Dongyang Yan
Summary: This paper proposes a new random walk method, CBDRWR, to analyze the potential risk of railway accidents. By combining accident causation network, we assign different restart probabilities to each node and improve the transition probabilities. In the case study, the proposed method effectively quantifies the potential risk and identifies key risk sources.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Nan Hai, Daqing Gong, Zixuan Dai
Summary: The current risk management of utility tunnel operation and maintenance is of low quality and efficiency. This study proposes a theoretical model and platform that offer effective decision support and improve the safety of utility tunnel operation and maintenance.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Tomoaki Nishino, Takuya Miyashita, Nobuhito Mori
Summary: A novel modeling methodology is proposed to simulate cascading disasters triggered by tsunamis considering uncertainties. The methodology focuses on tsunami-triggered oil spills and subsequent fires and quantitatively measures the fire hazard. It can help assess and improve risk reduction plans.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Mingjiang Xie, Yifei Wang, Jianli Zhao, Xianjun Pei, Tairui Zhang
Summary: This study investigates the effect of rockfall impact on the health management of pipelines with fatigue cracks and proposes a crack propagation prediction algorithm based on rockfall impact. Dynamic SIF values are obtained through finite element modeling and a method combining multilayer perceptron with Paris' law is used for accurate crack growth prediction. The method is valuable for decision making in pipeline reliability assessment and integrity management.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Saeed Jamalzadeh, Lily Mettenbrink, Kash Barker, Andres D. Gonzalez, Sridhar Radhakrishnan, Jonas Johansson, Elena Bessarabova
Summary: This study proposes an integrated epidemiological-optimization model to quantify the impacts of weaponized disinformation on transportation infrastructure and supply chains. Results show that disinformation targeted at transportation infrastructure can have wide-ranging impacts across different commodities.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Jiaxi Wang
Summary: This paper investigates the depot maintenance packet assignment and crew scheduling problem for high-speed trains. A mixed integer linear programming model is proposed, and computational experiments show the effectiveness and efficiency of the improved model compared to the baseline one.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
Article
Engineering, Industrial
Yuxuan Tian, Xiaoshu Guan, Huabin Sun, Yuequan Bao
Summary: This paper proposes a DFMs searching algorithm based on the graph neural network (GNN) to improve computational efficiency and adaptively identify DFMs. The algorithm terminates prematurely when unable to identify new DFMs.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2024)
