Article
Engineering, Marine
Anais Jacob, Ali Mehmanparast
Summary: This study conducted corrosion-fatigue tests on fracture mechanics specimens extracted from an S355 G10+M structural steel welded plate, showing significant effects of corrosive environment on fatigue crack growth rates, especially at the beginning of tests.
Review
Engineering, Marine
Yan Dong, Yordan Garbatov, C. Guedes Soares
Summary: This review focuses on the uncertainties in fatigue loads, damage, and crack growth that should be considered in reliability assessments. The study includes complex fatigue loads from wave, wind, and cargo loading and unloading actions. The S-N curve approach using Palmgren-Miner's rule and the crack growth approach are the commonly used formulations for fatigue life assessment. The associated governing factors and their uncertainties, which are necessary for fatigue reliability analyses, are given special attention.
Article
Materials Science, Multidisciplinary
Helen Ryan, Ali Mehmanparast
Summary: Corrosion-fatigue is a dominant failure mechanism in offshore structures, and this study proposes a new approach to accurately describe the corrosion-fatigue behaviour under various loading conditions and frequencies. Experimental data analysis shows the limitations of the traditional fracture mechanics parameter Delta K in elucidating the effects of frequency on CFCG rates. A new fracture mechanics parameter and CFCG model are developed, which correlate well with experimental data.
MECHANICS OF MATERIALS
(2023)
Article
Engineering, Marine
Paul Qvale, Hakon O. Nordhagen, Sigmund K. As, Bjorn H. Skallerud
Summary: Experimental observations indicate that pre-corrosion does not significantly affect fatigue life, while eight months of natural corrosion also has minimal impact on remaining fatigue life. It is unlikely that corrosion-induced crack tip blunting can retard fatigue crack growth, and anodic polarization accelerated corrosion is unsuitable for replicating natural corrosion of fatigue cracks.
Article
Engineering, Marine
Ming He, Ming Pang, Nian-Zhong Chen
Summary: This paper proposes an engineering critical assessment (ECA) framework for the monopile foundation of offshore wind turbines subjected to pitting. In this framework, a finite element (FE) analysis is conducted based on a 3D model of pitting, and the extended finite element method (XFEM) is used to predict the propagation behavior of pitting cracks. The critical size of pitting cracks is then assessed by a failure assessment diagram (FAD) according to the BS7910. The proposed ECA framework is more effective in assessing the effects of pits on crack propagation, avoiding excessive conservatism in fatigue failure assessment for pitting structures.
Article
Engineering, Mechanical
Wangwen Zhao
Summary: This study investigates the uncertainties in fatigue design of offshore structures and recalibrates the Design Fatigue Factors through a detailed reliability analysis. The results show that the Design Fatigue Factors vary for different environmental conditions while maintaining the same target reliability.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
K. Sadananda, N. Iyyer
Summary: Failure diagrams are essential for evaluating the safe use of structural components under service loads and determining the need for monitoring or replacement. They help assess fatigue life or crack growth caused by fluctuating loads, providing early warning of failure. Understanding subcritical crack growth behavior and its application in components is crucial.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Energy & Fuels
Stian H. Sorum, George Katsikogiannis, Jorgen Amdahl, Ana M. Page, Rasmus T. Klinkvort
Summary: A sensitivity study was conducted to investigate the impact of input parameter uncertainties on fatigue analyses of offshore wind turbines. The results showed that the uncertainty in the SN curves and fatigue capacity primarily governed the fatigue utilization. The uncertainty in environmental conditions, particularly wind loads, became increasingly important with larger turbine sizes. Accurate models and a focus on environmental conditions are recommended to reduce the uncertainty in design.
Article
Engineering, Mechanical
Wandong Wang, Lingzhen Li, Ardalan Hosseini, Elyas Ghafoori
Summary: The study proposes an innovative fatigue strengthening solution for metallic structures using iron-based shape memory alloy and bonding technique. Experimental results demonstrate that bonded prestressed Fe-SMA strips are much more effective than traditional CFRP strips in retarding fatigue crack growth, extending the fatigue crack growth life by a factor of 3.51.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
Noelle Easter C. Co, James T. Burns
Summary: The fatigue resistance of aerospace structures is affected by corrosion damage. The formation of fatigue cracks is influenced by the micro-scale corrosion morphologies and underlying microstructure. A modest correlation was found between the initiation of fatigue cracks and grains with high misorientation angles with respect to adjacent grains.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Chemistry, Multidisciplinary
F. He, V. K. Thakur, M. Khan
Summary: The study emphasizes the importance of comprehensive research on the crack propagation behavior of polymeric structures fabricated using three-dimensionally printed parts. Existing studies are found to be limited in accurately assessing the true crack growth phenomenon in real applications, posing a challenge for evaluating crack growth under time-dependent coupled loading conditions.
MATERIALS TODAY CHEMISTRY
(2021)
Article
Engineering, Chemical
Zhen-Ming Wang, Kyong-Ho Chang, Shazia Muzaffer, Mikihito Hirohata
Summary: In this paper, a 3D fatigue finite element analysis was conducted to predict the fatigue life and crack initiation of a welded monopile substructure. The analysis results were compared with hot spot stresses and Det Norske Veritas (DNV-GL) standards.
Article
Engineering, Mechanical
Sulaiman Shojai, Peter Schaumann, Moritz Braun, Soren Ehlers
Summary: This paper investigates the impact of pitting corrosion and stress concentration on the fatigue life endurance of structural steel used for offshore wind support structures. Experimental and numerical simulation results show that hotspots have a significant influence on the crack location and crack path.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Review
Engineering, Marine
Kingsley Sunday, Feargal Brennan
Summary: This paper highlights the unique design challenges of taller and heavier OWT monopile structures, as well as the future challenges facing OWT monopile concepts with increasing structure size and turbine capacity. The review focuses on technical aspects including grouted connection, damping, soil scouring, soil-monopile interaction modeling, and corrosion.
Article
Engineering, Mechanical
Victor Okenyi, Shukri Afazov, Neil Mansfield, Martin Alexander Eder, Asger Bech Abrahamsen, Soren Faester, Christopher Gottlieb Klingaa, Petros Siegkas, Mahdi Bodaghi
Summary: This study employed a novel corrosion-based fatigue model to assess the fatigue life of offshore welded structures. The model incorporated a corrosion factor concept to consider the influence of corrosion pits on the fatigue performance. By characterizing the parameters of the pits, fatigue S-N curves were predicted and compared with experimental data. This approach has the potential to be used for remaining life assessment of offshore structures.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
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
Energy & Fuels
Kingsley Sunday, Feargal Brennan
Summary: The appropriate offshore wind turbine monopile structural modelling technique is crucial for the successful design and installation of larger and heavier structures. The lack of clear design guidance and acceptable modelling techniques leads to conservative and expensive design and installation approaches. This study compares three modelling techniques and finds that 3D finite element modelling with mass soil results in improved structural response and reduced displacement, ultimately improving the structure's operational design life.
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, Marine
Shen Li, Andrea Coraddu, Feargal Brennan
Summary: This paper introduces a framework for optimizing sensor placement to support structural health monitoring systems. An illustrative example is used to demonstrate how to solve the inverse prediction problem using radial basis function approach, and the optimization is carried out using an evolutionary algorithm.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
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)
Article
Green & Sustainable Science & Technology
Abel Arredondo-Galeana, Gerrit Olbert, Weichao Shi, Feargal Brennan
Summary: We propose a hydrodynamic and structural model for designing a single foil wave cycloidal rotor in regular waves. The hydrodynamic part employs potential flow and represents the foil as a point vortex, taking into account unsteady effects through Theodorsen's function. The structural part uses beam theory to calculate the bending moments and stresses on the cyclorotor's foil. Through CFD validation and benchmarking against experimental measurements, we find that the hydrodynamic model accurately predicts the mean radial loading on the foil in attached flow conditions, and accurately predicts the mean tangential loading only when operating close to stall, at maximum lift conditions. By utilizing the coupled model, we design a rotor that operates optimally for a range of sea conditions, optimizing power extraction while maintaining the allowable stress level.
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
Mechanics
Yang Huang, Qing Xiao, Guillermo Idarraga, Liu Yang, Saishuai Dai, Farhad Abad, Feargal Brennan, Saeid Lotfian
Summary: The use of flexible materials in wave energy converters has attracted attention due to their potential to enhance reliability and conversion efficiency. Existing models for fluid-structure interaction in flexible wave energy converters lack accuracy and general applicability, necessitating a high-fidelity approach. In this study, a computational fluid dynamics and finite element analysis-based framework is developed to provide detailed flow field and structural response information. This tool accurately captures the nonlinear phenomena associated with wave-structure interaction in wave energy converters.
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
Green & Sustainable Science & Technology
M. Genovese, F. Piraino, P. Fragiacomo
Summary: This research proposes the concept of a hydrogen valley in southern Italy, where hydrogen is produced centrally and delivered via fuel cell hybrid trains to refueling stations, providing transportation services. The analysis from both technical and economic perspectives shows that the cost of hydrogen and energy efficiency reached competitive levels, and hydrogen rail transport offers significant benefits in terms of emissions reduction and economic gains compared to conventional diesel trains and fully electric trains.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Review
Green & Sustainable Science & Technology
Miaomiao Liu, Payam Nejat, Pinlu Cao, Carlos Jimenez-Bescos, John Kaiser Calautit
Summary: This article provides a critical review of the performance of windcatchers, pointing out the current research gaps and issues, and proposing directions for further investigation and market prospects.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Review
Green & Sustainable Science & Technology
Solomon Boadu, Ebenezer Otoo
Summary: Despite Africa's vast energy resources, including wind energy, the continent faces challenges in developing its wind energy industry. Northern African countries and South Africa currently dominate the wind energy sector in Africa. To uplift Africa's socio-economic status, strong political will, supportive policies, and institutional frameworks are needed to drive the development of wind energy and overcome existing challenges.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Article
Green & Sustainable Science & Technology
E. K. Grubbs, S. M. Gruss, V. Z. Schull, M. J. Gosney, M. V. Mickelbart, S. Brouder, M. W. Gitau, P. Bermel, M. R. Tuinstra, R. Agrawal
Summary: As the global population grows, the demand for food, energy, and water will increase significantly. However, limited land availability and competition for solar resources pose challenges to resource generation technologies. In the United States, both agriculture and solar energy production have adopted densification schemes to improve yields and energy output per unit of land. This research proposes an Agrivoltaic food and energy coproduction architecture that optimizes power generation while maintaining crop productivity by implementing ideal anti-tracking during critical growth periods. This technology offers a viable pathway for widespread solar implementation throughout the contiguous United States.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Review
Green & Sustainable Science & Technology
Han Shao, Rui Henriques, Hugo Morais, Elisabetta Tedeschi
Summary: The integration of offshore wind energy into the electric grid provides opportunities in terms of environmental sustainability and cost efficiency, but poses challenges to power quality. This survey offers a deeper understanding of disturbance detection and classification tools, exploring root causes, disturbance locations, and algorithmic solutions. It highlights synchronized waveform measurement and discusses evaluation metrics for detection and classification algorithms. Additionally, a novel system-wide monitoring framework is proposed.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Review
Green & Sustainable Science & Technology
Eleni Davidson, Yair Schwartz, Joe Williams, Dejan Mumovic
Summary: A continued upward trend in global greenhouse gas emissions poses risks to global infrastructure and built assets. Maintaining high indoor environmental quality standards is a challenge for higher education institutions under future climates. Passive cooling mechanisms may be insufficient to tolerate predicted temperature increases. Different building typologies have varying energy demand projections.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Article
Green & Sustainable Science & Technology
Kexin Pang, Jian Zhou, Stamatis Tsianikas, David W. Coit, Yizhong Ma
Summary: This study proposes a new framework for long-term microgrid expansion planning, using deep reinforcement learning method to consider various uncertainties and constraints. The framework aims to enhance the effectiveness of microgrid expansion planning from the perspectives of economy, resilience, and greenhouse gas emission reduction.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Article
Green & Sustainable Science & Technology
Jun Zhao, Kangyin Dong, Xiucheng Dong
Summary: The continuous growth of global electricity penetration has provided modern energy for alleviating energy poverty, but its impact on carbon neutrality has been overlooked. The research reveals that clean electricity from traditional fossil energy and renewable energy has a positive influence on the greenhouse effect. Eradicating energy poverty can effectively alleviate the greenhouse effect, especially in non-Belt and Road Initiative (B&RI) nations.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Review
Green & Sustainable Science & Technology
Hossein Shahbeik, Hamed Kazemi Shariat Panahi, Mona Dehhaghi, Gilles J. Guillemin, Alireza Fallahi, Homa Hosseinzadeh-Bandbafha, Hamid Amiri, Mohammad Rehan, Deepak Raikwar, Hannes Latine, Bruno Pandalone, Benyamin Khoshnevisan, Christian Sonne, Luigi Vaccaro, Abdul-Sattar Nizami, Vijai Kumar Gupta, Su Shiung Lam, Junting Pan, Rafael Luque, Bert Sels, Wanxi Peng, Meisam Tabatabaei, Mortaza Aghbashlo
Summary: This review explores the production of biocrude oil from biomass feedstocks through the process of hydrothermal liquefaction (HTL). It discusses the impact of process parameters on the quality, quantity, cost, and environmental impacts of biofuels. The review also highlights the challenges and prospects for the future development of biocrude oil.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Article
Green & Sustainable Science & Technology
Meysam Majidi Nezhad, Mehdi Neshat, Georgios Sylaios, Davide Astiaso Garcia
Summary: Digital twins promise innovation for the marine renewable energy sector by using modern technological advances and the existing maritime knowledge frameworks. This research presents critical aspects of digital twin implementation challenges in marine energy digitalization approaches that use and combine data systems.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Article
Green & Sustainable Science & Technology
Yeganeh Sharifian, Hamdi Abdi
Summary: This paper discusses the background and objectives of the multi-area economic dispatch problem, as well as various techniques and methods applied in this field. It also covers comprehensive formulations of the problem and important issues in the field of probabilistic MAED, along with some related concepts and suggestions.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Review
Green & Sustainable Science & Technology
J. G. B. Churchill, V. B. Borugadda, A. K. Dalai
Summary: The increasing global energy demand and the need to reduce fossil fuel reliance have created a demand for renewable and sustainable fuel sources. This review explores the potential of tall oil, a by-product of the pulping industry, as a feedstock for biofuels. The review provides an overview of tall oil production, purification, and treatment, and investigates recent trends and barriers towards tall oil-derived biofuels.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Review
Green & Sustainable Science & Technology
David C. Broadstock, Xiangnan Wang
Summary: This study provides a general review of research on district cooling, identifying key topics and themes and highlighting potential research priorities for future studies.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Article
Green & Sustainable Science & Technology
L. Scharnhorst, D. Sloot, N. Lehmann, A. Ardone, W. Fichtner
Summary: This study investigates and analyzes the barriers to demand response in industrial and commercial sectors, highlighting their significance. Concerns about diminished product quality, disruptions to production processes, human resource management, and revenue uncertainty are identified as the most frequently cited barriers. Overcoming these barriers requires bridging knowledge gaps, allocating sufficient resources, and adapting external incentives and policies.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
Review
Green & Sustainable Science & Technology
Tong Feng, Yuechi Sun, Yating Shi, Jie Ma, Chunmei Feng, Zhenni Chen
Summary: Air pollution is a significant global challenge, and policymakers have implemented policies to reduce it. Evaluating the effectiveness of these policies is critical, and our study reveals trends and gaps in air pollution policy research. We found that research has shifted from focusing solely on air pollutants to including methodologies, policies, and health implications. China has emerged as a major contributor in this field of research.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2024)
