Found 11 results
Open Access
Article
16 March 2026Research on the Bearing Characteristics of Bucket Foundations for Offshore Wind Turbines in Double-Layered Clay
Bucket foundations have been widely used in marine engineering, such as offshore wind power, due to their anti-overturning performance and convenient installation. In China’s coastal areas, clay soil is widely distributed, and most of the seabed has layered clay. However, the bearing capacity of bucket foundations in layered soil is significantly different from that in homogeneous soil. Currently, there is relatively little research on the bearing capacity of bucket foundations in layered clay. Therefore, the finite element analysis method is adopted to establish a bearing capacity calculation method of bucket foundations in double-layer clay. The axial failure mechanisms and ultimate bearing capacity of bucket foundations in double-layer clay are deeply discussed, and the corresponding ultimate bearing capacity calculation method is given based on the numerical analysis results. The combined bearing capacity of bucket foundations in double-layer clay is fully analyzed, and the evolution method of V-H, V-M, H-M, and V-H-M failure envelopes is given.
Open Access
Article
19 January 2026Life Cycle Assessment of the Emissions Reduction Potential of Recycled-Carbon-Fibre for Western-Australian Offshore Wind Turbine Blades
The objective of this study is to conduct a review of recycled-carbon-fibre (rCF) wind turbine blades’ feasibility, through a comparison of global and Australian wind sector waste, and a comparison of virgin-carbon-fibre (vCF) with rCF wind turbine blades’ greenhouse-gas GHG-emissions, and, recommend an approach for carbon-fibre CF-use in the fledgling Australian offshore wind industry, based on global-warning-potential GWP. This study assesses the life-cycle GHG-emissions of virgin-carbon-fibre wind turbine blades versus recycled-carbon-fibre wind turbine blades, in both non-structural and structural configurations. All production, use and recycling is assessed in terms of a West Australian context, in which the functional unit is three turbine blades used on an onshore wind farm, towards potential applicability for (as yet, non-existent) offshore WA fields. An approach incorporating a GaBi/Sphera database-study provides a timely screening/preliminary study, in which it was found that non-structural recycled carbon fibre wind turbine blades had very similar GHG emission levels compared to standard virgin carbon fibre blades, with sensitivity analysis revealing that in worst-case scenarios, non-structural carbon fibre has higher GHG emissions. Structurally recycled carbon fibre blades performed significantly better than standard virgin carbon fibre wind turbine blades with a 56% reduction in GHG emissions; savings were not affected significantly by parameter changes during sensitivity analysis. It is evident that recycled-carbon-fibre can significantly reduce wind turbine blades’ GWP and contribute to the circular economy in the fledgling West Australian offshore-wind-turbine sector.
Open Access
Review
23 December 2025A Review of Bolted Connections for the Assembly of Floating Offshore Wind Turbine Foundations
Bolted connections are being considered as an assembly method for the foundations of floating offshore wind turbines. A clear benefit of this method is the short assembly time of these foundations compared to welding. However, some concerns around corrosion, fatigue, and the ability of bolted connections to maintain preload remain. This review found that conventional ring flanges may not be suitable for the assembly of floating foundations, mainly due to the risk of bolt loosening and reduced fatigue life. However, the C1 Wedge Connection is an innovative bolted connection that has shown its ability to retain bolt preload during tests. Likewise, the Compact Flange Connection has shown its ability to retain preload without requiring maintenance during operational stages and furthermore, has a long and successful track record in offshore oil and gas applications. This review revealed several research gaps related to the use of bolted connections for the assembly of floating wind turbine foundations. These include: a lack of research on the effects of bolt loosening; dynamic loads and shear forces on bolted connections and their effect on fatigue life; structural health monitoring methods of bolted connections; and the health and safety of technicians in confined spaces with difficult accessibility. The Compact Flange Connection is perhaps the best suited bolted connection for the assembly of floating foundations. However, more research, and crucially, successful offshore demonstrations will be essential to increase confidence in the suitability of bolted connections for the floating offshore wind industry.
Open Access
Article
19 November 2025Effects of Platform Motions on Dynamic Responses in a Floating Offshore Wind Turbine Blade
Floating offshore wind turbines (FOWTs) offer great potential for harnessing deep-sea wind energy. This study examines the effects of six-degree-of-freedom (6-DOF) platform motions on the dynamic structural responses of a FOWT blade by comparing its performance with a fixed-bottom system. Integrated aero-hydro-servo-elastic simulations for a 5-MW spar-type FOWT were conducted under various design load cases. Results indicate that the floating tower’s first-order natural frequency was about 29% higher than that of the fixed-bottom tower. Platform motions markedly influenced blade flapwise and torsional responses, with the effect intensifying under larger waves. For instance, as the significant wave height increased from 1.70 m to 9.90 m, the differences in peak response between the floating and fixed-bottom systems grew from 0.104 m to 0.363 m for blade-tip flapwise deflection, from 528.1 kN·m to 1817.4 kN·m for the root flapwise bending moment, and from 5.02 kN·m to 18.73 kN·m for the root torsional moment. In contrast, blade edgewise responses showed negligible changes, with peak deflection differences below 0.05 m. Blade loads were more sensitive to wave conditions, while platform motion magnitudes were more affected by wind. These findings offer insights into the load characteristics and structural design of FOWT blades.
Open Access
Article
06 November 2025Application of Blades Aerodynamic Optimization Design Platform Based on the Performance of Offshore Wind Turbines
Optimizing aerodynamic performance with low loads is a core objective in high-power wind turbine blade design. This study develops a blade aerodynamic optimization design platform based on the performance of a wind turbine. By applying automated design principles, the platform rapidly iterates to obtain blade profiles that meet turbine development requirements, significantly improving design efficiency and reliability. Key findings include That Optimizing chord length and relative thickness distributions substantially contribute to enhancing power generation while reducing load levels. Relative thickness and twist angle distributions are critical parameters influencing stall characteristics during blade operation. Superior aerodynamic performance notably increases annual rated power generation hours but simultaneously elevates blade thrust and root loads. Among the evaluated designs meeting turbine specifications, the #436 blade achieves a maximum power coefficient of 0.4679 while maintaining low ultimate and fatigue loads. Furthermore, when paired with the wind turbine, its rated wind speed reaches 10.9 m/s, and its annual rated power generation hours under various inflow wind speed conditions all meet the turbine system’s development requirements. Consequently, the #436 blade demonstrates exceptional system compatibility, making the 8.5 MW turbine equipped with this blade highly competitive in the market.
Open Access
Review
22 August 2025The Recyclability of Wind Turbine Blade Material, Manufacturing Process, and Recycling Technology
As wind energy continues to be deployed at a significantly increasing rate, the number of decommissioned wind turbines is expected to increase accordingly. To improve material efficiency, a large amount of waste requires appropriate identification and recycling, particularly the composite materials used in wind turbine blades (WTB). This study focuses on two life cycle stages, manufacturing and the decommissioning stage, which contribute most to the waste generation of WTB. This study investigates the material efficiency factors in WTB and organises fragmental information in manufacturing waste management, focusing on the recycling factor and quantifying the recyclability of wind turbine blade material regarding the different recycling technologies. This study fills the gap in existing research by evaluating recycling methods for specified carbon fibre-reinforced polymers (CFRPs) and glass fibre-reinforced polymers (GFRPs) using a revised recyclability index. Additionally, innovative sustainable materials and recent composite recycling studies have also been incorporated into the quantification and evaluation to update the current progress. The current source of WTB post-production waste, the corresponding disposal method, and opportunities were also reviewed and identified. The findings quantified recyclability and revealed that the recyclability of WTB materials varies significantly depending on the specific composite type and the recycling method employed. Furthermore, the calculated recyclability, combined with other factors such as global warming potential (GWP), cost, and technology readiness level (TRL), is discussed, along with the potential for improving material efficiency by selecting future material recycling technology and effective manufacturing waste management.
Open Access
Article
14 August 2025Advanced Study on Structural Health Diagnosis and Maintenance for Floating Wind Turbines Using Computer Vision
Global offshore wind capacity has now surpassed 50 GW and is projected to reach 264 GW by 2050, highlighting the pivotal role of floating wind in the future of clean energy. Given the complexity of marine environments, intelligent diagnostics for floating turbines are crucial for improving operational efficiency, reducing costs, and ensuring robust and sustainable energy production. This paper presents a structural damage detection framework for floating wind turbines, integrating computer vision with advanced artificial intelligence technologies. First, a dataset is constructed through industry collaboration and open-source collection. Then, to optimise the YOLOv7 algorithm, SE attention mechanisms and WISE-IoU loss functions are incorporated, which significantly enhance the accuracy of surface damage detection. Experimental results indicate that the mAP (mean Average Precision) increases from 82.44% to 86.24% compared to the original YOLOv7. Finally, a deployment approach and an example are provided to use the diagnostic framework as a portable application. This enables real–time on–site analysis, enhances detection timeliness, and reduces maintenance costs. It allows for immediate issue identification and adaptation to diverse environments.
Open Access
Article
12 March 2025Influence of Soil Damping and Aerodynamic Damping on the Dynamic Response of Monopile Wind Turbines under Earthquake and Wind Loads
Vibration damping is essential for predicting the responses of wind turbines, and contributions mainly come from structural, soil, and aerodynamic damping. In engineering design, it is difficult to precisely account for the individual contributions of each damping source. As a result, a simplified approach is commonly used, where a total damping factor is applied that combines the effects of structural, soil, aerodynamic, and other damping sources. However, the accuracy of this simplified approach in predicting the dynamic response of turbines has not been thoroughly evaluated. This study primarily focuses on the applicability of vibration-damping simplification methods, particularly in analyzing the dynamic response of turbines under earthquake and wind loads.
Open Access
Article
12 February 2025Motion Control of Floating Wind-Wave Energy Platforms
Mitigating wave-induced motions in floating multi-body systems is a critical challenge in ocean engineering. For single floating structures, such as floating platforms or vessels, applying active control requires considerable energy. It is also a common solution to add auxiliary structures and a power take-off (PTO) device, thereby forming a multi-body system that utilises passive control. However, the effectiveness of this method is limited due to varying phase differences between control forces and motions, which change across different wave frequencies. The present work proposes a novel semi-active structural control method, which can effectively provide optimised control force to the main body within a multi-body system. The key point of this method is tuning the phases between the forces and motions of floating bodies. Proper tuning can neutralise the main floating body’s wave-induced motion by utilising the wave-induced motion of the auxiliary structure. The controller is developed under an optimal declutching control framework, adjusting the damping coefficients of the PTO system to provide discrete resistance to the target body. A floating semi-submersible (SS) platform equipped with a heave ring as an auxiliary structure is selected and analysed as the case study. The results demonstrate the method’s efficacy in reducing motion for floating wind turbine (FWT) platforms and its applicability to various types of multiple floating bodies. Interestingly, our optimal declutching control can “kill two birds with one stone”. It can simultaneously enhance motion reduction and increase power capture. In the current study, the proposed controller achieved a maximum motion reduction of 30% for the platform.
Open Access
Review
23 September 2024Icing Models and Mitigation Methods for Offshore Wind in Cold Climate Regions: A Review
Offshore wind turbines (OWTs) in cold climate regions have become increasingly significant due to the abundant wind resources with the development of renewable energy. These areas offer considerable potential for the development of OWTs. Generating energy for communities in cold climate regions involves overcoming significant challenges posed by the remote and harsh environmental conditions. This review presents the state-of-the-art research regarding prediction models for ice accretion on wind turbine components. Furthermore, this review summarizes advanced mitigation solutions, such as cold-weather packages and ice protection systems, designed to address icing issues. The present study identifies critical knowledge gaps in OWT deployment in cold climate regions and proposes future research directions.
