Techno Press
Tp_Editing System.E (TES.E)
Login Search
You logged in as...

was
 
CONTENTS
Volume 41, Number 5, November 2025 (Special Issue)
 

Abstract
Structural design of wind turbine support structures that focuses on optimal structural system performance and at the same time cost reduction is crucial to achieve economic competitiveness for the development of wind turbine technology. An important challenge, particularly for civil and structural engineers, arises from the increase in turbine diameter and power output, which increases the loads on the support structures. Specifically, three aspects are pivotal in their design and optimization process: a) the ultimate limit state strength for extreme load conditions; b) the fatigue strength under cyclic loads in operational conditions; c) the structural control for resonance in operational and extreme conditions. Within a design optimization approach based on global limit states, structural characteristics and details of the support structures are modified to enhance the global system performance in onshore and offshore wind turbines installations. Moreover, structural health monitoring for wind turbine installations, also based on digital-twin models, is a key factor to extent their durability. Finally, the application of design approaches based on passive or semi-active vibration control strategies is also considered, to reduce resonance and fatigue effects. This Special Issue is devoted to present recent advances in structural design and control of wind turbine supporting structures and their impacts on the advancement of wind energy industry. In particular, general and specific aspects are investigated, including the effects of structural details and control devices on the dynamic response of wind turbine supporting structures, the lessons gained by oil and gas installations, the use of Artifical Intelligence in health monitoring approaches for maintenance. Within this special edition, these array of topics related to optimal design of wind turbine supporting structures are covered. Sorge et al. (2025) analyzed the effective performance of a special passive control device (HSFD, Hinge-Spring Friction Device) for mitigating the dynamic effects on wind turbine towers in on-shore installations. They validated a specific design procedure to assess the perfomance of the control system against several wind loads associated to different operating scenarios. The results represent a significant advancement in the development of a vibration control strategy for horizontal axis wind turbines, and a key factor to extend their durability. Chuah et al. (2025) in their review explored the innovations and lessons learned from offshore oil and gas floating systems and their possible applications in floating wind turbine technology. Their findings provide valuable insights for the development of next-generation floating wind turbines, offering a pathway to expand renewable energy production and accelerate the technological advancement to the global transition towards sustainable energy sources. Ali et al. (2025) presented a high-fidelity Digital Twin framework for the prognostic health management of Offshore Wind Turbines subjected to synergistic Corrosion-Fatigue, which compromises the structural integrity of turbines. They proposed a novel methodology that integrates a coupled-physics degradation model with an AI driven physics-informed machine learning engine, establishing that such an integrated approach is essential for the reliable and economically viable management of offshore assets. Tekantappeh and Rebelo (2025) investigated the impact of varying Inter-Module Connections (IMCs) stiffness on the natural frequencies of Self-erected tower, that is a modular system composed of post-tensioned steel-concrete composite panels. The IMCs play a crucial role in the dynamic behaviour of this newly developed type of towers in wind turbines. The presented results show that a properly estimation and optimization of IMCs stiffness is essential for the design and performance of such modular tower structures. Hu et al. (2025) developed a Tuned Liquid Multi-Column Damper (TLMCD) system model integrated into a floating offshore wind turbine (FOWT) for the vibration control of flexible tower and platform motions. The results show that the platform motion parameters are significantly reduced with the TLMCD control system. In addition, the integration of a linear quadratic regulator control algorithm further enhances the structural performances under windy conditions.

Key Words


Address
Prof. Alberto Maria Avossa
University of Campania "L. Vanvitelli", Italy

Prof. Charalampos Baniotopoulos
University of Birmingham, United Kingdom & Leibniz University Hanover, Germany

Abstract
Large wind turbines face significant challenges in terms of structural stress due to wind loads. Such severe demand, if not properly managed, can reduce the turbine's service life and/or increase its maintenance costs. In this context, the present study focuses on the validation of a passive vibration control device, the Hinge-Spring-Friction Device (HSFD), designed to reduce the bending moment at the base of the tower against wind loads, thereby mitigating structural loads during turbine operation. The HSFD combines a spherical hinge, springs to provide rotational stiffness, and a friction system that dissipates energy through a rocking mechanism. This approach makes it possible to reduce the bending moment at the base of the tower without compromising the overall stability of the structure. In previous work, the design of the device was carried out by the authors considering two reference wind scenarios. Herein extensive validation is performed, against a wide series of operational scenarios representing different wind conditions. The numerical simulations presented in this study cover 91 wind load cases, divided over 13 wind speed ranges, according to IEC 64100-1. These include moderate, intermediate and extreme situations, even close to the turbine cut-out speed (25 m/s), when the turbine stops operating to avoid structural damage. The analyses provided a comprehensive overview of the control system's capacity, enabling the formulation of highly encouraging conclusions. Specifically, the device consistently enhances the system's performance, with the level of protection increasing as the demand for stress rises, achieving an average reduction of approximately 20%.

Key Words
wind turbines; vibration control; hinge-spring-friction device (HSFD); device; moment base demand

Address
Ettore Sorge:Department of Engineering, University of Naples "Parthenope", Napoli, 80143, Italy

Carlos Riascos:Department of Mechanics of Continuous Media and Theory of Structures, Università Politécnica de Valencia, 46022, Spain

Nicola Caterino:1)Department of Engineering, University of Naples "Parthenope", Napoli, 80143, Italy
2)Construction Technologies Institute, Italian National Research Council, Napoli, 80146, Italy

Abstract
Floating wind turbines represent a promising solution for harnessing wind energy in deep offshore locations. This review explores the innovations and lessons learned from offshore oil and gas floating systems and their applications in floating wind turbine technology. This study examines the evolution of floaters and station-keeping systems that have been successfully employed in the oil and gas industry for decades. By analysing these established technologies, we identified the vital adaptations and improvements necessary for their implementation in floating wind turbines. This review also highlights the importance of robust and flexible mooring systems capable of withstanding extreme weather conditions while allowing optimal turbine positioning. Furthermore, it addresses the challenges of scaling up these technologies for large-scale floating wind farms, including cost-effectiveness, maintenance strategies, and environmental impact mitigation. Innovative materials and design solutions that can reduce the mass and enhance the overall performance of floating platforms are essential. The findings of this study provide valuable insights for the development of next-generation floating wind turbines, offering a pathway to expand renewable energy production in previously inaccessible offshore areas. The floating wind turbine sector can accelerate technological advancement and contribute significantly to the global transition towards sustainable energy sources by leveraging the expertise and lessons gained from the oil and gas industry.

Key Words
anchor, moorings; floating wind turbine; oil and gas; semi-submersible; spar; station-keeping system; TLP

Address
Lee Heng Chuah:School of Engineering, University of Surrey, Guildford GU2 7XH, UK

Yukun Ma:School of Engineering, University of Surrey, Guildford GU2 7XH, UK

Benyi Cao:School of Engineering, University of Surrey, Guildford GU2 7XH, UK

Subhamoy Bhattacharya:1)School of Engineering, University of Surrey, Guildford GU2 7XH, UK
2)Renew Risk Limited, UK

Abstract
The expansion of offshore wind energy into harsh marine environments is critically challenged by synergistic corrosion-fatigue (C-F), which compromises the structural integrity of turbines. While digital twin (DT) technology offers a promising solution, existing frameworks for C-F prognostic health management are often limited by lack of adaptation to dynamic environmental data and simplistic, deterministic maintenance strategies. To address these deficiencies, this study develops and demonstrates a high-fidelity DT framework founded on three innovations: a coupled-physics model that captures the synergistic feedback between corrosion and fatigue; an artificial intelligence (AI)-driven, Gaussian Process (GP)-based physics-informed machine learning (PIML) engine for real-time environmental adaptation; and a stochastic, opportunistic condition-based maintenance (O-CBM) framework for risk-informed decision-making. These capabilities are demonstrated through a detailed theoretical case study of a floating offshore wind turbine (OWT) tower base, integrating Bayesian inference for model updating with Monte Carlo simulation for lifecycle performance evaluation. Results demonstrate that modeling C-F synergy is critical, reducing predicted service life by 67% compared to fatigue-only analysis, while the O-CBM policy, enabled by the DT's probabilistic intelligence, reduces lifecycle costs by 13.5% and failure risk by 21% over traditional approaches. The study establishes that such an integrated approach, combining coupled physics with AI-driven adaptation and stochastic optimization, is essential for the reliable and economically viable management of offshore assets.

Key Words
coupled corrosion-fatigue; digital twin; offshore wind turbine; opportunistic maintenance; physics-informed machine learning

Address
Yasmin Ali:1)Department of Civil Engineering, Sichuan University, Chengdu 610065, China
2)Department of Civil Engineering, Delta University for Science and Technology, Gamasa 11152, Egypt

Kaoshan Dai:1)Department of Civil Engineering, Sichuan University, Chengdu 610065, China 2)3State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, Sichuan
University, Chengdu 610065, China

Ahmed Elgammal:Department of Civil Engineering, Sichuan University, Chengdu 610065, China

Yuxiao Luo:1)Department of Civil Engineering, Sichuan University, Chengdu 610065, China 2)National Engineering Technology Research Centre for Prefabrication Construction in Civil Engineering, Tongji University, Shanghai 200092, China

Junlin Heng:Department of Civil Engineering, Sichuan University, Chengdu 610065, China

Charalampos Baniotopoulos:Department of Civil Engineering, School of Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK

Abstract
The increasing of modular constructions underscores the need for demountable structures. This is particularly crucial for wind turbine towers, which experience rapid ageing due to technological advancements. Inter-module connections (IMCs) play a crucial role in these structures; therefore, it is necessary to examine the properties of IMCs to understand their impact on the dynamic characteristics of a newly developed type of self-erected modular towers (SeT). This study investigates the impact of varying IMCs stiffness on the natural frequencies of SeT. To achieve this, a parametric study in ABAQUS was conducted using a full-scale model of a SeT with different vertical and horizontal IMC properties. Bushing connectors were utilized as IMCs, which are characterized by three translational and three rotational stiffness coefficients. The results indicate that IMC stiffness affects the natural frequencies of SeT. A ±10% variation in the stiffness of the IMCs resulted in a negligible effect on the natural frequency, with changes of less than 2%. However, Further variation in the stiffness led to substantial changes in natural frequencies across all modes and highlighted the sensitivity of SeT to IMC stiffness changes. These findings underscore the critical role of IMC properties in the dynamic behaviour of modular towers. Properly estimating and optimizing IMC stiffness is essential for the design and performance of such structures.

Key Words
dynamic characteristics; inter-module connection; modular construction; natural frequency; self-erecting wind tower

Address
Jafar M. Tekantappeh:University of Coimbra, ISISE, ARISE, Department of Civil Engineering, 3030-790 Coimbra, Portugal

Carlos Rebelo:University of Coimbra, ISISE, ARISE, Department of Civil Engineering, 3030-790 Coimbra, Portugal

Abstract
In this study, a 16-degree-of-freedom rigid-flexible coupled floating offshore wind turbine (FOWT) model is con structed based on the International Energy Agency (IEA) UMine 15-MW semi-submersible wind turbine. Similarly, a Tuned Liquid Multi-Column Damper (TLMCD) system model was developed and integrated into the FOWT-TLMCD model for vibration control of flexible tower and platform motions. The accuracy of the FOWT model was verified by comparing the dynamic response of the FOWT model with the simulation results from OpenFAST. Subsequently, a linear quadratic regulator (LQR) control algorithm was used to regulate the damping force of the TLMCD valve. Comprehensive numerical simulations were performed under various wind and wave conditions. The results show that the standard deviation of the platform pitching motion as well as the standard deviation of the tower top fore-and-aft displacement are significantly reduced with the TLMCD control system. In addition, the integration of the LQR control further enhances the suppression effect on platform pitch and tower top displacement, and this control effect becomes more and more obvious under windy conditions.

Key Words
floating offshore wind turbines; LQR control; tuned liquid multi-column dampers; vibration control

Address
Yinlong Hu:College of Artificial Intelligence and Automation, Hohai University,213200 Changzhou, China

Zhuang Han:College of Artificial Intelligence and Automation, Hohai University,213200 Changzhou, China

Wancheng Wang:College of Artificial Intelligence and Automation, Hohai University,213200 Changzhou, China

Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2026 Techno-Press ALL RIGHTS RESERVED.
P.O. Box 33, Yuseong, Daejeon 34186 Korea.
General Inquiries: info@techno-press.com / Journal Administration: admin@techno-press.com