Wind Action Research Articles

Patent Technology of Shipborne Stabilized Platform

Background: When a ship is sailing or operating at sea, it is unavoidable to produce sixdegrees- of-freedom movements of rolling, pitching, and yawing under the action of sea wind and waves, which seriously impacts the operation of precision equipment on the ship and the safety of personnel. The ship-borne stabilized platform can isolate the ship's motion and eliminate the impact of sea waves on the personnel and equipment on it to a large extent. With the increasing demand for ship surfaces in marine fields, such as navigation equipment, military facilities, and sea condition simulation, there is an urgent need to study ship-borne platforms with high stability and efficiency to isolate swaying and ensure ship performance. Objective: This study aims to analyse the patents and summarize the characteristics and existing problems of the shipborne platform to provide a reference for the future development of the shipborne stabilized platform. Methods: Various representative patents related to shipborne stabilized platforms and multi-DOF platforms were researched in this study. Results: Through the analysis and comparison of patent technology, the main problems existing in the structure and design principle of the existing shipborne stabilized platform are summarized, and the development trend and direction of the shipborne stabilized platform are discussed. Conclusion: Shipborne stabilization is highly significant in isolating the ship's motion. At present, the ship-borne stabilized platform has produced six degrees of freedom of movement, but due to the improvement of control response requirements, the structure of the platform needs to be further improved. With the development of test technology toward intelligent and big data-driven technology, the shipborne stabilized platform is moving toward cloud computing and large-scale testing.

Numerical simulation of the slamming effect of regular waves and freak waves on ultra heavy-lift amphibious connector

The Ultra Heavy-lift Amphibious Connector can be used for sea and land operations. When the amphibious connector opens the bow door, it will inevitably suffer from the combined action of wind, waves, currents, and other factors, resulting in the slamming of the wave on the hatch and various landing ship hull movements in the process. Due to the complexity of the actual UHAC model, in order to save computing resources, this paper selects the external load on the UAHC hatch when it is operated in water when the door is closed. The effects of crest height, draught, and focus position on UHAC slamming under the action of regular waves and freak waves were analyzed. Based on the viscous flow theory, the CFD commercial software FLUENT is used to simulate the interaction between the reduction of regular waves and floating structures. The simulation results are compared with the experimental results to verify the feasibility of the proposed method. Since the published UHAC data cannot be found in the network environment, this paper draws the UHAC based on the only data on the Internet and studies the slamming load of the wave on the UHAC on this basis.

Combined Effects of Thermal Buoyancy, Wind Action, and State of the First-Floor Lobby Entrance on the Pressure Difference in a High-Rise Building

The stack effect in high-rise buildings, stemming from an inside/outside temperature difference, may produce a significant pressure difference on the elevator doors, potentially causing elevator malfunctions. This effect can also be influenced by wind action and human behaviors, e.g., opening/closing of building entrances. In this study, a wind tunnel test was conducted to determine the real wind pressure distribution on a high-rise building in northern China. A numerical simulation utilizing the Conjunction of Multizone Infiltration Specialists software (COMIS) was carried out to investigate the pressure difference of elevator doors under the effects of thermal buoyancy, wind action, and opening/closing of the first-floor lobby entrance. An alternative solution of a locally strengthened envelope is proposed and validated for the studied building zone. The study reveals that the opening of the first-floor lobby entrance increases the pressure difference regardless of the environmental conditions, and the increase of wind speed tends to increase the pressure difference in winter but decrease it in summer. The proposed countermeasure combination, involving using revolving doors instead of swing doors, increasing additional partitions, and strengthening the local building envelope, was found to be synergistic and effective in reducing the pressure difference inside the building. The research findings offer practical engineering solutions for mitigating elevator door pressure challenges in high-rise buildings.

Comparison of Seismic and Wind Actions on Medium to High-Rise Buildings in Muscat, Oman

This study is a comparison of wind and seismic loads on medium and high-rise buildings in Muscat, Oman. It uses the proposed Omani Seismic Code and Eurocode EN1991 for seismic and wind calculations, respectively. Muscat falls under Zone-1 in the Omani seismic code and experience basic wind speed of 30 m/sec. The research investigates buildings with varying aspect ratios (1:1 and 1:2), heights (11, 15, and 19 stories), and structural layouts (frame only, core shear wall, and corner shear wall), using ETABS for structural analysis. The findings reveal that seismic actions are generally more significant than wind actions for buildings in Muscat. In frame-only structures, wind-induced base shear ranges from 16%-33% for 1:1 aspect ratio and 21%-43% in the x-direction and 10%-20% in the y-direction for 1:2 aspect ratio, when compared to seismic actions. This difference decreases with increasing building height. Incorporating shear walls notably reduces the maximum lateral displacement across all scenarios, with core-located walls being most effective, leading to a 49% reduction in lateral displacement. Shear walls also substantially mitigate first-story column shear forces and bending moments. The study concludes that seismic actions are more critical than wind actions in Muscat for simple moment-resisting frame systems. Additionally, using shear walls in these buildings is highly beneficial for controlling lateral displacements and reducing member forces.

Methodology to minimize the dynamic response of tall buildings under wind load controlled through semi-active magneto-rheological dampers

This paper proposes a methodology to evaluate and optimize the dynamic response of tall buildings under wind loading, controlled through semi-active Magneto-Rheological dampers (MR dampers). For this, a tall building, modeled as a 2D frame, is taken as case study and three structural control configurations are proposed. The original structural configuration of the building is the first configuration analyzed, called Uncontrolled Original (C1). In the second configuration, called Uncontrolled Optimized (C2), the fundamental frequency of the building is optimized via PSO algorithm as a function of its mass. Then, in the third configuration, Controlled Optimized (C3), a set of MR dampers with behavior formulated via the modified Bouc-Wen rheological model and controlled through the Linear Quadratic Regulator associated with the Clipped Optimal control strategy (LQR-CO) is applied to the structure. Finally, the dynamic response of the three scenarios under wind action is analyzed and compared to performance criteria established in the literature. The results demonstrate that the C3 configuration is the only one able of satisfying all the established performance criteria, proving that the proposed methodology y that combines structural optimization with MR dampers is a powerful tool for vibration control.

Effects of wind-wave-current-earthquake interaction on the wave height and hydrodynamic pressure based on CFD method

Wind-wave-current interaction is a phenomenon which is present in many practical engineering situations and vertical earthquakes may have significant influence on the hydrodynamic pressure of seawater in regions of active seismicity. This study is devoted to probe the wave height and hydrodynamic pressure of seawater caused by the joint wind, wave, current and earthquake action based on computational fluid dynamics (CFD) method, where a homogeneous multiphase model based on the noncompressible Reynolds Averaged Navier-Stokes (RANS) equation and the k-ε turbulence model implemented in ANSYS-Fluent code was used. First, a two-dimensional (2D) numerical flume excited by wind, wave, current and earthquake loadings was established through the secondary development of a user-defined function (UDF). Subsequent, effects of wind-wave interaction and wind-wave-current interaction on the wave height and hydrodynamic pressure of seawater were investigated. Finally, effects of wave-earthquake interaction and wave-current-earthquake interaction on the wave height and hydrodynamic pressure of seawater were investigated. The nonlinearity of seawater under joint wind, wave, current and earthquake action was also studied.

Influence of perforation on static characteristics of the enclosing corrugated panel under the wind action

The application of the enclosing panels with perforation in construction practice for protective structures is economic advantageous due to reduction of financial costs for their production, transportation and installation. But influence of perforation on static and dynamic characteristics of the enclosing panels was not enough investigated. With the purpose of wind protection of the buildings and structures at the Ukrainian Antarctic station „Akademik Vernadsky” static stress and stability analyses of the protective structure were executed in according with the first and second groups of limit states of State building regulations of Ukraine. The protective structure as the enclosing corrugated steel panel and supporting columns was appeared. In the article the results of numeral research of the stress strain state and stability of the corrugated panel are presented. The panel width and height were accepted permanent, and a panel thickness was explored and accepted according to requirements for its stiffness, strength and stability. The four corrugations in the form of trapezoids are located along the panel height. Perforation of the panel in the form of round holes with a radius of 12.5 mm was presented. Two finite element models of the corrugated panel using the software NASTRAN were built. The corrugated panel without perforation model as a collection of rectangular shell finite elements with six degrees of freedom at the node was modeled. This model contained 35161 finite elements and 32540 nodes. The finite element model of the enclosing corrugated panel with perforation contained 383043 triangular shell finite elements with six degrees of freedom at the node and 211609 nodes. Boundary conditions were imposed on the modal nodes along the height on both sides of the corrugated panel in the form of fixing, taking into account its rigid attachment to the columns. Wind action on the enclosing panel was presented as uniform distributed static load, the limit calculation values of which were got according to State building regulations of Ukraine and statistical data of wind at the Ukrainian Antarctic station. The main attention was given to research of influence of perforation on the corrugated panel equivalent stresses and displacements, critical values of wind load and form of loss of corrugated panel stability. Computational procedures of static stress and stability analyses of software NASTRAN were applied.

Correlation and modal analysis techniques for the study of the VIV response of a twin-box deck based on 3D LES simulations

AbstractTwin-box decks are prone to vortex-induced vibration (VIV) at moderate wind speeds, and previous studies have shown a complex interplay between the flow and the two parallel box girders. OpenFOAM is used to model the aerodynamic and aeroelastic responses of the twin-box deck of the Stonecutters Bridge by means of 3D LES simulations. Two cases are thoroughly analysed under smooth incoming flow: (i) static deck and ii) heave peak amplitude response at VIV excitation. The computational data provided by the CFD simulations have been exploited aiming at better understanding the complex aerodynamic and aeroelastic phenomena taking place. First, spanwise correlation analyses are applied to understand the level of organisation of the forcing flow actions, and identify the regions of the deck affected by different flow structures. Second, three different mode decomposition techniques (POD, SPOD and DMD) are applied to the time-dependent pressure distributions, revealing the pivotal role played by the leeward box in the twin-box deck response under wind action. The modal analyses are of utmost interest in the development of Reduced Order Models (ROM) for the VIV response of twin-box long-span bridges.

Typhoon- and temperature-induced responses of a cable-stayed bridge

Long-span bridges are subjected to wind and temperature actions. Wind action is generally the governing load of long-span bridges in design, while temperature action is also significant. Accurate separation of typhoon- and temperature-induced responses is thus necessary for in-depth investigation of their effects and comprehensive evaluation of structural performance. This paper separates the temperature- and typhoon-induced responses of the Qingzhou Bridge by using a unified global analysis approach. The field-monitored meteorological data and structural responses collected from the structural health monitoring system installed on the bridge are analyzed in detail, with emphasis on the comparison of those during typhoon Higos (Signal No. 9) and a typical sunny day after the typhoon. Results show that the quasi-static variation of displacement and stress responses are higher on a typical sunny day than those during the typhoon period, which is out of intuition. Through the unified analysis, the temperature-induced responses are calculated, and the typhoon-induced responses can be separated. The temperature- and typhoon-induced longitudinal displacement, mid-span deflection, and stress of the girder are compared. The temperature-induced response accounts for a large part of the total quasi-static recording either on a typical sunny day or during the typhoon period, whereas typhoon caused significant dynamic responses. The typhoon-induced quasi-static and dynamic responses are also in good agreement with the wind tunnel test results. This case study demonstrates the effectiveness of the unified global analysis in separating the temperature effect.

H hybrid control and MRD in a steel frame building subjected to excessive vibrations caused by the dynamic action of wind and earthquake

The dynamic loads from earthquakes and winds can destroy lives, cause collapse in civil structures, and interrupt basic services provided to the population. In this scenario, structural designs must be developed to decrease the damage induced by these actions. The objective of this work is to design a hybrid controller based on the H¥ optimization via state feedback and the magneto-rheological damper (MRD) to mitigate the excessive vibrations of a three-story steel frame building, represented through the shear building model, subjected to the simultaneous dynamic action of wind and earthquake. All research is based on computational simulation, experimental research and results will not be addressed. In the numerical analysis, digital computer and MATLAB® software are used, and implemented codes generate the expected results based on the mathematical modeling. With the application of the H¥ control technique via state feedback, the displacements were reduced by 77%. With MRD this reduction was 79%. With the hybrid controller, this reduction was 100%. Thus, the verifications in relation to maximum displacements were met for NBR 15421:2006, NBR 8800:2008 and NBR 6118:2014. From the results, it is concluded that the hybrid controller proved to be more efficient and achieved the proposed objective. The exogenous inputs had zero influence on the behavior of the system output.

Analysis of chaos and capsizing of a class of nonlinear ship rolling systems under excitation of random waves.

The action of wind and waves has a significant effect on the ship's roll, which can be a source of chaos and even capsize. The influence of random wave excitation is considered in order to investigate complex dynamic behavior by analytical and numerical methods. Chaotic rolling motions are theoretically studied in detail by means of the relevant Melnikov method with or without noise excitation. Numerical simulations are used to verify and analyze the appropriate parameter excitation and noise conditions. The results show that by changing the parameters of the excitation amplitude or the noise intensity, chaos can be induced or suppressed.

Comparative analysis of guyed lattice mast computations in terms of American and European standard

The paper presents an analysis of a 100-meter wind measurement guyed mast located in the north-western part of the United States, in the state of Oregon. Using the RFEM software [1], the influence of the wind on the mast was analyzed according to the guidelines of two standards: American TIA-222-H [2] and European EN 1993-3-1 [3]. The purpose of this work is to show the differences between the results of static computations of the mast in terms of the considered standards. Due to the limited content of the work, the icing load on the structure was ignored in the analysis and the focus was on determining the response of the mast only in terms of wind action. The author tried to describe the differences in this respect between the standard guidelines [2] and [3]. The comments and conclusions regarding the analysis of guyed masts presented in the article have some practical aspects and can be used in design practice.

Application of Response Surface-Corrected Finite Element Model and Bayesian Neural Networks to Predict the Dynamic Response of Forth Road Bridges under Strong Winds.

With the rapid development of big data, the Internet of Things (IoT), and other technological advancements, digital twin (DT) technology is increasingly being applied to the field of bridge structural health monitoring. Achieving the precise implementation of DT relies significantly on a dual-drive approach, combining the influence of both physical model-driven and data-driven methodologies. In this paper, two methods are proposed to predict the displacement and dynamic response of structures under strong winds, namely, a Bayesian Neural Network (BNN) model based on Bayesian inference and a finite element model (FEM) method modified based on genetic algorithms (GAs) and multi-objective optimization (MOO) using response surface methodology (RSM). The characteristics of these approaches in predicting the dynamic response of large-span bridges are explored, and a comparative analysis is conducted to evaluate their differences in computational accuracy, efficiency, model complexity, interpretability, and comprehensiveness. The characteristics of the two methods were evaluated using data collected on the Forth Road Bridge (FRB) as an example under unusual weather conditions with strong wind action. This work proposes a dual-driven approach, integrating machine learning and FEM with GNSS and Earth Observation for Structural Health Monitoring (GeoSHM), to bridge the gap in the limited application of dual-driven methods primarily applied for small- and medium-sized bridges to large-span bridge structures. The research results show that the BNN model achieved higher R2 values for predicting the Y and Z displacements (0.9073 and 0.7969, respectively) compared to the FEM model (0.6167 and 0.6283). The BNN model exhibited significantly faster computation, taking only 20 s, while the FEM model required 5 h. However, the physical model provided higher interpretability and the ability to predict the dynamic response of the entire structure. These findings help to promote the further integration of these two approaches to obtain an accurate and comprehensive dual-driven approach for predicting the structural dynamic response of large-span bridge structures affected by strong wind loading.

Effect of Internal Waves on the Hydrodynamics of a Mediterranean Sea Strait

In the present work, the effects of wind- and tide-induced internal waves in the Rio-Antirio Strait in western Greece were studied by using three-dimensional numerical simulations. For the wind-induced flow in the strait, it emerged that the internal waves’ initiation is associated with the direction of the wind. Tidal action, with or without the combined action of wind, also generates internal waves in the strait, with amplitudes higher than 20 m. The action of the internal waves causes a subsurface inflow of colder waters from the Gulf of Corinth to the Gulf of Patras, as has been also simulated for the case of the wind-induced flow, generating strong hypolimnetic currents. The exchange flowrate between the Gulf of Patras and the Gulf of Corinth appeared to undergo significant modification for the wind-induced flow and had little effect for the pure tidal flow (in windless conditions) due to the development and action of the internal waves at the strait. The combined action of the tide and the wind was found to marginally affect the exchange flowrate between the two gulfs compared to the pure tidal flow. The interaction between the Coriolis effect and internal waves, at least away from the strait, forms a characteristic horizontal structure of flow. The structure of turbulence in the near strait area under the action of internal waves generated by the wind and/or tide was also discussed and compared with the corresponding barotropic flow.

Sonic Journeys on the Open Sea: Testing the Faithful in Old English and Anglo-Latin Literature

Abstract This article examines a distinct literary environment in Anglo-Latin and Old English literature: the open sea. It argues that such an environment was formed primarily through sound, where the geophonic actions of water and wind were used to create a literary motif, a location both to test those seeking God and to showcase their faithfulness. Those tested include the pilgrim on their journey, often to Rome, and the saint, often in ascetic seclusion. In Anglo-Latin, the geophony of the open sea was sometimes rendered with the adjective undisonus (‘wave-sounding’), a rare word used consistently in two ways: first, to function as an impediment to the person on their journey; second, to form a miniature open sea to serve as an hagiographical desert. In Old English, the literary motif of the sonic open sea occurs in the poem Andreas, which uses active verbs such as hlynnan (‘to make a loud noise, sound, [or] resound’) to render the acoustic assaults of the sea at storm. Andrew, depicted as a miles Christi, remains faithful, and the open sea calms and silences, in declaration of his victory. By comparing texts in both the Anglo-Latin and Old English traditions, this article highlights in new ways the important role of sound, particularly geophonic productions, in early medieval English literature.

The indicative significance of grain size end-members and quartz surface microtextural features in Beglitsa loess sections at the Sea of Azov

The loess accumulation processes in the Azov Sea region leaves a record of atmospheric circulation trends in southern Russia, which can be used to explore aeolian dynamics and atmospheric circulation evolution. However, the historical aeolian transportation and accumulation processes of the loess deposits in this region remain controversial, which limits our understanding of aeolian dust dynamics. In the present study, based on grain size analysis and scanning electron microscopy imaging, grain size end-member and microtextural characteristics of loess sediments in the Beglitsa section of the Sea of Azov were studied to reveal their sedimentary environments and processes. According to the results, the Beglitsa section exhibits typical characteristics of aeolian sediment. EM analysis revealed that the Sea of Azov loess is composed of materials from both distant and proximal sources transported by high-altitude westerly and mesoscale regional winds, respectively. Particle shape and morphology indicated that the Azov loess materials have experienced wind and flow action. The application of the two methods revealed that the formation of the Azov loess is a complex process from source to sink. It results from the combined effects of high-altitude westerly winds, low-altitude local wind systems, and near-surface air flow in the course of development, which is also influenced by sea-level rise and fall. The results of the present study lay a foundation for the interpretation of historical aeolian dynamics and environmental significance of the Azov loess.

Experimental Study on the Effect of Wind on Armor Stone Stability

Wind is a significant factor influencing the stability of breakwater armor stones. However, few existing studies have considered the effects of wind on these structures. In this study, two-dimensional laboratory experiments were conducted to examine the effect of wind on the stability of breakwater armor stones. The stability factor (KD) of the armor stone, fluid velocity, runup, and rundown were observed under the action of waves and winds. A wind turbine was installed in front of the physical model of the breakwater to generate extreme wind conditions of 5.5 and 12 m/s. The results showed that KD decreased by 42.18% at 5.5 m/s and 57.82% at 12 m/s compared with that without wind. The maximum runup and rundown heights increased with wind velocity, following a Rayleigh distribution. The fluid velocity distribution conformed to a normal distribution, with the mean velocity directed offshore. Many studies have suggested that runup, rundown, and fluid velocity are the main factors affecting the stability of breakwater armor stones. The analysis revealed that wind affects these factors and lowers the stability coefficient. These wind-induced hydrodynamic changes suggest the need for a detailed hydrodynamic review of wind-wave conditions.

Assessment of the seasonal trends of air pollution: A case study of Gurugram city, Haryana, India

Introduction: The air pollution is a significant environmental issue that profoundly impacts urban areas and their surrounding regions. The processes involved in air pollution are complex, as primary pollutants are released into the atmosphere and then transported by the action of wind. Primary pollutants may undergo chemical reactions, change phases, and eventually be eliminated from the atmosphere through dry and wet deposition.
 Materials and methods: The Air Quality Index (AQI) has been used to analyse the variations in the AQI over a span of three years (2019-2021) for Gurugram city. The study aimed to quantify the changes in the AQI values on seasonal basis (winter, summer, and monsoon).
 Results: The results show that there has been a slight improvement in the air quality in certain areas, but it still remains critical. Therefore, it highlights the need for continued and concerted efforts to address the issue of air pollution. The deteriorating air quality poses severe threats, including the potential alteration into the natural state of atmospheric composition, besides health- related issues.
 Conclusion: It is closely linked to adverse health effects, such as respiratory problems, increased instances of asthma, cancer, and even leads to mortality in extreme cases. The measurements from four monitoring sites namely Seva Sadan, Sector-51, Gawal Pahari, and Manesar, were analysed and a comparison of seasonal trends among these sites were also attempted.

Nonlinear Finite Element Analysis of Tubular Steel Wind Turbine Towers near Man Door and Ventilation Openings to Optimize Design against Buckling

The safe and cost-effective design of wind turbine towers is a critical and challenging aspect of the future development of the wind energy sector. This process should consider the continuous growth of towers in height and blades in length. Among potential failure modes of tubular steel towers, shell local buckling due to static axial compressive stresses from the rotor, blades, and tower weight, as well as dynamic flexural compressive stresses from wind actions on the rotating blades and the tower itself, are dominant as thickness is optimized to reduce weight. As man door and ventilation openings are necessary for the towers’ operation, the local weakening of the tower shell in those areas leads to increased buckling danger. This is compensated for by tower manufacturers by the provision of stiffening frames around the openings. However, the cold-forming and welding of these frames are among the most time-consuming aspects of tower fabrication. Working towards the optimization of this design aspect, the buckling response of tubular steel towers near such openings is investigated by means of nonlinear finite element analysis, accounting for geometrical and material nonlinearity and imperfections (GMNIA), and also considering several wind directions with respect to the openings. The alternatives of stiffened and unstiffened openings are investigated, revealing that a thicker shell section around the opening may be sufficient to restore lost stiffness and strength, while the stiffener frame may also be eliminated, offering substantial benefits in terms of manufacturing effort, time and cost.

Vibration Control Effect Analysis of PTMD in Wind Turbine Tower Under Multi-Hazard Action of Earthquake and Vortex-Induced Wind

Considering the importance of wind turbine tower, its vibration under multi-hazard action consisting of vortex-induced load and seismic load needs to be controlled, especially as the height of the wind turbine tower increases, it increases the risk of its higher-order vibration. To address this issue, theoretical equations for vortex-induced load based on the governing equation of particle damping system are put forward, the vibration control of a 1/20 scale wind turbine model is studied, and the experimental and numerical analyses are conducted. Many studies have shown that wind turbine tower equipped with tuned mass damper (TMD) can result in an RMS response reduction ratio ranging from 20% to 40%. Compared to TMD, particle tuned mass damper (PTMD) has better vibration control effect under single seismic load, and still achieves good vibration control ability with a maximum RMS (root–mean–square) reduction ratio of 35.55% under multi-hazard action. Furthermore, MPTMD (multiple particle tuned mass damper) is proposed for controlling higher-order vibration mode, achieving a maximum RMS reduction ratio of 65.93%. Combining the spectrum diagram result, the ability to control higher-order mode vibration of MPTMD is confirmed.