Wind Load Effects Research Articles

An Experimental Investigation into Wind Effect on Tall Buildings with Pentagonal Cross Section

The effect of wind load is one of the very significant factors in building and structure design. An investigation has been carried out into the wind effect on a Pentagonal cross-section with an open circuit wind tunnel. The experiment was conducted at a constant flow velocity of 13.2 m/s and a Reynolds number of 4.22 x 104. The test was carried out on a single cylinder positioned facing across the flow direction at various angles of attack from 0° to 72° at a step of 9°. Each face of a pentagonal cylindrical model was divided into five tapping points and connected with inclined multi-manometers using copper capillary and plastic tubes to measure the surface static pressure on the cylinder surface. Pressure coefficients were calculated from the measured surface static pressure, which was then used to estimate the drag and lift coefficients. A significant drop of 0.52 in the drag coefficient values has been observed for the single pentagonal cylinder in comparison to that of the single square cylinder. The overall lift coefficient values of the single pentagonal cylinder are found to be lower than that of a single square cylinder except at 90. The fluctuation of the lift coefficient curve has a 90 phase shift than that of the square cylinder; however, the pattern of their variations has shown a similar trend except for the angle of attack of 00. The stagnation point was identified on the front face of the pentagonal cylinder. These findings will assist engineers and architects in designing much safer buildings.

Research on Key Problems and Optimization Based on Structural Design of Super High-rise Buildings

At present, complex super high-rise buildings and super high-rise buildings are emerging all over China, but there are still many problems to be solved in the design of super high-rise structures. For example, the wind pressure and earthquake risk of high-rise buildings, fire safety issues and personnel evacuation issues, earthquake will produce greater inertia force and bending force in high-rise buildings, wind load and wind pressure effect will be more significant, these are the parts that need to be carefully considered to ensure the safety and stability of the building structure. Therefore, it is necessary to analyze and optimize the problem of high-rise buildings. Taking a super high-rise building in Luohu District of Shenzhen City as an example, this paper analyzes the basic structure of super high-rise building, analyzes the key problems of structural design, and discusses the optimization method. This paper puts forward the optimization design method of building structure for seismic problem of super high-rise building structure, puts forward the solution to wind resistance problem, and puts forward the optimization layout method of building fire protection.

Numerical study on the sensitivity of photovoltaic panels to wind load on array layout

Offshore floating photovoltaics began to gradually enter people's vision due to the limitation of inland land resources. However, the offshore environment is harsh, and wind load is an essential factor in floating photovoltaic design. At the same time, the photovoltaic panel will be subjected to a large wind load in strong typhoon weather, which may cause a drag-driven or lift-driven instability for offshore floating photovoltaics. In this work, the effects of wind loads on six PV array structure configurations installed on offshore floating PV platforms at high Reynolds numbers are investigated by using the computational fluid dynamics numerical method. The differences in wind load on photovoltaic panels under different layout structures are analyzed and explained, including analysis of velocity and pressure distribution, turbulence field, and lift and drag coefficient of photovoltaic panels. The results showed array b with symmetrically staggered has less sensitivity to wind direction, less lifting torque, and relatively small pressure on the surface of the photovoltaic panel, which is a potential arrangement.

Computational Simulation of Wind Loads on Three Curved Eave Models with Different Height-Width Relationships

This work deals with the effects of wind loads on two industrial shed models with curved eaves aspect of different height-to-width ratios. Using Ansys Workbench software, the external pressure coefficients for the entire roof by applying refinement levels were determined. Also were studied the quality of the unstructured and tetrahedral grid according to recommendations to ensure greater efficiency in the simulation results. The results generated provided evidence that the wind in the transverse direction is more damaging in the windward region: for a wind at 45º the most critical region appeared both windward and leeward in the model with a ratio of h/b=0.5 (Model 1) and to windward in the models with a ratio of h/b=1 (Model 2) and h/b=1.5 (Model 3). The leeward suctions increased due to the reduction in the height-width ratio considering a wind direction of 45º. The increase in this ratio intensified the values of the external pressure coefficients in the windward region for the 90º wind direction.

Comparative study on dynamic responses of integrated installation process of a 5-MW and a 15-MW offshore wind turbine considering a pre-installed foundation

The integrated installation method for offshore wind turbines has the characteristics of high efficiency and low economic cost due to the small amount of construction work. However, the complexity of the entire system is exacerbated by environmental loads and mechanical couplings. Hence, it is urgent to investigate the dynamic response of OWTs during integrated installation procedures. This work compares the dynamic responses between NREL 5 MW and IEA 15 MW OWT installation systems. The hydrodynamics are calculated using the potential flow theory and the Morison equation, while the aerodynamics under wind turbine parked conditions are computed using the blade element momentum theory. Time domain simulations, considering various wind and wave conditions, are conducted via SIMA. This paper discusses the effects of wind and wave loads on the motion responses of catamaran installation vessel and spar, the relative motion at the mating point, and the sliding gripper forces, respectively. The results reveal that both the surge motions of the catamaran and the spar and the pitch motion of the spar exhibit sensitivity to wind loads. During installation, the motion response of the IEA 15 MW model is more dramatic than that of the NREL 5 MW system. Under wave-only conditions, the radial distances of the mating points for both NREL 5 MW and IEA 15 MW systems reach 1.65 m and 2.51 m, respectively. However, the influences of wind loads and wave incident angle are limited.

Wind load analysis and cost assessment of a dual-axis stand-alone photovoltaic structure

This study investigated the effect of wind load on the structural stability of a dual axis tracking system developed at the Botswana International University of Science and Technology (BIUST). Through simulations, the study explored wind speed variations, from 8 m s−1 to 28 m s−1, while simultaneously adjusting the azimuth and elevation angles of the structure. Utilizing computational methods and numerical simulations, the study models wind flow interactions with the dual-axis tracker system. This knowledge can be used to improve the system’s design, ensure safety, and optimize energy production and efficiency. The findings of this study contribute to the field of renewable energy, specifically in the context of solar power generation using dual-axis tracker systems. The results offer valuable insights into the wind load behavior, structural response, and energy consumption, facilitating the development of more robust and efficient tracker designs. Furthermore, the study used the levelized cost of electricity (LCOE) to investigate the cost effectiveness of the solar system. The aim was to establish how the energy production of the system, the installation, operation, and maintenance costs compare to other systems using the local electricity tariffs.

Wind-Induced Response Assessment of CAARC Building Based on LBM and FSI Simulation

It is very important for the wind-resistant design of high-rise buildings to assess wind-induced vibrations efficiently. The Lattice Boltzmann Method-based Large Eddy Simulation and Fluid–Structure Interaction techniques are used to identify the surface wind pressure and wind-induced dynamic response of a CAARC standard high-rise building. Compared with wind tunnel tests, a detailed analysis of the accuracy of simulated wind pressures and base moments of the CAARC model are discussed under multiple wind direction angles. The differences between one-way and two-way Fluid–Structure Interaction simulations are compared under two different reduced wind velocities. The research results show that the simulated mean surface wind pressures of building under seven wind direction conditions have an error within 15% compared to probe measurements, and the average and root mean square base bending moments agree well with the wind tunnel tests. The top transverse wind-induced vibrations of the buildings are significantly larger when the reduced wind velocity reaches 4.6, indicating that aerodynamic damping effects on structural responses should not be overlooked. The research findings of this article provide valuable technical references for the application of LBM methods in the wind load effect assessments of high-rise buildings.

Wind influence on the spent nuclear fuel safety in dry cask storage

This article examines the effect of wind load on the safety of spent fuel storage in a naturally ventilated building. To assess the influence of wind influences characteristic of the Akkuyu NPP site on the temperature of fuel rod cladding, a CFD model of the spent fuel storage building was developed. Reynolds-averaged governing equations of motion (RANS model) with a k-ε turbulence model were used. Computational grid included about 17 million cells. The CFD model allowed us to study different directions and intensities of wind loads, estimate the temperature around the containers and identify stagnant zones. Based on the modeling results, the dependences of the influence of wind load on the thermal fields in the building were obtained. These dependencies allowed for design decisions to be made that guaranteed safety and ensured the continuation of construction of the building.

Wind Load Effects and Gust Loading Factor for Cable-Suspended Photovoltaic Structures

The cable-suspended PV system has gained increasing popularity due to its large span and good site adaptability. However, this structure is quite sensitive to wind actions, and wind-induced module damage and structure failure have been frequently reported. Therefore, in this study, we carried out wind tunnel tests to study wind load effects on PV arrays with different lengths and widths. Considering the wind sheltering effects of upstream modules, reduction factors for the wind load were proposed in different array zones. Numerical simulations of wind-induced vibration and equivalent static analysis were conducted to yield gust loading factors for the PV array. This study showed that the maximum wind suction and pressure for the middle zone occurred at 0° and 180°, respectively, while those for the outermost zone appeared under oblique flows (e.g., 30° and 150°). For the PV modules beyond the windward fourth row, the reduction factors of the wind loads were 0.4 (maximum suction) and 0.2 (maximum pressure) for the middle zone and 0.5 (maximum suction) and 0.75 (maximum pressure) for the outermost zone. The gust loading factors for the typical wind directions of 0° and 180° varied from 2.2 to 2.7 for the middle zone and from 1.3 to 1.5 for the outermost zone.

Features of the Operation of Anchor Plates for Fixing Windows under the Action of Wind Loads

Numerical and laboratory studies have been carried out to study the static operation of anchor plates under the action of wind loads. Numerical studies of the operation of a standard anchor plate under the action of a compressive load acting perpendicular to the plane of the window have shown that its carrier is several times less than the force that occurs at the attachment points of window blocks when peak wind loads are applied to them. At the same time, the existing experience in the operation of window blocks shows that anchor plates in the vast majority of cases retain their bearing capacity throughout the entire working life of the window block. This indicates that the simplified design scheme of the anchor plate used in practice does not fully reflect its actual operation as part of the window structure. This statement was verified during laboratory tests of a window block with typical design fixed with anchor plates to a frame that simulates a window opening. It is established that the static operation of the anchor plate is significantly influenced by both the fastening of the window frame with mounting foam and the limitation of anchor plates deformations by window slopes. The issue of calculating anchor plates for the effect of wind loads should be considered by the professional community in order to develop both common approaches to the calculation of such fasteners and the fundamental possibility of their use for windows installation, especially in unique buildings.

Wind damage vulnerability analysis of narrow base tower for distribution line based on probabilistic reliability

Steel narrowbase tower has been widely used in distribution network in recent years because that it covers an area smaller than the conventional tower, and has stronger wind resistance than concrete pole. In order to fully understand the wind resistance performance of narrow base tower, a vulnerability performance of narrow base tower under different wind speeds was analyzed based on probabilistic reliability theory. According to the damage characteristics of narrow base tower and the corresponding tall structure specification, wind performance level indexes of narrow base tower were established. When calculating the effect of wind load on narrow base tower, the randomness of wind load, material properties and dimensions were considered. The probability of the narrow base tower appearing different degrees of damage under different wind speeds was calculated, and subsequently a wind vulnerability curve of the narrow base tower was drawn. It is found that the severe damage probability of narrow base tower is about 5% when the wind speed is 23.6m/s. And in the case of severe damage probability is 95%, the wind speed reaches 80m/s. Narrow base tower has good resistance to wind disaster.

Vacuum insulated glazing (VIG) units under wind load—part 1: global deformation and stresses on the outer glass surfaces

This paper presents the first part of a study on the effect of wind loads on Vacuum Insulated Glass (VIG) units. The study provides background information on VIG and relevant Standards, explains the numerical modelling process, and discusses the implications of the results in relation to European and North American codes and Standards. The focus of the study is on vertical windows and façade installations in low-rise buildings (< 25 m) commonly found in residential buildings. The mechanical behaviour of VIG was analysed using the Finite Element Method (FEM) with respect to various design parameters such as glass pane size, glass thickness, surface pressure magnitude, and edge boundary conditions. The study analysed global deformation as well as the stresses on the outer glass surfaces. The VIG features such as pillar geometry and contact dynamics, and material non-linear effects, were explicitly modelled. In addition, monolithic glass plates were also modelled, and the FEM results of the monolithic cases were in reasonable agreement with an analytical solution obtained from linear thin plate theory. These results highlight the limit of linear behaviour in monolithic plate bending. The centre-of-pane deflection of the VIG was in good agreement with the FEM and analytical solutions of the equivalent thickness monolithic pane, for sample sizes below 800 × 800 mm. However, for larger glass sizes, a deviation was found, and the VIG exhibited a higher plate stiffness than the equivalent thickness monolithic pane. The simulations also showed that the stresses in the glass panes are highly dependent on the edge of glass boundary condition. Finally, the results demonstrated that with appropriate design choices, the VIG can satisfy the Standards requirements for wind load and glass design in both Europe and North America.

Buckling failure analysis of storage tanks under the synergistic effects of fire and wind loads

Fire-induced domino effect is one of the main threats to hazardous material storage tanks, and many attempts have been conducted to assess the vulnerability of storage tanks exposed to fire to evaluate domino effect risk. However, past research ignored the influence of wind load on the thermal buckling behavior of storage tanks exposed to fire, which may underestimate the risk of exposed tanks. This paper thus conducts a numerical simulation of the thermal buckling behavior of steel vertical dome storage tanks under the synergistic effect of static wind loads and thermal effects. The effects of wind parameters and heat radiation parameters on the thermal post-buckling behavior and the time to failure (ttf) of storage tanks are investigated to analyze the synergistic effects of fire and wind loads. By comparing the circumferential and meridional stresses before and after the thermal post-buckling stage, it is found that under the disturbing effect of the positive wind pressure load, the thermal post-buckling of the tanks on downwind occurs earlier and more severe. Besides, the effects of wind angle, fire location height, and diameter on buckling damage were investigated. The comparative analysis of different scenarios shows that the tanks in the windy scenario are more prone to thermal post-buckling, and the deformation is intensified, with an increased likelihood of failure.

Experimental Study on Wind Load and Wind-Induced Interference Effect of Three High-Rise Buildings

Wind loads of high-rise buildings are a key parameter in architectural design. The magnitude and distribution characteristics of wind loads are of great importance for the safety and economy of structural design. The wind loads of high-rise buildings are quite different from those of monomer buildings. The wind-induced interference effect could significantly increase the local wind pressure of buildings, causing potential safety hazards for the main structure and enclosure structure. For the three common high-rise buildings, we adopted the wind tunnel test method to measure the surface pressure of each building. The corresponding Re number was 8.2×106. This paper studied the shape coefficients, fluctuating wind pressure coefficients and base bending moment coefficient of each building with different wind direction angles and different spacing ratios, and the maximum value of each parameter and the corresponding working condition were statistically analyzed. The results showed that, under any wind direction angle, the fluctuating wind pressure coefficients on all sides of the building were affected by the spacing ratio, and the fluctuation range was large. When the wind angle was 180º, the fluctuating wind pressure coefficients on the sides of Building 1 were most affected by the slope ratio. At this wind angle, the maximum value was 0.43 at a slope ratio of 5.0, which was 65% different from the minimum. Partition shape coefficients of some sides and top surfaces changed significantly with the spacing ratio. When the spacing ratio was 5.0, the base bending moment coefficients in the downwind and crosswind directions reached their maximum values, and the wind direction angles where the maximum values of the base bending moment coefficients in the downwind direction were 40º and 50º, respectively, and the wind direction angle where the maximum value of the base bending moment coefficients in the crosswind direction was 10º. Due to the influence of the wind angle and the building spacing ratio, the wind loads on the facades of the pyramidal group of buildings varied greatly, and the wind-induced interference effect was evident. The wind load between the building facades in the three buildings was different, and the wind disturbance effect was evident. Therefore, the most unfavorable stress state and interference state of the structure should be comprehensively considered in the wind resistance design of the three buildings. The building spacing ratio should preferably be set to 3.0, and wind angles of 10º, 40º, and 50º should be avoided whenever possible.

FEATURES OF THE STRESS-DEFORMED STATE OF VERTICAL CYLINDRICAL TANKS UNDER EXTERNAL PRESSURE

The paper investigates the features of the stress-deformed state of cylindrical shells under wind pressure, taking into account its actual distribution on cylindrical structures. The purpose of the work is to obtain a qualitative picture of the distribution of stresses and deformations in the cylindrical wall of the tank under wind load, to determine the effect of wind load on both the strength and stability of the tank. Practical significance. It is known that the stresses caused by the action of the wind load, due to their small value, are safe from the point of view of strength, at the same time, obtaining quantitative values of the stress-deformed state main components of the tank under wind load has a certain practical significance. The task is to solve the problem of deformation of the cylindrical shell under external uneven pressure of the wind type. Content of research. The solution of the deformation problem was performed in a linear formulation for cylindrical shells with geometric parameters corresponding to the geometric parameters of vertical tanks with a volume of 1,000…30,000 m3. The solution of the problem was carried out for several loads of the shell with wind pressure of different intensity q = (0,2…1,2) qcrw. Such formulation of the problem made it possible to investigate the features of the stress-deformed state of cylindrical shells under wind pressure both at small values of the external load and at pressure values close to the critical ones, which is important from the standpoint of shell stability. Conclusions. The static calculation of the shells under wind pressure showed that membrane stresses in the annular direction prevail. Membrane stresses in the meridional direction are the second largest. The distribution of these stresses along the perimeter of the shell corresponds to the wind pressure plot. The main feature of the bending stress graphs is their wave character along the perimeter of the shell. Plots of radial displacements w and deformed shells also have a wave character. The size of such wave deviations is insignificant, but their length is close to the length of the waves of the shell protrusion when it loses its stability. Thus, the process of deformation of cylindrical shells under wind pressure is generally stable. The wind load itself is safe from the strength point of view. However, the obtained nature of the deformation, namely the wave deviations of the surface of the shell, can significantly affect the stability of the shell, which requires additional research.

Large eddy simulation on wind-induced interference effects of staggered chamfered square cylinders

Chamfered corners in buildings are the main means to reduce the control effect of wind load on the structure, and the interference effect of chamfered buildings cannot be ignored. At present, only the mutual interference coefficients of square and rectangular section buildings are given in the Chinese code, without the interference effect of chamfered buildings being specified. Therefore, in this paper, aerodynamic force and wind pressure coefficients of chamfered square cylinders of different spacing are obtained by the large eddy simulation method. Wind load characteristics, non-Gaussian characteristics and interference effects of chamfered square cylinders with different arrangements are studied based on aerodynamic coefficients, wind pressure coefficients and interference coefficients. The results show that when the wall y plus value is 1, the large eddy simulation is the most accurate to simulate the wind load and wind field parameters. Besides, the aerodynamic effects, non-Gaussian characteristics and interference effects between the chamfered square cylinders are mainly controlled by the cross-wind interval and the spacing (4.0, 4.0) is the characteristic coordinate. That means, when the spacing is smaller than this coordinate, the interference effect of the square cylinder is more obvious. When the spacing coordinate is greater than (4.0, 4.0), the aerodynamic coefficients and non-Gaussian regional distributions of the principal square cylinder and the isolated cylinder are the same, and the interference factor approaches 1.

Nonlinear Behavior Study of Reinforced Concrete Coupling Beams Subjected to the Effect of Wind Loading

Reinforced concrete shear walls connected by coupling beams are considered an efficient structural system for tall buildings subjected to lateral loads. For seismic design of such buildings, performance-based design has been commonly used in regions with strong earthquakes for its ability to achieve economical and safe design, however the use of performance-based wind design (PBWD), which permits nonlinear response of ductile elements at specific locations under wind loads is still hindered due to the lack of information regarding the performance of these elements. In addition to that, there is still a need for developing an analytical model that can represent nonlinear behavior of these elements when subjected to wind loads. Therefore, in this study two analytical models using two different methods to consider bond slip effect (Bond SP01 (BS) model and steel modification factor (SMF) model) were developed and implemented in OpenSees software and validated with a tested specimen of reinforced concrete coupling beam subjected to a simulated windstorm loading protocol. Then, a parametric study was conducted using the SMF model to investigate the effect of axial restraint, and modification of the ductility demand. Results showed that both of the models showed good agreement with the experiment, however results of the SMF model were more accurate. As for the parametric study, it was concluded that with axial restraint, the beam behavior was dominated by shear, and a slight increase of strength was observed. At ductility demand of 1.8 θ y , the beam performed well with no significant damage and minor residual rotations.

Wind load and load-carrying optical performance of a large solar dish/stirling power system with 17.7 m diameter

Solar dish/Stirling power systems operating in open terrain, the optical performance is very sensitive to wind load because of their large windward area and poor wind permeability, so it is especially important to evaluate the optical performance under wind load. In this paper, a large 38 kW dish/Stirling system with 17.7 m diameter (named XEM-Dish system) is used, the wind loads are simulated and analyzed under 35 sets of wind conditions (17.1 m/s wind speed) with combination of wind direction angle θ∈[0°, 180°] and elevation angle β∈[0°, 90°], the correctness was verified by literature's results. Using an optical-mechanical integrated method, the effects of combined self-weight and wind load on its structural deformation, mirror slope error and flux distribution are evaluated, the main causes and manifestations of the optical deterioration of XEM-Dish system caused by wind load are found, which is similar to deviate-focusing problem affected by tracking errors. Only concentrator is deformed, the mirror slope error components SDx and SDy reach maximum value of 1.755 mrad and 1.828 mrad at worst 45°–0° condition, but optical efficiency still remains at 89.06%, which is excellent. When XEM-Dish system overall deformation, the SDx reached 7.702 mrad and flux distribution is extremely uneven at worst 45°–0° condition, but optical efficiency still reaches about 87.0%.

Применение динамических гасителей колебаний для повышения устойчивости башенных сооружений связи к ветровым воздействиям

Purpose: To investigate the application of dynamic vibration dampers in communication tower structures to protect them from the effects of wind loads. Methods: To analyze the design features of existing tower structures. To consider the effect of various factors including wind loads on the choice of tower structure design. To analyze the climatic parameters of the construction area and to determine the type of tower structure as the subject for conducting this research. To determine the quality criteria of vibration damping, on the basis of which the selection of design dynamic vibration dampener (DVD) construction is carried out, and to calculate its weight. To conduct the calculation study of the selected type of building with regard to wind loads and evaluate the effectiveness of the proposed solution of the dynamic vibration dampener to increase the stability of communication tower structures in areas with wind gusts over 25 m/s. Results: The results of the research of dynamic vibration dampener design aimed at improvement of operating conditions of telecommunication facilities in the areas with increased wind load are presented. Practical significance: It is shown that the use of dynamic vibration dampers in tower constructions of cellular communication makes it possible to reduce the vibration amplitude and the maximum horizontal displacements occurring in the tower structure under wind load.

ASD and LRFD lateral load combinations: Comparison of required strength and reliability for design of structural steel

ASCE 7, Minimum Design Loads for Buildings and Other Structures, provides load combinations for both Load and Resistance Factor Design (LRFD) and for Allowable Stress Design (ASD), defining the required strength of structural members and connections. Similarly, the AISC Specification for Structural Steel Buildings provides resistance factors for LRFD and safety factors for ASD to be applied to the nominal strength for each limit state, permitting design using either method in conjunction with the corresponding load combinations in ASCE 7. Previous publications have demonstrated that similar designs (with similar levels of reliability) result from the application of LRFD and ASD for cases in which the governing load combination has live load as the principal load. This study presents comparison of ASD and LRFD demands, and corresponding reliability indices, from ASCE 7 lateral load combinations, determined with different proportions of dead, live, wind, and seismic load effects and a range of levels of second-order effects. The findings indicate that the generally accepted uniformity between the two design methods established for gravity load combinations does not always extend to lateral load combinations. For a range of conditions, design using ASD load combinations provides significantly lower reliability than using LRFD and does not meet the ASCE 7 reliability target.