Wind Load Effects Research Articles

Study The Effects Of Various Wind Loadings In High Rise Rc-Framed Structures In Zone –V

The construction of high-rise buildings, both residential and commercial, is increasing. Every structural designer must be aware of the forces such as earthquake and wind effects. Every engineer is challenged to provide stability and strength for loads such as lateral forces (wind and seismic loading). That is why wind loading has become one of the most important issues in high-rise buildings. Lateral loads are crucial for drift; therefore, drift must be considered for high-rise structures. This research work focuses on the effects of various wind loads on high-rise structures with the provision suggested in IS 875(part 3):2015 and for seismic load using IS code 1893(part1):2016. For the study, four irregular plan building is used with G+20 story in seismic zone V and terrain category II with a basic wind speed of 44, 47, 50, and 55 m/s that is analyzed and designed using the structural analysis software tool STAAD Pro. The bending moment, shear forces, story displacements, story shear, and story drift are analyzed on every level of height on the building, and the results are compared with them.

Time-Dependent Reliability Evaluation for the Buckling Limit States of the Purlin with Sheeting Considering Typhoon-Induced Diaphragm Degradation Effect

Steel sheeting is usually provided at the upper flange of purlin in steel roof with screw connections. The resulting diaphragm effect provided by the sheeting enhances the buckling resistance of the purlin. However, this diaphragm effect will be reduced due to any abnormality in the screw connection caused by wind-induced fatigue particularly from typhoon. This would reduce the buckling resistance of the purlin with sheeting (the purlin-sheeting system), and it would affect subsequent condition evaluation during their service life. This problem is addressed in this paper with a framework of time-dependent reliability evaluation of the buckling limit state of the purlin-sheeting system. The buckling resistance reduction due to the degradation of the diaphragm effect from typhoon is taken into account in the resistance model. The randomness of wind intensity and landfall occurrence of typhoon during the service life of purlin are also accounted for in the wind load effect model. The time-dependent reliability of the purlin at different positions of a roof is studied. Then the variation of reliability of the system due to the effect of climatic changes in the design service life is discussed. The proposed strategy is then applied to the evaluation of a purlin-sheeting system in eleven cities in China with typhoon occurrences with some useful results for future studies in the provisions of the design code.

Multi-Hazard Effects of Crosswinds on Cascading Failures of Conventional and Interspersed Railway Tracks Exposed to Ballast Washaway and Moving Train Loads.

The interspersed railway track is an enhanced timber railway track, spot-replacing damaged wooden sleepers with new concrete sleepers to improve the bearing capacity of existing railway lines. Although this interspersed solution is characterised by low cost and short maintenance time, the interspersed tracks have worse stability than concrete tracks and can deteriorate quickly when exposed to extreme weather conditions such as heavy rains and floods. In many cases, heavy rains and floods are accompanied by strong winds. Ballast washaway can often be observed under flood conditions while the mass of trains is unevenly distributed on two rails due to the effect of lateral wind load and rail irregularities. The current work is the first in the world to investigate the collective multi-hazard effects of ballast washway and uneven axle loads on the vulnerability of conventional and interspersed railway tracks using nonlinear FEM software, STRAND 7. The train bogie is modelled by two sets of point loads. The maximum displacement, bending moment and twists have been studied to evaluate the worst condition. The novel insights will help the railway industry develop proper operations of interspersed railway tracks against naturally hazardous conditions.

Wind Load Effect Study on Large-Aperture Parabolic Trough Collector Mirror Fields

Abstract Large-aperture parabolic trough collectors (LPTCs) are recognized as one of the most promising next-generation linear-focus concentrating solar power (CSP) technologies. However, large apertures inevitably introduce higher wind loads and stronger inter-row interactions. In the present study, a multi-physics-coupled model is established to study the wind load effect on multiple rows of LPTCs. First, it is found that wind load fluctuates significantly in the first four rows and then decreases gradually. The first and second rows suffer the most and least damage, respectively. Because wind load effect is highly dependent on the row number, it is recommended to build wind fences and reinforce the strength of collectors according to their positions in the solar field. Second, the wind load reduction effectiveness of the varied focal length design, incorporated in the LPTC, is numerically validated so that the stress and optical efficiency loss can be reduced by 29.1% and 58.9%, respectively. Finally, the optical efficiency loss is first introduced to evaluate the wind load reduction performance of different mirror gap sizes. The optimal mirror gap size is found to be dependent on the weight coefficient between the wind load reduction and the optical efficiency, which should be determined by the actual scenario. For weight coefficients of 1:1, 1:2, and 2:1, optimal mirror gap sizes of 90 mm, 30 mm, and 120 mm, respectively, are recommended for reference.

Influences of Gap Flow on Air Resistance Acting on a Large Container Ship

In terms of speed lost and fuel consumed, wind loads are considered one of the main factors for large ship design, especially for container ships. Alongside water resistance, air resistance in strong wind conditions has a significant impact on the fuel efficiency and performance of container ships with large box-type bodies. This paper reports the effects of wind loads acting on a 20,000 TEU container ship carrying large numbers of deck containers using a commercial CFD software program (ANSYS Fluent V14.5 with RANS equation). A 1/255.3 scale model was used in this study to reveal the air resistance on the container ship configuration. The aerodynamic formations of the complex vortices, pressure, velocity contours, and streamlines, as well as the air forces acting on the container ship, are presented and discussed. The pressure distributions show that the gap air flows increase the stagnation pressure at the face side and decrease the pressure on the backside of each container gap through separate eddies. The difference in pressures created in the gaps contribute to the air resistance acting on the ship. It is confirmed that the use of side covers of deck containers to close the gap flows between container blocks can significantly reduce the air resistance for wind directions in the range of 30 to 60 degrees.

Effect of Wind Load on Milad Tower and Adjacent Buildings Case study: Shed Adjacent to Tower

Tall buildings are subject to wind loads as one of the effective lateral loads. An analysis of the effect of wind on Milad Tower is presented in this research. The wind tunnel testing results and numerical modelling implemented in computational fluid dynamics (CFD) using ANSYS software. For the numerical simulation, the K-epsilon model has been used. The study evaluated the flow around the tower in several deformation states and compared it with a model where the tower is modeled rigidly in the wind tunnel. The maximum coefficient of negative pressure (suction) at the top of the tower structure equals to -1.95, which occurs at q =90o, and the maximum coefficient of the positive pressure equals +1. Since the buildings near the tower are located a short distance from the tower, the shed's structure, which is located near the tower, has also been investigated. With the aid of Tecplot software. The wind pressure coefficients obtained from the wind tunnel test were plotted. As part of the wind loading analysis in the single-span and two-span shed models, the model is rotated with a step of 5o relative to the direction of wind application, and wind pressure is recorded.

Evaluation of Wind Effects on High-Rise Buildings Using Ansys CFX

Tall building is the growing pattern of cities, these buildings are highly vulnerable to wind loads. Wind load effects on the high-rise building can be found using wind tunnel testing and CFD tools. Wind tunnel facilities are limited all around the world, so CFD tools can be incorporated. In this study, ANSYS CFX is used to investigate the effects of wind on different shapes of high-rise buildings. The results of numerical simulation are compared with the international standards of various countries. Streamline patterns and pressure contours on different faces are discussed in this paper. It is found that building shape and size are having a direct effect on the pressure distribution on various surfaces of the building model. Windward face pressure will always be positive in nature. In this study, the comparison is presented for the variation in the cross-sectional shape of the building model. For this purpose Model C and Model I are having considerable variations and Model X is considered for validation purposes only. It is well established that the results are within the allowable limit. This paper aims to discuss these windgenerated effects in the tall building model.

Variation of wind load distribution on gable roof building

Wind forces and their impact on the structural integrity of roofs and walls are pivotal considerations in architectural and engineering design. This study discusses the effect of wind load on gable roof buildings with varying slopes. Gable roof structures find extensive application in industrial construction projects. Based on wind tunnels with rigid models, wind pressure distributions on gable roof buildings with different aspect ratios were measured simultaneously. Special attention is required for the safe design of the building. Information regarding the wind pressure coefficients on buildings is available in codes of practices of various countries dealing with wind loads; however, such information is very limited. The present study will examine the suitability of four building models with roof angles of 10º, 15º, 20º, and 25º and will be analyzed using IS 875 (Part 3), and various forces will be calculated. Then, the same buildings will be modeled using STAADPro/SAP2000, and the comparison of the analysis will be made. Further, a building situated at various slopes on a hill will be modeled using STAAD-Pro/SAP2000, and the variation of Wind Forces along the slope will be studied. The expected results of this study will be finding out the most critical slope of a gable roof on a building and reducing the effect of wind forces on it. Furthermore, the most savior location of a building along the hill slope will be investigated, and the ways to reduce the effect of these wind forces will be studied.

Analysis of Wind Effects on Different Shapes of Tall Buildings

The rapid expansion of cities and increasing population means that land is limited and what land is available is shaped in an erratic manner, while its demand is increasing day by day. Therefore, to cope with this increasing demand and to achieve maximum utilization of resources, tall buildings are being built. However, these buildings are extremely vulnerable to lateral loads, particularly wind loads.To ensure the safety of these buildings, wind tunnel studies are used to examine the effects of wind loads. To combat the issue of shortage of wind tunnel facilities in the world, numerical analysis is used instead. Thus, this project aims to analyse the impact of wind effects on high-rise buildings of different shapes with the help of CFD, by making use of ANSYS. The wind effects have been assessed by obtaining the velocity profile and turbulent profile, pressure contours for different faces of the building, and velocity streamlines for the plan and elevation of the building.

The evaluation of collapse probability of low-rise buildings based on Monte Carlo simulation

Over recent years, wind-caused activities such as typhoons, hurricanes, and tornadoes have happened frequently in coastal areas, causing damage or even the collapse of many buildings. This study designs a three-story teaching building located in Dalian to discuss the influence of different wind speeds on the stability of this building and propose some measurements. This study firstly uses Monte Carlo simulation to analyze the probability of collapse of the beam. Results show that the probability of frame collapse on windy days is 0.399%. It indicates that the wind speed could affect the stability of the structure. Higher wind speed could cause a higher internal force and structure displacement, leading to structural disability. The study also provides some wind-resistant designs to increase structural stability. The first is to choose a wind-resistant location, making reasonable site selection. The second is to select a suitable roof to resist heavy wind, and to increase the safety factor of the roof wind load design. The third is to increase the cross-section reinforcement method to reduce the dynamic wind load effect of the structure effectively. The externally bonded steel from the reinforcement method should be checked to avoid shear damage to the members after the bending bearing capacity increase.

Study of Along and Across Wind Load effects on RCC Chimneys

Chimney is a hollow, tall and slender structure to discharge smoke or pollutants at a height so that after dilution due to atmospheric turbulence, their concentration and that of their entrained solid particulates is within acceptable limits on reaching the ground under various atmospheric conditions. As large scale industrial developments are taking place all over the world a large number of chimneys would be required to be constructed. As for chimneys the predominant load is mainly wind load. This paper is aimed at deriving standard curves with the help of which one can easily calculate approximate wind load on chimney in shell completed condition. The curves have been plotted for chimneys of various heights, top internal diameter, taper and located in different wind zones. The importance of these curves would be in finalization of initial sizing of chimney and its supporting structure. Wind Analysis is done as per code IS 4998: 2015 and IS 875 (Part 3): 2015. SAP 2000 software is used to determine mode shapes. MS-Excel spreadsheets are used for loading calculations.

Effect of wind load on waveguide strength

The article considers the features of the influence of wind load in the Arctic and Far North regions on the static and dynamic state of direct waveguides. Waveguides have a thin-walled design with restrictions on wall deflections, so the theory of plates and shells is used to calculate them. In the static state, the wind load is modeled by uniform pressure on one side of the waveguide. This made it possible to obtain an analytical solution to the problem by the plate theory, identify the features of the stress distribution over the waveguide structure, and clarify the solution compared to the beam theory. Comparing the results of the calculation according to the proposed method with the results of beam theory showed good convergence. The dynamic state was estimated by the first natural frequency of waveguides, considering ice deposits. The results of the calculations showed a significant impact of ice deposits on the frequency of oscillations and showed the need for deicing.

Experimental investigations on the wind load interference effects of single-axis solar tracker arrays

Aiming at the interference effect of wind loads on single-axis solar tracker arrays, this study conducts rigid-model pressure measurement wind tunnel tests on a single-row solar tracker and solar tracker arrays. The effects of the tilt angle and wind direction on aerodynamic characteristics are examined. The basic characteristics of the wind-induced interference effects of a single-axis solar tracker array are clarified. The results reveal that when the tilt angle is small, the interference effect is small, the tilt angle increases, the interference effect becomes stronger. From the mean pressure and torque coefficients, the interference effect is mainly manifested as a shielding effect. Based on the fluctuating pressure and torque coefficients, the interference effect appears as a shielding effect and an amplification effect in small- and large-tilt angle ranges, respectively. The wind load power spectrum of the solar modules in the rear-row of the solar tracker arrays presents remarkable frequency peaks, and is more affected by wind-induced vibration than the front module. The influence of the wind direction results in nonuniform distributions of wind loads along the length of the solar tracker. Thus, the enhancement in wind loads on the edge areas of solar arrays caused by the wind direction should be considered.

PREDICTION OF WIND LOADS ON A HIGH-SPEED CATAMARAN DURING MANOEUVRING AT LOW SPEED

Abstract 
 The influence of wind on a ship’s manoeuvring performance has always been an important issue, particularly in a harbour environment and during the ship’s docking or disembarking. These types of ships have relatively shallow draft and a smaller cross-sectional area below the waterline compared with their above waterline area. It is therefore important that the designer has appropriate tools for accurate station keeping prediction.
 This paper presents aerodynamic coefficient estimates for a 112m high-speed wave piercing catamaran (built by Incat Tasmania) using RANS-based Computational Fluid Dynamics (CFD) and Experimental Fluid Dynamics (EFD) from wind tunnel testing. It demonstrates that CFD and EFD can be used to complement each other in quantifying the magnitude and effects of wind loading on a high-speed wave piercing catamaran. The results from CFD simulations correspond well with the wind tunnel experiments. 

Effect of nonstationary extreme wind speeds and ground snow loads on the structural reliability in a future Canadian changing climate

Extreme wind speeds and ground snow loads for many regions across North America exhibit non-stationarity in projected future climates. The adequacy of conventional return period design values estimated in the past for the future design life needs to be investigated. Nonstationary extreme value analysis methods were used in several previous studies to evaluate the nonstationarity of extreme wind and snow loads based on the latest future projections for Canada in the RCP8.5 (where RCP denotes the representative concentration pathway) emission scenario. These methods have not been considered in nonstationary reliability analyses. This study will examine the effect of including these nonstationary extreme value analysis methods in the reliability analysis. Investigations were conducted by applying the design value estimated in past stationary climate to the reliability analysis considering nonstationary climatic load effects in the future design life. Two non-stationary extreme value analysis methods were then used to determine the design level value in the nonstationary future climates for mitigating the climate change impact. These two approaches target different risk levels. Both nonstationary methods provide design level values greater than the conventional return period values and can maintain the probability of failure close to the target value at the end of the design life. Analyses were also conducted to examine the climate change impact on the structural reliability for considering principal wind load effects or snow load effects with the companion live load effects.

The Interference Effects of Wind Load and Wind-Induced Dynamic Response of Quayside Container Cranes

Strong wind has caused damage to group-arranged quayside container cranes in terminals and ports in recent years. Interference may amplify the wind loads in some cases. However, the interference effect among cranes has rarely been studied. In this study, high-frequency force balance tests were conducted to obtain the wind load of isolated and group-arranged container cranes. The results of the computational fluid dynamics simulation were validated by wind tunnel tests and provided the mean wind loads of all 15 types of member cranes. According to the results from wind tunnel tests, the fluctuating wind loads of each member were generated using the weighted amplitude wave superposition method. Based on dynamic finite element methods, the wind-induced responses were obtained considering the interference effect. It was found that the interference effect is the combined effects of both the shielding effect and the amplification of turbulence. Although in some cases the fluctuating and peak wind loads can increase by up to 16% and 6%, respectively, those in the most unfavorable cases are reduced by the interference effect. The interference factor for extreme nodal deformation is 0.56 and 0.69. The interference effect in container cranes mainly appears as a shielding effect, reducing the wind loads and response of the structures in unfavorable cases.

Статистический анализ поездопотока на участке Палласовка — Верхний Баскунчак с целью выявления ветровых нагрузок

Purpose: The given article is devoted to energy consumption problematics. The article relevance is especially high for our country steppe regions where high speed winds prevail most of the year that have a significant impact on fuel and energy resource (FER) consumption increase in train traction. This question is open and no analysis methods have been developed. Also, in locomotive depots, there is no clear energy expenditure normalization for train traction under exposure to additional drag to movement. Wind burden impacting train cars is one of the essential factors affecting energy consumption in a traction. Methods: The article shows high significance of this problem for Russian Railways (“Russian Railways” JSC). The article analyzes main factors, affecting fuel and power consumption, and major methods of normalization for FER. For the consideration, Pallasovka — Verkhniy Baskunchak section of Privolzhskaya railway in the traction with 2TE25KM series diesel locomotive was chosen. Histograms of specific fuel consumption for trains with fixed minimal and maximal axle loads were built and analyzed on the basis of samples from the given foot-plateman routes. Results: Conclusions on the effect of wind loads on specific fuel consumption were made basing on the numerical characteristics of the obtained samples. Contributions of wind loads to a significant increase in a specific fuel consumption have been proved in the article. Moreover, wind burden impact is higher for empty trains. Practical significance: The need to clarify fuel consumption norm is shown. The norm adjustment will allow to improve definition and record accuracy for energy resource expenditures at their normalizing in locomotive depots. The proposed adjustments can be recommended for a practical use on the considered section.

Wind‐Induced Response and Stow Position Analysis of the Flat Roof Parabolic Solar Collector

Under the action of wind load, the parabolic solar collector (PSC) is easily damaged. In order to ensure the stability and security of the flat roof parabolic solar collector (FRPSC), understanding the wind load effect on the FRPSC has always been an important research direction. This article studies the free vibration and wind-induced response characteristics of the FRPSC, and analyzes the optimal stow position of the FRPSC under strong wind. The modal analysis and wind-induced response calculation of the FRPSC are done through wind tunnel pressure experiment and finite element simulation. The changing laws of the FRPSC dynamic characteristic parameters, peak displacement response, and wind-induced vibration coefficient are obtained. The wind-induced response mechanism of the FRPSC under different working conditions is analyzed in detail. In addition, a comparison with the ground parabolic solar collector is made. Based on the research results, an optimal stow position is analyzed and proposed to minimize the impact of strong wind on the collector. This research work can provide a useful reference for the security design of the FRPSC.

Reliability-based calibration of site-specific design typhoon wind and wave loads for wind turbine

The wind turbines (WTs) that are designed, constructed, and installed near the coastline of mainland China are faced with geographically varying tropical cyclone hazards; failure of WTs due to the tropical cyclone (TC) hazards has been observed in this considered region. The reliability-based Chinese design code calibration of WTs subjected to TC hazards for the considered region seems missing in the literature. In the present study, we calibrate the site-specific design TC wind and wave loads for designing offshore and onshore WTs located in the considered region for selected target reliability indices. The calibration considers the correlated TC wind speed and significant wave height during the passage of TC events. Also, the companion load factors by considering wind load and inertial wave load effects are calibrated. Moreover, the statistics of the responses of the onshore and offshore versions of the National Renewable Energy Laboratory 5 MW wind turbines are calculated using the software package FAST. The statistics of the responses are used in the reliability-based verification analysis by considering the calibrated design TC wind load and wave load requirements. The results indicated that using the calibrated geographically varying TC wind and wave loads is adequate and can be used to aid structural design code making.

AUTOMATION OF GEODESIC MONITORING HIGH-RISE STRUCTURES

The article considers the existing methods used in the problem of geodetic monitoring of structures, analyzes the possibilities and gives a preliminary assessment of the accuracy of their use in monitoring high-rise structures. Methods have been identified that allow obtaining measurement results with a high sampling rate and have the potential for automation. Methods have been identified that allow solving the problem of calculating the daily fluctuations of a structure from the effects of solar radiation and wind load separately from the values of heel and draft.