Extreme Wind Pressures and Non-Gaussian Characteristics for Super-Large Hyperbolic Cooling Towers Considering Aeroelastic Effect

Ke, Shitang; Ge, Yaojun

doi:10.1061/(asce)em.1943-7889.0000922

Cited by 29 publications

(12 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There is no need for experimental filtering, and the computational load is small. So, it can be used to simulate structures with a high Reynolds number, such as cooling towers [10].…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Evolution Mechanism of Wind Vibration Coefficient and Stability Performance during the Whole Construction Process for Super Large Cooling Towers

Zhu

et al. 2019

Applied Sciences

Self Cite

View full text Add to dashboard Cite

Wind-induced damage during the construction process and the evolution of damage over time are important reasons for the wind-induced destruction of large cooling towers. In fact, wind vibration coefficient and stability performance will evolve with the construction height and material properties over time. However, the existing studies generally ignore the impact of wind load and structural performance during the construction period. In this study, we built the 3D physical model separately for all eight construction stages a super large cooling tower which is being currently constructed and stands 210 m. The dynamic characteristics of the cooling tower were analyzed in each stage. First, the flow field information and 3D time history of aerodynamic forces were obtained for the whole construction process using large eddy simulation (LES). Full transient dynamic finite element analysis was used to calculate the dynamic responses of the tower under the real-time changes of wind loads during the whole construction process. Five calculation methods were used to trace the evolution of wind vibration coefficient during the whole construction process of the super large cooling tower. Then the formula for wind vibration coefficient changing with the construction height was fitted. The differential values of wind vibration coefficient during the whole construction process of the cooling tower were discussed by taking the meridional axial force as the objective function. On this basis, the influence and working mechanism of wind vibration coefficient, concrete age, construction load, geometric nonlinearity, internal suction force on buckling stability, and ultimate bearing capacity of the cooling towers were investigated. This research provides an enhanced understanding on the evolution of wind-induced stability performance in super large cooling towers and a methodology to prevent wind-induced damage during the construction process.

show abstract

“…There is no need for experimental filtering, and the computational load is small. So, it can be used to simulate structures with a high Reynolds number, such as cooling towers [10].…”

Section: Methodsmentioning

confidence: 99%

“…In China, the height of newly built thermal and nuclear power plants has far exceeded the upper limit of standard or broken the world's record. This directly leads to substantial 3D dynamic wind load effect [10,11]. The construction period of the main structure and the construction difficulty also increase [12].…”

Section: Introductionmentioning

confidence: 99%

Evolution Mechanism of Wind Vibration Coefficient and Stability Performance during the Whole Construction Process for Super Large Cooling Towers

Zhu

et al. 2019

Applied Sciences

Self Cite

View full text Add to dashboard Cite

show abstract

“…Wind vibration coefficient consists of wind load type and response type. In this study, the latter was used:

β_{Ri} = \frac{R_{i}}{R_{italicei}} = 1 + \frac{{italicgR}_{italicfi}}{R_{italicei}},

where β Ri is response‐type wind vibration coefficient for node i ; R i , R ei , and R fi are total response, mean response, and fluctuating response for node i , respectively; g is peak factor for node i , with the value of 3.0 …”

Section: Calculation Methods and Description Of Parametersmentioning

confidence: 99%

“…where β Ri is response-type wind vibration coefficient for node i; R i , R ei , and R fi are total response, mean response, and fluctuating response for node i, respectively; g is peak factor for node i, with the value of 3.0. [37] The values of the measured damping ratio were selected as 0.5%, 1%, 2%, and 3%, along with the standard 5% damping ratio. From the wind tunnel test, the time histories of nonstationary fluctuating wind loads on the surface were derived; based on the definition of Strouhal number, the step length of time integration was 0.224 s, and the number of time steps was 6,000.…”

Section: Calculation Parameters For Wind Loadingmentioning

confidence: 99%

Identification of damping ratio and its influences on wind‐ and earthquake‐induced effects for large cooling towers

et al. 2018

Structural Design Tall Build

View full text Add to dashboard Cite

Summary Standard 5% damping ratio for high‐rise concrete structures is generally used for dynamic analysis under the action of wind and earthquakes in the existing cooling tower regulations and researches. But considering the unique configuration and material attributes of large cooling towers, the actual damping ratio must be far smaller than the recommended. However, only a few field measurements of damping ratio for large cooling towers have been conducted; neither are there thorough investigation into the qualitative and quantification of wind and seismic effects under different damping ratio. To fill this gap, field measurements of a large cooling tower standing 179 m in northwestern China was performed and acceleration vibration signals at representative positions of the tower under ambient excitation were obtained. The vibration signals were preprocessed combining random decrement technique and natural excitation technique. Three pattern recognition methods (auto‐regressive and moving mean model, Ibrahim time domain, and spare time domain (STD)) were applied to analyze the frequencies, damping ratios, and modes of vibration for the first 10 order modes. Following the line of thought of modal combination, the equivalent synthetic damping ratio was derived. Under 5 damping ratios (0.5%, 1%, 2%, 3%, and 5%), a comparative analysis on the dynamic responses of the cooling tower to wind and single seismic loading by using full transient method was performed. On this basis, the patterns of influence of damping ratio on wind‐induced vibration, wind vibration coefficient, and time history and extrema of seismic responses were extracted. Finally, different combinations of dead weight, wind, temperature in winter, sunshine duration, and seismic intensity and those of accidental seismic effects (8 working conditions) were considered, using equivalent synthetic damping ratio and standard damping ratio. Thus, the most unfavorable working conditions were identified under actual and standard damping ratios for the large cooling tower. Our research findings provide reference for determining the value of damping ratio in large cooling towers and deepening the understanding on the influence mechanism of damping ratio.

show abstract

“…Compared with the Gaussian wind pressures, the non-Gaussian wind pressures take on the feature of asymmetric and/or leptokurtic distribution, which is the nonnormal distribution. Many researchers have contributed to research on non-Gaussian processes [8][9][10][11][12][13]. Kumar and Stathopoulos [4,5] expounded the existence of the nonGaussian wind pressures on the flat and herringbone roofs of low-rise building and conduct the partitions of the Gaussian and non-Gaussian areas.…”

Section: Introductionmentioning

confidence: 99%

Comparative Study on Non‐Gaussian Characteristics of Wind Pressure for Rigid and Flexible Structures

Jiang

2018

Shock and Vibration

View full text Add to dashboard Cite

This paper summarizes a comprehensive study for non-Gaussian properties of wind pressure. The field measurements are implemented on the structure surface of a rigid structure, while a large-span membrane structure is selected as the flexible structure wind pressure contrast group. The non-Gaussian characteristics of measured pressure data were analyzed and discussed through probability density distribution, characteristic statistical parameters, power spectral density function, and the correlations, respectively. In general, the non-Gaussian characteristics of wind pressure present depending on tap location, wind direction, and structure geometry. In this study, the fluctuating wind pressures on the windward side and leeward side of the structures show obvious different degrees of non-Gaussian properties; that is, the surface of rigid structure shows strong non-Gaussian property in leeward, while the roof of flexible structure shows obvious non-Gaussian property in windward. Finally, this paper utilizes the present autospectrum empirical formula to fit the wind pressure power spectrum density of the measured data and obtains the conclusion that the existing empirical formula is not ideal for fitting of the flexible structure.

show abstract

Extreme Wind Pressures and Non-Gaussian Characteristics for Super-Large Hyperbolic Cooling Towers Considering Aeroelastic Effect

Cited by 29 publications

References 20 publications

Evolution Mechanism of Wind Vibration Coefficient and Stability Performance during the Whole Construction Process for Super Large Cooling Towers

Evolution Mechanism of Wind Vibration Coefficient and Stability Performance during the Whole Construction Process for Super Large Cooling Towers

Identification of damping ratio and its influences on wind‐ and earthquake‐induced effects for large cooling towers

Comparative Study on Non‐Gaussian Characteristics of Wind Pressure for Rigid and Flexible Structures

Contact Info

Product

Resources

About