scholarly journals On the Use of the Cubic Translation to Model Bimodal Wind Pressures

2019 ◽  
Vol 15 (2) ◽  
pp. 20-32
Author(s):  
François Rigo ◽  
Thomas Andrianne ◽  
Vincent Denoël
Keyword(s):  
Bimodal Distribution ◽  
Wind Pressure ◽  
Wind Engineering ◽  
Pressure Data ◽  
Direct Evaluation ◽  
Translation Model ◽  
Background Turbulence ◽  
Wind Pressures ◽  
Non Gaussian ◽  
Flat Roof

Abstract The cubic translation model is a well know tool in wind engineering, which provides a mathematical description of a non-Gaussian pressure as a cubic transformation of a Gaussian process. This simple model is widely used in practice since it offers a direct evaluation of the peak factors as a function of the statistics of the wind pressure data. This transformation is rather versatile but limited to processes which are said to be in the monotonic region. For processes falling outside this domain, this paper describes an alternative which is based on the physics of the wind flow. First, it is shown, with a classical example of a flow involving corner vortices on a flat roof, that the pressure data which does not meet the monotonic criterion is in fact associated with a bimodal distribution. Then, the proposed approach is to decompose this data into the two governing modes (slow background turbulence and fast corner vortices) and apply the usual translation model to each of them.

Mean Wind Pressure Field on the Typical Large-Span Roof Structures

2012 ◽  
Vol 166-169 ◽  
pp. 19-24
Author(s):  
Fang Hui Li ◽  
Ming Gu ◽  
Zhen Hua Ni ◽  
Shi Zhao Shen
Keyword(s):  
Pressure Field ◽  
Pressure Coefficient ◽  
Wind Pressure ◽  
Pressure Data ◽  
Shape Factors ◽  
Local Shape ◽  
Wind Pressure Coefficient ◽  
The Mean ◽  
Urban Terrain ◽  
Wind Pressures

The wind tunnel tests of some typical large roofs, including a saddle roof, pitched roof and domes, are carried out with various terrains which cover suburban and urban exposures. The wind pressure data of roofs are obtained by using the synchronous multi-pressure scanning technique. The wind pressure coefficient and local shape factors of the wind load was investigated. The effects of various terrains on wind pressures of roofs are discussed. From the results, we can see mean pressures of these roofs exposed to the mean pressures exposed to the suburban terrain are 2 or 3 times those exposed to the urban terrain. And the terrains are no directly influence to the wind pressure shape factors.

Wind Pressure Coefficients Determination for Pre-Homogenization Storage in Cement Mill

2011 ◽  
Vol 94-96 ◽  
pp. 1026-1030
Author(s):  
Yue Ming Luo ◽  
Yue Yin ◽  
Xi Liang Liu
Keyword(s):  
Wind Tunnel ◽  
Spherical Shell ◽  
Rapid Development ◽  
Wind Tunnel Test ◽  
Wind Pressure ◽  
Wind Engineering ◽  
Pressure Coefficients ◽  
Continuous Innovation ◽  
Structural Style ◽  
Wind Pressures

Due to the increasing of wind disaster, structural wind engineering arouses more and more attention recently, with rapid development on spatial structure and continuous innovation of structural style. The main purpose of structural wind engineering is to calculate the wind pressure coefficients of structure. In this paper, the numerical wind tunnel method (NWTM), based on the Computational Fluid Dynamics (CFD), is applied to study wind load. The wind pressure coefficients of reticulated spherical shell with the 4.6m high wall were first determined, using the NWTM. The results are then compared with the wind tunnel test (WTT) and good agreement is found. The feasibility and reliability of NWTM were then verified. As the second example, NWTM is carried out to predict wind-induced pressure on reticulated spherical shell without wall. Further the distribution behavior of wind pressures on this kind of structures is discussed which could provide professionals the reference for the design of structure.

Modeling of wind-induced pressure fluctuations on roofs of low-rise buildings

1999 ◽  
Vol 26 (4) ◽  
pp. 453-467 ◽  
Author(s):  
K Suresh Kumar
Keyword(s):  
Time Series ◽  
Pressure Fluctuations ◽  
Wind Pressure ◽  
Fourier Amplitude ◽  
Simulation Methodology ◽  
Fatigue Design ◽  
Building Modeling ◽  
Wind Pressures ◽  
Non Gaussian ◽  
Simulation Scheme

A systematic study on the modeling of wind-induced pressures on low building roofs with application to extreme value and fatigue analysis is described in this paper. Extensive wind tunnel measurements form a basis to carry out the modeling. Based on the Fourier representation of time series, a general approach for simulating Gaussian as well as non-Gaussian wind pressure fluctuations has been presented. Both Fourier amplitude and phase required for the simulations are modeled individually. A simple stochastic model is proposed for the generation of Fourier phase of non-Gaussian time series. An empirical model has been suggested for the synthetic generation of normalized spectra; synthetic spectra are utilized for the generation of Fourier amplitude part. Towards the generalization of the simulation scheme, the standard spectral shapes associated with various zones of each roof and their parameters are established. The efficiency of this simulation methodology is illustrated with several examples. Applications of the simulation methodology have also been discussed. The established simulation scheme can be used to generate fluctuating wind pressures on low building roofs in a generic fashion not only for the evaluation of extreme pressures but also for fatigue design purposes.Key words: low-rise building, modeling, roofs, wind pressure.

Estimation of extremes of non-Gaussian wind pressure on building roof: Sampling error in moment-based translation process model with no monotonic limit

2019 ◽  
Vol 23 (4) ◽  
pp. 810-826 ◽  
Author(s):  
Fengbo Wu ◽  
Min Liu ◽  
Qingshan Yang ◽  
Liuliu Peng
Keyword(s):  
Hermite Polynomial ◽  
Sampling Error ◽  
Polynomial Model ◽  
Wind Pressure ◽  
Transformation Model ◽  
Sampling Errors ◽  
Translation Process ◽  
Building Roof ◽  
Wind Pressures ◽  
Non Gaussian

Estimation of extremes of non-Gaussian wind pressure on building roof is necessary for cladding design. When limited length of non-Gaussian wind pressure is used for calculation, the estimated extreme involves sampling error. The moment-based Hermite polynomial model is extensively applied for estimation of extreme wind pressure due to the straightforwardness and accuracy, however, Hermite polynomial model has a monotonic limit resulting in a restricted application region of skewness and kurtosis combination. However, another two moment-based translation process models with no monotonic limit including Johnson transformation model and piecewise Hermite polynomial model have attracted some attention as these two models can be applied to a broader region of skewness and kurtosis combination. The sampling error in estimation of extremes of non-Gaussian wind pressure on building roof by Hermite polynomial model is proposed in the literature recently. Nevertheless, the sampling errors in Johnson transformation model and piecewise Hermite polynomial model have not been addressed. In this study, sampling errors in estimation of extremes of non-Gaussian wind pressures by Johnson transformation model are investigated. Formulations for estimating sampling errors of newly defined statistical moments and subsequent extremes in piecewise Hermite polynomial model are presented. The performance of sampling errors in Hermite polynomial model, Johnson transformation model, and piecewise Hermite polynomial model are finally compared with each other. Based on very long wind pressures from wind tunnel tests, it is shown that the sampling error of minimum wind pressure (suction) in Hermite polynomial model is generally the smallest compared to Johnson transformation model and piecewise Hermite polynomial model, while that of maximum wind pressure in piecewise Hermite polynomial model seems to be the smallest.

Wind Pressure and Wind-Induced Vibration of Heliostat

2008 ◽  
Vol 400-402 ◽  
pp. 935-940 ◽  
Author(s):  
Ying Ge Wang ◽  
Zheng Nong Li ◽  
Bo Gong ◽  
Qiu Sheng Li
Keyword(s):  
Dynamic Response ◽  
Wind Direction ◽  
Wind Load ◽  
Wind Pressure ◽  
Induced Response ◽  
Vertical Angle ◽  
Lateral Direction ◽  
Direction Angle ◽  
Wind Pressures ◽  
Fluctuating Wind

Heliostat is the key part of Solar Tower power station, which requires extremely high accuracy in use. But it’s sensitive to gust because of its light structure, so effect of wind load should be taken into account in design. Since structure of heliostat is unusual and different from common ones, experimental investigation on rigid heliostat model using technology of surface pressure mensuration to test 3-dimensional wind loads in wind tunnel was conducted. The paper illustrates distribution and characteristics of reflector’s mean and fluctuating wind pressure while wind direction angle varied from 0° to 180° and vertical angle varied from 0° to 90°. Moreover, a finite element model was constructed to perform calculation on wind-induced dynamic response. The results show that the wind load power spectral change rulers are influenced by longitudinal wind turbulence and vortex and are related with Strouhal number; the fluctuating wind pressures between face and back mainly appear positive correlation, and the correlation coefficients at longitudinal wind direction are smaller than those at lateral direction; the fluctuating wind pressures preferably agree with Gaussian distribution at smaller vertical angle and wind direction angle. The wind-induced response and its spectrums reveal that: when vertical angle is small, the background responsive values of reflector’s different parts are approximately similar; in addition, multi-phased resonant response occurring at the bottom. With the increase of , airflow separates at the near side and reunites at the other, as produces vortex which enhances dynamic response at the upper part.

Non-Gaussian Wind Pressure on Prismatic Buildings. II: Numerical Simulation

2001 ◽  
Vol 127 (9) ◽  
pp. 990-995 ◽  
Author(s):  
Massimiliano Gioffrè ◽  
Vittorio Gusella ◽  
Mircea Grigoriu
Keyword(s):  
Numerical Simulation ◽  
Wind Pressure ◽  
Non Gaussian

Automation of Wind Pressure Computation Using a Data Management Approach

1993 ◽  
Author(s):  
Yamini Gourishankar ◽  
Frank Weisgerber
Keyword(s):  
Data Management ◽  
Data Retrieval ◽  
Design Guidelines ◽  
Database Management System ◽  
Information Modeling ◽  
Wind Pressure ◽  
Management Approach ◽  
Analysis And Design ◽  
Design Requirements ◽  
Wind Pressures

Abstract It is observed that calculating the wind pressures on structures involves more data retrieval from the ASCE standard than any subjective reasoning on the designer’s part. Once the initial design requirements are established, the procedure involved in the computation is straightforward. This paper discusses an approach to automate the process associated with wind pressure computation on one story and multi-story buildings using a data management strategy (implemented using the ORACLE database management system). In the prototype system developed herein, the designer supplies the design requirements in the form of the structure’s exposure type, its dimensions and the nature of occupancy of the structure. Using these requirements, the program retrieves the necessary standards data from an independently maintained database, and computes the wind pressures. The final output contains the wind pressures on the main wind force resisting system, and on the components and claddings, for wind blowing parallel and perpendicular to the ridge. The knowledge encoded in the system was gained from ASCE codes, design guidelines and as a result of interviews with various experts and practitioners. Several information modeling methodologies such as the entity relationship model, IDEF 1X, etc. were employed in the system analysis and design phase of this project. The prototype is implemented on an IBM PC using the ORACLE DBMS and the ‘C’ programming language. Appendix A illustrates a sample run.

scholarly journals ESTIMATION OF PEAK FACTOR FOR NON-GAUSSIAN WIND PRESSURE

2002 ◽  
Vol 67 (557) ◽  
pp. 79-84 ◽  
Author(s):  
Kazuyoshi NISHIJIMA ◽  
Jun KANDA ◽  
Hang CHOI
Keyword(s):  
Wind Pressure ◽  
Peak Factor ◽  
Non Gaussian

scholarly journals Durability of Stone Cladding in Buildings: A Case Study of Marble Slabs Affected by Bowing

Buildings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 229 ◽  
Author(s):  
Sousa ◽  
Sousa
Keyword(s):  
Element Model ◽  
Pressure Effects ◽  
Wind Pressure ◽  
Stability Evaluation ◽  
Building Facade ◽  
Building Facades ◽  
Anchoring Strength ◽  
Wind Pressures ◽  
Loss Of Strength

Bowing is an uncommon pathology that can affect marble stone cladding of building façades, causing a large permanent deflection and the degradation of the flexural and anchoring strength of the stone slabs, which can lead to the cladding falling from the façades. Moreover, the combination of bowing with wind pressure effects on the building façades can increase the risk of fracture and collapse of the stone slabs, especially if this combination is not properly evaluated during design. Motivated by a case study, this work describes a stability evaluation of a 15-year-old building façade coated with marble stone cladding affected by bowing and subjected to wind pressures. This evaluation was focused on the stone slabs, and was performed through finite element model (FEM) numerical simulations of these slabs submitted to wind pressures and through lab tests using samples of stone slabs removed from the building façade. The results obtained demonstrated stability problems on the stone slabs caused by wind pressure-induced stresses combined with the loss of strength due to aging and bowing effects, especially for slabs with larger dimensions.

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