Comparison of Wind Pressure Coefficients with Wind Load Provisions

2013 ◽  
Vol 831 ◽  
pp. 124-128
Author(s):  
Jong Won Lee ◽  
Yun Bae Kong ◽  
Sung Woo Shin

This study has compared the equivalent external pressure coefficients, (GCpf)eq, with 6 wind load provisions and wind tunnel test data. The wind load provisions are the ASCE 7-10, NBCC 2010, AS/NZS 2011, EN 2005, AIJ 2004 and KBC 2009. Experiment data on low-rise building have been obtained at the University of Western Ontario (UWO) to contribute to the NIST aerodynamic database [. For the experiment, a model with 1:12 of roof slope and 4.9 and 12.2m of eave height was used under open terrain conditions (See also Ref. [). (GCpf)eq was re-normalized based on the external pressure coefficients, GCpf, of ASCE 7-10. When compared to (GCpf)eq of the experiment data with 4.9m of eave height, consequently, ASCE 7-10 (81%), NBCC 2010 (84%), AS/NZS 2011 (70%), AIJ 2004 (68%) and KBC 2009 (53%) were all underestimated. Among them, KBC 2009 reveals the lowest value. On the contrary, EN2005 was overestimated with 122%. When the eave height was 12.2m, in addition, the same pattern was observed in most codes. EN2005 was slightly overestimated with 115%.

2011 ◽  
Vol 94-96 ◽  
pp. 1026-1030
Author(s):  
Yue Ming Luo ◽  
Yue Yin ◽  
Xi Liang Liu

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.


Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 342
Author(s):  
S. M. Ashfaqul Hoq ◽  
Johnn P. Judd

The adequacy of the directional and envelope procedures for the design of the main wind force resisting system is not well understood. The purpose of this study is to evaluate the directional and envelope procedures based on wind tunnel test data for a set of low-rise enclosed buildings with gable-shaped roofs in open terrain (Exposure C). The base shear force and the conditional reliability index are used to determine the adequacy of the procedures. The base shear was compared to the design base shear in each direction based on the horizontal component of the wind load on the wall and roof. The reliability index, β conditional on the occurrence of the design wind speed was computed for a range of system capacities. The main findings are (1) the directional procedure produced a larger design base shear compared to the envelope procedure, primarily due to the difference in external pressure coefficients, (2) the directional procedure provided a higher β, and (3) the envelope procedure provided a β that did not meet the standard target β equal to 3.0 for the main wind force resisting systems with low variability in capacity, but neither procedure met the standard target β for the main wind force resisting systems with high variability in capacity.


2014 ◽  
Vol 590 ◽  
pp. 341-348
Author(s):  
Shu Guo Liang ◽  
Xiao Hui Peng ◽  
Lei Wang

Field measurement and wind tunnel test of wind pressure on the surfaces of Wuhan International Stock Building were carried out in this paper, and the mean wind pressure coefficients, RMS wind pressure coefficients, wind pressure spectra as well as coherence functions were discussed. Meanwhile wind pressure distributions were analyzed. The results demonstrated that the distribution of the surface mean wind pressure coefficients obtained by wind tunnel test approximately agreed with that by field measurement, especially the mean wind pressure coefficients on the windward obtained by the wind tunnel test fitted those obtained by the field measurement well, while the RMS wind pressure coefficients of the wind tunnel results are smaller than those of field measurement, and the RMS wind pressure coefficients of some measure points of field measurement fluctuated greatly.


2013 ◽  
Vol 639-640 ◽  
pp. 523-529
Author(s):  
Fu Bin Chen ◽  
Q.S. Li

The Shenzhen New Railway Station (SNRS) has roof dimensions of 450 m long and 408 m wide. This paper presents the results of wind loads acting on the large-span roof structure. In the wind tunnel test, wind-induced pressures including mean and fluctuating components were measured from the roof of a 1:200 scale SNRS model under suburban boundary layer wind flow configuration in a boundary layer wind tunnel of HD-2 at Hunan University. Based on the data obtained simultaneously from the wind tunnel tests, the distributions of the mean and fluctuating wind pressure coefficients and the characteristics of probability density functions of wind pressures of typical pressure taps were analyzed in detailed. The outcomes of the experimental study indicate that: (1) The maximum mean negative wind pressure coefficients on the roof occur at the windward leading edge region, where the maximum fluctuating wind pressure coefficients occur also in this region; (2) There are some differences of the maximum mean negative wind pressure coefficients and RMS wind pressure coefficients under conditions with different number of trains inside the station, but such effects on the overall pressure distributions on the whole roof are negligible; (3) There are clearly negative skewed distributions for some pressure taps at the windward leading roof edge and much longer negative tails are observed, which follow Non-Gaussian distributions. The results presented in this paper are expected to be of considerable interest and of use to researchers and professionals involved in designing complex long-span roof structures.


2021 ◽  
pp. 0309524X2110445
Author(s):  
Hiroshi Noda ◽  
Takeshi Ishihara

Mean wind forces and peak pressures acting on ellipsoidal nacelles are investigated by wind tunnel tests. The wind force coefficients of the ellipsoidal nacelles for the wind turbine design and the peak pressure coefficients for the nacelle cover design are proposed based on the experimental data. The wind force coefficients are expressed as functions of yaw angles. The proposed formulas are compared with Eurocode, Germanischer Lloyd and ASCE7-16. It is found that the mean wind force coefficients for the wind turbine nacelles are slightly underestimated in Eurocode. The equivalent maximum and minimum mean pressure coefficients are proposed for use in Design Load Case 6.1 and Design Load Case 6.2 of IEC 61400-1. The peak pressure coefficients are derived using a quasi-steady theory. The proposed equivalent maximum and minimum mean pressure coefficients are much larger than those specified in Germanischer Lloyd.


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