Research of area-averaged pressure on saddle roofs

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Journal of Vibration and Shock ›› 2011, Vol. 30 ›› Issue (7) : 21-30,6.

论文

Research of area-averaged pressure on saddle roofs

Dong xin; Ye Ji-hong

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Abstract

In order to complete the wind resistant design of enclosure structure and cladding elements, concept of area-averaged pressure is proposed, and its characteristics are systematically studied by wind tunnel test. Firstly, starting from conical vortex, the approaching flow conditions which cause the generation of conical vortex are identified. Based on suction and correlation coefficient of vortex cores, the most unfavorable attack angle for saddle roof is confirmed to be along the connection of high points. Secondly, the area-averaged pressures are calculated by averaging all pressure taps within the area at each instant of time. The relationships between peak loads over various tributary zones and increasing tributary area are presented and fitted, which are verified by the cumulative probability curve of single point pressure. Non-Gaussian feature of area-averaged pressure time series is analyzed and compared with that of point pressure according to skewness and kurtosis. Results indicate that area-averaged pressure, whose uniform fluctuations concentrate on low-frequency range, is more normally distributed than individual pressure.