Test method for wind-induced internal pressure of building with openings to avoid effect of air column resonance

Abstract

The invention belongs to the technical field of building construction, and discloses a test method for wind-induced internal pressure of a building with openings to avoid the effect of air column resonance. The test method comprises the steps of when the test sampling frequency is 331 Hz, the sampling time is 61.8 seconds, and the total volume after compensation is different times of the originalvolume, verifying the existence of an air column resonance phenomenon; forming partition openings of different sizes to compare and analyze the adverse effect of the air column resonance on the measurement of the pulsating internal pressure; determining the height of a volume compensation box by the calculation of the air column resonance frequency; determining the length and width of the compensation box according to the similar law of internal pressure and the principle that the compensation box is "deep and narrow", ensuring that the air column resonance frequency is in a high frequency region of an internal pressure power spectral density curve, and reducing the effect of the air column resonance energy on the pulsating internal pressure. The calculation formula of the air column resonance frequency of an internal pressure model cavity is introduced through a complex compressor piping system, and the size of the volume compensation box is determined in advance to avoid the adverseeffect of the air column resonance and directly increase the peak response of the internal pressure.

Description

technical field [0001] The invention belongs to the technical field of building construction, and in particular relates to a test method for wind-induced internal pressure of an open building avoiding the influence of air column resonance. Background technique [0002] At present, compared with the external pressure, one of the biggest characteristics of the wind-induced internal pressure of the open structure is that the airflow will vibrate back and forth at the opening, and the characteristic frequency of this airflow vibration is the Helmholtz resonance frequency. The occurrence of Helmhotlz resonance will directly increase the peak response of internal pressure. Under the joint action of internal and external pressure, roof panels, doors and windows and other enclosure structures are easily damaged. [0003] In the wind tunnel test, if the wind-induced internal pressure of the open structure is to be simulated correctly, the Helmholtz resonance frequency must be correct...

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Problems solved by technology

Starting from the similarity of the damping between the open building model and the prototype, Sharma et al. also derived a conclusion similar to that of Holmes; they further compared and studied two types of compensation boxes with the same compensation volume but different shapes (“deep and narrow” and “ The internal pressure power spectrum characteristics when shallow and wide"), the results show that the shape of the compensation box has a significant impact on the wind-induced internal pressure characteristics, and the "deep and narrow" volume compensation effect is the best, which can ensure accurate simulation of fluctuating internal pressure, However, the "shallow and wide" volume compensation box will cause an additional resonance peak to appear on the internal pressure power spectrum, which is inconsistent with the single-cavity internal pressure resonance theory, and should not be used in the test.

[0004] To sum up, the problem existing in the prior art is that the "shallow and wide" volume compensation box will cause an extra narrow resonance peak to appear on the power spectrum of the internal pressure, which is inconsistent with the resonance theory of single-cavity internal pressure. should not be used

A "deep and narrow" volume compensation box is suitable, but it should not be too deep, otherwise there will be air column resonance, which will directly affect the measurement accuracy of pulsating internal pressure

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