A Dynamic Calibration Method of High Frequency Base Force Balance

Abstract

The invention discloses a dynamic calibration method for a high-frequency base force balance, which comprises the following steps: whitening a measurement signal x(t) to obtain a whitened signal z(t); seeking an orthogonal matrix V such that z(t)= Vq(t), and then obtain the separation signal q(t); under the modal coordinates, identify the natural frequency and modal damping ratio of the separation signal; modify the separation signal according to the parameters obtained by identification; inversely deduce from the separation signal , to get the corrected aerodynamic load. The invention separates the coupling signal, and uses the curve fitting method to identify the natural frequency and modal damping ratio of the separated signal one by one for the independent components obtained by the separation, combined with the aerodynamic characteristics, and then corrects and eliminates the modal coupling system. The dynamic amplification effect of the method can finally obtain the real aerodynamic load spectral density matrix, which can maximize the reliability of parameter identification and corresponding HFFB dynamic signal calibration, and lay an important foundation for the subsequent accurate estimation of wind-induced response of high-rise building prototypes.

Description

technical field [0001] The invention belongs to the technical field of instrument calibration, and in particular relates to a dynamic calibration method of a high-frequency base force balance. Background technique [0002] The high-frequency base force balance (HFFB) technology is widely used in the wind resistance test research of super high-rise buildings due to its simple model making and short test period. HFFB belongs to the category of multi-component (usually five-component or six-component) balances. Multi-component balances will have problems of mutual interference or coupling between components to varying degrees. Usually, it is necessary to calibrate before leaving the factory to determine the simulation of each component and the corresponding sensor output. The transformation matrix of the signal finally achieves decoupling. Strictly speaking, this calibration technique is only suitable for static measurement. When the balance is installed on the measured model,...

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Problems solved by technology

[0007] Among the above methods, the BMS natural frequency and damping ratio identified by the conventional tapping method in method 1 cannot reflect the influence of wind-structure interaction (WSI). This problem also exists in method 2. Ignoring the WSI effect will lead to the BMS natural frequency In particular, the error in the identification of the modal damping ratio will affect the correction effect of the measurement signal at the cross-resonance peak, so that the signal cannot be effectively corrected across the resonance region; method 2 uses a preconceived method to assume the mode shape of the BMS, This is equivalent to thinking that the signal separation matrix of the BMS is assumed. This method obviously violates the basic principles of parameter identification. When the assumed mode shape does not match the mode shape of the actual model, it will affect the separation effect of the signal, and then affect the natural frequency. And the correct identification of the damping ratio, in the end, it is also impossible to effectively correct the signal across the resonance region; method 3 is only a rough approximation when no reasonable solution is found

In summary, the existing methods have a certain positive effect on the correction of the distortion degree of the measured signal within a certain frequency range, but there are still deficiencies.

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