Method for correcting FFT data in stayed-cable force of stayed-cable bridge detected by frequency method

Abstract

The invention discloses an FFT data correction method in the detection of the stay cable force of a cable-stayed bridge with a frequency method; an acceleration sensor is arranged on a stay cable and connected with a control box; a fundamental frequency generation module is arranged inside the control box; the fundamental frequency generation module comprises an FFT module, a waveform correction module and a secondary FFT module; the acceleration sensor captures a time-domain vibration signal of the stay cable and inputs the signal into the control box; the time-domain signal is then processed through FFT spectral analysis by the FFT module, so that the spectrum curve of the signal can be obtained; the data of the frequency within 7.5-25Hz on the spectrum curve is kept, while the remaining data is made zero; after the data of the frequency within 7.5-25Hz obtained in the third step is processed through secondary FFT transformation analysis by the secondary FFT module, the fundamental frequency of the stay cable of the cable-stayed bridge can be detected. Through the FFT spectrum analysis data correction and the secondary FFT transformation, the invention can accurately detect the fundamental frequency of the stay cable of the cable-stayed bridge and eliminates the abnormal phenomena due to the cable force detection through a frequency method.

Description

technical field [0001] The invention relates to the technique of detecting cable forces of cable-stayed cables of cable-stayed bridges using a frequency method in the field of bridges, in particular to a method for processing detected cable force data. Background technique [0002] The cable force of cable-stayed bridge is an important technical index parameter. After the bridge is completed, the stay cables need to be monitored to understand the working status of the stay cables. Therefore, it is of great practical significance to accurately estimate the cable force of the stay cables. [0003] There are many methods for cable force detection, the traditional ones are oil pressure gauge reading method, sensor reading method, frequency method and so on. Because the oil pressure gauge reading method and the sensor reading method are usually limited by environmental conditions, they are only suitable for construction cable force monitoring; while the frequency method is simpl...

AI Technical Summary

Problems solved by technology

However, when the actual cable vibrates, some strong low-frequency interference signals will be mixed in. These interference frequencies can be seen on the primary frequency spectrum, which will affect the inaccurate calculation of the fundamental frequency, resulting in the abnormality of the calculated cable force.

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