A comprehensive self-verification analysis method of cable frequency based on dynamic test

Abstract

The invention discloses a comprehensive self-verification analysis method of cable frequency based on dynamic test: obtaining cable vibration response time history data; using Fourier transform method module, empirical mode decomposition module and variational mode decomposition module to process respectively Cable dynamic response time-history data; according to the three module methods in the above steps, the cable frequency values ​​are decomposed respectively, according to each group of output frequency results to determine whether the corresponding vibration order of the frequency value can be determined, if so, output a frequency value. First-order vibration frequency results, compare the first-order vibration frequencies obtained by the three modules, and judge whether the three sets of data meet the convergence conditions; otherwise, output the minimum frequency results obtained by the three module analysis methods, and compare whether the results of the three modules satisfy the frequency order. Determine whether the vibration order corresponding to each frequency can be determined. If it cannot be determined, the effective frequency cannot be extracted from this group of measurement data, otherwise the dynamic analysis result will be output.

Description

technical field [0001] The invention relates to the technical field of in-service detection and evaluation of prestressed cable structures, and more particularly to a prestressed cable frequency that performs multi-algorithm comprehensive analysis on the measured dynamic data of the cable, combined with the dual self-verification of the algorithm and the multi-order frequency. Analytical method. Background technique [0002] The prestressed cable force is directly related to the bearing, deformation and dynamic performance of the structure, and is an important evaluation index for the service state of the structure. For prestressed cables in service, if there is no embedded sensor, the indirect method is often used to detect the cable force. Generally, the dynamic sensor is used to test the vibration time history signals such as the acceleration of the cable, and the frequency of the cable is obtained according to the time-frequency analysis. The cable force of the cable is...

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Problems solved by technology

However, this technology has high requirements on the test reflective surface, and the signal loss on the long-distance low-reflection surface is large, and the main natural vibration frequency of civil engineering structures is generally low (within 10Hz), and the environmental noise interference is large. Under the long-distance test condition, the data The signal-to-noise ratio is low, and how to ensure the accuracy of testing and analysis has rarely been studied, which has become an important bottleneck problem restricting the application and development of non-contact detection technology in the field of civil engineering

On the other hand, there is no effective and convenient verification method in engineering whether the data obtained by using a single test sensor is consistent with the actual situation of the cable

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