Bridge structure modal parameter authenticity and falsity discrimination method and terminal device

Abstract

The invention belongs to the bridge monitoring technical field and provides a bridge structure modal parameter authenticity and falsity discrimination method and a terminal device. The method includesthe following steps that: the monitoring data of the structure of a bridge under an environmental excitation condition are obtained through data acquisition devices disposed in a plurality of measuring points of the bridge; the NExT (natural excitation technique) is adopted, at first, the cross power spectrum density function of the monitoring data is calculated, and Fourier inverse transformation is performed on the cross power spectrum density function, so that the cross-correlation function of the monitoring data is obtained, the cross-correlation function is adopted as the input data of amodal parameter identification algorithm, so that modal parameter identification can be carried out, and a stability diagram can be drawn; the auto-power spectrum density function and cross-power spectrum density function of the monitoring data of the measuring points are calculated, the auto-power spectra and cross-power spectra of all the measuring points are summated, and the auto-spectra andthe cross spectra are summated in the same order of magnitude, so that the sum function of the power spectra can be obtained; and a diagram of the sum function, and true and false modal parameters canbe discriminated according to the stability diagram of the sum function. According to the method, the stability diagram method and a power spectrum summation peak method are combined to perform bridge structure modal parameter authenticity and falsity discrimination, so that discrimination accuracy can be improved.

Description

technical field [0001] The invention belongs to the technical field of bridge monitoring, and in particular relates to a method for discriminating true and false bridge structural modal parameters and a terminal device. Background technique [0002] It is extremely expensive or even impossible to excite large-scale structures such as cable-stayed bridges, and the identification of modal parameters of cable-stayed bridges under environmental excitations has attracted attention. The modal analysis under ambient excitation (Ambient Excitation) is a kind of Operational Modal Analysis (Output-Only Modal Analysis, OMA), which has the advantages of uninterrupted traffic, cost saving, online and real-time structural modal parameters Identification and health monitoring. [0003] The modal parameter identification under environmental excitation needs to go through two steps of modal parameter identification and true and false mode identification after the early signal processing (su...

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Problems solved by technology

[0007] In view of this, the embodiment of the present invention provides a bridge structural modal parameter identification method and terminal equipment to solve the problem of low identification accuracy in the prior art

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