A damage monitoring method for leakage structures based on stochastic resonance

Abstract

The invention discloses a monitoring method for damages of a drainage structure based on stochastic resonance. Firstly, a sensor disposed in the structure collects vibration responses under normal state of the structure, and the vibration responses are respectively stored according to different operation conditions. Secondly, waveform judging parameters and damage criterions are constructed. Lastly, the drainage structure is monitored in real time and observed of characteristics of dynamic vibration waveforms, meanwhile, the waveform judging parameters in every statistic period are calculated in real time and compared with criterion values of the normal structure under corresponding operation states in order to obtain the damage criterions and judge the operation states of the structure. According to the method, the sensor arranged on the drainage structure is adopted to monitor, so the method has the advantages of simple structure, convenient construction, easy maintenance and low project cost and can achieve remote control, online real-time monitoring of dynamic security criterions of arch dams or offline detailed analysis to data.

Description

technical field [0001] The invention relates to the field of water conservancy and hydropower engineering, more specifically, to the technical field of automatic monitoring of discharge structures in water conservancy and hydropower engineering, and is an intelligent dynamic monitoring method based on the theory of structural stochastic resonance. Background technique [0002] In water conservancy projects, the working conditions of the discharge structure are extremely complicated. Due to the strong turbulence of the water flow, the pulsating pressure generated acts on the structure, which is very likely to cause strong vibration of the structure and even lead to the destruction of the structure. Therefore, effective monitoring methods must be found to quickly and accurately discover hidden dangers in the discharge structure and effectively predict its safety status. At present, the monitoring of the discharge structure mainly includes static and quasi-static monitoring bas...

AI Technical Summary

Problems solved by technology

Observation instruments for static or quasi-static monitoring are generally pre-buried in the discharge structure during the construction period. Due to the influence of changes in the reference point and the monitoring range of the instrument, they cannot well reflect the damage of the discharge structure during operation; dynamic real-time Monitoring makes up for the deficiency of static monitoring to a certain extent, but the existing dynamic monitoring indicators cannot well reflect the operating state of the structure

For example, since the vibration characteristics of the structure are often unknown, the dominant frequency of its response power spectrum is not necessarily the operating frequency of the structure itself, and the direct index of the dominant frequency cannot accurately reflect the working state of the discharge structure; at the initial stage of damage, its vibration The amplitude generally does not exceed the allowable upper limit; in addition, the kurtosis coefficient and skewness coefficient reflect the degree of vibration deviation from the normal distribution, and the amplitude ratio coefficient reflects the sudden change of vibration. The test shows that when damage occurs, The vibration response of the structure usually still satisfies the normal distribution, and the damage of the leakage structure is often a fatigue damage process, and there will be no obvious sudden change in the response, so the above indicators are not intuitive and sensitive to the damage situation

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