Recognition and Extraction Method of Transverse Crack Feature of Stepped Cylindrical Shaft Elastic Wave Signal

Abstract

The invention discloses a method for identifying and extracting transverse crack features of a stepped cylindrical axis elastic wave signal. The existing method for analyzing the elastic wave signal of the rotating shaft is interfered by the frequency multiplier signal during the feature extraction. The present invention respectively filters the collected elastic wave signals at both ends of the stepped cylindrical shaft to be tested, decomposes them into a plurality of IMF components and residual signals by using EMD, EEMD or CEEMD methods, and then converts the multiplied frequency components from the decomposed The signal is subtracted, and then the center frequency of the stop band of the transverse crack and the relationship between the bandwidth and the time distribution are used as the characteristic parameters of the crack, which are analyzed and matched with the characteristic database to obtain the position and depth information of the transverse crack. The invention decomposes and removes the double frequency component in the elastic wave signal, overcomes the problem of large frequency double signal interference when analyzing the energy of the elastic wave component, and makes the final analysis result of the transverse crack more accurate.

Description

technical field [0001] The invention belongs to the field of signal processing and non-destructive detection of cracks, in particular to a method for identifying and extracting transverse crack features of stepped cylindrical axis elastic wave signals. Background technique [0002] During the operation of the rotating shaft of rotating machinery, fatigue cracks are prone to occur due to the action of complex external loads. The expansion of these fatigue cracks will cause serious fracture accidents, and even cause huge damage to human life and property. The vibration of the rotating shaft during operation propagates in it in the form of elastic waves. The propagation characteristics of the elastic wave in the rotating shaft are affected by many factors such as the geometric size of the rotating shaft and the physical properties of the material. When there are defects such as cracks in the rotating shaft, the propagation characteristics of the elastic wave will be affected. T...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art, and provide a method for identifying and extracting transverse crack features of stepped cylindrical axial elastic wave signals, mainly to solve the problem that existing methods are interfered by frequency-doubled signals during feature extraction

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