Transverse crack feature identification and extraction method of stepped cylinder shaft elastic wave signals

Abstract

The invention discloses a transverse crack feature identification and extraction method of stepped cylinder axis elastic wave signals. The existing analysis method of rotating shaft elastic wave signals is influenced by frequency doubling signals. According to the transverse crack feature identification and extraction method disclosed by the invention, after elastic wave signals collected at bothends of a tested stepped cylinder shaft are respectively filtered, the elastic wave signals are decomposed into multiple IMF components and residual signals by using an EMD, EEMD, or CEEMD method, then a frequency doubling component is subtracted from the decomposed signal, and then the center frequency of a transverse crack attenuation band and the relationship characteristics of bandwidth and time distribution are used as characteristic parameters of the crack to perform analysis and matching with a characteristic database to obtain position and depth information of the transverse crack. Inthe transverse crack feature identification and extraction method disclosed by the invention, the frequency doubling components in the elastic wave signals are decomposed and removed, the problem of large interference of the frequency doubling signals during the analysis of the energy of the wave components of the elastic waves is overcome, and then the final analysis result of the transverse crack is 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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