Effective Identification and Localization of Single and Multiple Breathing Cracks in Beams under Gaussian Excitation Using Time-Domain Analysis

Abstract

The output response of any intact oscillatory system subjected to a Gaussian excitation is also Gaussian in nature. On the contrary, when the system contains any type of underlying nonlinearity, the output signal is definitely non-Gaussian. In beam structures, the presence of fatigue-breathing cracks significantly influences the dynamic response characteristics under Gaussian excitation. The presence of such cracks alters the response to be nonlinear, and the non-Gaussianity of the system will arise. In order to examine the non-Gaussianity features and ability for the detection and localization of fatigue cracks, several breathing crack identification scenarios in beam-like structures are presented in this paper. The effects of single and multiple breathing cracks corresponding to different boundary conditions on the responses of beams are studied. The results are analyzed based on the higher-order time-domain transformations. Higher-order transformations, namely the skewness and kurtosis coefficients in addition to the Shannon entropy, are exploited to provide dynamic details about the response, which the conventional second-order statistics cannot show. The results exhibit that the proposed methods are robust and immune to noise and can detect and localize breathing cracks with different sensitivities.

An algorithm for localization of fatigue crack in spinning rotor based on proof by negation

“…Integration of optical flow and information entropy was used by Xin et al [21] and similar advanced algorithms have been reported. Similar high-end algorithms have been reported for the prognosis of stationary structures like structural beams by Al-hababi et al [22], and Kumar and Singh [23].…”

“…The frequency domain response, η i is derived from the full spectrum of η(t) and the time domain response η(t) may be attained from the time integration of equation (22).…”

A novel time domain-based multiple breathing crack diagnosis technique using Quadratic-Teager Kaiser Energy (Q-TKE)

“…Therefore, the development of a generalized procedure for the localization of multiple breathing cracks is challenging. [13][14][15][16][17][18][19][20][21][22][23][24][25] Nonlinear multiple breathing cracks detection utilizing direct zeros estimation of higher-order frequency response function was studied by Chomelette. 19 However, the method is less accurate in localizing the crack close to the support (cantilever beam).…”

“…There exists a lot of research evidence on extraction of low amplitude nonlinear features such as superharmonics and mixed harmonics or intermodulations from the vibration response using frequency domain approaches. [1][2][3][4][5][6][7][8] Only very few studies are completely time-domain approaches [22][23][24][25] and they mostly aim at addressing single breathing crack identification. The extraction and enhancement of the nonlinear features in the time domain especially toward multiple breathing crack localization is highly complex and challenging.…”

“…Time domain-based nonlinear indicator functions such as harmonic distortion, auto and cross correlation, skewness, kurtosis, entropy etc., were used for breathing cracks diagnosis. 24 Al-hababi et al 25 evaluated three time domain indicators namely skewness, kurtosis, and shanon entropy for multiple breathing crack identification. The authors concluded that shanon entropy is a robust indicator among the others; however, localization of more than three cracks is still challenging using noisy measurements and demands high fidelity sensing.…”