A Time-Frequency Research for Ultrasonic Guided Wave Generated from the Debonding Based on a Novel Time-Frequency Analysis Technique

Abstract

Carbon fibre composites have a promising application in the future of the vehicle, because of their high strength and light weight. Debonding is a major defect of the carbon fibre composite. The time-frequency analysis is fundamental to identify the defect on ultrasonic nondestructive evaluation and testing. In order to obtain the instantaneous frequency and the peak time of modes of the ultrasonic guided wave, an algorithm based on the Smoothed Pseudo Wigner-Ville distribution and the peak-track algorithm is presented. In the algorithm, a masking step is proposed, which can guarantee that the peak-track algorithm can automatically exact the instantaneous frequency and the instantaneous amplitude of different modes on the Smoothed Pseudo Wigner-Ville distribution. An experiment for detecting the debonding for a type of carbon fibre composite is done. The presented algorithm is employed on the experimental signals. The processed result of experimental signals reveals that the defect can stimulate new modes, and there is a quantitative relationship between the defect size and the frequency of the new mode. The presented technique provides a valuable way to detect the presentence, calculate the size, and locate the position of the debonding defect.

A Signal Decomposition Method for Ultrasonic Guided Wave Generated from Debonding Combining Smoothed Pseudo Wigner-Ville Distribution and Vold–Kalman Filter Order Tracking

“…Step (3), we construct a corresponding filter in time domain based on the primary IAs of different modes obtained in Step (4). And the equation is as follows:…”

“…Debonding defect is a major defect of the carbon fibre composites. A great number of investigations of the nondestructive evaluation and testing (NDE/NDT) have done research for this type of defect [1][2][3][4][5].…”

Numerical and Experimental Identification of Seven‐Wire Strand Tensions Using Scale Energy Entropy Spectra of Ultrasonic Guided Waves

“…Therefore, UGW propagation characteristics are strongly affected by boundary conditions and local media defects, compared with body waves used for traditional ultrasonic testing, and can effectively provide waveguide defect characteristics and mechanical boundary variation. Thus, UGW based methods have been widely used for defects detection, for example, in bolts [11], pipes [12], and plates [13].…”

Characterization of contact condition in a flange connection by longitudinal waves

“…A phase angle of the wave can express one of the features in a waveform and can be estimated with an instantaneous frequency (Pavopoulou et. al., 2013, Wu et al, 2017, Inoue et al, 2011a, 2016b. Figure 1 shows an experimental setup for measuring transmitting and reflecting longitudinal waves at the interface of two Al alloy disks (A and B in Fig.…”