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.
Highlights
Carbon fibre composite is a type of composite material with a high strength
Debonding defect is a major problem of the carbon fibre composites
This paper presents a time-frequency algorithm aiming to analyze the characteristics of ultrasonic guided wave (GW) generated in a NDT for the debonding in a type of composite material
Summary
Carbon fibre composite is a type of composite material with a high strength. The specific strength and specific stiffness are better than other lightweight materials. For multicomponent signals, mashing operation should be conducted to guarantee that just one mode in time-frequency panel is processed by using the peak-track algorithm. To realize automatically mashing operation, a step based on the minimal and maximal values of a statistic parameter of the time-frequency distribution is presented to extract and separate valuable modes on the time-frequency panel. A time-frequency analysis of debonding of a type of carbon fibre composites is conducted to discuss the feasibility of identifying the presence, size, and location of the defect.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have