Damage localization in carbon fiber composite plate combining ultrasonic guided wave instantaneous energy characteristics and probabilistic imaging method

The ultrasonic guided wave (UGW) imaging technique has become a promising tool in composite structure health monitoring. However, most algorithms extract damage characteristics with time or frequency domain method. These methods cannot characterize the nonlinear and nonstationary damage signals. Based on the Hilbert–Huang transform, the phenomenon of instantaneous energy increase and decrease is studied, and the rule of energy change and distance from damage to sensor path is summarized. The damage index based on instantaneous energy characteristics is proposed. A probabilistic imaging method is proposed, which introduces a probability distribution function based on the elliptical method for fusion imaging with traditional probability distribution function. The experiment of 74 points on carbon fiber composite plate was performed. The average localization error was 3.56 mm and the maximum was 9.68 mm. The proposed method has high localization accuracy and stability and has application prospects in high-end equipment composite structure health monitoring.