Damage Detection and Imaging of Resilient Wheel Using High-Resolution Phased Array Ultrasonic Imaging Method Based on FDMAS-TFM

Resilient wheel is a multilayer composite structure with discontinuous impedance, the internal structure is prone to damage due to repeated interaction. It is a difficult point for damage detection and imaging of the resilient wheel. This article proposes a phased array ultrasonic imaging method based on filtered delay multiply and sum-total focusing method (FDMAS-TFM), and high-resolution imaging for defects in the different positions of the resilient wheel is investigated. This method introduces a pairwise multiplication between the delay and summation on the ultrasonic signals, which utilize the spatial coherence of signals, then the second harmonic component is filtered out for ultrasonic imaging. Finite element simulation and experimental results indicate that the imaging performance of FDMAS-TFM is better than that of the total focusing method total focusing method (TFM), mainly embodied in higher imaging resolution and stronger noise rejection. For imaging defect inside the wheel rim, the FDMAS-TFM increases signal-to-noise ratio (SNR) by up to 21.55 dB compared with the TFM. For imaging defect at the joint between wheel rim and rubber block, the FDMAS-TFM reduces array performance index (API) by at least 36% compared with the TFM. The results show practical application capability of the proposed method in the resilient wheel.