Study on the railway wheel ultrasonic inspection method using the full matrix capture

The quality of wheel is especially important for the safety of high speed railway. In this paper, a new ultrasonic array inspection method, the Full Matrix Capture (FMC) and Total Focus Method (TFM) algorithm, has been studied and applied to the high speed railway wheel inspection, especially in the wheel web from the tread. The Total Focusing Method (TFM) which processing image with the data set captured by the approach of Full Matrix Capture (FMC) has been adopted in the field of industrial non-destructive evaluation from medical field since 2005. In this paper, the model is introduced to discuss the principle of FMC and the signal processing method of Hilbert transform which to solve the analytic signal to recover the instantaneous phase information for high resolution imaging. Then the TFM as the reconstruction algorithm is discussed and simulated with different size of aperture to evaluate the performance of TFM. The experiments on the PA block and railway wheel are carried out based on the conventional Phased Array (PA) and FMC method. The inspection result, such as the reliable detection, SNR and image resolution, has been analyzed and discussed according to the different active aperture size based the TFM algorithm, comparison to the conventional phased array UT. It is demonstrated that this TFM algorithm is with good potential for the wheel inspection.