Imaging localisation of damages on switch rail foot based on laser ultrasonic testing

The corrosion on the switch rail's foot may easily lead to rail breakage. Laser ultrasound detection is often used to assess the integrity of rails. Nevertheless, the inadequate photoacoustic conversion efficiency and vulnerability to surface interference of the entirely non-contact laser ultrasound result in a diminished signal-to-noise ratio (SNR), hence impeding the efficient detection and analysis of minor damages in the rail. This work demonstrates piezoceramic material lead zirconate titanate (PZT) wafers in conjunction with a pulsed laser to create a sensor array capable of accurate array image inspections. The PZT sensor arrays are manufactured in a flexible format that may be easily installed and altered to complicated geometries. Pulsed lasers are used to achieve dense and high-frequency array excitation. This study proposes a novel probabilistic picture location identification strategy by merging the variable mode decomposition algorithm based on parameter optimization (PVMD) and the principle component analysis (PCA) algorithm. The aim is to enhance the SNR and increase the accuracy of damage findings. Simulation and experimental tests have demonstrated the accuracy of the suggested mechanisms and algorithms in identifying damaged regions.