Time-domain Signal Simulation of Anti-symmetrical Mode Ultrasonic Lamb Wave

Multi-modes and dispersion characteristic of ultrasonic Lamb wave make it very complicated in exciting, propagating, receiving and signal processing and difficult to be used in industry ultrasonic non-destructive evaluation and testing. In this paper, firstly the anti-symmetric mode Lamb dispersion characteristics are analysed. Then the anti-symmetric mode dispersion curve in a specific material plate is calculated. Through theoretically analysing the ultrasonic Lamb wave time-domain signal, the ultrasonic testing expression model in time-domain is built. By numerical simulation analysis, combined with anti-symmetric mode propagation characteristics, the zero-order time-domain signal propagated a certain distance in a plate without a defect is simulated. The computer simulation results show that the algorithm can effectively calculate the anti-symmetric single-mode Lamb wave waveform in time-domain, which provides a theoretical basis for the application of anti-symmetric Lamb wave measurement technology in time domain in the industry.