Time-delay estimation for the multi-mode ultrasonic Lamb waves based on the chirplet dispersion transform

Multi-mode ultrasonic Lamb waves, which are suitable for nondestructive testing of thin plates, have dispersion characters and accompany with a lot of useful information of time delay. But there are many difficulties to estimate the time delay parameter. Based on the adaptive chirplet dispersion transform, a new method was put forward for the time delay estimation to make the parameter estimation possible. The results of the simulations and experiments show its effectiveness.