Trailing Waves

We report a special phenomenon: trailing waves. They are generated by the propagation of elastic waves in plates at large frequency-thickness (fd) product. Unlike lamb waves and bulk waves, trailing waves are a list of non-dispersive pulses with constant time delay between each other. Based on Raleigh-Lamb equation, we give the analytical solution of trailing waves under a simple assumption. The analytical solution explains the formation of not only trailing waves but also bulk waves. It helps us better understand elastic waves in plates. We finally discuss the great potential of trailing waves for nondestructive testing.