Pulsed laser generation of circumferential surface waves on coated cylinders

The surface wave fields on fast and slow coated cylinder have been investigated both in theory and experiment. The cylindrical surface waves are generated by a pulsed laser line source and detected by a laser interferometer. Dispersive relations estimated with experiment signals on both slow coated cylinder(zinc/steel)and fast coated cylinder (copper/tin)are compared with that calculated in theory.Further more,transient normal displacement fields of the surface waves are calculated by using residue theory and FFT technique.The results show that both theoretical surface wave signals and dispersive curves agree well with experimental results,but the two kinds of circumferential surface waves are dramatically different in dispersive properties and transient signals.Theoretical analysis and numerical computational method used in this paper provide a way to quantitatively characterize and invert the coating parameters of coated cylinder by using laser generated surface waves.