Lamb waves generation using a flat multi-element array device

Lamb waves are used in the nondestructive evaluation (NDE) of composite materials as they can propagate over long distances. The usual method of generation relying on a transducer that can not be reduced to a low thickness, the development of a thin transducer using a comb-like array of piezoelectric elements has been investigated. It requires a deep understanding of the dispersion relations in the material, in order to determine its geometrical parameters for a set of frequencies. Then, a prototype designed to work on surface is presented and Lamb wave generation using “in-phase” and “varying phase” methods is discussed