investigation of the effect of angle beam transducer parameters on the lamb wave field in the three–layer plate by normal mode expansion method

The effect of angle beam transducer parameters such as wedge angle and width transducer on the lamb wave field generated in the elastic-viscoelastic three-layer plate has been investigated using normal mode expansion method. at first, the propagation of lamb wave in the three-layer plate has been investigated using global matrix method, and all the modes that are propagated in the three-layer plate have been specified. then, the optimum parameters of angle beam transducer have been obtained to generate a mode with minimum attenuation at a specific frequency. in addition to this mode, other modes are also generated in the three-layer plate, but this mode has maximum energy in the three-layer plate. the results indicate that the energy contribution of the mode with minimum attenuation at a specific frequency is 99.9% of the total energy and this mode has the highest energy contribution.