Generation of Lamb waves through surface mounted macro-fiber composite transducers

Abstract

The paper describes a numerical approach for the analysis of Lamb wave generation inplate structures. Focus is placed on the investigation of macro-fiber composite (MFC)actuators and their directivity properties when actuated individually, or as part of rosetteconfigurations. A local finite element model of the electro-mechanical behavior of theactuator/substrate system estimates the distribution of the interface stresses between theactuator and the substrate, which are subsequently provided as inputs to the analyticalprocedure that estimates the far-field response of the plate. The proposed approach allowshandling of complex actuation configurations, as well as the presence of a bonding layer.The technique is first validated against the results available in the literature, and it is thenapplied to the analysis of macro-fiber composites. Rosette configurations show a richdirectional behavior which can be tuned through the selection of phase and amplituderelations among the components of the rosette. The results suggest the potential of theapproach as a tool for the optimization of the directivity of rosette actuators andfor the prediction of the excitation provided by actuators of complex shapes.