FE simulations of piezoceramic disks with a front layer of varying thickness

Piezoceramic disks with a front layer of varying thickness have been investigated using the FE method. Emphasis is laid on the frequency bands around the fundamental thickness extensional mode (TE1) and the first radial mode (R1) of the disks. The influence of varying the density and the compressional and shear velocity of the front layer material has been investigated using electrical input conductance, average displacement and mode shapes. For the frequency band around the TE1 mode, agreement with 1D transmission line model simulations has been found, and further interpretation has been possible. For the frequency band around the R1 mode, similar effects to the ones for the frequency band around the TE1 mode are seen for a front layer material with low characteristic impedance. For higher-impedance front layer materials, the situation changes significantly