Size-dependent mechanical response of a nano-sized piezoelectric transducer with axially polarized multilayers

Axially polarized piezoelectric fibers have been widely used in smart composites. This paper presents a theoretical investigation on the size-dependent mechanical response of a nano-sized piezoelectric cylindrical transducer with axially polarized multilayers subjected to an external harmonic voltage load. An electro-elastic surface/interface model is introduced to analyze the size-dependent stress in the transducer. Based on the plane stress assumption, the dynamic solution with surface/interface energy effect is expanded, and the expanded constants are solved by satisfying the boundary conditions at the surfaces/interfaces. An example is used to analyze the distribution of stress along the radial direction. It is found that the piezoelectric surfaces/interfaces in the nano-sized transducer exert greater effect on the mechanical response than the elastic surfaces/interfaces. The surfaces/interfaces effect on the inner layers is more evident than that on the outer layers. The surfaces/interfaces energy effect under different frequencies is also examined.