A.K. Soh

Three-dimensional electromechanical responses of a parallel piezoelectric bimorph

This paper proposes a three-dimensional study for parallel piezoelectric bimorphs, which are used commonly as sensors and actuators. Firstly, a general analysis is performed based on the state space formulation combined with an asymptotic expansion technique. By properly truncating the expansions, a analytical expressions for the three-dimensional distributions of electric and mechanical fields in the bimorph is obtained in terms of the displacements on the mid-plane. These displacements are governed by two-dimensional equations formally similar to those in the classical plate theory. Thus, a three-dimensional solution to the bimorph generates directly, provided the two-dimensional equations are solved. As an example, a piezoelectric cantilever bender with a clamped edge is considered, and detailed numerical results are illustrated.

A high precision element with a central circular hole

An eight-node rectangular membrane element with a central circular hole has been developed using complex potentials to define stress and strain functions. This new element type can be combined with the conventional elements, e.g., isoparametric elements, with no modifications required. Two numerical examples were employed to illustrate the superiority and versatility of the proposed element type. The results obtained using the said element type are closer to the theoretical results as compared with those obtained by similar types of elements.