This paper proposes a three-dimensional study for parallel piezoelectric bi
morphs, which are used commonly as sensors and actuators. Firstly, a genera
l 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 displacem
ents 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 cantil
ever bender with a clamped edge is considered, and detailed numerical resul
ts are illustrated. (C) 2001 Elsevier Science Ltd. All rights reserved.