Author(s)

H. Bossong, S. Lentzen & R. Schmidt

Abstract

This paper presents a method to predict the actuation strain in a smart cantilever beam numerically with the help of experimental parameter identification in com-bination with a finite element code. The hysteretic electric field-strain relation of an unconstrained laminar piezoceramic actuator is measured directly by Michel-son interferometry. The observed nonlinear material behaviour is modelled by a classical Preisach model. This is used for the determination of the piezoelectric coupling coefficient, which depends nonlinearly on the strains. For the numerical investigation of the active structure a finite element code is interacting in an itera-tive procedure with the Preisach model. Keywords: smart structures, finite element method, actuators, piezoelectri-city, hysteresis, Preisach model. 1 Introduction Piezoelectric actuators are widely used in shape and vibration control of active structures. The actuators commonly used in smart structures are made of ceramics, preferably consisting of Lead Zirconate Titanate (PZT). Ceramics have, compared to piezoelectric crystals, the advantage of exhibiting a very high piezoelectric cou-pling factor. Additionally, the characteristic properties of these materials can be designed during production. The disadvantage is, that piezoelectric ceramics have a number of nonidealities like hysteresis, creep, depoling and a nonlinear electric field-strain relation for high electric fields. Normally for commercially available piezoelectric actuators only material parameters for linear constitutive equations

Keywords

smart structures, finite element method, actuators, piezoelectri-city, hysteresis, Preisach model.