Author(s)

S. Lentzen & R. Schmidt

Abstract

A geometrically non-linear composite shell element with integrated magnetostrictive layers is presented. Three translational and two rotational nodal degrees of freedom are used for the first-order transverse shear approximation. The finite element is used in order to investigate the shape control of a cantilevered plate. The numerical approximations to this static problem are obtained using the total Lagrangian formulation for the moderate rotation shell theory. The significance of a geometrically non-linear formulation in order to predict the actuator behaviour is demonstrated. Keywords: magnetostriction, actuators, shape control, geometrical non-linearity. 1 Introduction The importance of introducing smart materials into structures to improve their performance has been emphasised frequently. The most common smart materials used in these problems are piezoelectric and magnetostrictive materials and shape memory alloys, in decreasing number of occurrence. Geometrically non-linear effects in piezoelectrically actuated structures have been discussed e.g. by Lentzen and Schmidt [1]. The advantage of actuated magnetostrictive materials is the larger range of actuation strains as compared to the piezoelectric materials, facilitating large deformations. Geometrically as well as physically linear finite element models can be found in literature (see e.g. Murty et al. [2, 3], Reddy and Barbosa [4], Engdahl [5]). Geometrically non-linear finite element models to analyse these structures are found considerably less. In this work a geometrically non-linear finite shell ele-

Keywords

magnetostriction, actuators, shape control, geometrical non-linearity