Finite element procedure for modelling fibre metal laminates

Abstract

A geometrically and physically nonlinear solid-like shell element is presented to analyse the behaviour of laminated structures. The geometrically nonlinear formulation of the element is derived from threedimensional continuum mechanics and accounts for the change of thickness. The geometry of the element is described by sixteen nodes which are located at the top and the bottom surface of the element. At each node three translational degrees of freedom are defined. Additionally, four internal degrees of freedom are assumed to improve the description of the internal stretching. The physically nonlinear behaviour is assumed to be governed by the Hoffmann yield criterion for orthotropic materials and the von Mises yield criterion for isotropic materials. It is explained how the element can be applied to laminated structures. By calculating benchmark tests obtained from the literature the behaviour of the element is compared with that of standard finite shell and solid elements. From these tests it is concluded that the solid-like shell element is well suited to compute laminated structures. Finally, the element is applied to compute the behaviour of a tensile specimen made of the Fibre Metal Laminate GLARE ® which gives results which are in good agreement with experimental data.