Higher order nonlinear shell formulations : theory and application

In the present study nonlinear finite element formulations for laminated anisotropic shells are presented. A 7-parameter formulation is derived which is also to simulate large strain effects for any three-dimensional material low. If this theory is extended to a layer-wise model -a so-called multidirector formulation- it is capable to consider even extreme differences in thicknesses and material properties of the individual layers. Besides this, the aspect of finite element technology concerning shear locking is briefly discussed. Several examples confirm the advantageous properties and the wide range of applicability of the proposed formulations.