Dynamic analysis of airships with small deformations

Abstract

The theory of modelling and control of airships was mostly imported from the fields of science and engineering of underwater vehicles. However the main hypothesis of rigidity of the structure may be improved to take into account the flexibility of the hull of an airship. We present an approach for analysing dynamic elastic deformable airships in an ideal fluid. Our model uses the updated Lagrangian method in combination with a large displacement and small deformation (Green) strain tensor formulation. Analogy is made with classical structural dynamics. The description of the behaviour of the airship consists of a continuous differential equation that is solved using a Rayleigh-Ritz technique combined with the finite element method. The method proposes also to take into account the coupling between the rigid body motion and the deformation as well as the interaction and coupling with the fluid surrounding.