A LARGE-DISPLACEMENT ANALYSIS OF A BEAM USING A CAD GEOMETRIC DEFINITION

In industrial applications, the design of beam and shell structures is generally based on global representations for curves and surfaces, su ch as Bezier curves, splines and NURBS. On the other hand, the mechani cal analysis of these structures by the finite element method generall y requires a refined discretization of the geometry. It is shown here that this analysis can be performed directly from the CAD representati on which involves a small number of variables. Assuming a Bezier repre sentation, the theory is developed in the framework of large displacem ents and then is applied to the static analysis of a beam undergoing l arge rotations. a compatible parametrization of the beam displacements is discussed. A formulation for the large displacement beam mechanics is summarized and applied to a straight beam submitted to various loa ding cases. Finally, three illustrative examples are presented.