Flexible multibody systems models using composite materials components

The use of a multibody methodology to describe the large motion of complex systems that experience structural deformations enables to represent the complete system motion, the relative kinematics between the components involved, the deformation of the structural members and the inertia coupling between the rigid body motion and the elastodynamics. Here, a flexible multibody formulation of complex models is extended to include elastic components made of composite laminated or anisotropic materials. The deformation of the structural member must be elastic and linear if described in a coordinate frame fixed to its domain, regardless of the complexity of its geometry. To achieve the proposed flexible multibody formulation a finite element model for each flexible body is obtained. For beam composite material elements, the sections properties are found using an asymptotic procedure that involves a two-dimensional finite element analysis of their cross-section. The equations of motion of the flexible multibody system are solved using an augmented Lagrangean formulation and the accelerations and velocities are integrated in time using a multi-step integration algorithm.