On the Formulation of Flexible Multibody Systems with Constant Mass Matrix

A flexible body in a multibody system isdescribed only by the position of the nodes in theinertial frame. With this description we can formulatethe mass matrix of the flexible multibody as aconstant matrix. This matrix can be inverted in apreprocessing stage which yields a more efficientacceleration calculation and thus a faster numericalintegration procedure. It also follows from thisdescription of a flexible body that no referenceconditions have to be applied, since the number ofequations used to describe the flexible body is thesame as the number of degrees of freedom. Anotheradvantage of this formulation is that neither thecentrifugal nor the Coriolis forces appear in theequations due to the description of the flexible body.