Modal Representation of Stress in Flexible Multibody Simulation

An application of the floating frame of reference formulation together with the nodal approach using quasi-comparison functions as shape functions allows an efficient analysis of stress in the flexible bodies of a multibody system. This is demonstrated using two simple examples. They are chosen to demonstrate the effects of various choices of shape functions and associated body reference frames. In the floating frame of reference formulation the equations of motion are linearized assuming the deformations to be small. The quasi-comparison functions, i.e. shape functions, can be selected in ways to increase the range of validity of the linearized equations of motion. The latter goal is achieved as well by so-called substructuring techniques. Combining both of the methodologies, one obtains efficient models for flexible multibody simulation