The focus of this thesis at hand is on the use of a modal transformed
finite element model for elastic body representation in multibody systems.
The aim is the development of a method of model order reduction on the
basis of a turbo gear model with variable output speed to simplify the
calculation of the dynamic foundation loads. Therefore an overview of the
common finite element model reduction methods is given at the beginning.
Then a simplified method of dynamic foundation load calculation out of
equivalent static loads is introduced to answer the question how the
simplified method can be improved by use of a finite element model. To
retain the structural response to dynamic excitation in the frequency range
of the input shaft a Craig-Bampton-Reduction with normal modes of the
structure with restrained degrees of freedom at the external nodes is
performed. Afterwards the normal modes of the structure are compared to the
normal modes of the free, flexible body. Then the component mode synthesis
of the flexible body is introduced and after that there is a multibody
system described which can be used for further model order reduction. The
transmission characteristics of the dynamic loads from the input shaft
bearings over the housing to the foundation is used to compare the
multibody system with the original finite element model. Finally a summary
of the studies and an outlook are given.