Mechanical systems including flexible bodies in ride comfort analysis

The Finite-Element-Method and mechanical systems have been used in numerical vibration analysis for a long time. The advantage of the finite element models is the complete elastic description of the components. Due to the large number of degrees of freedom linear models are in many cases restricted to the analysis in the frequency domain with harmonic excitations. Mechanical systems permit the consideration of non-linear effects during an analysis in the time domain. However, the results are only valid for low excitation frequencies. This is caused mainly by the idealisation of the model components as rigid bodies. This paper gives a description of the combination of both simulation methods. The new method combines the advantages of both approaches. Rigid parts of the mechanical system can be replaced by linear elastic finite element models using a simple mathematical approach. The size of the models is reduced by means of the modal description of the elastic parts, First analyses and the comparison of the results to test data show the ability of the new method to be used early in the conceptual development phase of new vehicles.