Integrated MBS - FE - Durability Analysis of Truck Frame Components by Modal Stresses

1 Summary The computation procedure which is presented, introduces a modally based fatigue analysis and realizes a parallel integration of FE and MBS into durability computations. The common data base consists of component modes, which are used for importing the FE structures into MBS. As extension to the standard FE procedure of Component Mode Synthesis, the Modal Stresses are determined. The succeeding MBS computes the transient structural response of the FE - MBS hybrid system and provides the Modal Coordinates which correspond to the Modal Stresses. In analogy to the superposition of eigenvectors in vibration analysis, the transient stress state of the flexible body is reconstructed by superposing the modal stresses, utilizing the time dependent modal coordinates. This leads to the advantage that • the fatigue analysis considers all vibration effects and utilizes the nonlinear capacities of the MBS. • very long transient time series and large structures can be evaluated, using a relative small amount of data which is comparable to that of a quasistatic solution. • the FE computation of stresses after the MBS is not required and potential errors are omitted.