Comparison between measured forces (left) and forces computed by using a full inertance matrix TPA-Form method (right) 

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... order to quantify the overall influence of deviations between measured and calculated inertances on force calculation, the full inertance matrix method was used to compute forces induced by the shakers in operational condition as a last step. For verification Campbell plots of the force measured in operational condition and the force computed by a full matrix TPA using inertances calculated by TPA-Form are compared in Figure 9 . It is a comparison between measured forces (left) and forces computed by using a full matrix method (right) containing inertances calculated by TPA-Form. As can be seen, both diagrams show a very good agreement of measured and computed forces. The TPA-Form method, which was used for determination of the inertances, could be verified with the described experimental set-up and a very positive result. The methodology with TPA-Form described here by AVL allows a significant better description of the transfer behav- iour in vehicles as similar methods. Up to now TPA is used in the optimisation of vehicles available in hardware. This not only leads to advantages in common TPA applications but is also a requirement to integrate the TPA into the vehicle development process earlier as before. For a use of TPA before first prototypes are available, a connection to CAE data has to be accomplished. Thus the advantages of CAE based calculations (simple variant calculation, early use in the development process, no prototype needed, etc.) can be combined with these of TPA (no upper frequency restric- tion, measurement data verified in hardware, etc.). The integration of this data leads es- sentially to two challenges: First, the data transfer has to be realised between the different programs. Second out of theoretical view, the possibly most accu- rate accordance of induced forces position and induced forces direction between calculation model and measurement is of much higher importance. This would allow again obtaining important advantages in early development steps. The big benefit of TPA-Form in this frame is an exact matching of force positions and directions acting on the chassis structure. TPA data from pre- vious vehicles can be used in connection with CAE data of a new power train. First applications in this direction have been performed at AVL and are re- ported in [6]. With such an approach reli- able TPA data can help to predict vehicle interior noise in early development stag- es where still no hardware is ...