An experimental gear noise propagation method for a gearbox on a test bench

With Dynamic Substructuring, a systems structural dynamics is derived from the structural dynamics of its subsystems. With known external forces and boundary conditions on the subsystems one can furthermore calculate the responses of the total system. In vehicle dynamics such external forces can be seen as the engine excitation, gear noises and road contact forces. In this article a new gear noise propagation method for gearboxes is introduced. The method suggest to determine the nonmeasurable gear excitation at the gearboxes connection points on a test bench. These forces can be used, when the gearbox is build into some other system, to calculate the exact responses in other system components. The method is exact for a rigid test bench. This is however a restriction which probably will not be realizable in reality. The method is extended for this case. It is shown that one can compensate for the inuences of the test bench on the knowledge of the gearboxes structural dynamics.