Acoustic Optimization of a Power Take-off Gear Box Using Numerical Transfer Path Analysis

In this contribution, a method is proposed which allows for a target-oriented structural optimization of drive train systems using transfer path analysis on a multi body system simulation with respect to the airborne sound. It combines the existing approaches of multi body simulation (MBS) and experimental transfer path analysis (TPA) with sound radiation calculations thereby creating a new tool chain to not only identify critical operation points but also critical transfer paths of an MBS model. This approach combines the advantages of elastic MBS (i.e. information about modes and forces acting between different components in critical operating points) with the advantages of TPA (i.e. identifying critical paths from the excitation to the receiver) thereby enabling the designer to numerically deduct and evaluate target-oriented structural optimizations already in early stages of the development process. It therefore reduces development times and costs by reducing iteration loops and the manufacturing of physical prototypes. The method is demonstrated on a power take-off (PTO) gear box, of which the sound pressure level was reduced by 6 dB within three virtual optimization loops that each only take a few hours by applying the proposed method.