Examples of Using Transfer Path Analysis (TPA) together with CAE-Models to Diagnose and Find Solutions for NVH Problems Late in the Vehicle Development Process

This paper discusses the use of experimental transfer path analysis (TPA) to find optimized solutions to NVH-problems remaining in late vehicle development stages. After a short review of the established TPA methods, a couple of practical cases are discussed to illustrate how TPA, FE-models and practical experiments can supplement each other efficiently for finding optimum and attribute-balanced solutions to remaining, complex NVH issues late in the development process.

The first example discusses an interesting idle noise and vibration problem for a front-wheel drive car with a pendulum engine suspension and torque rods attached to a resiliently mounted subframe. The second example illustrates the somewhat different approach used for TPA at mid- and high frequencies. The third example illustrates analysis “shortcuts” that sometimes can save precious calendar time close to SOP, provided that the simplifications are based on qualified, expert judgments. Finally, an example of a tricky, but not unusual transfer path separation situation, when attachments are in close proximity, is discussed and a pragmatic solution approach is proposed.