Abstract
This paper presents an effective new data processing method, which will further enhance measurability of rigid body modes in a power train during modal testing. The rigid body modes have been identified as the one of main factors determine vehicle vibration qualities, such as ideal and ride shake. Therefore, accurate determination and measurements of such modes are paramount importance. However, the difficulties arise when there are relatively high dampings or coupled modes in the system. The principle idea behind the proposed method is to transform the forces and responses on the surface of powertrain system to the ones at the center of gravity. Using such an approach, one was able to extract more accurate and robust modal testing results. The applicability of the method was subsequently verified by conducting a series of modal testing.