Investigating modal requirements for vibration isolation in driveline installations: A parametric study of the correlation between modal quantities and dynamic response

Abstract

The Performance and Driveability team at Volvo Cars Corporations works to ensure a smooth and comfort ride for the vehicle occupants. This includes to isolate longitudinal vibrations that can be perceived as disturbing. This thesis focuses on finding a modal requirement on the engine set-up that can declare the time domain performance regarding vibration isolation. A parametric study has been conducted to see how deviations in parameter values affect the performance of the driveline configuration. This was done with the Latin Hypercube Sampling method to generate designs that was simulated in Adams View. From Adams, modal data and time domain data were obtained and the performance was evaluated by using the vibration dose value in the longitudinal direction, which is known to be a good measurement of comfort in vehicles. Modal kinetic energy and participation factors are shown to be good measurements of the coupling between eigenmodes, and their different terms are tried as modal requirement. No definitive value was obtained but an idea is that a combination of different modal terms could perform well regarding correlation. The parametric study shows that inertia properties heavily influence the performance of the engine set-up and that a well performing set-up is less sensitive to variations than a worse performing one. In addition, this thesis work has provided a framework for modal analysis that can be used by Volvo Cars Corporations in further research within this subject or for other purposes.