Driveline Torsional Vibration Analysis and Clutch Damper Characteristics Optimization for reducing Commercial Vehicle Noise and Vibrations 2021-01-1102

The automotive world has seen an increase in customer demands for vehicles having low noise and vibrations. One of the most important source of noise and vibrations associated with vehicles is the vibration of driveline systems. For commercial vehicles, the refinement of drivelines from NVH point of view is complex due to the cost and efficiency constraints. The typical rear wheel drive configuration of commercial vehicles mostly amplifies the torsional vibrations produced by engine which results into higher noise in the vehicle operating speed range.

Theoretically, there are various options available for fine tuning the torsional vibration performance of the vehicle drive train. The mass moments of inertia and stiffness of the drivetrain components play significant role in torsional vibration damping, however, except minor changes to flywheel mass, it is hardly possible to change other components, subject to design limitations. Considering this, clutch disc torque twist characteristics plays an important role in mitigating the NVH concerns. The drive train represents a vibration system with several resonance frequencies which can be calculated using various simulation tools. With the help of simulation tools like 1D or multi body dynamics, optimized solution for the driveline fine tuning can be obtained which can reduce vehicle level noise.

In this paper, 1D simulation model is used for the prediction of torsional vibration performance of the vehicle. Theoretical model of drivetrain component engine, clutch, gearbox etc. were built considering mass, inertia and stiffness values. Clutch damper parameters are optimized based on the simulation results and effect is validated by vehicle level noise and torsional vibration measurements.