EVALUATION OF DRIVELINE NVH PERFORMANCE USING LINEAR DYNAMIC FINITE ELEMENT SIMULATION

Automotive driveline design plays an important role in the NVH characteristics of the overall vehicle. Driveline systems are an integral part of delivering torque from the engine/transmission to the tires which propel the vehicle and drivelines often experience a wide frequency of excitation which poses unique NVH challenges. With the increasing trend in the automotive industry to introduce turbocharged engines with fewer cylinders while delivering the same torque / power, the driveline systems are excited with increased lower frequency torsional vibration in addition to other vibrations transmitted from powertrain and road. In this paper, we address the key design consideration for developing an optimal driveline system with consideration to NVH while keeping durability and other functional requirements in perspective. We consider the example of a front wheel drive-based vehicle architecture with independent suspension. The effect of fundamental prop shaft frequency to determine segmentation and the isolation, motion control and mode management of driveline systems to determine bushing rates and location. All driveline systems experience numerous types of excitations which are listed as unique load cases for analysis, for e.g. driveline imbalance, engine block vibration, torsional vibration, axle whine, power hop, etc. This paper presents the effect of prop shaft mode segmentation on driveline response (forces transmitted to the vehicle) under excitation from engine block and torsional vibrations, also considerations for optimal bushing location and rates for rear differential module (RDM).