Evaluation of Driveline NVH Performance Using Linear Dynamic Finite Element Simulation

Automotive driveline design plays an important role in defining a vehicle’s Noise, Vibration and Harshness (NVH) characteristics. Driveline system, responsible for torque transfer from the engine/transmission to the wheels, is exposed to a wide spectrum of vibrational excitations. The industry’s shift toward turbocharged engines with fewer cylinders while maintaining the equivalent torque and power has led to increased low-frequency torsional vibrations. This paper presents some key design considerations to drive the NVH design of a driveline system using linear dynamic FE simulations. Using an E-W All-Wheel Drive driveline architecture with independent suspension as a case study, the influence of various subsystem modes on driveline NVH performance is examined. The paper further explores the strategies for vibration isolation, motion control, and mode management to identify the optimal bushing rates and its location. Furthermore, it examines the ideal bushing specifications for different rear differential module (RDM) configurations. Excitation scenarios including propshaft imbalance, engine block vibration, torsional vibration, and axle whine are analyzed as distinct load cases. The study also emphasizes how propshaft mode segmentation affects force transmission to vehicle body under the driveline excitations. The findings contribute to a deeper understanding of driveline NVH behavior and offer practical guidance for achieving improved driveline NVH performance.