Noise & Vibration refinement of automotive vehicles is becoming important parameter due to its influence on environmental aspect and comfort perceived by occupants. NVH parameters are driving factors in current vehicle design strategy. Drivers comfort is extremely important, and driver’s expectations from commercial and heavy-duty trucks are as good as refined passenger cars.
Other trends in commercial vehicle segment such as engine downsizing, weight, cost reduction and meeting stringent emission norms have influenced vehicle design dynamics. These parameters are critical and often contribute to vehicle NVH issues. Considering these new trends in commercial vehicle segment, it becomes challenging for an NVH engineer to provide optimized solutions.
NVH issues could be related to the various subsystems such as driveline, axle, transmission steering wheel etc. in the vehicle and its resonant frequencies. In commercial vehicles, driveline design parameters, power train mounting system and secondary isolation of cab mounting system plays vital role in providing optimized solutions to the NVH refinement.
This paper represents a case study on a commercial vehicle for low frequency NVH performance evaluation and refinement using experimental techniques to achieve targeted NVH performance. This paper describes optimization of cab mounts and driveline design parameters through DOE method to reduce the vibrations transmitted in a passenger cabin at tactile locations and corresponding cabin noise.
The results of the analysis depict the significant improvement in vibration transmitted to the driver’s and passenger locations with reduced stiffness of engine mounts, cab mounts and optimized driveline parameters.