Noise, Vibration and harshness control in motor vehicular parts; a mechanical approach

Abstract

Over the years, noise, vibration and hardness in vehicles has been a major challenge in the field of automobile engineering. With the introduction of new vehicle models, vehicle parts design has been so complex and sometimes we wonder why this happens. NVH which is the internal noise we experience inside the vehicle is generated by several sources inside the vehicle of which includes the engine, the propeller shaft, the differential shaft, the tires and the vehicle body. NVH is divided into vibrating force, the resonance system, the transmission system and the vibrating element. The vibrating force is generated on the tire of the vehicle as a result of imbalance it normally occurs when the vehicle has been parked on one spot over a long period of time. It is also generated in the vehicle engine due to the force fluctuation due to combustion in the engine, this usually cause the booming noise we experience in our vehicle. The exhaust pipe forms the resonance system, it amplifies the noise till it reaches the exhaust pipe support which forms the transmission system, of which the sound goes up to the vehicle body. The vehicle body is the vibrating element, it causes the air to vibrate thereby forming noise around the vehicle. Therefore, this paper discusses the causes of NVH in motor vehicular parts, factors affecting the NVH as well as ways in which it can be controlled.