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High noise at Operator Ear Level (OEL) of tractor is the major cause of fatigue to the operator. With growing competition, and upcoming legislative requirement there is ominous need for the agricultural tractor manufacturers to control noise levels. Objective of the present study is noise reduction on agriculture tractor by identifying and controlling key noise sources unaffecting performance parameters like power, torque and fuel efficiency to meet upcoming noise legislations. Noise Source Identification (NSI) is carried out to identify and rank airborne and structure borne noise sources. The airborne sources such as cooling fan, exhaust silencer and intake are evaluated using elimination method at tractor level. The NSI on engine is carried out separately in hemi anechoic chamber to identify the major noise radiating components by using noise and vibration measurement, sound intensity mapping tools.

Transfer Path Analysis (TPA) is an important tool used worldwide to identify noise and vibration sources in vehicle(s). A complete TPA can be performed on proto-type vehicle or a fully built vehicle but it is time consuming and resource sensitive. New advancements in TPA include combining both acoustic and structural loads from stationary response functions and actual noise/vibration during operating conditions. So it is becoming important to define a known set of frequency response functions in order to understand vehicle's operational behavior. In this paper, an attempt has been made to simulate vehicle cab from structural and acoustic viewpoint with the help of vibro-acoustic transfer functions. Vibro-acoustic modal parameters, vibration transfer functions (VTF) and Noise Transfer Functions (NTF) were predicted using FEA techniques. A set of experiments on a simple model was carried out to validate the predicted FE results.

Seat system resonant frequencies play an important role in seat design and ride dynamics. So NVH performance of the seats should be assessed from the viewpoint of tactile, acoustic and visual sense. Tactile response is the response of sub-systems, which is induced when the human body contacts steering wheel, footrest or seats. Acoustic response is the behavior of the seat system at the cavity resonance frequencies and visual sense is what we perceive under actual operating conditions. The objective of the present work is to conduct and correlate experimental modal test with FE modal test to identify tactile vibrations. Then the identified main seat modes will be used to set the mode map (seat target) at the stage of full vehicle level. This work will present a practical approach in understanding varied methods and techniques for determining resonant characteristics and for subsequent refinement of FE model.