Noise Reduction on Agricultural Tractor by Stiffening Sheet Metal Components

The automotive market has seen a steady increase in customer demands for quiet and more comfortable tractors. 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. The objective of this study is noise reduction on agricultural tractor by stiffening sheet metal components. The design and analysis plays a major role for determining the root cause for the problem. Once the problem and its root cause were well defined, the solution for addressing the problem would be made clear. The engine excitation frequency and Sheet metal Components such as fender and platform natural frequency were coming closer and are leading to resonance. The resonance increases vibration level on the tractor and structure borne noise is generated from the sheet metal components, which is contributing to overall noise levels. The Vibration reduction methodologies like stiffening the structure, isolating the source from excitation and dampening techniques were studied. The test methodology and data acquisition methodology is formulated. The dynamic behavior is assessed using Modal analysis & Frequency Response technique. Correlation is done between the test data and Simulation data. The Systematic approach is demonstrated to reduce tractor Sheet metal Components vibrations by 30% - 40% through concept design, virtual analysis and experimental validation. Finally, The Overall noise level at OEL is reduced.