Specialized Noise Control Materials in the Automotive Industry
Sharad R. Mahajan1, Prasad Vilas Bapat2
1Dr.Sharad R. Mahajan, Professor, Rajaram Shinde.College of Engineering, Alore, Mumbai University, Chiplun, India.
2Prof. Prasad Vilas Bapat, Mechanical Dept., Mumbai University, Rajaram Shinde .College Of Engineering, ,Alore, Chiplun; Mumbai , India.
Manuscript received on November 11, 2013. | Revised Manuscript received on November 15, 2013. | Manuscript published on November 25, 2013. | PP:35-41 | Volume-2 Issue-1, November 2013. | Retrieval Number: A0582112113/2013©BEIESP
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© The Authors. Published By: Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Abstract: The automotive industry is currently spending millions of dollars on NVH work to develop new materials and damping techniques. The new design methods are starting to consider NVH issues throughout the whole design process. This involves integrating extensive modeling, simulation, evaluation, and optimization techniques into the design process to insure both noise and vibration comfort. New materials and techniques are also being developed so that the damping treatments are lighter, cheaper, and more effective. Some of the methods used to control noise, vibration, and harshness include the use of different carpeting treatments, the addition of rubber or asphalt material to car panels, gap sealant, and the injection of expandable foam into body panels. The carpeting treatments include varying types of foam padding combined with different weights of rubber-backed carpet. The overall result of this technique is a mass-spring system that acts as a vibration absorber. The rubber or asphalt materials are attached to various car panels to add damping and mass loading to reduce vibration levels and the rattling sounds from the panels. Sealant is applied to close gaps in order to increase the transmission loss from the engine, wind, and road noise sources to the vehicle interior. Expandable foam injected between panels, such as the dashboard and firewall, helps to add stiffness and vibration absorption. All of these current methods are effective at reducing sound and vibration levels in a vehicle at higher frequencies. However, some of the treatments become almost ineffective at lower frequencies below 200 Hz. The treatments also add a substantial amount of weight to the vehicle, thus affecting its fuel economy, as well as adding cost. Choosing the correct product for your application can be really easy if you properly identify the noise from the start. There are many contributors to automotive noise and the noise exists across a wide bandwidth of frequencies. To effectively reduce the noise floor within a vehicle, a combination of materials must be used. This technique will result in a greatly reduced installation time, a serious reduction in the amount of added weight to the vehicle and bunch of money saved in your wallet. When trying to reduce or eliminate various types of automotive noise, it is often necessary to utilize a variety of specialized noise control materials.
Keywords: Noise, vibration, and harshness, Floor Barrier, vinyl barrier, Thermo-Acoustic under hood Liner, Gasketing Foam.