Kolano and Saha Engineers Inc

Kolano and, United States

Kolano and Saha Engineers Inc

Kolano and, United States
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Moritz C.,Blachford Inc. | Deshpande S.,Kolano and Saha Engineers Inc
SAE Technical Papers | Year: 2017

As part of the update process to SAE J1637, Laboratory Measurement of the Composite Vibration Damping Properties of Materials on a Supporting Steel Bar, the Acoustical Materials Committee commissioned a round robin study to determine the current laboratory-to-laboratory variation, and to better understand best practices for composite loss factor measurements. Guidance within the current standard from a previous round robin study indicates a coefficient of variation of 35% for laboratory-to-laboratory measurements. It was hoped that current instrumentation and test practices would yield lower variability. Over the course of 2 years, 8 laboratories tested 4 bars, three damped steel bars and one bare steel bar. These bars were tested at -20°C, -5°C, 10°C, 25°C, 40°C, and 55°C. The damping materials were intentionally selected to provide low damping, moderate damping, and high damping as difficulties in determining the composite loss increase with increased damping. Additional items for this study included a study of the differences between automated and manual data acquisition systems, and contact and non-contact transducers. The initial results of this study are summarized in this paper and will be used for potential recommendations to the next SAE J1637 recommended practice and any laboratory measuring composite loss factors. Copyright © 2017 SAE International.


Saha P.,Kolano and Saha Engineers Inc. | Deshpande S.P.,Kolano and Saha Engineers Inc.
SAE Technical Papers | Year: 2017

This paper discusses the importance of a dissipative sound package system in the automotive industry and how it works. Although this is not a new technique at this stage, it is still a challenge to meet the subsystem target levels that were originally developed for parts based on the barrier decoupler concept. This paper reviews the typical construction of a dissipative system and then emphasizes the importance of different layers of materials that are used in the construction, including what they can do and cannot do. The paper also discusses the importance of the proper manufacturing of a part. Copyright © 2017 SAE International and Copyright © 2017 Institute of Noise Control Engineering.


Kolano R.A.,Kolano and Saha Engineers Inc. | Brown D.J.,Kolano and Saha Engineers Inc.
SAE Technical Papers | Year: 2017

A large reverberation room of approximately 310 m3 (11,000 ft3) used in the air conditioning, heating and refrigeration industry, was in need of improvements to meet the updated requirements of the American Heating and Refrigeration Institute (AHRI) Standard 220. In addition, it was desired to extend the measurement qualification of the room down to the 63 Hz octave band. The initial qualification test results showed that the room did not qualify for the extended low frequency range and also had some irregularities in the 100 Hz third octave band. This paper reports the results of a three-part investigation to correct reverberation room response irregularities in the 100 Hz third octave band, to establish performance that qualifies relative to the most recent standard, and to determine and integrate the means by which its qualification could be extended down to the frequency bands of 50, 63, and 80Hz. Copyright © 2017 SAE International.


Saha P.,Kolano and Saha Engineers Inc.
SAE Technical Papers | Year: 2017

Traditionally, the damping performance of a visco-elastic material is measured using the Oberst bar damping test, where a steel bar is excited using a non-contacting transducer. However, in an effort to reduce the weight of the vehicles, serious effort is put in to change the body panels from steel to aluminum and composite panels in many cases. These panels cannot be excited using a non-contacting transducer, although, in some cases, a very thin steel panel (shim) is glued to the vibrating bar to introduce ferrous properties to the bar so it can be excited. In the off highway vehicles, although the panels are made of steel, they are very thick and are difficult to excite using the Oberst bar test method. This paper discusses a measurement methodology based on mechanical impedance measurements and has the potential to be a viable/alternate test method to the Oberst bar testing. In the impedance method, the test bar is mounted to a shaker at the center (Center Point method). The damping performance is measured from the frequency response function obtained from the excitation force and the corresponding velocity level, both measured at the same point. Copyright © 2017 SAE International.


Deshpande S.P.,Kolano and Saha Engineers Inc. | Saha P.,Kolano and Saha Engineers Inc. | Cone K.,John Deere Global Crop Harvesting
SAE Technical Papers | Year: 2017

Most of NVH related issues start from the vibration of structures where often the vibration near resonance frequencies radiates the energy in terms of sound. This phenomenon is more problematic at lower frequencies by structureborne excitation from powertrain or related components. This paper discusses a laboratory based case study where different visco-elastic materials were evaluated on a bench study and then carried on to a system level evaluation. A body panel with a glazing system was used to study both airborne and structureborne noise radiation. System level studies were carried out using experimental modal analysis to shift and tune the mode shapes of the structure using visco-elastic materials with appropriate damping properties to increase the sound transmission loss. This paper discusses the findings of the study where the mode shapes of the panel were shifted and resulted in an increase in sound transmission loss. This eventually resulted in reduced sound level inside the cabin. Copyright © 2017 SAE International.


Saha P.,Kolano and Saha Engineers Inc.
SAE Technical Papers | Year: 2011

This paper discusses the thought process that one needs to go through for developing an appropriate sound package treatment for a vehicle. In the development process one needs to put proper emphasis on understanding the source, path, and the receiver system. One needs to have an understanding on how to reduce the noise at the source, path, and/or receiver location. One may need to conduct a feasibility study of the benefits of various noise control options. In terms of sound package treatments one needs to understand the fundamentals of acoustical materials how they work and why one material performs differently than another one, as well as the importance of a well documented specification that every supplier has to meet. Copyright © 2011 SAE International.


Kolano R.,Kolano and Saha Engineers Inc.
SAE Technical Papers | Year: 2013

This paper presents the design, construction, and implementation of a novel sound transmission loss (STL) testing fixture that is unique to the automotive industry. This fixture was built within a large 1.68 m high × 2.74 wide (56 × 90) opening in the wall between a 497 m3 (17,591 ft 3) reverberation room and an adjacent anechoic chamber. The fixture was designed and built to accommodate interchangeable plugs that allow STL measurements on an automotive buck as well as on flat sample materials. It features a removable sample holding frame system that simply and quickly clamps in place and acoustically seals with a pneumatically inflated seal. Copyright © 2013 SAE International.


Kolano R.,Kolano and Saha Engineers Inc. | Abhyankar S.,Ford Motor Company | Martin T.,Ford Motor Company
SAE Technical Papers | Year: 2013

This paper presents the upgrades and improvements needed to bring an old and seldom used reverberation room test suite up to current standards. The upgrades and improvements included eliminating a below-floor pit that was open to the reverberation room, improving the acoustical diffusion within the room, enlarging the opening between the reverberation room and an adjacent anechoic chamber, renovating the anechoic receiving chamber, constructing an innovative sound transmission loss test fixture, and installing of a high power reverberation room sound system. Copyright © 2013 SAE International.


Kolano R.A.,Kolano and Saha Engineers Inc
SAE International Journal of Passenger Cars - Mechanical Systems | Year: 2011

This paper presents an overview of the acoustical design of a small volume self-contained acoustical testing facility (SCATF). The design focuses on a small volume (25m 3) reverberation room for testing the random incidence sound absorption performance of small samples of acoustical materials and automotive parts. This reverberation room also couples to a small volume hemi-anechoic room and serves as the random incidence source room for sound transmission loss testing. These testing approaches respectively target the SAE J2883 (pending) and J1400 test standards. © 2011 SAE International.


Kolano R.,Kolano and Saha Engineers Inc.
SAE Technical Papers | Year: 2015

This paper presents the results of a study to reduce the background noise level within a large Quiet Room located adjacent to other laboratory testing environments and below a mechanical mezzanine which houses an extensive array of mechanical and electrical equipment including banks of low-temperature chiller compressors, air handling units, and electrical switchgear that serves the entire building complex. This equipment was installed atop the concrete mezzanine floor deck without provisions for isolating vibration. As a result, structure-borne noise from that equipment travels through the floor, radiates from the underside of the floor deck, and intrudes into the Quiet Room below. This causes the background noise level within the Quiet Room to be too high for conducting low sound level measurements and studies on vehicles brought into the Quiet Room. Conclusions of the study are that provisions originally intended to isolate the Quiet Room from the mezzanine floor deck were both insufficient and poorly installed, resulting in excessive noise transmitted into the Quiet Room. Recommended corrective measures include enhancement of the Quiet Room ceiling to improve the sound transmission loss performance of that assembly, and changes made to the mezzanine floor deck to isolate structure-borne noise. This work is being installed in phases and completion of the initial phase has shown very promising results. Copyright © 2015 SAE International.

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