ASA-S2.22-1998-R2007.pdf

AMERICAN NATIONAL STANDARD RESONANCE METHOD FOR MEASURING THE DYNAMIC MECHANICAL PROPERTIES OF VISCOELASTIC MATERIALS Accredited Standards Committee S2, Mechanical Vibration and Shock Standards Secretariat Acoustical Society of America 120 Wall Street, 32nd Floor New York, New York 10005-3993 ANSI S2.22-1998 ANSI S2.22-1998 Copyright Acoustical Society of America Provided by IHS under license with ASA Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/07/2007 01:17:50 MDTNo reproduction or networking permitted without license from IHS -,-,- Reaffirmed by ANSI on 31 July 2002 Reaffirmed by ANSI July 5, 2007 The American National Standards Institute, Inc. (ANSI) is the na- tional coordinator of voluntary standards development and the clear- ing house in the U.S. for information on national and international standards. The Acoustical Society of America (ASA) is an organization of sci- entists and engineers formed in 1929 to increase and diffuse the knowledge of acoustics and to promote its practical applications. Copyright Acoustical Society of America Provided by IHS under license with ASA Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/07/2007 01:17:50 MDTNo reproduction or networking permitted without license from IHS -,-,- American National Standard Resonance Method for Measuring the Dynamic Mechanical Properties of Viscoelastic Materials Secretariat Acoustical Society of America Approved 22 June 1998 American National Standards Institute, Inc. Abstract This Standard defi nes a method for measuring the dynamic mechanical properties of viscoelastic materials using longitudinal resonance in a bar-shaped test sample. The dynamic mechanical properties are expressed in terms of the frequency dependence of Youngs modulus and loss factor at a given reference temperature. The Standard provides information for constructing such equipment and analyzing the results obtained. ANSI S2.22-1998 Copyright Acoustical Society of America Provided by IHS under license with ASA Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/07/2007 01:17:50 MDTNo reproduction or networking permitted without license from IHS -,-,- AMERICAN NATIONAL STANDARDS ON ACOUSTICS The Acoustical Society of America (ASA) provides the Secretariat for Accredited Standards Committees S1 on Acoustics, S2 on Mechanical Vibration and Shock, S3 on Bioacoustics, and S12 on Noise. These committees have wide represen- tation from the technical community (manufacturers, consumers, and general- interest representatives). The standards are published by the Acoustical Society of America through the American Institute of Physics as American National Stan- dards after approval by their respective standards committees and the American National Standards Institute. These standards are developed and published as a public service to provide standards useful to the public, industry, and consumers, and to Federal, State, and local governments. Each of the Accredited Standards Committees operating in accordance with pro- cedures approved by American National Standards Institute (ANSI) is responsible for developing, voting upon, and maintaining or revising its own standards. The ASA Standards Secretariat administers committee organization and activity and provides liaison between the Accredited Standards Committees and ANSI. After the standards have been produced and adopted by the Accredited Standards Committees, and approved as American National Standards by ANSI, the ASA Standards Secretariat arranges for their publication and distribution. An American National Standard implies a consensus of those substantially con- cerned with its scope and provisions. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consen- sus requires that all views and objections be considered and that a concerted effort be made towards their resolution. The use of American National Standards is completely voluntary. Their existence does not in any respect preclude anyone, whether he or she has approved the standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standards. NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffi rm, revise, or withdraw this Standard. Standards Secretariat Acoustical Society of America 120 Wall Street, 32nd Floor New York, New York 10005-3993 USA Telephone: 11 212 248 0373 Telefax:11 212 248 0146 E-mail:asastdsaip.org Internet:http:/asa.aip.org © 1998 by the Acoustical Society of America. This Standard may not be reproduced in whole or in part in any form for sale, promotion, or any commercial purpose, or any purpose not falling within the provisions of the Copyright Act of 1976, without prior written permission of the publisher. For permission, address a request to the Standards Secretariat of the Acoustical Society of America. Copyright Acoustical Society of America Provided by IHS under license with ASA Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/07/2007 01:17:50 MDTNo reproduction or networking permitted without license from IHS -,-,- Contents Page Foreword. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ii 0Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 1Scope, purpose, and applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 1.1Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 1.2Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 1.3Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 2Informative references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 3 Defi nitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 3.1Youngs modulus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 3.2Loss factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 3.3Fast Fourier transform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 3.4Frequency response function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 3.5Time-temperature superposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 3.6Shift factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 3.7Glass transition temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 4Test equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 4.1Electromagnetic shaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 4.2Accelerometers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 4.3 Charge amplifi ers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 4.4Test stand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 4.5Environmental chamber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 4.6Dual channel spectrum analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 4.7Computer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 5Operating procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 5.1Sample preparation and mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 5.2Data acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 5.3Temperature cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 6Analysis of results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 6.1Modulus and loss factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 6.2Time-temperature superposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 6.3Data presentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Figures 1Schematic diagram of resonance apparatus . . . . . . . . . . . . . . . . . . . . .2 2Typical acceleration ratio (solid line) and phase (dashed line) vs. frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 i Copyright Acoustical Society of America Provided by IHS under license with ASA Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/07/2007 01:17:50 MDTNo reproduction or networking permitted without license from IHS -,-,- Foreword This Foreword is for information only, and is not a part of ANSI S2.22-1998American National Standard Resonance Method for Measuring the Dynamic Mechanical Properties of Viscoelastic Materials. This Standard was developed under the jurisdiction of Accredited Standards Com- mittee S2, Mechanical Vibration and Shock, which has the following scope: Standards, specifi cations, methods of measurement and test terminology in the fi elds of mechanical vibration and shock and condition monitoring and diagnos- tics of machines, but excluding those aspects which pertain to biological safety, tolerance, and comfort. At the time this Standard was submitted to Accredited Standards Committee S2, Mechanical Vibration and Shock, for approval, the membership was as follows: D. J. Evans,Chair R. F. Taddeo,Vice Chair A. Brenig,Secretary Acoustical Society of America . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D. J. Evans R. F. Taddeo (Alt.) Boyce Engineering International . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. P. Boyce C. Meher-Homji (Alt.) Bruel Tele- phone: 11 212 248 0373; Fax 11 212 248 0146. iii Copyright Acoustical Society of America Provided by IHS under license with ASA Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/07/2007 01:17:50 MDTNo reproduction or networking permitted without license from IHS -,-,- American National Standard Resonance Method for Measuring the Dynamic Mechanical Properties of Viscoelastic Materials 0Introduction Viscoelastic materials are used extensively to re- duce vibration amplitudes in structural systems through dissipation of energy (damping) or isola- tion of components, and in acoustic applications which require a modifi cation of the refl ection, transmission, or absorption of energy. Such sys- tems often require specifi c dynamic mechanical properties in order to function in an optimum man- ner. Energy dissipation is due to interactions on the molecular scale and can be measured in terms of the lag between stress and strain in the mate- rial. The viscoelastic properties, modulus and loss factor, of most materials depend on frequency, temperature, and strain amplitude. The choice of a specifi c material for a given application determines the system performance. This Standard applies to the linear behavior observed at small strain ampli- tudes. 1Scope, purpose, and applications 1.1Scope This Standard defi nes a procedure for measure- ment and analysis of the dynamic properties of viscoelastic materials using a resonance method. The Standard applies to materials used in sound and vibration damping systems operating at fre- quencies from a fraction of a hertz to about 20 kHz. 1.2Purpose The purpose of this Standard is to assist users of this method in setting up the measurement equip- ment, performing the measurements, and analyz- ing the resultant data. A further purpose is to pro- mote uniformity in the use of this method. 1.3Applications This Standard applies to the use of the resonance method to evaluate material characteristics for re- search, quality control, and materials selection. 2Informative references 1ASTM D 792-91, Standard Test Method for Density and Specifi c Gravity (Relative Density) of Plastics by Displacement. 2 T. Pritz, Transfer Function Method for Investi- gating the Complex Modulus of Acoustic Materials: Rod-like Specimen,J. Sound and Vibration81, 359-376 (1982). 3 W. M. Madigosky and G. F. Lee, Improved resonance technique for material characteriza- tion,J. Acoust. Soc. Am. 73, 1374-1377 (1983). 4 J. L. Buchanan, Numerical solution for the dy- namic moduli of a viscoelastic bar,J. Acoust. Soc. Am. 81, 1775-1786 (1987). 5 J. D. Ferry,Viscoelastic Properties of Poly- mers, 3rd ed., Wiley, New York, 1980, pp 264-320. 3 Defi nitions For the purposes of this Standard, the following defi nitions apply: 3.1Youngsmodulus.Quotientoftensile stress, in pascals, to resulting tensile strain, or fractional change in length. Youngs modulus for viscoelastic materials is a complex quantity with symbolE*, having a real partE8and an imaginary partE9. Unit, pascal (Pa). NOTE Physically, the real component of Youngs modulus represents elastic stored mechanical en- ergy. The imaginary component is a measure of mechanical energy loss. See 3.2. 3.2loss factor. Ratio of the imaginary part of the Youngs modulus of a material to the real part of the Youngs modulus (the tangent of the argu- ment of the complex Youngs modulus). NOTE When there is energy loss in a material, the strain lags the stress by a phase angle,d. The loss factor is equal to tand. 3.3fast Fourier transform. An algorithm or cal- culation procedure for obtaining the discrete Fou- rier transform (DFT) with a greatly reduced num- ber of arithmetic operations compared with a direct evaluation. AMERICAN NATIONAL STANDARDANSI S2.22-1998 1© 1998 Acoustical Society of America Copyright Acoustical Society of America Provided by IHS under license with ASA Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/07/2007 01:17:50 MDTNo reproduction or networking permitted without license from IHS -,-,- 3.4frequency response function. For the pur- poses of this Standard, the quotient of the cross spectrum of the signals produced by accelerom- eters at the output and input of a sample under tes