1、BS ISO18437-4:2008ICS 17.160NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDMechanical vibrationand shock Characterization of thedynamic mechanicalproperties of visco-elastic materialsPart 4: Dynamic stiffness methodThis British Standardwas published underthe au
2、thority of theStandards Policy andStrategy Committee on 30November 2008 BSI 2008ISBN 978 0 580 56645 5Amendments/corrigenda issued since publicationDate CommentsBS ISO 18437-4:2008National forewordThis British Standard is the UK implementation of ISO 18437-4:2008.The UK participation in its preparat
3、ion was entrusted to TechnicalCommittee GME/21, Mechanical vibration, shock and conditionmonitoring.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are respo
4、nsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.BS ISO 18437-4:2008Reference numberISO 18437-4:2008(E)ISO 2008INTERNATIONAL STANDARD ISO18437-4First edition2008-06-01Mechanical vibration and shock Characterization of the dynamic mech
5、anical properties of visco-elastic materials Part 4: Dynamic stiffness method Vibrations et chocs mcaniques Caractrisation des proprits mcaniques dynamiques des matriaux visco-lastiques Partie 4: Mthode de la raideur dynamique BS ISO 18437-4:2008ISO 18437-4:2008(E) PDF disclaimer This PDF file may c
6、ontain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the respons
7、ibility of not infringing Adobes licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
8、parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2008 Al
9、l rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country
10、of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2008 All rights reservedBS ISO 18437-4:2008ISO 18437-4:2008(E) ISO 2008 All rights reserved iiiContents Page F
11、oreword iv Introduction v 1 Scope 1 2 Normative references 1 3 Terms and definitions .2 4 Principle4 5 Equipment 5 5.1 Hardware.5 5.2 Set-up5 6 Recommended set-up for applying the different types of strain to the test piece and calculation of quotients, E,G,K.9 6.1 Choosing test piece size.9 6.2 Rig
12、id plastics9 6.3 Rubbery materials10 6.4 Viscous materials 11 6.5 Bulk modulus of all materials.13 7 Test pieces .13 7.1 Choosing the shape and size of the test piece.13 7.2 Instructions for manufacturing and preparing test pieces .14 8 Conditioning.16 8.1 Storage16 8.2 Temperature .16 8.3 Mechanica
13、l conditioning.16 8.4 Humidity conditioning.16 8.5 Measurement conditioning .16 9 Main error sources.17 10 Measurement results and processing .17 10.1 Frequency-temperature superposition17 10.2 Data presentation.18 10.3 Test report 19 Bibliography 20 BS ISO 18437-4:2008ISO 18437-4:2008(E) iv ISO 200
14、8 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a
15、subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission
16、 (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical com
17、mittees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not
18、 be held responsible for identifying any or all such patent rights. ISO 18437-4 was prepared by Technical Committee ISO/TC 108, Mechanical vibration, shock and condition monitoring. ISO 18437 consists of the following parts, under the general title Mechanical vibration and shock Characterization of
19、the dynamic mechanical properties of visco-elastic materials: Part 2: Resonance method Part 3: Cantilever shear beam method Part 4: Dynamic stiffness method The following parts are under preparation: Part 1: Principles and guidelines Part 5: Poissons ratio based on finite element analysis BS ISO 184
20、37-4:2008ISO 18437-4:2008(E) ISO 2008 All rights reserved vIntroduction Visco-elastic materials are used extensively to reduce vibration magnitudes, of the order of hertz to kilohertz, in structural systems through dissipation of energy (damping) or isolation of components, and in acoustical applica
21、tions that require modification of the reflection, transmission, or absorption of energy. The design, modelling and characterization of such systems often require specific dynamic mechanical properties (the Young, shear, and bulk moduli and their corresponding loss factors) in order to function in a
22、n optimum manner. 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 material. The visco-elastic properties (modulus and loss factor) of most materials depend on frequency, temperature, and strain amplitude. The c
23、hoice of a specific material for a given application determines the system performance. The goal of this part of ISO 18437 is to provide details, in principle, of the operation of the direct dynamic stiffness method, the measurement equipment used in performing the measurements, and the analysis of
24、the resultant data. A further aim is to assist users of this method and to provide uniformity in the use of this method. This part of ISO 18437 applies to the linear behaviour observed at small strain amplitudes, although the static stiffness may be non-linear. BS ISO 18437-4:2008BS ISO 18437-4:2008
25、INTERNATIONAL STANDARD ISO 18437-4:2008(E) ISO 2008 All rights reserved 1Mechanical vibration and shock Characterization of the dynamic mechanical properties of visco-elastic materials Part 4: Dynamic stiffness method 1 Scope This part of ISO 18437 specifies a direct method for measuring the complex
26、 dynamic moduli of elasticity (the Young, shear and bulk moduli, and their respective loss factors corresponding to the tensile, shear and all compressive strains) for polymeric (rubbery and viscous polymers, as well as rigid plastics) materials over a wide frequency and temperature range. Measureme
27、nts are performed by the dynamic stiffness method, which uses electric signals from sensors attached to a test piece. These signals are proportional to the dynamic forces acting on the test piece and the strains in the test piece due to the effect of these forces. The measurement frequency range is
28、determined by the size of test piece, the accuracy required on the dynamic modulus measurements, the relationship between the stiffness of the oscillation generator and the stiffness of the test piece, and by the resonance characteristics of the test fixture used. The method presented in this part o
29、f ISO 18437 allows measurement under any static pre-load allowed for the test piece (including the test piece having the non-linear characteristics under different static loads), but under small dynamic (acoustic) strains, i.e., in limits where the linear properties of the test piece are not distort
30、ed. Depending on the pre-load conditions, the relation between the moduli is unique. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of t
31、he referenced document (including any amendments) applies. ISO 472, Plastics Vocabulary ISO 483, Plastics Small enclosures for conditioning and testing using aqueous solutions to maintain the humidity at a constant value ISO 2041, Mechanical vibration, shock and condition monitoring Vocabulary ISO 4
32、664-1, Rubber, vulcanized or thermoplastic Determination of dynamic properties Part 1: General guidance ISO 6721-1, Plastics Determination of dynamic mechanical properties Part 1: General principles ISO 6721-4, Plastics Determination of dynamic mechanical properties Part 4: Tensile vibration Non-res
33、onance method ISO 6721-6, Plastics Determination of dynamic mechanical properties Part 6: Shear vibration Non-resonance method BS ISO 18437-4:2008ISO 18437-4:2008(E) 2 ISO 2008 All rights reservedISO 10112, Damping materials Graphical presentation of the complex modulus ISO 10846-1, Acoustics and vi
34、bration Laboratory measurement of vibro-acoustic transfer properties of resilient elements Part 1: Principles and guidelines ISO 23529, Rubber General procedures for preparing and conditioning test pieces for physical test methods NOTE ISO 10846-1 is concerned with the global measurement of dynamic
35、input and transfer stiffness and mechanical resistance of resilient fixtures. This part of ISO 18437 is concerned with the characterization of the dynamic Young modulus, shear modulus, bulk modulus, and corresponding loss factors of the visco-elastic materials that are used in the fixtures. 3 Terms
36、and definitions For the purposes of this part of ISO 18437, the terms and definitions given in ISO 472, ISO 483, ISO 2041, ISO 4664-1, ISO 6721-1, ISO 6721-4, ISO 6721-6, ISO 10112, ISO 10846-1, ISO 23529, and the following apply. 3.1 dynamic mechanical properties visco-elastic materials fundamental
37、 elastic properties, i.e., elastic modulus, shear modulus, bulk modulus and loss factor 3.2 damped structure structure containing elements made from damping materials 3.3 Young modulus modulus of elasticity E ratio of the normal stress to linear strain NOTE 1 Adapted from ISO 80000-4-18.1:20069. NOT
38、E 2 The Young modulus is expressed in pascals. NOTE 3 The complex Young modulus, E*, for a visco-elastic material is represented by E* = E + iE, where E is the real (elastic) component of the Young modulus and E is the imaginary (loss modulus) component of the Young modulus. The real component repre
39、sents elastically stored mechanical energy, while the imaginary component is a measure of mechanical energy loss. 3.4 shear modulus modulus of rigidity Coulomb modulus G ratio of the shear stress to the shear strain NOTE 1 Adapted from ISO 80000-4-18.2:20069. NOTE 2 The shear modulus is expressed in
40、 pascals. NOTE 3 The complex shear modulus, G*, for a visco-elastic material is represented by G* = G + iG, where G is the real (elastic) component of the shear modulus and G is the imaginary (loss modulus) component of the shear modulus. BS ISO 18437-4:2008ISO 18437-4:2008(E) ISO 2008 All rights re
41、served 33.5 bulk modulus modulus of compression K the negative ratio of pressure to volume strain NOTE 1 Adapted from ISO 80000-4-18.3:20069. NOTE 2 The bulk modulus is expressed in pascals. NOTE 3 The complex bulk modulus is represented by K* = K + iK, where K is the real (elastic) component of the
42、 bulk modulus and K is the imaginary (loss modulus) component of the bulk modulus. 3.6 loss factor ratio of the imaginary component to the real component of a complex modulus NOTE When a material shows a phase difference, , between dynamic stress and strain in harmonic deformations, the loss factor
43、is equal to tan. 3.7 magnitude of complex modulus absolute value of the complex modulus NOTE The magnitude of the complex moduli are defined as: a) magnitude of the Young modulus: E= (E)2+ (E)2; b) magnitude of shear modulus: G= (G)2+ (G)2; c) magnitude of bulk modulus: K= (K)2+ (K)2. These magnitud
44、es are expressed in pascals. 3.8 frequency-temperature superposition principle by which, for visco-elastic materials, frequency and temperature are equivalent to the extent that data at one temperature can be superimposed upon data taken at different temperature merely by shifting the data curves al
45、ong the frequency axis 3.9 shift factor measure of the amount of shift along the logarithmic axis of frequency for one set of data at one temperature to superimpose upon another set of data at another temperature 3.10 glass transition temperature Tgvisco-elastic materials temperature at which a mate
46、rial changes state reversibly from glassy to rubbery NOTE 1 The glass transition temperature is expressed in degrees Celsius. NOTE 2 The glass transition temperature is typically determined from the inflection point of a specific heat vs. temperature plot and represents an intrinsic material propert
47、y. NOTE 3 Tgis not the peak in the dynamic mechanical loss factor. That peak occurs at a temperature higher than Tgand varies with the measurement frequency, hence it is not an intrinsic material property. BS ISO 18437-4:2008ISO 18437-4:2008(E) 4 ISO 2008 All rights reserved3.11 linearity visco-elas
48、tic materials property of dynamic behaviour of a resilient material if it satisfies the principle of superposition NOTE 1 The principle of superposition can be stated as follows: if an input x1(t) produces an output y1(t) and in a separate test an input x2(t) produces an output y2(t), superposition
49、holds if the input x1(t) + x2(t) produces the output y1(t) + y2(t), where and are arbitrary constants. This must hold for all values of , and x1(t), x2(t). NOTE 2 In practice, the above test for linearity is impractical and a limited check of linearity is done by measuring the dynamic modulus for a range of input levels. For a specific preload, if the dynamic modulus is nominally invariant, the system measurement can be considered lin
