1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 6721-1:2011Plastics Determination of dynamic mechanical propertiesPart 1: General principles (ISO 6721-1:2011)BS EN ISO 6721-1:2011 BRITISH STANDARDNational forewordThi
2、s British Standard is the UK implementation of EN ISO 6721-1:2011. It supersedes BS EN ISO 6721-1:2002,which is withdrawn.The UK participation in its preparation was entrusted to T e c h n i c a l C o m m i t t e e P R I / 2 1 , T e s t i n g o f p l a s t i c s .A list of organizations represented
3、on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 72843 3 ICS 83.080.01 Compliance with a British Standard cannot confer imm
4、unity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2011.Amendments issued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 6721-1 May 2011 ICS 83.080.01 Su
5、persedes EN ISO 6721-1:2002English Version Plastics - Determination of dynamic mechanical properties - Part 1: General principles (ISO 6721-1:2011) Plastiques - Dtermination des proprits mcaniques dynamiques - Partie 1: Principes gnraux (ISO 6721-1:2011) Kunststoffe - Bestimmung dynamisch-mechanisch
6、er Eigenschaften - Teil 1: Allgemeine Grundlagen (ISO 6721-1:2011) This European Standard was approved by CEN on 14 May 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard w
7、ithout any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any oth
8、er language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic,
9、 Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORM
10、ALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 6721-1:2011: EBS EN ISO 6721-1:2011 EN ISO 6721-1:2011 (E) 3 Foreword This docum
11、ent (EN ISO 6721-1:2011) has been prepared by Technical Committee ISO/TC 61 “Plastics“ in collaboration with Technical Committee CEN/TC 249 “Plastics” the secretariat of which is held by NBN. This European Standard shall be given the status of a national standard, either by publication of an identic
12、al text or by endorsement, at the latest by November 2011, and conflicting national standards shall be withdrawn at the latest by November 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held
13、responsible for identifying any or all such patent rights. This document supersedes EN ISO 6721-1:2002. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croati
14、a, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of
15、 ISO 6721-1:2011 has been approved by CEN as a EN ISO 6721-1:2011 without any modification. BS EN ISO 6721-1:2011ISO 6721-1:2011(E) ISO 2011 All rights reserved iiiContents Page Foreword iv Introductionvi 1 Scope1 2 Normative references1 3 Terms and definitions .2 4 Principle .8 5 Test apparatus .10
16、 5.1 Type 10 5.2 Mechanical, electronic and recording systems .10 5.3 Temperature-controlled enclosure 10 5.4 Gas supply .11 5.5 Temperature-measurement device11 5.6 Devices for measuring test specimen dimensions11 6 Test specimens11 6.1 General .11 6.2 Shape and dimensions .11 6.3 Preparation.11 7
17、Number of test specimens .11 8 Conditioning 12 9 Procedure.12 9.1 Test atmosphere12 9.2 Measurement of specimen cross-section.12 9.3 Mounting the test specimens.12 9.4 Varying the temperature .12 9.5 Varying the frequency.13 9.6 Varying the dynamic-strain amplitude 13 10 Expression of results13 11 P
18、recision 13 12 Test report14 Annex A (informative) Resonance curves15 Annex B (informative) Deviations from linear behaviour19 Bibliography20 BS EN ISO 6721-1:2011ISO 6721-1:2011(E) iv ISO 2011 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federa
19、tion 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 subject for which a technical committee has been established has the right to be represented on that committ
20、ee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance
21、 with the rules given in the ISO/IEC Directives, Part 2. Draft International Standards adopted by the technical committees 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 dra
22、wn to the possibility that some of the elements of this part of ISO 6721 may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 6721-1 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 2, Mechanical properties.
23、 This third edition cancels and replaces the second edition (ISO 6721-1:2001), of which it constitutes a minor revision involving the following changes: a new subclause (9.6), covering the case when the dynamic-strain amplitude is varied, has been added to the procedure clause; the expression of res
24、ults clause (Clause 10) and the test report clause (Clause 12) have been modified accordingly Clause 10 by the addition of a new paragraph (the third) and Clause 12 by the addition of a new item, item n). ISO 6721 consists of the following parts, under the general title Plastics Determination of dyn
25、amic mechanical properties: Part 1: General principles Part 2: Torsion-pendulum method Part 3: Flexural vibration Resonance-curve method Part 4: Tensile vibration Non-resonance method Part 5: Flexural vibration Non-resonance method Part 6: Shear vibration Non-resonance method Part 7: Torsional vibra
26、tion Non-resonance method Part 8: Longitudinal and shear vibration Wave-propagation method Part 9: Tensile vibration Sonic-pulse propagation method Part 10: Complex shear viscosity using a parallel-plate oscillatory rheometer BS EN ISO 6721-1:2011ISO 6721-1:2011(E) ISO 2011 All rights reserved v Par
27、t 11: Glass transition temperature Part 12: Compressive vibration Non-resonance method BS EN ISO 6721-1:2011ISO 6721-1:2011(E) vi ISO 2011 All rights reservedIntroduction The methods specified in the first nine parts of ISO 6721 can be used for determining storage and loss moduli of plastics over a
28、range of temperatures or frequencies by varying the temperature of the specimen or the frequency of oscillation. Plots of the storage or loss moduli, or both, are indicative of viscoelastic characteristics of the specimen. Regions of rapid changes in viscoelastic properties at particular temperature
29、s or frequencies are normally referred to as transition regions. Furthermore, from the temperature and frequency dependencies of the loss moduli, the damping of sound and vibration of polymer or metal-polymer systems can be estimated. Apparent discrepancies may arise in results obtained under differ
30、ent experimental conditions. Without changing the observed data, reporting in full (as described in the various parts of ISO 6721) the conditions under which the data were obtained will enable apparent differences observed in different studies to be reconciled. The definitions of complex moduli appl
31、y exactly only to sinusoidal oscillations with constant amplitude and constant frequency during each measurement. On the other hand, measurements of small phase angles between stress and strain involve some difficulties under these conditions. Because these difficulties are not involved in some meth
32、ods based on freely decaying vibrations and/or varying frequency near resonance, these methods are used frequently (see ISO 6721-2 and ISO 6721-3). In these cases, some of the equations that define the viscoelastic properties are only approximately valid. BS EN ISO 6721-1:2011INTERNATIONAL STANDARD
33、ISO 6721-1:2011(E) ISO 2011 All rights reserved 1Plastics Determination of dynamic mechanical properties Part 1: General principles 1 Scope The various parts of ISO 6721 specify methods for the determination of the dynamic mechanical properties of rigid plastics within the region of linear viscoelas
34、tic behaviour. This part of ISO 6721 is an introductory section which includes the definitions and all aspects that are common to the individual test methods described in the subsequent parts. Different deformation modes may produce results that are not directly comparable. For example, tensile vibr
35、ation results in a stress which is uniform across the whole thickness of the specimen, whereas flexural measurements are influenced preferentially by the properties of the surface regions of the specimen. Values derived from flexural-test data will be comparable to those derived from tensile-test da
36、ta only at strain levels where the stress-strain relationship is linear and for specimens which have a homogeneous structure. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For un
37、dated references, the latest edition of the referenced document (including any amendments) applies. ISO 291, Plastics Standard atmospheres for conditioning and testing ISO 293, Plastics Compression moulding of test specimens of thermoplastic materials ISO 294 (all parts), Plastics Injection moulding
38、 of test specimens of thermoplastic materials ISO 295, Plastics Compression moulding of test specimens of thermosetting materials ISO 1268 (all parts), Fibre-reinforced plastics Methods of producting test plates ISO 2818, Plastics Preparation of test specimens by machining ISO 4593, Plastics Film an
39、d sheeting Determination of thickness by mechanical scanning ISO 6721-2:2008, Plastics Determination of dynamic mechanical properties Part 2: Torsion-pendulum method ISO 6721-3, Plastics Determination of dynamic mechanical properties Part 3: Flexural vibration Resonance-curve method BS EN ISO 6721-1
40、:2011ISO 6721-1:2011(E) 2 ISO 2011 All rights reserved3 Terms and definitions For the purposes of this document, the following terms and definitions apply. NOTE Some of the terms defined here are also defined in ISO 4727. The definitions given here are not strictly identical with, but are equivalent
41、 to, those in ISO 472. 3.1 complex modulus Mratio of dynamic stress, given by () ( )Aexp i2 ,tft= and dynamic strain, given by () ( )Aexp i 2 ,tft =of a viscoelastic material that is subjected to a sinusoidal vibration, where Aand Aare the amplitudes of the stress and strain cycles, f is the frequen
42、cy, is the phase angle between stress and strain (see 3.5 and Figure 1) and t is time NOTE 1 It is expressed in pascals (Pa). NOTE 2 Depending on the mode of deformation, the complex modulus might be one of several types: E, G, Kor L(see Table 3). M= M + iM (see 3.2 and 3.3) (1) where ()1/ 2i1 1= =
43、For the relationships between the different types of complex modulus, see Table 1. NOTE 3 For isotropic viscoelastic materials, only two of the elastic parameters G, E, K, Land are independent (is the complex Poissons ratio, given by = + i). NOTE 4 The most critical term containing Poissons ratio is
44、 the “volume term” 1 2, which has values between 0 and 0,4 for between 0,5 and 0,3. The relationships in Table 1 containing the “volume term” 1 2 can only be used if this term is known with sufficient accuracy. It can be seen from Table 1 that the “volume term” 1 2 can only be estimated with any con
45、fidence from a knowledge of the bulk modulus K or the uniaxial-strain modulus L and either E or G. This is because K and L measurements involve deformations when the volumetric strain component is relatively large. NOTE 5 Up to now, no measurement of the dynamic mechanical bulk modulus K, and only a
46、 small number of results relating to relaxation experiments measuring K(t), have been described in the literature. NOTE 6 The uniaxial-strain modulus L is based upon a load with a high hydrostatic-stress component. Therefore values of L compensate for the lack of K values, and the “volume term” 1 2
47、can be estimated with sufficient accuracy based upon the modulus pairs (G, L) and (E, L). The pair (G, L) is preferred, because G is based upon loads without a hydrostatic component. NOTE 7 The relationships given in Table 1 are valid for the complex moduli as well as their magnitudes (see 3.4). NOT
48、E 8 Most of the relationships for calculating the moduli given in the other parts of this International Standard are, to some extent, approximate. They do not take into account e.g. “end effects” caused by clamping the specimens, and they include other simplifications. Using the relationships given
49、in Table 1 therefore often requires additional corrections to be made. These are given in the literature (see e.g. References 1 and 2 in the Bibliography). NOTE 9 For linear-viscoelastic behaviour, the complex compliance Cis the reciprocal of the complex modulus M, i.e. M= (C)1(2) Thus () ()22iiCCMMCC+=+(3) BS EN ISO 6721-1:2011ISO 6721-1:2011(E) ISO 2011 All rights reserved 3a) b) The phase
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1