1、BRITISH STANDARDBS ISO 4666-4:2007Rubber, vulcanized Determination of temperature rise and resistance to fatigue in flexometer testing Part 4: Constant-stress flexometer ICS 83.060g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36
2、g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS ISO 4666-4:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2007 BSI 2007ISBN 978 0 580 54399 9National forewordThis British Standard is the UK
3、implementation of ISO 4666-4:2007.The UK participation in its preparation was entrusted to Technical Committee PRI/22, Physical testing of rubber.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the nec
4、essary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsReference numberISO 4666-4:2007(E)INTERNATIONAL STANDARD ISO4666-4First edition
5、2007-08-01Rubber, vulcanized Determination of temperature rise and resistance to fatigue in flexometer testing Part 4: Constant-stress flexometer Caoutchouc vulcanis Dtermination de llvation de temprature et de la rsistance la fatigue dans les essais aux flexomtres Partie 4: Flexomtre contrainte con
6、stante BS ISO 4666-4:2007ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Principle. 2 5 Apparatus 2 6 Test piece 8 7 Test conditions . 8 8 Procedure 9 9 Precision 13 10 Test report . 14 Annex A (informative) Precision . 15 Annex B (i
7、nformative) Guidance for using precision results 18 Bibliography . 19 BS ISO 4666-4:2007iv Foreword 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 o
8、ut 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 committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO c
9、ollaborates closely with the International Electrotechnical Commission (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
10、 Standards. 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. ISO 4666-4 was prepared by Technical Committee ISO/TC 45, Rub
11、ber and rubber products, Subcommittee SC 2, Testing and analysis. ISO 4666 consists of the following parts, under the general title Rubber, vulcanized Determination of temperature rise and resistance to fatigue in flexometer testing: Part 1: Basic principles Part 2: Rotary flexometer Part 3: Compres
12、sion flexometer Part 4: Constant-stress flexometer BS ISO 4666-4:2007vIntroduction This part of ISO 4666 describes a method of compression flexometer testing with constant-stress dynamic loading. The features and usefulness of constant-stress flexometer testing are as follows: a) In order to exactly
13、 simulate the behaviour of a rubber product in use, an important consideration is where the temperature is measured. The constant-stress flexometer measures the temperature directly at the centre of the inside of the test piece (the source of heat generation), using a device as shown in Figure 4 of
14、this part of ISO 4666, while in Part 3 of this International Standard the temperature is measured on the surface of the test piece. b) A servo control system based on real-time feedback of the strain or stress is used to enable the measurement of dynamic properties (viscoelastic parameters) of the r
15、ubber as a function of time during the test run. c) The accumulation of feedback information allows the detection of an initial stage, or the first signs of breakdown due to heat generation, which was once thought to be very difficult. It has been reported1how well the rise in tyre temperature corre
16、lates with the temperature rise in the constant-stress flexometer test in comparison with the result from the method in Part 3 of this International Standard. The International Organization for Standardization (ISO) draws attention to the fact that it is claimed that compliance with this document ma
17、y involve the use of a patent concerning the flexometer specified in Clause 5. ISO takes no position concerning the evidence, validity and scope of this patent right. The holder of this patent right has assured ISO that he is willing to negotiate licences under reasonable and non-discriminatory term
18、s and conditions with applicants throughout the world. In this respect, the statement of the holder of this patent right is registered with ISO. Information may be obtained from: Bridgestone Corporation, 3-1-1 Ogawahigashi-Cho, Kodaira-Shi, Tokyo 187-8531, Japan. Attention is drawn to the possibilit
19、y that some elements of this document may be the subject of patent rights other than those identified above. ISO shall not be held responsible for identifying any or all such patent rights. BS ISO 4666-4:2007blank1Rubber, vulcanized Determination of temperature rise and resistance to fatigue in flex
20、ometer testing Part 4: Constant-stress flexometer WARNING Persons using this International Standard should be familiar with normal laboratory practice. This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to estab
21、lish appropriate safety and health practices and to ensure compliance with any national regulatory conditions. 1 Scope This part of ISO 4666 specifies a constant-stress flexometer test for the determination of the temperature rise and resistance to fatigue of vulcanized rubbers. Many rubber products
22、, such as tyres and belts, are tested by subjecting them to an oscillating load with a constant peak stress amplitude. In order to obtain good correlation between accelerated tests and in-service exposure of these products, this part of ISO 4666 gives instructions for carrying out measurements under
23、 such conditions. This method is not recommended for rubber having a hardness greater than 85 IRHD. 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 late
24、st edition of the referenced document (including any amendments) applies. ISO 48, Rubber, vulcanized or thermoplastic Determination of hardness (hardness between 10 IRHD and 100 IRHD) ISO 4664-1, Rubber, vulcanized or thermoplastic Determination of dynamic properties Part 1: General guidance ISO 466
25、6-1, Rubber, vulcanized Determination of temperature rise and resistance to fatigue in flexometer testing Part 1: Basic principles ISO 4666-3, Rubber, vulcanized Determination of temperature rise and resistance to fatigue in flexometer testing Part 3: Compression flexometer ISO 23529, Rubber General
26、 procedures for preparing and conditioning test pieces for physical test methods BS ISO 4666-4:20072 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 4664-1 and ISO 4666-1 apply. 4 Principle A cylindrical test piece is subjected to dynamic loading wit
27、h constant peak stress cycles in compression superimposed on a static prestress. The temperature rise of the test piece is measured, and the fatigue life of the test piece is given by the number of cycles, or the test time, until breakdown occurs. The change in height (creep) and dynamic properties
28、are also measured as a function of time, and the compression set is measured at the end of the test. 5 Apparatus The apparatus is shown schematically in Figure 1, and an example is shown in Figure 2. 5.1 Anvils A pair of anvils (upper and lower) support the test piece. The lower anvil is connected t
29、o an oscillator to apply static and dynamic compression deformation to the test piece, and the upper anvil transmits the static and dynamic compression loads, via a shaft, to a load detector. The parts of the upper and lower anvils which come in contact with the test piece shall be made of a heat-in
30、sulating material of thermal conductivity 0,28 W/(mK) maximum. A hole shall be provided in the centre of the upper anvil for insertion of a needle-type thermometer for measuring the temperature inside the test piece. An example of upper and lower anvil construction is shown in Figure 3. 5.2 Oscillat
31、or The oscillator used to apply static and dynamic compression loads to the test piece shall have a capacity of at least 2 kN and be capable of applying an oscillating force of 0,75 kN peak amplitude at 50 Hz. A hydraulic servo-control system is preferably used to control the oscillator. The maximum
32、 stroke is preferably 20 mm to 25 mm. 5.3 Displacement detector The displacement detector shall be capable of measuring the motion of the lower anvil (the deformation of the test piece in compression) to within 0,01 mm, and shall have a response time suitable for the maximum frequency used. 5.4 Load
33、 detector The load detector shall be capable of measuring the compression load up to a maximum of 2,0 kN in 5 N increments, shall have a response time suitable for the maximum frequency used, and shall have a high natural frequency. BS ISO 4666-4:20073Key 1 position controller 2 load detector 3 need
34、le-type temperature detector 4 upper anvil 5 temperature controller 6 computer control unit 7 test piece 8 lower anvil 9 heating chamber 10 oscillator 11 displacement detector Figure 1 Principle and fundamental structure of a constant-stress flexometer BS ISO 4666-4:20074 Key 1 position controller 2
35、 load detector 3 temperature controller 4 upper anvil 5 needle-type temperature detector 6 test piece 7 heating chamber 8 lower anvil 9 oscillator 10 displacement detector Figure 2 An example of a constant-stress flexometer BS ISO 4666-4:20075Dimensions in millimetres Key 1 upper anvil 2 needle-type
36、 temperature detector 3 test piece 4 thermal insulator 5 lower anvil Figure 3 An example of upper and lower anvils for a constant-stress flexometer BS ISO 4666-4:20076 5.5 Heating chamber and temperature controller The temperature of the heating chamber shall be set at a temperature within the range
37、 40 C to 100 C as specified in ISO 23529, and be controlled to within 1 C. The temperature in the chamber shall be measured at positions 6 mm to 9 mm away from the end of each anvil and also midway between the upper and lower anvils. A temperature sensor wire at least 100 mm in length shall be inser
38、ted into the chamber. A grid shelf on which to condition test pieces should preferably be installed in the chamber at a similar height to that of the lower anvil, although conditioning of test pieces may also be carried out in another heating chamber. 5.6 Needle-type temperature detector A needle-ty
39、pe temperature detector with a diameter at the tip of 1,0 mm and resolution of 0,5 C shall be used. An example of a needle-type temperature detector is shown in Figure 4. Dimensions in millimetres Figure 4 Example of a needle-type temperature detector 5.7 Temperature-detector position controller The
40、 position controller shall be capable of adjusting the position of the needle-type temperature detector using the feedback data on the test piece height sent from the displacement detector through the computer control unit during the test in real time. NOTE The height of a test piece refers to the a
41、verage value of the maximum height and the minimum height in one cycle of a compression-oscillating test piece. In general, this value decreases gradually during the test due to creep of the test piece. An example of a temperature-detector position controller is shown in Figure 5. BS ISO 4666-4:2007
42、7Key 1 stepping motor 2 clamp 3 guide 4 needle-type temperature detector 5 test piece Figure 5 Example of a temperature-detector position controller BS ISO 4666-4:20078 5.8 Computer control unit The computer control unit shall be capable of the following: a) controlling the action of the oscillator
43、so that the static compression stress applied to the test piece always coincides with the value specified in the test conditions; b) controlling the action of the oscillator so that the amplitude of the dynamic stress applied to the test piece always coincides with the value specified in the test co
44、nditions (constant-stress control); c) recording and displaying the temperature at the centre of the test piece detected by the needle-type temperature detector; d) calculating, recording and displaying the creep of the test piece from the values measured by the displacement detector; e) (when deter
45、mining the fatigue life from dynamic properties) calculating, recording and displaying the dynamic properties of the normal storage modulus E, normal loss modulus E“ and tangent of the loss angle (tan) from the measured parameters (see 8.3.4) fed back from the sensors in real time, these values bein
46、g preferably calculated at 1 s intervals; f) ending the test at the time specified in the test conditions or at the time when the recorded values reach specified limits. 5.9 Measuring gauge The gauge for measuring the height and diameter of test pieces shall conform to the requirements of ISO 23529.
47、 A dial gauge having a circular foot probe of diameter 10 mm and exerting a pressure of 22 kPa 5 kPa is suitable. 6 Test piece The test piece, prepared from vulcanized rubber, shall be cylindrical in shape, having a diameter of 30,00 mm 0,30 mm and a height of 25,00 mm 0,25 mm. The standard method o
48、f preparing the test piece shall be direct moulding of the cylinder. It is suggested, for purposes of uniformity and closer tolerances in the moulded test piece, that the dimensions of the mould be specified and shrinkage compensated for therein. NOTE A plate cavity of diameter 30,40 mm 0,05 mm and
49、depth 25,40 mm 0,05 mm, having overflow cavities at both top and bottom when assembled with two end plates, represents one such type of mould. 7 Test conditions The conditions specified in Table 1 or Table 2 are normally used in tests with the constant-stress flexometer. The dynamic-load amplitude shall be less than the static load. BS ISO 4666-4:20079Table 1 Test conditions for measurement of temperature rise Conditions Nominal value Range Chamber temperature Standard laboratory temperature (40 1)
