1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationOptical fibresPart 1-31: Measurement methods and test procedures Tensile strengthBS EN 60793-1-31:2010National forewordThis British Standard is the UK implementation of EN 60793-
2、1-31:2010. It isidentical to IEC 60793-1-31:2010. It supersedes BS EN 60793-1-31:2002which is withdrawn.The UK participation in its preparation was entrusted by Technical CommitteeGEL/86, Fibre optics, to Subcommittee GEL/86/1, Optical fibres and cables. A list of organizations represented on this c
3、ommittee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application. BSI 2010 ISBN 978 0 580 66885 2 ICS 33.180.10Compliance with a British Standard cannot confer immunity from l
4、egal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2010.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 60793-1-31:2010EUROPEAN STANDARD EN 60793-1-31 NORME EUROPENNE EUROPISCHE
5、NORM September 2010 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2010 CENELEC - All rights of exploitation in any form and by any
6、 means reserved worldwide for CENELEC members. Ref. No. EN 60793-1-31:2010 E ICS 33.180.10 Supersedes EN 60793-1-31:2002English version Optical fibres - Part 1-31: Measurement methods and test procedures - Tensile strength (IEC 60793-1-31:2010) Fibres optiques - Partie 1-31 : Mthodes de mesure et pr
7、ocdures dessai - Rsistance la traction (CEI 60793-1-31:2010) Lichtwellenleiter - Teil 1-31: Messmethoden und Prfverfahren - Zugfestigkeit (IEC 60793-1-31:2010) This European Standard was approved by CENELEC on 2010-09-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations
8、which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This Europ
9、ean Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are t
10、he national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Sloven
11、ia, Spain, Sweden, Switzerland and the United Kingdom. EN 60793-1-31:2010 - 2 - Foreword The text of document 86A/1285/CDV, future edition 2 of IEC 60793-1-31, prepared by SC 86A, Fibres and cables, of IEC TC 86, Fibre optics, was submitted to the IEC-CENELEC parallel vote and was approved by CENELE
12、C as EN 60793-1-31 on 2010-09-01. This European Standard supersedes EN 60793-1-31:2002. The main change with respect to the previous edition is the addition of comprehensive details, such as examples of fibre clamping as given in Annexes A, B and C. Attention is drawn to the possibility that some of
13、 the elements of this document may be the subject of patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent rights. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national
14、 standard or by endorsement (dop) 2011-06-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2013-09-01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60793-1-31:2010 was approved by CENELEC as a Euro
15、pean Standard without any modification. In the official version, for Bibliography, the following note has to be added for the standard indicated: IEC 61649 NOTE Harmonized as EN 61649. _ BS EN 60793-1-31:2010- 3 - EN 60793-1-31:2010 Annex ZA (normative) Normative references to international publicat
16、ions with their corresponding European publications 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 the referenced document (including any amendments) applie
17、s. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60793-1-20 - Optical fibres - Part 1-20: Measurement methods and test procedures - Fibre geometry EN 60793-1-20 - IEC 60793-1-21
18、- Optical fibres - Part 1-21: Measurement methods and test procedures - Coating geometry EN 60793-1-21 - BS EN 60793-1-31:2010 4 60793-1-31 IEC:2010(E) CONTENTS INTRODUCTION.6 1 Scope.7 2 Normative references .7 3 Apparatus.7 3.1 General .7 3.2 Gripping the fibre at both ends 8 3.3 Sample support .8
19、 3.4 Stretching the fibre 8 3.5 Measuring the force at failure 9 3.6 Environmental control equipment 9 4 Sample preparation 9 4.1 Definition.9 4.2 Sample size and gauge length.9 4.3 Auxiliary measurements 10 4.4 Environment 11 5 Procedure 11 5.1 Preliminary steps.11 5.2 Procedure for a single specim
20、en .11 5.3 Procedure for completing all samples for a given nominal strain rate. 11 6 Calculations .12 6.1 Conversion of tensile load to failure stress 12 6.2 Preparation of a Weibull plot .13 6.3 Computation of Weibull parameters .13 7 Results .14 7.1 The following information should be reported fo
21、r each test: .14 7.2 The following information should be provided for each test:.14 8 Specification information 14 Annex A (informative) Typical dynamic testing apparatus.15 Annex B (informative) Guideline on gripping the fibre. 17 Annex C (informative) Guideline on stress rate 21 Bibliography22 Fig
22、ure 1 Bimodal tensile strength Weibull plot for a 20 m gauge length test set-up at 5 %/min strain rate10 Figure A.1 Capstan design.15 Figure A.2 Translation test apparatus 15 Figure A.3 Rotating capstan apparatus 16 Figure A.4 Rotating capstan apparatus for long lengths .16 Figure B.1 Gradual slippa
23、ge 17 Figure B.2 Irregular slippage17 Figure B.3 Sawtooth slippage 18 Figure B.4 Acceptable transfer function .18 Figure B.5 Typical capstan.19 BS EN 60793-1-31:201060793-1-31 IEC:2010(E) 5 Figure B.6 Isostatic compression .19 Figure B.7 Escargot wrap.20 Figure C.1 System to control stress rate 21 F
24、igure C.2 Time variation of load and loading speed21 BS EN 60793-1-31:2010 6 60793-1-31 IEC:2010(E) INTRODUCTION Failure stress distributions can be used to predict fibre reliability in different conditions. IEC/TR 62048 shows mathematically how this can be done. To complete a given reliability proj
25、ection, the tests used to characterize a distribution shall be controlled for the following: Population of fibre, e.g., coating, manufacturing period, diameter Gauge length, i.e., length of section that is tested Stress or strain rates Testing environment Preconditioning or aging treatments Sample s
26、ize This method measures the strength of optical fibre at a specified constant strain rate. It is a destructive test, and is not a substitute for prooftesting. This method is used for those typical optical fibres for which the median fracture stress is greater than 3,1 GPa (450 kpsi) in 0,5 m gauge
27、lengths at the highest specified strain rate of 25 %/min. For fibres with lower median fracture stress, the conditions herein have not demonstrated sufficient precision. Typical testing is conducted on “short lengths”, up to 1 m, or on “long lengths”, from 10 m to 20 m with sample size ranging from
28、15 to 30. The test environment and any preconditioning or aging is critical to the outcome of this test. There is no agreed upon model for extrapolating the results for one environment to another environment. For failure stress at a given stress or strain rate, however, as the relative humidity incr
29、eases, failure stress decreases. Both increases and decreases in the measured strength distribution parameters have been observed as the result of preconditioning at elevated temperature and humidity for even a day or two. This test is based on the theory of fracture mechanics of brittle materials a
30、nd on the power-law description of flaw growth (see IEC TR 62048). Although other theories have been described elsewhere, the fracture mechanics/power-law theory is the most generally accepted. A typical population consists of fibre that has not been deliberately damaged or environmentally aged. A t
31、ypical fibre has a nominal diameter of 125 m, with a 250 m or less nominal diameter acrylate coating. Default conditions are given for such typical populations. Atypical populations might include alternative coatings, environmentally aged fibre, or deliberately damaged or abraded fibre. Guidance for
32、 atypical populations is also provided. BS EN 60793-1-31:201060793-1-31 IEC:2010(E) 7 OPTICAL FIBRES Part 1-31: Measurement methods and test procedures Tensile strength 1 Scope This part of IEC 60793 provides values of the tensile strength of optical fibre samples and establishes uniform requirement
33、s for the mechanical characteristic tensile strength. The method tests individual lengths of uncabled and unbundled glass optical fibre. Sections of fibre are broken with controlled increasing stress or strain that is uniform over the entire fibre length and cross section. The stress or strain is in
34、creased at a nominally constant rate until breakage occurs. The distribution of the tensile strength values of a given fibre strongly depends on the sample length, loading velocity and environmental conditions. The test can be used for inspection where statistical data on fibre strength is required.
35、 Results are reported by means of statistical quality control distribution. Normally the test is carried out after temperature and humidity conditioning of the sample. However, in some cases, it may be sufficient to measure the values at ambient temperature and humidity conditions This method is app
36、licable to types A1, A2, A3, B and C optical fibres. Warning This test involves stretching sections of optical fibre until breakage occurs. Upon breakage, glass fragments can be distributed in the test area. Protective screens are recommended. Safety glasses should be worn at all times in the testin
37、g area. 2 Normative references The following referenced documents are indispensable for the application of this document. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60793-1-20, Optical fibres Part 1-20: Measurement methods and test p
38、rocedures Fibre geometry IEC 60793-1-21, Optical fibres Part 1-21: Measurement methods and test procedures Coating geometry 3 Apparatus 3.1 General This clause prescribes the fundamental requirements of the equipment used for dynamic strength testing. There are many configurations that can meet thes
39、e requirements. Some examples are presented in Annex A. The choice of a specific configuration will depend on such factors as: gauge length of a specimen stress or strain rate range environmental conditions strength of the specimens. BS EN 60793-1-31:2010 8 60793-1-31 IEC:2010(E) 3.2 Gripping the fi
40、bre at both ends Grip the fibre to be tested at both ends and stretch it until failure occurs in the gauge length section. The grip shall not allow the fibre to slip out prior to failure and shall minimize failure at the grip. Record a break that occurs at the grip, but do not use it in subsequent c
41、alculations. Since fibre strain is increasing during the test, some slippage occurs at the grip. At higher stress levels, associated with short gauge lengths, slippage can induce damage and cause gripping failures that are difficult to ascertain. The frequency of such failures can often vary with st
42、ress or strain rate. Careful inspection of the residual fibre pieces, or other means, is required to prevent the possibility of including gripping failures in the analysis. Use a capstan, typically covered with an elastomeric sheath, to grip the fibre (see Figure A.1). Wrap a section of fibre that w
43、ill not be tested around the capstan several times and secure the fibre at the ends with, for example, an elastic band. Wrap the fibre with no crossovers. The capstan surface shall be tough enough so that the fibre does not cut into it when fully loaded. The amount of slippage and capstan failures d
44、epends on the interaction of the fibre coating and the capstan surface material, thickness, and number of wraps. Careful preliminary testing is required to confirm the choice of a capstan surface. Design the diameter of the capstan and pulley so that the fibre does not break on the capstan due to be
45、nd stress. For typical silica-clad fibres, the bend stresses shall not exceed 0,175 GPa. (For typical 125/250 m silica fibre, the minimum capstan diameter is then 50 mm.) A particular gripping implementation is given in Annex B. 3.3 Sample support Attach the specimen to the two grips. The gauge leng
46、th is the length of fibre between the axes of the gripping capstans before it is stretched. To reduce the space required to perform the test on long gauge lengths, one or more pulleys may be used to support the specimen (see Figure A.4). The pulleys shall be designed, and their surfaces kept free of
47、 debris, so the fibre is not damaged by them. The remainder of the fibre, away from pulleys and capstans, shall not be touched. When multiple fibres are tested simultaneously, as in Figure A.5, a baffle arrangement is required to prevent a broken fibre from snapping into, or otherwise perturbing the
48、 other fibres under test. 3.4 Stretching the fibre Stretch the fibre at a fixed nominal strain rate until it breaks. The nominal strain rate is expressed as the percent increase in length per minute, relative to the gauge length. There are two basic alternatives for stretching the fibre: Method A: I
49、ncrease the separation between the gripping capstans by moving them apart at a fixed rate of speed, with the starting separation equal to the gauge length (Figure A.2 of Annex A). Method B: Rotate a capstan at a fixed rate to take up the fibre and strain the section between capstans (Figures A.3 to A.5 of Annex A). The rotation shall not result in crossovers on the capstan. Calibrate the strain rate to within 10 % of the nominal strain rate. S
