1、BRITISH STANDARD Testing of welded joints of thermoplastics semi-finished products - Part 7: Tensile test with waisted test specimens The European Standard EN 12814-7:2002 has the status of a British Standard ICs 26.160.40 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN
2、B 2 81 4-79002 British :Standards BS EN 12814-7:2002 National foreword This British Standard is the official English language version of The UK participation in its preparation was entrusted to Technical Committee PRU80, Welding of plastics, which has the responsibility to: EN 12814-72002. - - aid e
3、nquirers to understand the text; present to the responsible internationalEuropean committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. - A list of organizatio
4、ns represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondenc
5、e Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itsel
6、f confer immunity from legal obligations. This British Standard, having been prepared under the direction of the Materials and Chemicals Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 21 October 2002 Summary of pages This doc
7、ument comprises a front cover, an inside front cover, the EN title page, pages 2 to 9 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. IDate I Comments O BSI 21 October 2002 ISBN O 580 40629
8、6 EUROPEAN STDMD NORME EUROPENNE EUROPISCHE NORM EN I28147 October 2002 ICs 25.160.40 English version Testing of welded joints of thermoplastics semi-finished products - Part 7: Tensile test with waisted test specimens Essais des assemblages souds sur produits semi-finis en thermoplastiques - Partie
9、 7: Essai de traction avec prouvettes entailles en U Prfen von Schweiverbindungen aus thermoplastischen Kunststoffen -Teil 7: Zugversuch an Probekrpern mit Rundkerbe This European Standard was approved by CEN on 19 August 2002. CEN members are bound to comply with the CENKENELEC Internal Regulations
10、 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 Management Centre or to any CEN member. This European S
11、tandard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the national sta
12、ndards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Noway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITEE FOR STANDARDIZATION EUROPISCHES KOMITEE FOR NORMUNG COMITB EUROPEN
13、DE NORMALISATION Management Centre: rue de Stassart, 36 B-1050 Brussels O 2002 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12814-7:2002 E EN 12814-7:2002 (E) Contents Page Foreword 3 1 Scope 4 2 Normative references 4 3 Symbols
14、 and designations . 4 4 Principle of the test 4 5 Sampling procedures 5 6 Dimensions of test Specimens . 5 7 8 Mechanical testing . 6 9 Test equipment 6 IO Determination of the tensile energy welding factor . 6 11 Test report 7 Annex A (informative) Test speeds for some thermoplastics materials . 8
15、Bibliography 9 Cutting of test specimens . 6 2 EN 12814-7:2002 (E) Foreword This document EN 12814-7:2002 has been prepared by Technical Committee CENTTC 249 “Plastics“, the secretariat of which is held by IBN. This European Standard shall be given the status of a national standard, either by public
16、ation of an identical text or by endorsement, at the latest by April 2003, and conflicting national standards shall be withdrawn at the latest by April 2003. Annex A is informative. This standard includes a Bibliography. According to the CENKENELEC Internal Regulations, the national standards organi
17、zations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. 3 EN 12834-7:20
18、02 (E) The tensile energy welding factor 1 Scope - This European Standard specifies the dimensions, the method of sampling, the preparation of the test specimens and the conditions for performing the tensile test with waisted test specimens in order to determine the tensile energy welding factor. A
19、tensile test with waisted specimens may be used in conjunction with other tests (e.g. bend, tensile, tensile creep, macro .) to assess the performance of welded assemblies, made from thermoplastics materials. The test is applicable to Co-axial or Co-planar welded assemblies made from thermoplastics
20、materials filled or unfilled, but not reinforced, irrespective of the welding process used. It is not applicable to tubular assemblies with a nominal outside diameter less than 90 mm. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publ
21、ications. These normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revis
22、ion. For undated references the latest edition of the publication referred to applies (including amendments). EN 131 00-1, Non destructive testing of welded joints of thermoplastics semi-finished products - Visual examination. EN IS0 527-1, Plastics - Determination of tensile properties - Part 1: Ge
23、neral principles (IS0 527-1:1993). IS0 5893, Rubber and plastics test equipment - Tensile, flexural and compression types (constant traverse) - Description. 3 Symbols and designations Symbols and designations are given in Table I. Table i - Symbols and designations Symbols and abbreviations f, l D“
24、The value of energy to break of the welded test specimen used in the calculation off, a Joule I The value of energy to break of the unwelded test specimens taken from the same test piece, used in the calculation off, Nominal thickness of the test piece I miltimetre Nominal outside diameter of the tu
25、be I miiiimetre a Area under the load/extension curve of the welded test specimen. Area under the load/extension curve of the unwelded test specimen. 4 Principle of the test rate of The test specimen is extended along its major longitudinal axis at constant speed until the test specimen fractures. D
26、uring this procedure the load and extension sustained by the test specimen is measured and the energy to break is calculated. 4 EN 12814-7:2002 (E) 5 Sampling proceures The test specimens (welded and unwelded) shall be cut perpendicular to the welded joint at least eight hours after welding. Each te
27、st specimen shall be marked in order to identify its original position within the test piece. No heat treatment or mechanical straightening operations shall be carried out on the test specimen. 6 Dimensions of test specimens The dimensions of test specimens are given in Figure 1 Dimensions in millim
28、etres Key a Extensometer gauge length Figure 1 -Waisted tensile tsst specimen 5 EN 92814-7:2002 (E) Where the beads are left intact in service, they should be left intact for the test. Where the beads are removed in service, they should be removed prior to testing. 7 Cutting of test specimens The te
29、nsile test specimens shall be cut with parallel sides as shown in Figure I. During cutting, heating of the test specimen shall be minimized. The radiused portions of the test specimen shall be smooth but the surface finish of the other remaining edges is not critical. After cutting, a visual examina
30、tion of the weld, according to EN 13100-1, shall be carried out and recorded. 8 Mechanical testing Test specimens shall be conditioned at a temperature of (23 * 2) “C for not less than 12 h for test specimen thicknesses less than or equal to 12 mm, or for not less than 24 h for test specimen thickne
31、sses greater than 12 mm. Unless otherwise specified, the temperature of the test specimen at the beginning of the test shall be (23 f 2) OC. The test speeds and tolerances shall be in accordance with EN IS0 527-1. Examples of test speeds for some relevant thermoplastics materials are listed in annex
32、 A. An extensometer shall be attached to either side of the specimen waisted section, between the loading holes (see Figure I), to measure true elongation of the specimen during the test. The extensometer shall comply with EN IS0 527-1. The complete load/extension curve and failure mode (brittle, du
33、ctile or mixed) shall be recorded for each specimen. At least five test specimens shall be tested for each welded and unwelded test piece. Welded and unwelded test specimens shall be of the same geometry and shall be tested at the same speed. 9 Test equipment The test equipment shall conform to the
34、requirements given in IS0 5893. The crosshead displacement shall be continuous, uniform and in accordance with clause 8 of this standard. 1 O Determination of the tensile energy welding factor In order to determine the tensile energy welding factor, welded and unwelded test specimens shall be tested
35、. The tensile energy welding factor is determined from the arithmetic mean values of the energy to break of the welded test specimens (E,) and the unwelded test specimens (E,). - E, Er Tensile energy welding factor, 5 = = 6 EM 12814-7:2002 (E) The values of E, and E, are determined from the areas un
36、der the loadlextension curves of the welded and unwelded test specimens, respectively, and can be determined using an electronic integrator, planimeter, counting squares or weighing the cut-out curve. At least ten test specimens (five welded and five unwelded) shall be used in the evaluation of the
37、tensile energy welding factor. No test specimen shall be disregarded unless failure occurs at the loading holes. 11 Test report The test report shall refer to this standard and it shall include at least the following information: description and identification of the test piece and test specimens; a
38、ppearance of the test pieces before the test: I) visual examination of weld; 2) beads removed or not; weld type; nominal outside diameter of the tube, if applicable; number of test specimens; appearance of all surfaces of the test specimens, (e.g. flaws, scratches, visual imperfections); thickness o
39、f test specimen; type of extensometer; temperature of the test specimen at the beginning of the test; room temperature during the test; the crosshead speed; visual examination of the ruptured surface (failure mode); calculated individual energy to break values; calculated average energy to break val
40、ues (E, and E, ); calculated value of the tensile energy welding factor ve); identification of the laboratory; date of the test; - - r) name and signature of the person responsible for the test report. 7 EN 12814-?:2002 (E) PE Annex A (informative) mmlmin 5 Best speeds for some thermoplastics materi
41、als The test speeds used for some thermoplastics materials are giver: in Table A.l Table A.t - Test speeds for some thermoplastics materials I Speed I I Material I PP I 5 I 8 EN 12814-7:2002 (E) Bibliography IS0 13953, Polyethylene (PE) pipes and fittings - Determination of the tensile strength and
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