1、DEUTSCHE NORM March 2000 I DIN sem i-fin ished products - Testing of welded joints of thermoplastics IEN 12814-2 Part 2: Tensile test English version of DIN EN 12814-2 ICs 25.160.40 Prfen von Schweiverbindungen aus thermoplastischen Kunststoffen -Teil 2: Zugversuch European Standard EN 12814-2 : 200
2、0 has the status of a DIN Standard. A comma is used as the decimal marker. National foreword This standard has been prepared by CEN/TC 249. The responsible German body involved in its preparation was the Normenausschuss Kunststoffe (Plastics Standards Committee), Technical Committee Fgen von Kunstst
3、offen. DIN EN IS0 527-1 is the standard corresponding to International Standard IS0 527-1 referred to in clause 2 of the EN. National Annex NA Standard referred to (and not included in Normative references) DIN EN IS0 527-1 Plastics - General principles for the determination of tensile properties (I
4、S0 527-1 : 1993 + Corr 1 : 1994) EN comprises 1 O pages. No pari of this standard may be reproduced without the prior permission of Y Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany, s the exclusive right of sale for German Standards (DIN-Normen). Ref. No. DIN E
5、N 12814-2 : 2000-0 English price group O7 Sales No. 1107 08.00 EUROPEAN STANDARD NORME EUFIOPEENNE EUROPISCHE NORM EN 12814-2 January 2000 ICs 25.160.40 English version Testing of welded joints of thermoplastics semi-finished products Part 2: Tensile test Essais des assemblages souds sur produits se
6、mi-finis en thermo- plastiques - Partie 2: Essai de traction Prfen von Schweiverbindungen aus thermoplastischen Kunststoffen - Teil 2: Zugversuch This European Standard was approved by CEN on 1999-1 1-27. CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the co
7、nditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national stand- ards may be obtained on application to the Central Secretariat or to any CEN member. The European Standards exist in th
8、ree 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 Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of A
9、ustria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr
10、 Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 2000. CEN - All rights of exploitation in any form and by any means reserved worldwide for CEN national members. Ref. No. EN 12814-2 : 2000 E Page 2 EN 1281 4-2 : 2000 Con te nt s Page Foreword . 2 1 Scope ,.,. 3 2 Normative referen
11、ces ,., 3 3 Symbols and designations , 4 4 Principle of the test 4 5 Sampling procedures . 5 6 Dimensions of test specimens 5 7 Cutting of test specimens 7 8 Mechanical testing ,.,.,. 7 9 Test equipment . 8 10 Determination of the short term tensile welding factor 8 11 Test report ., 8 Annex A (info
12、rmative) Test speed for some thermoplastics materials . 1 O Annex B (informative) Notched tensile test specimen . 1 O Foreword This European Standard has been prepared by Technical Committee CENTTC 249 “Plastics“, the secretariat of which is held by IBN. This European Standard shall be given the sta
13、tus of a national standard, either by publication of an identical text or by endorsement, at the latest by July 2000, and conflicting national standards shall be withdrawn at the latest by July 2000. According to the CENKENELEC Internal Regulations, the national standards organizations of the follow
14、ing countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Page 3 EN 1281 4-2 : 2000 1 Scope This stan
15、dard specifies the dimensions, the method of sampling, the preparation of the test specimens and the conditions for performing the tensile test in order to determine the short term tensile welding factor. A tensile test may be used in conjunction with other tests (e.g. bend, tensile creep, macro .)
16、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 materials filled or unfilled, but not reinforced, irrespective of the welding process used. 2 Normative references This Europ
17、ean Standard incorporates by dated or undated reference, provisions from other publications. 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 publication
18、s apply to this standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. IS0 527-1, Plastics - Determination of tensile properties - Part 7 : General principles IS0 5893: 1 993, Rubber and plastics test equipmen
19、t - Tensde, flexural and compression pes (constant rate of traverse) - Description ISO/DIS 1 3953:1996, Polyethylene (FE) pipes and Wings - Determination of the tensile strength of test specimens from a butt-fused joint EN 131 00-1, Non destructive testing of weldedjoints of thermoplastics semi-fini
20、shedproducts - Part 7: Wsuai examination Page 4 EN 1281 4-2 : 2000 3 Symbols and designations Symbols and designations are given in table 1. Table 1 - Symbols and designations I I Symbols and abbreviations Designations Units millimetre Minimum measured thickness of the test specimen within calibrate
21、d and parallel length Nominal thickness of the test piece Width of calibrated and parallel length of the test specimen a millimetre millimetre Width of shoulder of the test specimen millimetre I D, Nominal outside diameter of the tube millimetre The value of force of the unwelded test specimens take
22、n from the same test piece, used in the calculation of 4 Newton The short term tensile welding factor The value of force of the welded test specimen used in the calculation of 4 Newton I L Total length of the test specimen millimetre millimetre millimetre millimetre I 4 Minimum distance between the
23、clamping jaws Calibrated and parallel length of the test specimen I L, Maximum width of the weld bead of the test spec i m e n Lw Radius of shoulder of the test specimen rnillimetre N/mm2 The value of stress of the unwelded test specimens taken from the same test piece, used in the calculation of 4
24、The value of stress of the welded test specimens used in the calculation of 4 N/mm2 4 Principle of the test The test specimen is extended along its major longitudinal axis at constant speed until the test specimen fractures or yields. During this procedure the load sustained by the test specimen is
25、measured. Page 5 EN 1281 4-2 : 2000 D, or an b la 20 I D, 100 or flat assemblies : a, I 10 15 120 10 20 1,5 an 200 1 5 Sampling procedures The test specimens (welded and unwelded) shall be cut perpendicular to the welded joint at least eight hours after welding. Each test specimen shall be marked in
26、 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. L 2 120 2 170 2 170 2 300 2 400 6 Dimensions of test specimens For tubes of nominal outside diameter D, less than 20 mm the whole tube s
27、hall be tested and the minimum distance between the clamps shall be 200 mm. The dimensions of test specimens are given in table 2 and table 3. Table 2 - Dimension of type 1 test specimens (Dimensions in millimetres) Page 6 EN 1281 4-2 : 2000 10 30 1,5 a, I- L I 20 40 80 Key 1 Weld Figure 1 - Type 1
28、test specimen for flat and tubular assemblies Table 3 - Dimension of type 2 test specimens (Dimensions in miliimetres) Dnr a, D, 2 100 or flat assemblies : a, 5 10 1 O 20 b+ 10 D,l an + - 10 b+ 10 D, 10 an + - 80 120 120 120 200 L 2 120 2 170 2 170 2 300 2 400 r 60 60 60 60 60 Page 7 EN 1281 4-2 : 2
29、000 Key 1 Weld Figure 2 - Type 2 test specimen for flat and tubular assemblies Where the beads are left intact in service, they shall be left intact for the test. Where the beads are removed in service, they shall be removed prior to testing. The tolerance for bshall be f 1 mm and the minimum value
30、shall be 6 mm. The tolerance for Lo shall be f 2 mm. The variation of b over the length Lo shall not exceed k 2 % of the average value of 6. The forms of the test specimens are given in Fig.1 and Fig.2. 7 Cutting of test specimens The tensile test specimens shall be cut with parallel sides as shown
31、in figures 1 and 2. During cutting, heating of the test specimen shall be minimised. Cutting of the test specimen shall not produce notches. After cutting, a visual examination of the weld, according to EN 13100-1, shall be carried out and recorded. 8 Mechanical testing Test specimen shall be condit
32、ioned to a temperature of (23 12) “C and unless otherwise specified, the test shall be carried out at a room temperature of (23 +2/-5) OC. The test speeds and tolerances shall be in accordance with IS0 527-1 For all materials the test speed shall be chosen to ensure that the test is terminated io ab
33、out one minute. Examples of test speeds for some relevant thermoplastics materials are listed in annex A. Page 8 EN 1281 4-2 : 2000 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 test
34、ed at the same speed with the same distance between the clamps. If all welded test specimens fracture or yield within the calibrated length, but outside of the weld (L), the unwelded test specimen do not need to be tested, and the short term tensile welding factor shall be taken as 1. In order to ac
35、hieve a failure in the weld and thus a better differentiation of the weld quality, the test specimens should be as described in ISO/DIS 13953:1996 or in annex B. 9 Test equipment The test equipment shall conform to the requirements given in IS0 5893:1993. The crosshead displacement shall be continuo
36、us, uniform and in accordance with clause 8. 10 Determination of the short term tensile welding factor In order to determine the short term tensile welding factor, welded and unwelded test specimens shall be tested. The short term tensile welding factor is determined from the arithmetic mean values
37、of the fracture stresses of the welded test specimens (a.,) and the unwelded test specimens (a), where : FW ab fTw = - F, ab Or = - If the test specimens yield prior to fracture, the yield stress shall be used instead of fracture stress. OW Short term tensile welding factor f, = = Or - _ If Dw)Or, t
38、hen f, = 1 At least ten test specimens (five welded and five unwelded) shall be used in the evaluation of the short term tensile welding factor. No test specimen shall be disregarded unless failure occurs in the clamps. In the case of the type 1 test specimens, failure within a distance of 1 times s
39、pecimen width (6) from the clamps shall be regarded as failure in the clamp. If type 1 test specimens consistently fail in the clamps then type 2 test specimens shall be used. In the case of type 2 test specimens, failure outside of the calibrated length (Lo) shall be regarded as failure in the clam
40、p. In the case of the whole tube tensile test, failure within a distance of 1,5 0, from the clamps shall be regarded as failure in the clamp. 11 Test report The test report shall refer to this standard and it shall include at least the following information : a) description and identification of the
41、 test piece and test specimens ; Page 9 EN 1281 4-2 : 2000 b) appearance of the test pieces before the test : 1) visual examination of weld ; 2) beads removed or not ; c) weld type ; d) maximum width of the weld bead, if applicable (L) ; e) nominal outside diameter of the tube, if applicable (O,) ;
42、f) number of test specimens ; g) type of test specimen ; h) appearance of all surfaces of the test specimens, (e.g. flaws, scratches, visual imperfections) ; i) thickness of test specimen (a) ; j) width of calibrated and parallel length (b) ; k) calibrated and parallel length (b) ; i) total length o
43、f the test specimen (L) ; m) width of the test specimen shoulder, if applicable (4); n) radius of shoulder (r) ; o) distance between the clamping jaws ; p) temperature of the test specimen (OC) ; q) room temperature during the test (“C) ; r) the crosshead speed (mm/min) ; s) visual examination of th
44、e ruptured surface, if applicable ; t) individual values of measured forces (6 and 15 ); u) individual values of calculated stresses (aw and a,) ; v) values of calculated average stresses (OW and Or) ; - - w) calculated value of the short term tensile welding factor (4) ; x) identification of the la
45、boratory ; y) date of the test ; z) name and signature of the responsible person for the test report. Page 10 EN 1281 4-2 : 2000 Material PVC PVDF, PP-H, PP-B PE, PP-R Annex A Speed mm/min 10 20 50 (informative) Test speed for some thermoplastics materials The test speeds used for some thermoplastic
46、s materials are given in table A.l : Annex B (informative) Notched tensile test specimen If a short term tensile welding factor of 1,0 is achieved then a notched tensile test can be used in order to optimise welding parameters, etc. However, the values determined using the notched tensile test shall not be correlated with the values of 15 determined using type 1 or type 2 test specimens. The test specimen used for the notched tensile test is described in figure B.l Dimensions in millimetres c I60 1 Key 1 Weld line Figure B.l - Notched tensile test specimen
