EN 12384-1999 en Copper and Copper Alloys - Determination of Spring Bending Limit on Strip《铜和铜合金 带材弹性弯曲极限值的测定》.pdf

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1、STDIBSI BS EN L2384-ENGL 1999 Lb24bb9 0854977 3TT BRITISH STANDARD Copper and copper alloys - Determination of spring bending limit on strip The European Standard EN 12384:1999 has the status of a British Standard ICs 77.160.30 BS EN 12384:1999 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED B

2、Y COPYRIGHT LAW STDOBSI BS EN L2384-ENGL 1999 = 1624669 0854978 236 BS EN 123841999 10970 chrmhnNo. 1 National foreword July 2000 Amends equation (1). This British Standard, having been prepared under the direction of the Engineering Sector Conunittee, was published under the authority of the Sandar

3、ds Committee and comes int effect on 15 July 1999 O BSI 07-2000 This British Standard is the English language version of EN 12384:1999. The UK participation in its preparation was entrusted by Technical Committee “FBI, Copper and copper alloys, to Subcommittee NFE/34/1, Wrought and unwrought copper

4、and copper alloys, which has the responsibility to: - aid enquirers to understand the text; - present to the responsible European committee any enquiries on the - monitor related international and European developments and promulgate interpretation, or proposals for change, and keep the UK interests

5、 informed; them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretaty Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under

6、 the section entitled “Internaiona,i Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A BriW Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct applic

7、ation. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 9 and a back cover. The BSI coyright notice displayed in this document indicates when the

8、document was last issued. Amendments issued since publication ID* POmments Amd. No. ISBN O 680 32069 3 STD-BSI BS EN 12384-ENGL L77 I 1624667 0854979 172 = EUROPEAN STANDARD EN 12384 NORME EUR0PEE”E EXJROP is the is the thickness of the ship, in millimetres; 2 Normative references This European Stan

9、dard incorporates, by dated or undated reference, provisions from other publications. These nodve 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 th

10、is European Standard only when incorporated in it by amendment or revision. For undated references, the Wt edition of the publication referred to applies. EN 1654, Copper and copper a)3 4xwxs where: E F 1 s t is the modulus of easticity (Youngs modulus), in newtons per square metre; is the force, in

11、 newtons; is the distance between the supports, in millimetres; is the deflection, in millimetres; is the thickness of the strip, in millUnelxes; and relieved of load, shows a permanent deflection It is calculated on the basis of equation (3): of5opn. GXEXtXsic 1 41 + 17 (S*)I =m= 2 where: am is the

12、 spring bending limit, in newtons per square miiiimetre; E is the modulus of elasticity as defined in 3.1; s* is the forced deflection which, given the distance between supports specified in this standard on the basis of equation (2), results in a permanent deflection of 50 pn. NOTE Equation (3) is

13、an approximation. In accordance with W. Kutschera i, at the extreme low end of the thickness range within the scope of this standard, the deviation from the real value of spring bending limit would be 1,2 % max 4 General principle The test takes the form of a bend test with the test piece supported

14、on two supports near the ends of the test piece, and a load applied midway between the supports. Elastic deflection is measured to determine the modulus of elasticity and permanent deflection is measured to determine the spring bendmg limit. 5 Details of the test For technical and metrologica reason

15、s, the given range of thicknesses is divided for test purposes into range A (see Table 1) for strip with thicknesses from 0,15 mm up to and includmg 1,O mm, and range B (see Mle 1) for strip with thicknesses from 0,05 mm up to and Where the two ranges overlap, i.e. for thicknesses from 0,15 mm up to

16、 and including 0,20 mm, the resuits of testing are the same. Unless explicitly referring to them separately, the requirements of clauses 6 to 9 apply to both ranges. including 0,20 mm. w is the width of the test piece, in millimetres. 6 Apparatus 3.2 - .- 6.1 General The test Set-up (see Figure 1) s

17、hail consist of two supports, which are able to slide, and a deflectometer, which comprises a weight for applying load and a spring bending limit to flexural stress without a given small pastic deformation being exceeded. It is defined as the outer deflection The deflectometer act on the fibre stres

18、s in a test piece of thickness t which, when resng on supports with a distance between them of value up to which the my be subjected at its centre between the supports. NOTE Equation (3) is applicable to deflections up to 1=1OO$iX (2) S* = 0,46 X 1. O BSI 07-2000 STD-BSI BS EN L2384-ENGL 1999 I Lb24

19、bb9 0854982 767 Thickness Width 1,0 to 0,30 10 c 0,30 to 0,15 0,zo to 0,lO c OJO to 405 Page 4 EN 12384A999 Length 150 70 60 50 3 u 4 1 loading nose 2 test piece 3 support with straight, horizontal edge 4 support with curved edge Figure 1 - Test Set-up (schematic) 6.2 Supports The supports shall be

20、two steel blocks, 10,2 mm wide and of rightangled triangular section. Sharp supporting edges shail be formed by a60“ angle of the triangular section, with edge radius less than 0,03 mm. One of the supporting edges shall be straight and the other one convex with a radius of curvature of 15 mm perpend

21、icular to the right angle tsiangular section. The distance between the supports shall be continuously adjustable, symmetricaly to the axis of loading, to within0,l mm in a range from 15mm up to and including 100 mm. 6.3 Loading nose The loading nose used for applying the load and producing the defle

22、ction shall be in contact with the test piece at two points (see Figure 2). The two points at which the load is applied shall lie to the left and right of the longitudinal axis of the test piece. The centre of the test piece shall be left nee to permit measurement of the deflection. 1 2 i 1 test pie

23、ce 2 loading nose Figure 2 - Loading nose (schematic) 6.4 Loading weight The loading weight required for determining the modulus of elasticity shall have a mass of 100,O g f 1,0 g for range A (see Table 1) test pieces and 10,O g f OJO g for range B (see Table 1) test pieces. 6.6 Permanent deflection

24、 The permanent deflection required for calculating the spring bending limit shall be produced by progressive forced deflection and relief. Increments of 0,667 mm have been found to be expedient. 7 Wst pieces 7.1 General Test pieces corresponding to the dimensions given in Table 1 shall be cut from s

25、amples of strip. Test pieces shall be taken nom the sample in such a way that the characteristics of the material ase not affected Scissors shall not be used. The test pieces shail be cut or milled from the sample with the aid of a cutting tool, the edges being as free from buns as possible and the

26、direction of cut being parallel to that of rolling unless another alignment is requested by the purchaser. Table 1 - Dimensions of test pieces -ge A B The longitudinal edges shall be deburred, care being taken to avoid deforming the test pieces or damaging their surfaces. On no account shall test pi

27、eces be straightened or bent, as this alters their spring Characteristics. 7.2 Number A total of four test pieces is required for determining the moduius of elasticity and the spring bending Mt. Two test pieces per surface side shall be measured hm each sample. 7.3 Marking The sides of the test piec

28、es shall be unambiguously marked as top or bottom of the strip. Normally the convex side of strips curved lengthwise is indicated as the top and the concave side as the bottom Q BSI 07-2000 STD.BS1 BS EN 12384-ENGL 1999 E Lb24bb9 0854983 bT3 Page 5 EN 123a1999 7.4 Determination of the thickness Sice

29、 the thickness of the test piece enters the calculation of the modulus of elasticity, raised to the third power, it shall be measured with great care. The thickness of each test piece sha be determined in the middie, to the nearest 1 pn. 8 Procedure 8.1 General The elastic deflection, when the modul

30、us of eiasticity is being measured, and the permanent deflection, in the case of spring benclhg limit measurements, shall be measured midway between the supports. The deflection shall be measured when the test piece is relieved of load. The limits of error shall not exceed a maximumof2pn. The modulu

31、s of elasticity may be determined more than once for the same test piece. Test pieces which have already been tested in order to determine the modulus of elasticity may be used to determine the spring bending limit, but this may be determined oniy once per test piece as the eiastic and plastic c-hti

32、cs of the test pieces are changed as a result of the test. The test shall be carried out at a temperature between 18 OC and 28 OC. 8.2 Determination of the modulus of elasticity To determine the modulus of elasticity, the distance between the supports shall be: - for range A test pieces: 100 X t; -

33、for range B test pieces: 215,4 X t. The modulus of elasticity of test pieces less than 0,07 mm thick shall not be determined, as the uncertainty of measurement increases inversely to the span between the supports. In such cases, the spring bending limit may be calculated using the guideline value sp

34、ecified for the modulus of elasticity. The following applies to test pieces of both ranges. The test piece shail be placed symmetrically on the supports, this position being taken to be the zero position for the deflection measurement. The deflection s produced by the loading weight shall be measure

35、d and the result used to calculate the modulus of elasticity in accordance with equation (1). The modulus of elasticity of four test pieces per sample shail be determined, two being tested top side up, and two bottom side up. For calculating the spring bending limit, either the mean or the respectiv

36、e single value of the modulus of elasticity may be used 8.3 Determination of spring bending limit 8.3.1 General The spring bending limit shal be determined by one of the methods in 8.3.2 or 8.3.4, or indirectly from a knowledge of the value of modulus of elasticity, as described in 8.3.3. The spring

37、 bending limit of four test pieces per sample sha be determined, two being tested top side up, and two bottom side up. 8.3.2 Determination by measurement of permanent is the permanent deflection of 50 pq is the permanent deflection, in micrometres, under the penultimate load, is the permanent deflec

38、tion, in micrometres, under the final load. 8.3.3 Determination using modulus of elasticity Table Al is intended to facilitate the determinaiion of the spring bending limit am. The tabulated value of am* derived from equation (5) was obtained by introducing a value of Eo = 100 O00 N/mm2 for the modu

39、lus of elasticity in equation (3). 6 X t X s* X 100O00 E2 41 + 17 (S*/2)2,4 am* = The value of -* obtained from the table shall then be multiplied by E Eo E being determined as specified in 8.2, in order to obtain the spring bending limit am. O BSI 07-2000 Page 6 EN 123w1999 STDOBSI BS EN L2384-ENGL

40、 1999 E 1b24bb9 0854984 53T 8.3.4 Determination for materucls having a spring bending limit greater than 700 Nhm2 In cases of materials having a very high spring bending limit, the permanent deflection of 50 pm specified here, owing to the type of equipment used, may not have been achieved even aRer

41、 all load leveis have been applied. In such cases, the distance between supports may be adjusted to: where: 1 = 100 $53 (6) 1 k t is the distance between the supports, in miliimeres; is a constant, 0,4 mrq is the thickness of the strip, in millimetres. and evaluaton made on the basis of a permanent

42、deflection of 25 pm. The spr bending limit shall be calculated in accordance with eqdon (3), I being substituted for 1. If this method is applied, it shail be noted in the test report. 10 Wst report The test report shall include the following informatiom a) reference to this European standard (EN 12

43、384); b) thickness of the test piece, to the nearest 1 pxq c) aiignment of the test piece to the strip, if requested by the purchaser to be other than pdel to the direction of roiling; d) modulus of elasticity of four test pieces together with the arithmetic mean of these values, ail of them express

44、ed to the nearest 1 kNh2; e) spring bening limit, separately for each side of the test piece, together with the arithmetic mean of these values, to the nearest 10 Nmim2; f) position of the test piece during the test, this being identified wherever possible by reference to the natural curvature of th

45、e test piece, i.e. “convex cw upwards” or “convex curvature downwards”. 9 Precision Experience has shown that the mean values obtained for range A material from measurements, made according to the methods specified here, on the same strip by different laboratories wil scatter by approximately %I % f

46、or the modulus of eiascity, and % % for the spring bending limit. O BSI 07-2000 STD-BSI BS EN 12384-ENGL 1999 L624bb9 0854985 476 Page 7 EN 123M1999 W o a a .5 I 1 N- 1 a - u2 - 8 mm 2121 yj o 0- olli -! 1 O BSI 07-2000 - STD-BSI BS EN 12384-ENGL 1999 I1624669 0854986 302 Page 8 EN 12384:1999 - 3 An

47、nex B (informative) Bibliography In the preparation of this European Standard, use was mae of a number of documents for reference purposes. These informative references are cited at the appropriate places in the text and the publications are iisted hereafter. i W. Kutschera, Siemens Forschungs- und

48、Entwicklungsbericht, Bd. 7 (1978) Ni. 4, Springer Verlag 1978. Page 9 EN 12384:1999 O BSI 07-2000 BS EN 123W.1999 BSI 389 Chiswi High Road London w4 4AL STD-BSI BS EN L238Y-ENGL 3999 W 3b24bb9 0854988 L85 BSI - British Standards Institution BSI is the independent national body responsible for prepar

49、ing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British %dards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard wodd inform the Secretary of the technical committee responsible, the ident