EN ISO 14129-1997 en Fibre-Reinforced Plastic Composites - Determination of the in-Plane Shear Stress Shear Strain Response Including the in-Plane Shear Modulus and Strength by the.pdf

1、STD-BSI ES EN IS0 14129-ENGL 1998 D 1624669 Ob93505 467 BRITISH STANDARD Fibre-reinforced plas tic composites - Determination of the in-plane shear stresdshear strain response, including the in-plane shear modulus and strength by the k 45“ tension test method The European Standard EN IS0 14129 : 199

2、7 has the status of a British standard ICs 83.120 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN IS0 14129 : 1998 STDmBSI BS EN IS0 L4L27-ENGL 1978 Lb24667 Ob73506 313 BS EN IS0 14129 : 1998 direction of the Sector Board for Materiais and Chemicals, was published under

3、the authority of the Standards Board and comes into effect on 15 Apd 1998 hd. No. National foreword Da Text affected This British Standard is the English language version of EN IS0 14129 : 1997. It is identical with IS0 14129 : 1997. The UK participation in its preparation was entrusted to Technical

4、 Committee PW42, Fbre reinforced thermosetting plastics and prepregs, which has the responsibility to: - aid enquirers to understand the text; - present to the responsible internationalEuropean committee any enquiries on the interpretation, or proposals for change, and keep the UK inter - monitor re

5、lated intedonal and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to ils secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC standards normaiiy include an annex which lists normative r

6、eferences to intedonai publications with their corresponding European publications. The British standards which implement intedonai or European publications may be found in the BSI Standards Cataiogue under the section entitled international Standards Correspondence Index, or by using the %in 83.140

7、.20 Descriptom: see IS0 dowment English version Fibre-reinforced plastic composites - Determination of the in- plane shear stresdshear strain response, including the in-plane shear modulus and strength, by the +/- 45 tension test method (IS0 14129:1997) Compodtes plastiques renforc69 de fibres - Det

8、emilnation de la rpanse cmtrai- en cisaiflement pian, module a ) divided by the corresponding shear strain difference (y,; = 0,005 - yli = 0,001) see 10.3, equation (3). It is expressed in megapascals (MPa). 4.5 specimen coordinate axes: For the specimen shown in figure 1, the direction parallel to

9、the specimen longitudinal axis is the “x“ direction and the direction perpendicular to it is the “y“ direction. The fibres are oriented at f 45“ to these directions. The coordinate axes for a unidirectional reinforced composite material plate element are shown in figure 2. 5 Apparatus 5.1 Test machi

10、ne 5.1.1 General The machine shall conform to IS0 5893 as appropriate to the requirements given in 5.1.2 and 5.1.3. 5.1.2 Speed of testing The speed of testing v shall be kept constant in accordance with IS0 5893. 2 Dimensions in millimetres I- L = 250 Key 1 Strain gauges 2 Tab 8 Fibre angle (= 45“)

11、 Specimen thickness h = 2 mm Figure 1 - Fibre-reinforced plastic composite specimen showing fibre axes * * IB Figure 2 - Unidirectional reinforced composite plate element showing symmetry axes 5.1.3 Load indicator The load indicator shall be such that the error in the indicated force is less than +_

12、 1 O/O of the full-scale reading (see IS0 5893). 5.2 Strain measurement The procedure requires the strain to be measured both parallel and perpendicular to the specimen axis. Strain gauges, applied as in figure 2, or extensometers shall be accurate to I1 % of the full scale. The gauges, surface prep

13、aration and bonding agents shall be chosen to give adequate performance on the subject materials, and suitable strain-recording equipment shall be employed. 5.3 Micrometer, or equivalent, capable of reading to 0,Ol mm or less, and suitable for measuring the thickness h and width b of the test specim

14、en. The micrometer shall have contact faces appropriate to the surface being measured (Le. flat faces for flat, polished surfaces and hemispherical faces for irregular surfaces). 3 6 Test specimens 6.1 Shape and dimensions The specimen shall have a width of 25 mm k 0,5 mm and a length of 250 mm. Unl

15、ess otherwise specified, the thickness shall be 2 mm k 0,2 mm. The longitudinal edges of individual specimens shall be parallel to within 0,2 mm. The dimensions of the specimen are shown in figure 1. For materials made with layers thicker than 0,125 mm, the laminate shall consist of 16 layers. 6.2 P

16、reparation of specimens 6.2.1 General A panel shall be prepared in accordance with IS0 1268 or another specified/agreed procedure with the required balanced and symmetrical f 45“ fibre orientation. Cut individual specimens or groups of specimens to the required size. Some parameters for machining ar

17、e specified in IS0 281 8. Further guidance on cutting specimens is given in annex A. 6.2.2 End tab materiel Providing failure does not occur at or within the grip, unbonded tabs or no tabs may be used. If tabs are used, they shall be constructed from a cross-ply or fabric laminate made of glass-fibr

18、ehesin, or from the material under test, with the fibre axes of the fabric set at f45“ to the specimen axis. The tab material thickness shall be between 0,5 mm and 2 mm, with a tab angle of 90“ (.e. not tapered). 6.2.3 Application of end tabs Bonded end tabs, if used, shall be applied to the specime

19、n with a high-elongation adhesive, as shown in annex A. NOTE - A similar procedure can be used for individual specimens or for a group of specimens. 6.2.4 Machining the specimens The test specimens shall be cut with their axis at 45“ to the fibre directions. 6.3 Checking the test specimens The speci

20、mens shall be flat and free of twist. The surfaces and edges shall be free from scratches, pits, sink marks and flashes. The specimens shall be checked for conformity to these requirements by visual observation against straight-edges, squares and flat plates, and by measuring with micrometer callipe

21、rs. Specimens showing measurable or obsetvable departure from one or more of these requirements shall be rejected or machined to the required size and shape before testing. 7 Number of test specimens 7.1 At least five test specimens shall be tested. The number of measurements may be more than five i

22、f greater precision of the mean value is required. It is possible to evaluate this by means of the confidence interval (95 % probability, see IS0 2602). 4 7.2 The results from test specimens that rupture at or inside the grips or end tabs shall be discarded and new specimens tested in their place. 8

23、 Conditioning Where applicable, condition the test specimens as specified in the standard for the material under test. In the absence of such information, select the most appropriate conditions from IS0 291, unless agreed otherwise by the interested parties. 9 Procedure 9.1 Test atmosphere Where app

24、licable, test the specimen as specified in the standard for the material under test. In the absence of such information, select the most appropriate conditions from IS0 291, unless agreed otherwise by the interested parties (e.g. for testing at elevated or reduced temperatures). 9.2 Measurement of s

25、pecimen dimensions Measure, at the mid-point of each test specimen, the width of the specimen to the nearest 0,l mm and the thickness to the nearest 0,02 mm. II _. - _. - 9.3 Specimen strain measurement - _. Apply extensometers or strain gauges along and perpendicular to the specimen axis (see figur

26、e 2) to measure the * * longitudinal (EJ and transverse (E,) strains, respectively. VI 9.4 Speed of testing Where applicable, set the speed of testing as given in the standard for the material being tested. In the absence of this information, the speed of testing v shall be 2 mm/min. 9.5 Data collec

27、tion Monitor the load and both of the strain values throughout the test. 9.6 Test termination Terminate the test at y12 = 0,05 if failure has not occurred. 9.7 Maximum load Record the failure load or the load at y12 = 0,05. 9.8 Mode of failure Check and record the mode of failure (see also 7.2). STD

28、mBSI BS EN IS0 LYL27-ENGL 1778 Lb2Ybb7 06935L 035 m EN IS0 14129 : 1997 10 Calculation and expression of results 10.1 Calculate the in-plane shear stress q2, expressed in megapascals, using the following equation: F T12 =- 2bh where F b h is the instantaneous load, in newtons; is the width, in milli

29、metres, of the test specimen; is the thickness, in millimetres, of the test specimen. 10.2 Calculate the in-plane shear strength q2M, expressed in megapascals, using the following equation: where F, is the load, in newtons, at failure, or at y12 = 0,05 if the test was terminated prior to failure. 10

30、.3 Calculate the shear strain yl2 using the following equation: Y12 = Ex - is the strain in the direction perpendicular to the specimen axis. * . . (1) . . . (2) . . . (3) 10.4 Calculate the in-plane shear (chord) modulus G12, expressed in megapascals, using the following equation (see figure 3): .

31、. . (4) where q2 is the shear stress at a shear strain y12 = 0,001; q2” is the shear stress at a shear strain y12” = 0,005. 10.5 Calculate the arithmetic mean of the individual determinations and, if required, the standard deviation and the 95 Oh confidence interval of the mean value using the proce

32、dure given in IS0 2602. 10.6 Calculate the stresses and the modulus to three significant figures. 6 STDmBSI BS EN IS0 L4129-ENGL 1998 = 1624669 0693519 T71 = EN IS0 14129 : 1997 I 112 = 0,001 o 12“ = 0,005 Shear strain, ,2 Figure 3 - Shear stresdshear strain diagram 11 Precision The precision of thi

33、s test method is not known because interlaboratory data are not available. When interlaboratory data are obtained, a precision statement will be added at the following revision. This method may not be suitable for use in specifications or in the case of disputed results as long as these data are not

34、 available. 12 Test report The test report shall include the following information: a) a reference to this International Standard (.e. IS0 14129); * * (o b) all details necessary for complete identification of the material tested, including type, source, manufacturers code number, form and previous

35、history, where these are known; c) the accuracy grading of the test machine (see IS0 5893); d) the method of preparing the test specimens; e) the dimensions of the test specimens; f) the number of specimens tested; g) the test conditions and the conditioning procedures, if applicable; h) the type of

36、 strain measurement used; i) the individual determinations, including shear stresskhear strain diagrams, if required; i) the mean values of the individual determinations; k) the standard deviations and the 95 % confidence intervals of the mean values, if required; I) the type(s) of failure obtained;

37、 m) a statement as to whether any test specimens were rejected and, if so, the reasons; n) any operation not specified in this International Standard, as well as any incident likely to have affected the results; o) the date of the test. 7 Annex A (normative) Specimen preparation A.l Machining the sp

38、ecimens In all cases, take the following precautions: - Avoid working under conditions that would create a large build-up of heat in the test specimen; it is recommended that a coolant is used. If a liquid coolant is used, dry the test specimens immediately after machining. - Check that all cut surf

39、aces of the test specimen are free from machining defects. A.2 Attachment of end tabs A recommended method is as follows: Cut out from the material under test a sheet having the length of the intended test specimens and of a width suitable for the number of specimens required. To form the end tabs,

40、cut rectangular strips of the required width and length. Attach the strips as follows (see figure A.1): If required, rub with fine abrasive paper or lightly blast with suitable grit all surfaces to which adhesive wiil be applied. Remove any dust and clean these surfaces with a suitable solvent. For

41、bonding, use a high-elongation adhesive system, strictly following the manufacturers instructions. NOTE - It is recommended that a film adhesive with a thin carrier be used. The adhesive should preferably have a shear strength greater than 30 MPa. it is desirable that the adhesive used be flexible i

42、n nature with an elongation at break greater than that of the material under test. Keep the assembled parts at the pressure and temperature recommended by the adhesive manufacturer for the time recommended by the manufacturer. Superpose the strips at the ends, parallel with each other and normal to

43、the length direction of the specimens. The sheets together with the strips constituting the end tabs are the test blanks ready for cutting into test specimens. 8 STD=BSI BS EN IS0 14129-ENGL 1998 1b24bb9 Ob93521 b2T EN IS0 14129 : 1997 Figure A.l - Tabbed panel for specimen preparation - STD-BSI ES

44、EN IS0 L4127-ENGL L778 I1624667 0673522 566 EN IS0 14129 : 1997 Annex ZA (normative) Normative references to international publications with their relevant European publications This European Standard incorporates by dated or undated reference, provisions from other publications. These normative ref

45、erences 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 revision. For undated references th

46、e latest edition of the publication referred to applies. Publication Year - EN - Year IS0 291 1997 Plastics - Standard atmospheres for conditioning and testing IS0 281 8 1994 Plastics - Preparation of test specimens by machining EN IS0 291 1997 EN IS0 2818 1996 BS EN IS0 14129 : 1998 BSI 389 Chiswic

47、k High Road London w4 4AL STD-BSI BS EN IS0 14129-ENGL 1998 1b24bb9 0693523 4T2 BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by R

48、oyal Charter. Contract requirements A British Standard does not purport to include ail the necessary provisions of a conhct. Users of British Stan- are responsible for their correct application. Revisions British Standards are updated by amendment or revision. Users of British Standards should make

49、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 would inform the Secretary of the responsible technical committee, the identity of which can be found on the inside front cover. Tel: O181 996 9ooo; Fax: 0181 996 7400. BSI offers members an individual updating service cailed PLUS which ensures that subscribers automatically receive the latest editio