1、BRITISH STANDARD CONFIRMED OCTOBER1983 BS2782-10: Method 1005: 1977 EN63 Methods of testing Plastics Part10: Glass reinforced plastics Method1005: Determination of flexural properties. Three point method IMPORTANT NOTE. Before reading this method it is essential to read the foreword, general introdu
2、ction and instructions to BS 2782. UDC 678.5/.8.046.364:620.174BS2782-10:Method 1005:19977 This British Standard was published under the authority ofthe Executive Board on 31 August 1977 BSI 03-1999 The following BSI references relate to the work on this standard: Committee reference PLC/- Draft for
3、 comment74/54599 DC ISBN 0 580 09755 2 Cooperating organizations The European Committee for Standardization, under whose direction this European Standard was prepared, comprises the national standards organizations of the following Western European countries: A British Standard does not purport to i
4、nclude all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. 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, pa
5、ges i and ii, theENtitle page, pages2 to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Austria Oesterreichisches Normungsinstitut Belgium
6、Institut Belge de Normalisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliitto, r.y. France Association Franaise de Normalisation Germany DIN Deutsches Institut fr Normung Ireland Institute for Industrial Research and Standards Italy Ente Nazionale Italiano di Unificazione N
7、etherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Repartio de Normalizao Spain Instituto Nacional de Racionalizacin y Normalizacin Sweden Sveriges Standardiseringskommission Switzerland Association Suisse de Normalisation United Kingdom British Standards Ins
8、titution Amendments issued since publication Amd. No. Date of issue CommentsBS2782-10:Method 1005:1977 BSI 03-1999 i Contents Page Cooperating organizations Inside front cover Foreword 2 National Appendix A Origins of work and relationship with other British Standards Inside back coverii blankEUROPE
9、AN STANDARD NORME EUROPENNE EUROPISCHE NORM EN63 Edition 1 March 1977 UDC678.5/8:677.521:620.174 Key words: Plastics, glass reinforced plastics,tests, mechanical tests, flexing tests, flexural stress, modulus of elasticity, testequipment, test specimens, testing conditions English version Glass rein
10、forced plastics. Determination of flexural properties. Three point method Matires plastiques renforces au verre textile. Dtermination des caractristiques de flexion. Mthode des trois pannes Glasfaserverstrkte Kunststoffe. Biegeversuch. Dreipunkt-Verfahren This European Standard was accepted by CEN o
11、n1977-03-31. The CEN members are bound to adhere to the CEN Internal Regulations which specify under which conditions this European Standard has to be given, without any alteration, the status of a national standard. Up-to-date lists and bibliographical references concerning such national standards
12、may be obtained on application to the CEN Central Secretariat or to any CEN member. This European Standard exists in three versions (English, French, German), recognized by CEN as equivalent. National versions in other languages rank as translations and in case of doubt shall be checked against one
13、of the recognized versions. CEN members are the national standards organizations of Austria, Belgium, Denmark, Finland, France, Germany, Ireland, Italy, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisa
14、tion Europisches Komitee fr Normung Central Secretariat: Rue de Brderode,2, B-1000 Brussels Copyright reserved to all CEN membersEN63:1977 BSI 03-1999 2 Brief history This European Standard was drawn up by CEN Technical Committee66 “Testing of glass fibre reinforced plastics”, the Secretariat of whi
15、ch is held by AFNOR. The contents of this standard were submitted for ballot to the members of CEN in November1974 in view of its adoption as a European Standard. This European Standard was adopted by CEN as a result of its acceptance by the following member countries: Belgium, Denmark, France, Germ
16、any, Italy, Portugal, Spain, Sweden, United Kingdom. Foreword This standard is technically equivalent to Recommendation ISO178-1975, “Determination of flexural properties of rigid plastics materials” insomuch as it deals with glass reinforced plastics. Contents Page Brief history 2 Foreword 2 1 Scop
17、e 3 2 Reference 3 3 Definitions 3 4 Apparatus 3 5 Test specimen 3 6 Procedure 4 7 Calculation and expression of results 5 8 Test report 6 Figure 1 Orientation of test pieces 6 Figure 2 Detail of testing machine 6EN63:1977 BSI 03-1999 3 1 Scope This European Standard describes a method for the determ
18、ination of flexural properties of textile glass reinforced plastics in the form of rectangular bars of standard or non-standard dimensions, moulded directly or cut from sheets or other moulded shapes. It only applies to simple, freely supported beams, loaded at mid-span (three point loading test) 1)
19、 . The following properties may be determined using the method described: 1.1 The flexural stress and the deflection at break of materials that break before, or at, the conventional deflection. 1.2 The flexural stress at the conventional deflection of materials that do not break before, or at, the c
20、onventional deflection. 1.3 The flexural stress at the maximum force for materials that show maximum force before, or at, the conventional deflection. 1.4 The flexural stress at break or at maximum force, when the conventional deflection is exceeded, if so required by the material specification. NOT
21、EIf the conventional deflection is exceeded it may not be possible to make direct comparison of results of flexural stress on test specimens of different thicknesses. 1.5 Optional: the apparent modulus of elasticity in flexure (modulus of elasticity determined by flexure test). NOTEThe modulus of el
22、asticity in flexure is to be considered only as an approximate value of Youngs modulus of elasticity. 2 Reference EN62Glass reinforced plastics Standard atmospheres for conditioning and testing 3 Definitions For the purposes of this European Standard the following definitions apply. 3.1 deflection t
23、he distance over which the top or bottom surface of the test specimen at mid-span has deviated during flexure from its original position 3.2 flexural stress at a given time of the test the maximum outer fibre stress of the material in the section of the test specimen mid-span. It is calculated accor
24、ding to the relationship (4) given in7.1 3.3 flexural stress at the conventional deflection the flexural stress at a deflection equal to1.5times the thickness of the test specimen 3.4 flexural stress at maximum force The flexural stress developed when the force reaches the first maximum 3.5 flexural
25、 stress at rupture The flexural stress developed at the moment of rupture 4 Apparatus Standard testing machine (shown schematically in Figure 2) properly constructed and calibrated, which can be operated at an approximately constant rate, V, of relative movement of the loading nose and the supports,
26、 and in which the error for indicated forces does not exceed 1% and for indicated deflections does not exceed 2%. The supports and loading nose shall be at least as wide as the test specimen and shall be parallel to each other. The radius r 1of the loading nose and the radius r 2of the supports shou
27、ld be as follows: The distance between the supports, L, should be adjustable. 5 Test specimen If the test piece cannot be taken from a finished product, a sheet, from which the test specimens are taken, may be prepared in a pre-agreed manner approximating to the manufacturing process. 1) It may be u
28、seful to provide an optional method in which the force is applied by two loading noses (four point loading test). A four point loading test allows measurement of a pure flexural force in the middle part of the test specimen. The compressive stresses due to the two central noses are much lower in com
29、parison with the stresses induced under the one central loading nose of the three point test. (This European Standard does not cover the four point loading test.) r 1 : (5 0.1)mm r 2 : (2 0.2)mmEN63:1977 4 BSI 03-1999 5.1 Dimensions of test specimens. The minimum length l should be20h, where h is th
30、e thickness. The width b should be also a function of thickness, as shown in the following table. When very coarse textile glass fibre roving is used as the reinforcement, it may be necessary to increase the width of the test specimens. 5.2 Anisotropic materials 5.2.1 In the case of anisotropic mate
31、rials, the test specimens should be chosen so that the flexural stress in the test procedure will be applied in the same direction as that which will be applied in service to products (moulded articles, sheets, etc.) similar to those from which the test specimens are taken. The chosen test specimen
32、and the application will determine the possibility or impossibility of using standard test specimens and, in the latter case, will govern the choice of the dimensions of the test specimens in accordance with5.1. It should be noted that the position or orientation and the dimensions of the test speci
33、mens sometimes have a very significant influence on the test results (seeFigure 1). 5.2.2 If the material shows a significant difference in flexural properties in two principal directions, it is to be tested in those two directions (see Figure 1). If, in service, this material is subjected to stress
34、 at some specific orientation to the principal direction, it is desirable to test the material at that orientation. 5.3 Number of test specimens 5.3.1 Use the number of test specimens determined by experiment as necessary to obtain a mean with the required precision with a95% probability confidence
35、level. In any case, use at least5 test pieces. 5.3.2 The results from test specimens that break outside the central one-third of the length between the supports should be discarded and new test specimens should be tested in their place. Such cases should be mentioned in the test report. 5.4 Precondi
36、tioning. The test specimens shall be conditioned as required by the particular specification of each reinforced plastics material tested. If no specification exists, condition the test specimens for temperature and humidity for at least16hours in accordance with European Standard EN62 (atmosphere23C
37、/50% r.h.). 6 Procedure 6.1 Test atmosphere. Perform the test in one of the standard laboratory atmospheres specified in European Standard EN62. 6.2 Measurement of dimensions. In the central part of the test specimen measure the width, b, to the nearest0.1mm and make three measurements of the thickn
38、ess to the nearest0.02mm, using the arithmetic mean for calculation. Adjust the distance, L, between supports to: Measure this length with an accuracy of0.5%. NOTEFor very thick and unidirectional reinforced test specimens it may be necessary to use a distance between supports calculated on a higher
39、 ratio of L/h to avoid delamination in shear. For very thin test specimens, it may be necessary to use a distance between supports calculated on a lower value of L/h to enable measurements to be made within the force capacity of the testing machine. 6.3 Testing. Adjust the testing machine to the rat
40、e V, determined as follows. 6.3.1 If there is no specification for the material to be tested, one or the other of the two following methods can be used. Method A. In non-routine testing of a material, a speed (expressed in mm/min) shall be chosen numerically equal to half the test specimen thickness
41、 (expressed inmm) i.e. Method B. For routine and screening tests V =10mm/min 6.3.2 If there is a specification for the material, either a) the rate of movement of the loading nose is specified, and is the rate to be used; or b) the straining rate is specified, for example0.01, in which case the rate
42、 V of relative movement of the loading nose may be calculated by the following formula: Dimensions in millimetres Thickness h width b 1h 10 15 0.5 10h 20 30 0.5 20h 35 50 0.5 35h 50 80 0.5 L=(16 1) h (1) V = (2) V (mm/min) = (3) h 2 - Sr .L 2 6 h -EN63:1977 BSI 03-1999 5 where 6.4 Place the test spe
43、cimen symmetrically across the two parallel supports (as shown in Figure 2) ensuring that the length of the test specimen is at right angles to each of these. Ensure that the loading nose is positioned exactly at the mid-span position and apply the force at a uniform rate without impact. 6.5 If it i
44、s desired to measure the modulus of elasticity, read the force and the deflection values simultaneously sufficiently frequently so that a smooth force/deflection curve may be plotted. A continuous registration of force and deflection, or better, a direct plotting of the force/deflection curve is pre
45、ferable. 6.6 For test specimens that break before or at the moment of reaching the conventional deflection (see3.3), record the force and deflection at break. 6.7 For test specimens that do not break before or at the conventional deflection (see3.3), record the force at the conventional deflection.
46、Alternatively, if required by the material specification, continue the test without interruption beyond the conventional deflection until the test specimen breaks or a maximum force is reached, and record the force and deflection at whichever of these points is specified. 6.8 For test specimens that
47、 show maximum force before the conventional deflection is reached, record the maximum force and the corresponding deflection. 7 Calculation and expression of results 7.1 Flexural stress fat a force F is calculated in megapascals using the formula where M is the bending moment at force F, given by in
48、 which F is the force, in newtons, and L is the distance between supports, in millimetres; W is the section modulus, in millimetres cubed. For a rectangular section, the section modulus is given by where b and h are respectively the width and the thickness of the section in millimetres. Hence, flexu
49、ral stress is calculated by the following formula: NOTE11N/mm 2 = 1 MN/m 2 = 1MPa. NOTE 2For a more accurate calculation of the flexural stress which takes into account the horizontal component of the flexural moment at deflection d, the following equation may be used: where d is the deflection at mid-span, in millimetres. 7.2 Modulus of elasticity in flexure E b . Plot a force/deflection curve using the data collected. Determine the modulus of elasticity from the initial linear portion of the force/deflection cur
