www bzfxw com BRITISH STANDARD AEROSPACE SERIES BS EN 2377 1989 Glass fibre reinforced plastics — Test method — Determination of apparent interlaminar shear strength This European Standard EN 2377 has[.]
BRITISH STANDARD AEROSPACE SERIES Glass fibre reinforced plastics — Test method — Determination of apparent interlaminar shear strength This European Standard EN 2377 has the status of a British Standard UDC 678.067.5-41:620.176:629.7 BS EN 2377:1989 BS EN 2377:1989 Cooperating organizations The European Committee for Standardization, under whose supervision this European Standard was prepared, comprises the national standards organizations of the following Western European countries This British Standard, having been prepared under the direction of the Aerospace Standards Policy Committee, was published under the authority of the Board of BSI and comes into effect on 30 November 1989 © BSI 01-2000 The following BSI references relate to the work on this standard: Committee reference ACE/64 Draft for comment 88/70403 DC ISBN 580 17743 Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y France Association franỗaise de normalisation Germany Deutsches Institut fỹr Normung e.V Greece Hellenic Organization for Standardization Iceland Icelandic Council for Standardization Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxemburg Inspection des travails et des mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Português da Qualidade Spain Instituto Espol de Normalización Sweden Standardiseringskommissionen i Sverige Switzerland Association suisse de normalisation United Kingdom British Standards Institution Amendments issued since publication Amd No Date of issue Comments BS EN 2377:1989 Contents Cooperating organizations National foreword Brief history Text of EN 2377 National appendix A National appendix B © BSI 01-2000 Page Inside front cover ii Inside back cover Inside back cover i BS EN 2377:1989 National foreword This British Standard has been prepared under the direction of the Aerospace Standards Policy Committee and is the English language version of EN 2377 “Aerospace series Glass fibre reinforced plastics Test method Determination of apparent interlaminar shear strength”, published by the European Committee for Standardization (CEN) EN 2377 was produced as a result of international discussion in which the UK took an active part A British Standard does not purport to include 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, pages i and ii, the EN title page, pages to 6, 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 ii © BSI 01-2000 EUROPEAN STANDARD EN 2377 NORME EUROPÉENNE January 1989 EUROPÄISCHE NORM UDC: 678.067.5-41:620.176:629.7 Key words: Aircraft industry, glass reinforced plastics, plates, test method, shear stress English version Aerospace series Glass fibre reinforced plastics Test method Determination of apparent interlaminar shear strength Luft- und Raumfahrt Glasfaserverstärkte Kunststoffe Prüfverfahren zur Bestimmung der scheinbaren interlaminaren Scherfestigkeit Série aérospatiale Plastiques renforcés de fibres de verre Méthode d’essai Détermination des propriétés en cisaillement apparent interlaminaire This European Standard was accepted by CEN on 1988-03-17 CEN members are bound to comply with the requirements of CEN Internal Regulations 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 Central Secretariat or to any CEN member This European Standard 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 CEN Central Secretariat has the same status as the official versions CEN members are the national standards organizations of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxemburg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom CEN European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © CEN 1989 Copyright reserved to all CEN members Ref No EN 2377:1989 E EN 2377:1989 Brief history This draft European Standard has been prepared by the European Association of Aerospace Manufacturers (AECMA) After enquiries and votes carried out in accordance with the rules of this Association, this draft has successively received the approval of the National Associations and the Official Services of the member countries of AECMA, prior to its presentation to CEN In accordance with the Common CEN/CENELEC Rules, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxemburg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom Contents Brief history Scope and field of application References Definition Principle of the method Test specimens Apparatus Conditioning Procedure Test results 10 Calculation and expression of results 11 Test report Annex A Determination of the estimated value of standard deviation Figure Figure — Testing device Figure 3.a — Shear modes of failure Figure 3.b — Non-shear modes of failure Page 3 3 4 4 5 4 © BSI 01-2000 EN 2377:1989 Scope and field of application 5.1 Dimensions This standard defines a method for the determination of the apparent interlaminar shear strength by delamination of textile glass fibre reinforced plastics produced in sheet form for aerospace use 5.1.1 Standard specimens References 5.1.2 Alternative specimens EN 62, Glass reinforced plastics — Standard atmospheres for conditioning and testing EN 2374, Aerospace series — Glass fibre reinforced mouldings and sandwich composites — Production of test panels When it is not possible or desirable to use the standard specimens, the following rules shall be observed: a) The length and the thickness of the test specimen shall be in the same ratio as in the standard specimen: = 6,7 h ± 0,5 mm b) The width and the thickness of the test specimen shall be in the same ratio as in the standard specimen: b = 3,3 h ± 0,2 mm WARNING: If the thickness of the test specimen is greater than mm excessive compressive stresses may occur under the loading nose Definition The apparent interlaminar shear strength is the maximum interlaminar shear stress at the moment of first failure It is expressed in MPa Principle of the method For the determination of the resistance in interlaminar shear parallel to the layers of reinforcement, a specimen of rectangular cross section is tested in flexion The specimen resting on two supports and the force applied by means of a loading nose midway between the supports Test specimens The test specimens are prepared according to EN 2374 Length : (20 ± 0,5) mm Width b : (10 ± 0,2) mm Thickness h : (3 ± 0,2) mm 5.2 Position of specimens See Figure 5.3 Number of test specimens 5.3.1 The number of test specimens shall be a minimum of from each direction 5.3.2 When the material shows a significant difference in shear properties in two principal directions, it is to be tested in these two directions (see Figure 1, specimen A and B) When the fibres are oriented unidirectionally, the test shall be carried out in that direction only Figure © BSI 01-2000 EN 2377:1989 Apparatus Calibrated standard testing machine, which can be operated at a constant rate of the loading nose and in which the accuracy of measurement shall be within ± % The loading nose and supports shall be made from steel having a tensile strength U 000 MPa The span shall be adjustable Measure the dimensions of b and h to the nearest 0,05 mm, respectively and adjust the span to lV = h ± 0,1 mm Load the specimen without bumping with a rate of the loading nose of V = (1 ± 0,1) mm/min (see Figure 2) The load shall be taken as a function of time or displacement of the loading nose Test results Conditioning The standard atmosphere shall be in accordance with EN 62 The test specimens shall be conditioned at (23 ± 2) °C and (50 ± 5) % relative humidity during at least 16 h Procedure Unless otherwise specified, carry out the test at (23 ± 2) °C and (50 ± 5) % relative humidity 9.1 If the specimens fail in horizontal shear approximately at the neutral fibre axis (see Figure 3.a), the true interlaminar shear stress shall be calculated in accordance with the formula in clause 10 9.2 If test specimens fail in flexural i.e tension or compression failure of the outer surface (see Figure 3.b), the results calculated by the formula in clause 10 are not true shear stresses These results shall only be used for a comparison of test series of a same material (i.e batch control) Figure — Testing device NOTE In the case of translucent materials an off-white colour becomes evident Figure 3.a — Shear modes of failure © BSI 01-2000 EN 2377:1989 Figure 3.b — Non-shear modes of failure 10 Calculation and expression of results The apparent shear stress shall be calculated as follows: F Ùô = - -4 b.h where: E = The apparent shear stress in MPa F = Maximum force at the moment of the first failure, in N b = Width of specimen in mm h = Thickness of specimen in mm 11 Test report The test report shall include the following informations: 11.1 Number of this standard, brand, identification mark, origin, date of receipt and further data of the tested material 11.2 Data about the preparation of the test specimens © BSI 01-2000 11.3 Measured dimensions of the test specimens and of the span 11.4 Actual radii of the loading nose and supports 11.5 A graph representing the load measured as a function of time or displacement 11.6 When test specimens have been broken in shear the single values, the arithmetic mean and the standard deviation (see Annex A) shall be recorded 11.7 When test specimens have not been broken in shear a full description of type of failure shall be given with the note, that the calculated stresses are not true shear stresses The single values, the arithmetic mean and the standard deviation (see Annex A) shall be recorded 11.8 Test conditions i.e temperature and relative humidity if deviating from this standard 11.9 Observations on any circumstances liable to influence the results EN 2377:1989 Annex A Determination of the estimated value of standard deviation The estimated value of standard deviation S is calculated from the formula: where: xi observations x arithmetical mean of the values xi n number of observations NOTE With sufficient exactness for most purposes the value of the standard deviation of a series of results can be calculated as follows: Standard deviation S = 0,430 R where: R The difference in value between the highest and lowest result in the series of tests © BSI 01-2000 BS EN 2377:1989 National appendix A The United Kingdom participation in the preparation of this European Standard was entrusted by the Aerospace Standards Policy Committee (ACE/-) to Technical Committee ACE/64, upon which the following bodies were represented: British Plastics Federation Ministry of Defence Society of British Aerospace Companies Limited National appendix B The British Standards corresponding to the European Standards referred to in the text are identical in number and title with those given in clause with the exception of EN 62, for which the corresponding British Standard is BS 2782 “Methods of testing plastics” Part 10: Method 1004 “Standard atmospheres for conditioning and testing” (content identical) © BSI 01-2000 BS EN 2377:1989 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 Royal Charter Revisions British Standards 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 would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover Tel: 020 8996 9000 Fax: 020 8996 7400 BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest 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