1、BRITISH STANDARD AEROSPACE SERIES BS EN 2557:1997 Carbon fibre preimpregnates Determination of mass per unit area The European Standard EN2557:1997 has the status of a British Standard ICS 49.025.40BSEN2557:1997 This British Standard, having been prepared under the directionof the Engineering Sector
2、Board, was published underthe authority of the Standards Board and comes intoeffect on 15 August1997 BSI09-1999 The following BSI references relate to the work on this standard: Committee reference ACE/64 Draft for comment88/78342 DC ISBN 0 580 28200 7 Committees responsible for this British Standar
3、d The preparation of this British Standard was entrusted to Technical Committee ACE/64, Aerospace structural reinforced plastics, upon which the following bodies were represented: British Plastics Federation Ministry of Defence Society of British Aerospace Companies Amendments issued since publicati
4、on Amd. No. Date CommentsBSEN2557:1997 BSI 09-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 1 Scope 3 2 Normative references 3 3 Principle 3 4 Apparatus 3 5 Specimens 3 6 Procedure 5 7 Expression of results 5 8 Health and safety requirements 5 9 Test
5、report 5 Figure 1 Example of positioning of specimens on woven carbon fibrefabricssample across the width 3 Figure 2 Example of positioning of specimens on woven carbon fibrefabricsample along an axis inclined at an angle as close as possible totheweft direction 4 Figure 3 Example of positioning of
6、specimens on carbon fibre unidirectionalsheet or tape sample 4 List of references Inside back coverBSEN2557:1997 ii BSI 09-1999 National foreword This British Standard has been prepared by Technical Committee ACE/64 and is the English language version of EN2557:1997 Aerospace series Carbon fibre pre
7、impregnates Determination of mass per unit area, published by the European Committee for Standardization (CEN). EN2557:1997 was produced as a result of international discussions in which the United Kingdom took an active part. Cross-references The British Standards corresponding to the European Stan
8、dards referred to in the text are identical in number and title with those given in clause2. 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 no
9、t of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorp
10、orated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN2557 March1997 ICS 49.025.40 Descriptors: Aircraft industry, preimpregnated product, carbon fibre, determination, specific area English version Aerospace series Carbon
11、fibre preimpregnates Determination of mass per unit area Srie arospatiale Primprgns de fibres de carbone Dtermination de la masse surfacique Luft- und Raumfahrt Kohlenstoffaser-Prepregs Bestimmung der flchenbezogenen Masse This European Standard was approved by CEN on1996-08-04. CEN members are boun
12、d to comply with the CEN/CENELEC 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 Ce
13、ntral Secretariat or to any CEN member. The European Standards exist 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 the Central Secretariat has the same status as
14、 the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Eu
15、ropen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997 CEN All rights of exploitation in any form and by any means reserved worldwide for CENnational Members. Ref. No. EN2557:1997 EEN2557:1997 BSI 09-1999 2 Foreword This European Standard
16、has been prepared by the European Association of Aerospace Manufacturers (AECMA). After inquiries and votes carried out in accordance with the rules of this Association, this Standard has received the approval of the National Associations and the Official Services of the member countries of AECMA, p
17、rior to its presentation to CEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September1997, and conflicting national standards shall be withdrawn at the latest by September1997. According to t
18、he CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerl
19、and and the United Kingdom.EN2557:1997 BSI 09-1999 3 1 Scope This standard specifies a method for determining the mass per unit area of carbon fibre preimpregnates for aerospace use. 2 Normative references This European Standard incorporates by dated or undated reference provisions from other public
20、ations. 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 publications apply to this European Standard only when incorporated in it by amendment or revision
21、. For undated references the latest edition of the publication referred to applies. EN2743, Aerospace series Reinforced plastics Standard procedures for conditioning prior to testing 1) . 3 Principle Weighing of specimens of known area after conditioning in a specified atmosphere. 4 Apparatus 4.1 Ba
22、lance with an accuracy of0,1mg 4.2 Template of standard specimen 4.3 Ancillary items such as a sharp knife and tweezers 5 Specimens 5.1 Shape and dimensions The specimen shall be square and have sides of(100 1)mm. Other specimens may be used, subject to agreement between the user and manufacturer on
23、 condition that they have an area of100cm 2with a tolerance of 2%. 5.2 Number and distribution A minimum of three specimens shall be used. They shall: be evenly distributed across the width of the sample; have their centres positioned along a straight line. See Figure 1 for wide woven fabrics, Figur
24、e 2 for narrow woven fabrics and Figure 3 for unidirectional sheet or tape. 1) Published as AECMA Prestandard at the date of publication of this standard Figure 1 Example of positioning of specimens on woven carbon fibre fabrics sample acrossthe widthEN2557:1997 4 BSI 09-1999 Figure 2 Example of pos
25、itioning of specimens on woven carbon fibre fabric sample along anaxis inclined at an angle as close as possible to the weft direction Figure 3 Example of positioning of specimens on carbon fibre unidirectional sheet ortapesampleEN2557:1997 BSI 09-1999 5 6 Procedure 6.1 Conditioning 6.1.1 Preimpregn
26、ates stored at ambient temperature The amount of preimpregnate required for testing shall be sampled and then conditioned in the test atmosphere (see6.2) for a minimum of2h, unless otherwise specified. 6.1.2 Preimpregnates stored below ambient temperature The preimpregnate, suitably packed in an air
27、tight and solvent resistant bag to prevent moisture pickup, shall be allowed to reach ambient temperature over a period of time depending on its mass. This line shall not be less than8h. When the material has reached ambient temperature, the amount required for testing shall be sampled and then cond
28、itioned in the test atmosphere (see6.2) for a minimum of2h, unless otherwise specified. 6.2 Atmosphere for testing EN2743, condition class B. 6.3 Time interval between conditioning and testing After conditioning, the sample shall be maintained in the test atmosphere. Unless otherwise specified, test
29、s shall be carried out within6h. 6.4 Tests Cut the specimens. Weigh each specimen with its protective films to the nearest milligram (m 1 ). Remove the protective films and reweigh these to the nearest milligram (m 2 ). 7 Expression of results M =(m 1 m 2 ) K 8 Health and safety requirements It is t
30、he responsibility of the user of this standard to adopt appropriate health and safety precautions. 9 Test report It shall include the following: number of this standard; all data ensuring the traceability of the material (trade mark, identification marking, date of receipt etc.); all information reg
31、arding the sampling procedure; form and dimensions of specimen; period of conditioning; test atmosphere, for example temperature, relative humidity if these differ from6.2; time interval between conditioning and testing (see6.3); individual values and arithmetic mean of the mass per unit area; any i
32、ncident which may have affected the results. where: M is the mass per unit area, in grams persquare meter; m 1 is the mass of the specimen plus protective films, in grams; m 2 is the mass of the protective films, ingrams; K =100m 2 .6 blankBSEN2557:1997 BSI 09-1999 List of references See national fo
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