BRITISH STANDARD AEROSPACE SERIES
I S B ) c ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S L H : y p o C d e s n e c i L
Carbon fibre reinforced plastics — Unidirectional laminates — Tensile test parallel to the fibre direction
The European Standard EN 2561:1995 has the status of a British Standard ICS 49.040.10
UDC 678.6.046:667.494-039.626:620.172.629.7
BS EN 2561:1995
BS EN 2561:1995
Committees responsible for this British Standard I S The preparation of this European Standard was entrusted to Technical B ) Committee ACE/64, Aerospace structural reinforced plastics, upon which c ( following bodies were represented: , y p o British Plastics Federation C Ministry of Defence d e l Society of British Aerospace Companies Limited l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S This British Standard, having L been prepared under the H direction of the Engineering : Sector Board, was published y under the authority of the p o Standards Board and comes Amendments issued since publication C into effect on 15 December 1995 d e Amd. No. Date Comments s © BSI 09-1999 n e c i L The following BSI references relate to the work on this standard: Committee reference ACE/64 Draft for comment 88/72264 DC ISBN 0 580 23109 7
the
BS EN 2561:1995
Contents I S B ) c ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S L H : y p o C d e s n e c i L
Committees responsible National foreword Foreword Text of EN 2561 List of references
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Page Inside front cover ii 2 3 Inside back cover
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BS EN 2561:1995
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 2561:1995 Aerospace series — Carbon fibre reinforced plastics — Unidirectional laminates — Tensile test parallel to the fibre direction, published by the European Committee for Standardization (CEN). EN 2561 was produced as a result of international discussions in which the United Kingdom took an active part.
I S B ) c ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S L H : y p o C d e s n e c i L
Cross-references Publication referred to
Corresponding British Standard
EN 2744:1992
BS EN 2744:1992 Non-metallic materials — Preferred test temperatures
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 2 to 10, 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 09-1999
EUROPEAN STANDARD
EN 2561
NORME EUROPÉENNE September 1995
EUROPÄISCHE NORM I S B ) c ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S L H : y p o C d e s n e c i L
ICS 49.040.10
Descriptors: Aircraft industry, laminates, reinforced plastics, carbon fibres, thermosetting resins, tension tests
English version
Aerospace series — Carbon fibre reinforced plastics — Unidirectional laminates — Tensile test parallel to the fibre direction
Série aérospatiale — Plastiques renforcés de fibres de carbone — Stratifiés unidirectionnels — Essai de traction parallèlement à la direction des fibres
Luft — und Raumfahrt — Kohlenstoffaserverstärkte Kunststoffe — Unidirektionale Laminate — Zugprüfung parallel zur Faserrichtung
This European Standard was approved by CEN on 1995-09-19. CEN members are bound 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 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 the Central Secretariat has the same status as 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 Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels
© 1995 Copyright reserved to CEN members
Ref. No. EN 2561:1995 E
EN 2561:1995
I Foreword S B ) This European Standard has been prepared by the c ( European Association of Aerospace Manufacturers , y (AECMA). p o After inquiries and votes carried out in accordance C with the rules of this Association, this Standard has d e successively received the approval of the National l l Associations and the Official Services of the member o r t n countries of AECMA, prior to its presentation to o CEN. c n This European Standard shall be given the status of U , a national standard, either by publication of an 7 identical text or by endorsement, at the latest by 0 0 March 1996, and conflicting national standards 2 0 shall be withdrawn at the latest by March 1996. 0 : According to the CEN/CENELEC Internal 0 0 Regulations, the following countries are bound to + T implement this European Standard: Austria, M Belgium, Denmark, Finland, France, Germany, G Greece, Iceland, Ireland, Italy, Luxembourg, 9 Netherlands, Norway, Portugal, Spain, Sweden, 0 : 4 Switzerland and United Kingdom. 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S L H : y p o C d e s n e c i L
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Contents
Foreword 1 Scope 2 Normative references 3 Definitions 4 Principle 5 Apparatus 6 Specimens 7 Procedure 8 Expression of results 9 Designation 10 Test report Annex A (normative) Form, dimensions of specimen, test fixture Figure 1 Figure A.1 — Specimen and test fixture, types A and B Figure A.2 — Specimen and test fixture, type C Table A.1
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EN 2561:1995
I S B ) c ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S L H : y p o C d e s n e c i L
1 Scope This standard specifies the method of determination of the ultimate tensile strength, tensile modulus and, if required, the Poisson’s ratio and strain at failure in tension of carbon fibre reinforced plastics in the form of unidirectional laminates. This method is only applicable to specimens where the axis is parallel to the direction of the fibres. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from oth er publications. 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. For undated references the latest edition of the publication referred to applies. EN 2489, Aerospace series — Fibre reinforced plastics — Determination of the action of test fluids. EN 2565, Aerospace series — Preparation of carbon fibre reinforced resin panels for test purposes 1). EN 2743, Aerospace series — Reinforced plastics — Standard procedures for conditioning prior to testing 1). EN 2744, Aerospace series — Non-metallic materials — Preferred test temperatures. EN 2823, Aerospace series — Fibre reinforced plastics — Test method for the determination of the effect of exposure to humid atmosphere on physical and mechanical characteristics 1).
3 Definitions For the purposes of this standard, the following definitions apply: 3.1 tensile stress
tensile load experienced by the specimen at any moment during the test, per initial unit cross sectional area within the free length 3.2 ultimate tensile strength (Ö T 11)
tensile stress at the moment failure occurs 3.3 ultimate tensile strength related to the fibre (Ö f )
the ultimate tensile strength calculated as a function of the fibre cross sectional area and based on the hypothesis that all the tensile load is carried by the fibres 3.4 strains (¼11 and ¼22)
change in the distance between reference points in the specimen free length, produced by a tensile load and expressed with respect to the initial distance between these points ¼11 is the strain measured parallel to the fibre direction ¼22 is the strain measured perpendicular to the fibre direction (in the plane of the laminate) 3.5 percentage strain to failure ( A %)
increase in the distance between reference points in the specimen free length, produced by a tensile load and expressed as a percentage of the initial distance between these points and measured at t he moment of failure
1) Published as AECMA Prestandard at the date of publication of this standard
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EN 2561:1995
I 3.6 S secant modulus between P /10 and P /2 (E ) R R T 11 B ) slope of the straight line passing through: c ( , — the point of the stress/strain diagram parallel to the load axis, corresponding to a stress calculated y p from P R/2; o C — the point on the same diagram corresponding to a stress calculated from P R/10. d e P R is the load at failure of the specimen l l o r 3.7 t n secant modulus related to the fibre (E f ) o c the secant modulus calculated as a function of the fibre cross sectional area and based on the hypothesis n U that all the tensile load is carried by the fibres , 7 3.8 0 0 poisson’s ratio (v12) 2 0 absolute value of the ratio of the difference in strain ¼22 to the difference in strain ¼11, measured between 0 : P R/10 and P R/2 (see Figure 1) 0 0 + 4 Principle T M The method consists of the measurement of the longitudinal and, if required, the lateral strains in the G material, in relation to the load applied, during a tensile test carried out at a constant rate of displacement 9 until failure occurs. 0 : 4 3 : 5 Apparatus 2 1 5.1 Micrometer with 6 mm diameter flat faces and accurate to 0,01 mm 6 2 5.2 Testing machine, accurate to within 1 % in the load range used t c O 5.3 A means of recording strains, in relation to the load (extensometer or strain gauges), accurate to i r within 1 % in the strain range used. The instrument shall not mark the specimen in a way which may cause F premature failures. , h t 5.4 If necessary, heated cabinet, regulated so as to conform to EN 2744 for tests at temperatures other than a B ambient f o 5.5 Thermocouple and recorder for tests at temperatures other than ambient y t i s r 6 Specimens e v Take specimens from panels prepared according to EN 2565. i n U 6.1 Form and dimensions , h t See Annex A. u o 6.2 Number S Minimum of five L H 7 Procedure : y p 7.1 Conditioning o C — EN 2743 for tests in the initial state; d — EN 2489 for tests after immersion; e s n — EN 2823 for tests after humidity exposure. e c i 7.2 Tests L 7.2.1 Measure the width to within 0,01 mm in the centre of the specimen and at two opposite points
located 30 mm from the centre. b is the arithmetic mean of these three measurements.
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EN 2561:1995
I S B ) c ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S L H : y p o C d e s n e c i L
Measure the thickness to within 0,01 mm in the centre of the specimen and at two opposite points on the specimen axis and located 30 mm from the centre. h is the arithmetic mean of these three measurements. 7.2.2 For tests at temperatures other than ambient, the period separating the conditioning and start of the test shall conform to the following conditions: — For specimens which have not been aged or subjected to immersion, the exposure time at the test temperature shall be established by preliminary tests. — For specimens subjected to immersion, see EN 2489. — For humidity aged specimens, see EN 2823. 7.2.3 The alignment of the specimen in the test machine jaws shall be sufficient to avoid the introduction of any bending loads. 7.2.4 The jaws shall entrap the tabs of the specimens of types A and B (see Figure A.1). 7.2.5 The load shall be applied at a constant rate of jaw separation of 2 mm/min. 7.2.6 Record the strain ¼11 and, if necessary, the strain ¼22 using the extensometer or strain gauges as a function of load. 7.2.7 Record the load at failure P R and, if necessary, the strain at failure (¼11)R. 8 Expression of results 8.1 Ultimate tensile strength Ö T 11 (MPa) P
Ö T 11
= -------R
b h
where: is the load at failure, in newtons; is the width, in millimeters; is the thickness, in millimeters.
P R b h 8.2
Ultimate tensile strength related to the fibre Ö f (MPa)
Ö f
P Ô
R f = -----------------
n b M sf
where: n M sf Ô f
P R b
is the number of plies; is the mass per unit area of fibre, in grams per square meter, per ply; is the density of fibre, in kilograms per cubic meter; is the load at failure, in newtons; is the width, in millimeters.
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EN 2561:1995
I 8.3 Secant modulus E T 11 (MPa) between P R/10 and P R/2 S B Determine the strains from the recorded load/strain diagram (Figure 1): ) c ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O Figure 1 i r F , h t a B f o y t i where: s r is the load at failure, in newtons; P R e v i is the width, in millimeters; b n U is the thickness, in millimeters; h , h t (¼11) A is the strain parallel to the fibre direction corresponding to P R/10; u o (¼11) B is the strain parallel to the fibre direction corresponding to P R/2. S L 8.4 Secant modulus E f (MPa) between P R/10 and P R/2 related to the fibre H : y p o C d e where: s n is the load at failure, in newtons; P R e c i is the number of plies; n L Ô f
M sf b
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is the density of fibre, in kilograms per cubic meter; is the mass per unit area of fibre, in grams per square meter; is the width, in millimeters;
© BSI 09-1999
EN 2561:1995
I S B ) c ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S L H : y p o C d e s n e c i L
(¼11) A (¼11) B 8.5
is the strain parallel to the fibre direction corresponding to P R/10; is the strain parallel to the fibre direction corresponding to P R/2.
Poisson’s ratio É12
where: (¼11) A (¼11) B (¼22) A (¼22) B
is the strain parallel to the fibre direction corresponding to P R/10; is the strain parallel to the fibre direction corresponding to P R/2; is the strain perpendicular to the direction corresponding to P R/10; is the strain perpendicular to the direction corresponding to P R/2.
Percentage strain to failure A % A % = 100 (¼11)R (¼11)R = strain to failure parallel to the fibre direction 8.6
8.7 Validity
The failure shall occur within the free length of the specimen but ma y extend under the end tabs or within the test machine jaws. 9 Designation EXAMPLE:
10 Test report It shall include the following: — designation (see 9); — all data ensuring the traceability of the material (trade mark, identification, marking, date of receipt etc.); — all information regarding specimen preparation; — specimen dimensions; — test conditions, for example test temperature, relative humidity if these differ from this standard; — exposure time at the test temperature; — load/strain diagram; — ultimate tensile strength Ö T 11 and mode of failure; — method of strain measurement (extensometer or strain gauges); — secant modulus E T 11 between P R/10 and P R/2; — Poisson’s ratio É12 (if required); — ultimate tensile strength related to the fibre Ö f (if required); — secant modulus E f between P R/10 and P R/2 related to the fibre (if required); — percentage strain to failure A (%); — individual values, arithmetic mean and standard deviation; — any incident which may have affected the results.
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EN 2561:1995
I Annex A (normative) S B Form, dimensions of specimen, test fixture ) c See Figure A.1 and Figure A.2 and Table A.1. The dimensions are expressed in millimetres. ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e Figure A.1 — Specimen and test fixture, types A and B v i n U , h t u o S L H : y p o C d e s n e c i L
Figure A.2 — Specimen and test fixture, type C
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EN 2561:1995
I S B ) c ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S L H : y p o C d e s n e c i L
Table A.1 Specimen type Symbol
b ha
A b
10 ± 0,5 2 ± 0,2
Bb
15 ± 0,5 1 ± 0,2
Cc
15 ± 0,5 1 ± 0,2
a If the ply thickness causes any uncertainty regarding the number of layers necessary to obtain a laminate of the required
thickness, this number of layers shall be specified in the relevant material standard. b Specimens provided with end tabs of 1581 type glass -epoxy laminate, arranged at ± 45° (thickness between 0,5 mm and 1 mm). End tabs are bonded onto the specimen using an adhesive. The type of adhesive and its curing cycle shall be compatible with the test conditions, the thermal characteristics of the end tabs and those of the material. c Specimens without end tabs reserved for machines with jaws whose grip pressure is regulated during the test (hydraulic device o r equivalent).
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I S B ) c ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S L H : y p o C d e s n e c i L
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BS EN 2561:1995
List of references I S B ) c ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S L H : y p o C d e s n e c i L
See national foreword.
© BSI 09-1999
BS EN 2561:1995
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I S B ) c ( , y p o C d e l l o r t n o c n U , 7 0 0 2 0 0 : 0 0 + T M G 9 0 : 4 3 : 2 1 6 2 t c O i r F , h t a B f o y t i s r e v i n U , h t u o S L H : y p o C d e s n e c i L
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