1、STD*BSI BS EN 25b2-ENGL 1797 Lb2Ybb7 Ob3LOb8 872 W BRITISH STANDARD AEROSPACE SERIES Carbon fibre reinforced plastics - Unidirectional laminates - Flexural test parallel to the fibre direction The European Standard EN 2562 : 1997 has the status of a British Standard ICS 49.025.40 BS EN 2562 : 1997 N
2、O COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGH LAW STDeBSI BS EN 25bZ-ENGL 1777 1b24bb9 Ob310b7 707 BS EN 2662 : 1997 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technicai Committee ACE/, Aerospace stsuctural reinforced
3、 plastics, upon which the following bodies were represented. British Plastics Federation Minishy of Defence Society of British Aerospace Companies This British Standard, having been prepared under the direction of the Engineering Sector Board, was published under the authority of the Standards Board
4、 and comes inh effect on 15 August 1997 O BSI 1997 Amendments issued since publication I Date Amd. No. 1 Textanected The following BSI references relate to the work on this standard Committee reference ACE164 Draft for comment 88/7224 DC ISBN O 580 26697 4 STD-BSI BS EN 25b2-ENGL 1777 Lb211bb7 Ob310
5、70 q20 BS EN 2662 : 1997 Contents page Inside front cover Nationai foreword ii 2 1 Scope 3 Committees responsible Foreword Specification 3 3 4 2 Nonnative references 3 Definitions 4 Principle 5 Apparatus 4 6 Specimens 5 5 7 Procedure 6 8 Expressionofresults 9 Designation 8 8 10 Testreport i O BSI 19
6、97 _ _ STD-BSI BS EN 25b2-ENGL 1777 = libEiibb9 Ob31071 3b7 W BS EN 2662 : 1997 National foreword This British Standard has been prepared by Technical Committee ACWM and is the English language version of EN 2562 : 1997 Aerospace series - Cut%on fibre reinfmd plastics - Unidirectional laminates - Fl
7、exuml test pa the point on the same diagram corresponding to a stress calculated from PRAO. PR is the load at failure of the specimen. The calculated stresses and strains are those present at the surface of the specimen and parallel to its axis. 4 Principle The method consists of the measurement of
8、the deflection at the central loading nose as a function of the applied load during a flexural test on three supports carried out at constant rate of displacement until failure occurs. The strain parallel to the fibre direction is calculated as a function of the applied stress. 5 Apparatus 5.1 Micro
9、meter with 6 mm diameter flat faces and accurate to 0,Ol mm 5.2 Testing machine, accurate to within 1 % in the load range used 5.3 range used Device for recording the deflection as a function of load, accurate to 1 % in the deflection 5.4 If necessary, heated cabinet, regulated so as to conform to E
10、N 2744 for tests at temperatures other than ambient. 5.5 Thermocouple and recorder for tests at temperatures other than ambient. 5.6 Test fixture See figure 1 and table 1. It shall ensure accurate positioning of the specimen. Misalignment between loading nose and supports shall not exceed 0,l mm. ST
11、D-BSI BS EN 25b2-ENGL 1777 = Lb24bb7 Ob31076 947 Symbols b L Page 5 EN 2562:1997 Type A 2) Type B 10 f 0,2 10 i: 0,2 100 f 1 60 f 1 6 Specimens Take specimens from panels prepared according to EN 2565. 6.1 Shape and dimensions See figure 1 and table 1, - I I Figure 1 Table 1 Dimensions in millimetre
12、s 1 I h 1) I 2 f 0.2 I 2 f 0.2 I l I r1 I 12,5 f 0,l 12,5 0,l r2 I 5 *0,1 I 5 f 0,l 1) 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. 2) T
13、ype A specimens shall be used unless otherwise specified in material standard. 6.2 Number Minimum of five 7 Procedure 7.1 Conditioning EN 2743 for rests in the initial state, EN 2489 for tests after immersion, EN 2823 for tests after exposure to humid atmosphere. _ STD-BSI BS EN 25b2-ENGL 1777 M 1b2
14、4bb7 Ob31077 AA5 M Page 6 EN 2562:1997 7.2 Tests 7.2.1 Determine h by calculating the arithmetic mean of three measurements of the thickness to within 0,Ol mm taken across the width at the centre of the specimen. Measure the width b to within 0,Ol mm at the centre of the specimen. Measure the distan
15、ce between supports to within 0,l mm. 7.2.2 of the test shall conform to the following conditions : For tests at temperatures other than ambient, the period separating the conditioning and start - for specimens which have not been aged or subjected to immersion, the exposure time at the test tempera
16、ture shall be established by preliminary tests ; - for specimens subjected to immersion, see EN 2489 ; - for specimens subjected to humid atmosphere, see EN 2823. 7.2.3 contact with the loading nose, ensuring that its axis is perpendicular to the supports. Locate the specimen in the test fixture, wi
17、th the face specified in the material standard in If the face in contact with the loading nose is not specified, record its nature (for instance mould side, bag side,.). 7.2.4 - of 5 rnm/rnin for specimen type A ; The load shall be applied at constant displacement rate : - of 2 mm/min for specimen t
18、ype B. 7.2.5 7.2.6 Record the deflection f as a function of load Record the load at failure PR 8 Expression of results 8.1 Flexural strength q, (MPa) where q, PR b h 1, is the flexural strength, in megapascals ; is the load at failure, in newtons ; is the width, in millimetres ; is the thickness, in
19、 millimetres ; is the distance between supports, in millimetres. 8.2 Measure the deflections from the diagram, see figure 2. Flexural modulus E, (MPa) between PR/10 and PR/2 V fl f2 Page 7 EN 2562:1997 Figure 2 Eb = Fk 1v3 10 b h3 (15 - 4) where : Eb PR b h i, f, f, is the flexural modulus, in megap
20、ascals ; is the load at failure, in newtons ; is the width, in millimetres ; is the thickness, in millimetres ; is the distance between supports, in millimetres ; is the deflection corresponding to PR/f# in millimetres ; is the deflection corresponding to PR/2, in millimetres. 8.3 Validity The speci
21、men is held over a sufficiently large span that the failure does not occur in shear and that strains due to shear loads may be neglected. The test is only considered to be representative of the flexural behaviour of the material if the break is in tension or compression, see figure 3. If a specimen
22、has not broken in flexure (tension or compression failure), the calculated strength according to 8.1 will be lower than the true strength of the material. EXAMPLES : Tensile (valid) h Shear (not valid) I -5- Compression (valid) Figure 3 Page 8 EN 2562:1997 9 Designation EXAMPLE : Number of this stan
23、dard Type of specimen (see table 1) 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 ; - t
24、est conditions, for example test temperature, relative humidity if these differ from the requirements in 7.2.2 ; - time interval between conditioning and testing (see 7.2.21 ; - face in contact with the loading nose, if necessary ; - load deflection diagram ; - flexural strength ab and mode of failu
25、re, see figure 3 ; - flexural modulus tFb between PR/10 and PR/2 ; - individual values, arithmetic mean and standard deviation ; - any incident which may have affected the results. STDOBSI BS EN 25b2-ENGL 1997 lbZibb9 Ob31080 37T = BS EN 2662 : 1997 List of references see national foreword. O BSI 19
26、97 STD BSI BS EN 2562 : 1997 BSI 389ChiswickHighbad London w4 4AL 3s EN 25b2-ENGL 2777 M 2b29bb7 Ob3LU82 20b m BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the TJK view on standards in Europe and at the internationa
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