1、AECMA PREN2563 89 W $0123LJ 0003527 Edition approved for publication 25th April 1989 A.E.C.M.A. STANDARD NORME A.E.C.M.A. A.E.C.M.A. NORM Comments should be sent within six months C7 Chairman after the date of publication decision 88, Bd. Malesherbes A.E.C.M.A. Mr BEZAUD 75008 PARIS - FRANCE prEN 25
2、63 Issue P 1 April 1989 - DIT PAR LASSOCIATION EUROPEENNE DES CONSTRUCTEURS DE MATERIEL AEROSPATIAL 88, boulevard Malesherbes, 75008 PARIS -TL. 45-63-82-85 UDC : Key words : ENGLISH VERSION Aerospace series Unidirectional laminates carbon-thermosetting resin Test method - Determination of apparent i
3、nterlaminar shear strength Srie arospatiale Luft- unc Raumfahrt Stratifis unidirectionnels Unidirektionale Kohlenstoffaser- carbone-rsine thermodurcissable Duroplast-Verbundwerkstoffe Prfverfahren zur Bestimmung der interlaminaren Scherfestigkeit Mthode dessai - Dtermination de la rsistance en cisai
4、llement apparent interlaminaire This Aerospace Series pre-standard has been drawn up under the responsibility of AECMA (Association Europenne des Constructeurs de Matriel Arospatial). It is published on green paper for the needs of AECMA-Members. It has been technically approved by the experts of th
5、e concerned AECMA Commission folowing comment by the Member countries. Subsequent to the publication of this pre-standard, the technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, without re-identification of the standard. After examina
6、tion and signature of the AECMA Standard Checking Centre (NPS) and formal agreement of the Official Services of the Member countries it will be submitted as a draft European Standard to CEN (European Committee for Standardization) for final vote. aecma 1989 AECMA PREN2563 87 LOL23Ll 0003528 2 prEN 2
7、563 Page 2 Issue P 1 Contents 1 2 3 4 5 6 7 a 9 Scope and field of application References Definitions Principle of the method Test specimens Apparat us Conditioning Procedure Test results 10 Expression of results 11 Test report e AECMA PREN2563 89 m 10L23LL 0003529 Lt Ulkllk prEN 2563 Page 3 Issue P
8、 1 1 Scope and fielcl of application This standard defines a method for the determination of the apparent interlaminar shear by delamination of unidirectional carbon fibre reinforced thermosetting resin composites produced in sheet form for aerospace use. It is intended for unidirectional specimens
9、in which the length is parallel to the fibre direction. Note : This method can equally be applied to fabrics. In the case of cross plied laminates comprising layers orientated in different ways, the formula given in clause 1Ois only a nominal value and shall only be used to compare tests carried out
10、 on identical layups. 2 References EN 2489 Aerospace series - Fibres reinforced plastics - Determination of the action of liquid chemicals 1) EN 2565 Aerospace series - Preparation of carbon fibre reinforced resin panels for test purposes 1) EN 2743 Aerospace series - Fibres reinforced plastics - St
11、andard atmospheres for conditioning and testing 2) EN 2744 Aerospace series - Non-metallic materials - Preferred test temperatures 2) EN 2823 Aerospace series - Fibres reinforced plastics materials - Exposure to humid atmosphere - Parameters for conditioning and testing 2) 3 Definitions The apparent
12、 interlaminar shear strength is the maximum shear stress calculated at half. thickness of test specimen at the moment of first failure. It is expressed in MPa. 1) Published as AECMA pre-standard 2) In preparation AECMA PREN25b3 89 1012311 0003530 O prEN 2563 Page 4 Symbols Issue P 1 Values 4 Princip
13、le 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 as a simple beam, the bar resting on two supports and the force applied by means of a loading nose midway between the s
14、upports, This test provides information on the quality of the fibre/resin bond, 5 Test specimens The test specimens are taken in panels prepared according to EN 2565. 5.1 Shape and dimension of test specimens O 3- -I- Figure 1 - Test specimen and testing device Dimensions in millimetres - rl Radius
15、Radius - Width = b2 Length =L Supported length =1 Thickness of specimen 1) = h“ 3 + 0,l 3 T 0,l 10 T 0,2 10 T 0.1 20 T 0,25 2 3 O92 I The machined edges of the specimen shall be parallel to within 0,02 mm. The length direction of the specimen is parallel to the fibre orientation. 1) If the layer: th
16、ickness may lead to uncertainty regarding the number of layers required to obtain material of thickness (2 +. 0,2) mm, the number of layers should be stated in the relevant standard for t%e product. a AECMA PREN25b3 89 3032333 0003533 2-W prEN 2563 Page 5 Issue P 1 5.2 Number of test specimens The n
17、umber of test specimens shall be a minimum of 5. 6 Apparatus 6.1 Micrometer fitted with 6 mm diameter flat measuring faces, accurate to within O,O1 mm. 6.2 Testing machine accurate to 1% in the range of loads used. 6.3 Device for recording load with respect to time or to loading nose displacement. 6
18、.4 Where required, a temperature chamber controlled so as to conform to EN 2744 for tests at temperatures other than ambient. 6.5 A thermocouple with recorder (see clause 6.4) for tests at temperatures other than ambient 6.6 The test fixture (see figure 1) shall ensure correct positioning of the spe
19、cimen and shall have less than a 0,02 mm off-centre defect of loading nose with respect to supports. 6.7 The inisalignment between loading nose and supports shall not be greater than U,O2 mm. AECMA PREN2563 A M 1012312 0003532 Li prEN 2563 Page 6 Issue P 1 6.8 supports shall be adjusted so that lV =
20、 5 . h where : h = the arithmetic mean thickness of each set of specimens. The scatter between specimen thicknesses within a set shall be such that : For qualification testing and in case of disagreement, the distance between - h max. - h min. - 0,05 h 6.9 The loading nose and supports shall be made
21、 from steel having an ultimate tensile strength 2 1000 MPa. 7 Conditioning In case of tests in the initial condition, the conditioning shall be in accordance with EN 2743. In case of tests after immersion, the conditioning shall conform to EN 2489. In case of tests after exposure to moist heat, the
22、conditioning shall conform to EN 2823. 8 Procedure 8.1 Measure the thickness and width at 3 points on the specimen within 0,Ol mm. 8.2 For tests at temperatures other than ambient, the period separating the conditioning and start of the test shall conform to the following conditions : 8.2.1 For spec
23、imens which have not been aged or subjected to immersion the soak time at the test temperature shall be established by preliminary experiment and shall be noted in the test report. I AECMA PREN25b3 87 m LOI12311 0003533 b m prEN 2563 Page 7 Issue P 1 8.L.2 Por specimens subjected to immersion, follo
24、w the procedure described in EN 2489. 8.2.3 For humidity aged specimens, follow the procedure described in EN 2823. 8.3 Adjust the distance between supports if required. 8.4 Locate the test specimen in the test jig, ensuring that its axis is perpendicular to the supports. 8.5 Load the specimen smoot
25、hly at a constant rate of the loading nose of v = (i 2 0,i) mm/min. 8.6 The load shall be taken as a function of time or displacement of the loading nose. 8 7 The load at failure (P,) shall be recorded. 9 Test results 9.1 If the specimens fail in horizontal shear approximately at the neutral fibre a
26、xis (see figure 2.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. flexure or plastic deformation of the outer surface (see figure 2.b), the results calculated by the formula in clause 10 are not true
27、shear stresses at failure. AECMA PREN25b3 89 W 1012311 0003534 B W prEN 2563 Page 8 Issue P 1 These results shall only be used for a comparison of test series of a same material (i.e. batch control). Single shear Multiple shear Figure 2.a - Shea modes of failure Platic deformation Flexure Figure 2.b
28、 - Non-shear modes of failure AECMA PREN2563 89 10123LL 0003535 T = I prEN 2563 Page 9 Issue P 1 10 Expression of results ! The apparent shear stress shall be calculated as follows : 2= 3 PR 4 b.h where : 7 - The apparent shear stress, in MPa PR = Maximum force at the moment of the first failure, in
29、 N I) b = Width of specimen, in mm h = Thickness of specimen, in mm. 11 Test report The test report shall include the following information : 11.1 Number of this standard, brand, identification mark, origin, date of receipt and further data of the tested material. 11.2 Dat.a about the preparation of
30、 the test specimens. e 11.3 Measured dimensions of the test specimens and of the span. AECMA PREN2563 B7 1012311 0003536 I W prEN 2563 Page 10 Issue P 1 11.4 A graph representing the load measured as a function of time or displacement of the loading nose. 11.5 When test specimens have been broken in
31、 shear the single values, the arithmetic mean and the standard deviation shall be recorded, 11.6 When test .specimens have not been broken in shear a full description of type of failure shall be given with the note, that the calcuiated stresses are not interlaminar shear. stress. The single values,
32、the arithmetic mean and the standard deviation shall be recorded. 11.7 Test conditions i.e. temperature and relative humidity if deviating from this standard. 11.8 Period of soak at the test temperature, for tests after imersion (see EN 2489), or exposure to humid atmosphere (see EN 2823). 11.9 Observations on any circumstances liable to influence the results.
