1、 AECMA PRENxbOb2 95 LOL23LL OOL0079 774 AECMA STANDARD NORME AECMA AECMA NORM prEN 6062 Edition PI November 1995 PUBLISHED BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES (AECMA) Gulledelle 94 - 6-1 200 BRUXELLES - Tel. (32) 2 775 81 10 - Fax. (32) 2 775 81 11 ICs : Descriptors : ENGLISH VERSION
2、 Aerospace series Fibre reinforced plastics Test method Flatwise tensile test of composite sandwich panel Srie arospatiale Matires plastiques renforces de fibres Mthode dessai Essai de traction perpendiculaire dun panneau composite sandwich Luft- und Raumfahrt Faserverstrkte Kunststoffe Prfverfahren
3、 Zugversuch senkrecht zur Decklage von faserverstrkten Kernverbundplatten This “Aerospace Series“ Prestandard has been drawn up under the responsibility of AECMA (The European Association of Aerospace Industries). It is published on green paper for the needs of AECMA-Members. It has been technically
4、 approved by the experts of the concerned Technical Committee follo wing comment by the Member countries. Subsequent to the publication of this Prestandard, the technical content shall not be changed to an extent that interchangeability is affected, ph ysically or functionally, without re-identifica
5、tion of the standard. After examination and signature of the AECMA Standard Checking Centre (NPSI 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 formal vote. Nota - Extra copi
6、es can be supplied by B.N.A.E. - Technopolis 54 - 199, rue Jean-Jacques Rousseau - 921 38 ISSY-LES-MOULINEAUX CEDEX Comments should be sent within six months after the date of publication to I Edition approved for publication 1995-1 1-30 AECMA Gulledelle 94 B-1200 BRUXELLES AIB/TF6 Chairman Mr K. Sc
7、hneider aecrna 1995 AECMA PRENnbOb2 95 1012311 0010080 496 Page 2 prEN 6062 : 1995 Contents list 1 2 3 4 5 6 7 8 9 10 Scope Normative references Definitions Principie of the method Designation of the method Apparatus Test specimen Procedure Presentation of the results Test report AECMA PRENrbOb2 95
8、m LOL23LL OOLOOBL 322 m Page 3 prEN 6062 : 1995 1 Scope This standard specifies the flatwise tensile test, which is the procedure for the determination of the tensile strength, perpendicular to the honeycomb sandwich panels. The specimen is designed to fail in one of the core to skins bonds. This st
9、andard may be used to obtain strength and compatibility data on unidirectional and woven fabric laminates, structural adhesives and epoxy resin used for repair purposes. This standard does not give any directions necessary to meet health and safety requirements. It is the responsibility of the user
10、of this standard to consult and establish appropriate health and safety precautions. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the public
11、ations 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 lates edition of the publication referred to applies. EN 2334 Aerosp
12、ace series Acid chromate pickling of aluminium alloys ” EN 2419 Aerospace series Aluminium alloy 2024-T351 plate 6 s a s 80 mm ” EN 2514 Aerospace series Aluminium alloy 5052-1 91 ) EN 2743 Aerospace series Reinforced plastics Standard procedures for conditioning prior to testing EN 2823 Aerospace s
13、eries Fiber reinforced plastics Test method for the determination of the effect of exposure to humid atmosphere on physical and mechanical characteristics Parameters for conditioning and testing ) 3 Definitions 3.1 Flatwise tensile strength Flatwise tensile strength is the ratio between the measured
14、 ultimate load F and the bonded surface area. 3.2 Standard test panel A laminate core composite structure panel which has been bonded under the conditions defined in section 7.1 and from which the test specimens are taken. I Published as AECMA Prestandard at the date of publication of this standard
15、Page 4 prEN 6062 : 1995 3.3 Failure mode The failure mode is assessed according to the following criteria: Adhesive failure = 1 failure at one bonding surface - resin or adhesive removed from honeycomb or laminate Cohesive failure = failure in the resin or adhesive - resin or adhesive remains on bot
16、h fracture surf aces. 4 Principle of the method This test on honeycomb core composite structures is carried out to determine the tensile strength by subjecting the test specimen to a tensile load perpendicular to the panel skins until fracture. 5 Designation of the method The designation of the meth
17、od used shall be drawn up according to the following example Description block I Identity block Fibre reinforced plastics Flatwise tensile test of composite sandwich panels Number of this standard Specimen type (see figure 1) 6 Apparatus 6.1 Calibrated tensile test machine accurate to within 1 %, eq
18、uipped with facilities to record maximum load. 6.2 Chamber adapted to the machine to carry out tests at temperatures other than ambient. The tempera- ture shall be maintained within i 3 OC. 6.3 Thermocouples with recorder to monitor temperature for tests at other than ambient. 6.4 Fixing blocks made
19、 of aluminium alloy according to EN 2419, which will be coupled to the test machine by means of two cylindrical pins. (see figure 1) 6.5 Vernier calliper accurate to the nearest 0.1 mm AECMA PRENwbUb2 95 = LOlr23LL 0010083 lT5 Page 5 prEN 6062 : 1995 7 Test specimen 7.1 Manufacturing of standard tes
20、t panels Honeycomb core with or without corrosion protection for the determination of tensile strength up to + 150 OC test temperature. Honeycomb core: 6.4-96 aluminium alloy 5052 H191 according to EN 2514 Depth of honeycomb core: 13 mm Dimensions: Refer to figure 3 The Oo direction in unidirectiona
21、l tapes or the warp of fabrics shall be parallel to the ribbon direction of the honeycomb core. The number of layers depends on the material. The skin thickness shall not exceed 1 mm. Depending on specimen type, an additional adhesive film shall be used. (see figure 1) The test panels shall be manuf
22、actured according to the relevant specification invoking the test. 7.2 Preparation of test specimen The standard test panel shall be visually inspected in order to eliminate panels containing manufacturing defects, such as wrinkles, cracks, delaminations etc. Wait for at least two hours after the fi
23、nal curing before sawing the test specimens shown in figure 2 out of the standard test panel. The opposite sides of the test specimens must be parallel, adjacent sides must be normal to each other. The specimens shall be marked in such a way that they can be easily assigned. Choose the sawing condit
24、ions (sawing speed, no. of saw teeth, pitch of saw teeth) in such a way that friction heating of the bond will be kept to minimum. The surface of the metallic blocks (6.4) shall be pretreated for bonding to prevent failure at the block faces (preferred method: sulphocromic pickling according to EN 2
25、334) The selection of the adhesive system to bond the specimen to the metallic fixing block will depend on the temperature at which the test is going to be performed and possible past cure effects to the sandwich. It shall be determined by the specification invoking the test. The bonding jig used mu
26、st provide the means of aligning the fixing blocks and the test specimens as well as for applying pressure to the joints between the fixing blocks and the test specimen. 1 Cover the sides of the test specimen with adhesive tape to prevent the adhesive from escaping from the joint and creating an add
27、itional bond between the honeycomb core and the top layer, which would lead to misleading results. 7.3 Number of specimens Five specimens shall be tested per test condition, except when otherwise specified in the specification invoking the test. If tests are carried out after ageing or at a temperat
28、ure different from RT, care should be taken to assure that RT/dry reference specimens, obtained from the same panel as the specimens under investigation are also tested. Page 6 prEN 6062 : 1995 7.4 Ageing of specimen Specimens shall be exposed to humid atmosphere without blocks. For bonding the bloc
29、ks afterwards the use of a cold curing system is mandatory. For tests after exposure to humid atmosphere, the conditioning shall be in accordance with EN 2823. 8. Procedure 8.1 Conditioning The storage and testing of as received specimens shall be carried out at 23 i: 2 OC, 50 i 5 % relative humidit
30、y in accordance with EN 2743. Aged specimens shall be tested within a maximum of 8 hours after removal from the exposure environment. 8.2 Determination of dimensions Measure and record length and width of each test specimen before mechanical testing. Use a vernier calliper (6.5). 8.3 Testing at ambi
31、ent temperature Clamp the tension blocks and the bonded test specimen in the testing machine in such a way that bending stresses are avoided during load application. Select the load range that failure occurs between 10 % and 90 % of full scale. Tensile load shall be applied at a constant cross head
32、speed of 1 mm/min. Record the maximum load. 8.4 Elevated and sub-zero temperature tests Apply a thermocouple as close as possible to the centre of the bonding using a small hole in the block. After a dry specimen has reached a temperature of 2 OC below the required elevated temperature or 2 OC above
33、 the required sub-zero temperature, the specimen shall be maintained at the required condition for five minutes prior to testing. The above time for aged specimen is 1 minute. For test specimen that have undergone humidity ageing, apply EN 2823. Follow the same procedure as for the test at ambient t
34、emperature. AECMA PRENxbOb2 95 1012311 0010085 T78 m Page 7 prEN 6062 : 1995 9 Presentation of the results 9.1 Flatwise tensile strength Calculate the flatwise tensile strength as follows: where: 0, F L w is the flatwise tensile strength, in N / mm2 is the maximum load during the test, in Newton is
35、the length, in millimetres is the width, in millimetres 9.2 Evaluation of failure mode For the test to be considered valid, the failure must be produced by debonding between skin and honeycomb core. Estimate the percentage of the bonding area affected by the different fracture types and record in th
36、e test report. 10 Test report The test report shall refer to this standard and shall include the following: 10.1 Complete indication of the material tested, including at least type, source, manufacturers code number, fibre areal weight, filament count, processing details, lay up, batch number and ma
37、nufacturing date. 10.2 All details regarding layup of laminates, adhesive type, designation and specification (Type I only), honeycomb core including specification and processing of the standard test panel. 10.3 All details regarding extraction of test specimens from the standard test panel, prepara
38、tion of test specimen and fixing block surfaces for bonding adhesive type and processing used to prepare test specimen for evaluation. 10.4 The measured specimen dimensions. 10.5 Ageing and/or exposure conditions prior to the test. AECMA PREN*bOb2 95 LOL23LL OOLOOBb 904 M Page 8 prEN 6062 : 1995 10.
39、6 Date of test, facility and identification of individuals performing the test. 10.7 Equipment and test parameters used. 10.8 Individual values, arithmetic mean and standard deviation of flatwise tensile strength, failure mode. 10.9 Any incident which may have affected the results and any deviation
40、from this standard. AECMA PREN*b062 95 1012311 0010087 840 Page 9 prEN 6062 : 1995 I I I I I 1 View A Metallic fixing block Laminate Adhesive (only for type I) Honeycomb Adhesive (only for type I) Laminate 1J Metallic fixing block Type I : with adhesive Type II :without adhesive all dimensions in mm
41、 Figure1 : Test specimen with fixing blocks AECMA PRENahOb2 75 = LOL2311 OOLOO88 787 = Page 10 prEN 6062 : 1995 Warp (Oo) direction Ribbon direction of honeycomb 50 k 0,5 I-+ Figure 2 : Test specimen 50f0,5 (1 ) -Po I I area t t : Laminate thickness (see 7.1) ( 1 ) or multiples if required) Figure 3 : Standard test panel +
