1、AECNA PREN2747 70 E 1012311 0004071 5 W 1- I A, E. CI M. A. STAN DAR D prEN 2747 NORME A.E.C.M.A. Issue P 1 A.E.C.M.A. NORM August 1990 Edition approved for publication 1990-08-24 DIT PAR LASSOCIATION EUROPENNE DES CONSTRUCTEURS DE MATRIEL AROSPATIAL 88, boulevard Malesherbes, 75008 PARIS -TL. 45-63
2、-82-85 UDC : Key words : Comments should be sent within six months C7 Chairman after the date of publication decision A.E.C.M.A. 88, Bd. Malecherbes Mr. BEZAUD 75008 PARIS - FRANCE ENGLISH VERSION Aerospace series Glass fibre reinforced plastics Determination of tensile properties Srie arospatiale L
3、uff- und Raumfahrt Matires plastiques renforces au verre textile Dtermination des caractristiques en traction Glasfaserverstrkte Kunststoffe Zugversuch This Aerospace Series pre-standard has been drawn up under the responsibility of AECMA (Association Europenne des Constructeurs de Matriel Arospatia
4、l). It is published on green paper for the needs of AECMA-Members. It has been technically approvedby the experts of the concerned Commission following comment by the Member countries. Subsequent to the publication of this pre-standard the technical content shall not be changed to an extent that int
5、erchangeability is affected, physically or functionally, without re-identification of the standard. After examination 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 C
6、EN (European Committee for Standardization) for final vote. 0 aecrna 199 Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,- _ AECMA PREN2747 90 M 1012311
7、 0004092 7 M prEN 2747 Page 2 Content s 1 2 3 4 5 6 7 8 9 10 Scope and field of application Eeferences De.f initions Designation of the method Apparatus lest specimens Ccnditioning Procedure Calculations and expression of results Test report Copyright Association Europeene des Constructeurs de Mater
8、iel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I AECMA PREN27Li7 90 a LOLZ3LL _ 0004073 7 a I prEW 2747 Page 3 1 Scope and fielcl of application 1.1 This standard specifies a method for the determination of t
9、ensile properties of glass fibre reinforced plastic materials. The method is applicable to reinforced thermosetting resins and equally to reiiif orced thermoplastic resins. The results from injection nioulded test specimens fron: glass fibre reinforced therxoplastics are mainly influenced by the ori
10、entation of the fibre. This manufacturing method may be used, when other methods for manufacturing test specimen are not possible. 1.2 This method enables the following tensile properties to be determined : - tensile strength at break, - tensile moduli of elasticity, - elotigat ions. 2 References EW
11、 2374 Aerospace series - Glass bre reinforced mou composites - Production of test panels ings and sanciw,:h EN 2489 Aerospace series - Fibre reinforced plastics - Determination of the action of liquid chemicals 1) EN 2743 Aerospace series - Bein.forced plastics - Standard atmospheres for corditionin
12、g and testing 2) EN 2823 Aerospace series - Fibre reinforced plastics - Test method for the determination of the effect of exposure to humfd atmosphere on physical and mechanical characteristics 2) 3 Definitions 3.1 Tensile stress Tensile load borne by the test specimen throughout the test, per unit
13、 initial cross sectional/area of the straight portion of the specimens. 3.2 Elongation Increase in distance between reference-marks on the straight portion of the test specimen prodiiced by a tensile load and expressed as a percen.tage of the initial distance between the ref erence-marks . 1) Publis
14、hed as AECMA pre-standard at the date of publication of the present standcrd 2) In preparation at the date of publication of the present standard Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or network
15、ing permitted without license from IHS-,-,-AECMA PREN2q 90 LOL23LL OOOqO7q O 9 psEh 2747 Pc,ge 4 3.3 Modulus of elasticity Quotient of the tensile stress and the corresponding relative deformation in the ultimate maximum strain that a material can bear without deviating from the proportion deformati
16、on-stress, that is the grdient of the relative stress/deformaticn diagram obtained in a tersile test. When the ultimate proportion is exceeded or when it does not exist, it is necessary to distinguish : 3.3.1 Initial tangent modulus Gradient to the tangent at the zero point (see note) of the relativ
17、e load /apparent st rain diagram. Note : With certain types of equipment, it may happer. that the diagrams obtained show local irregularities at the outset which must be discounted when. plotting the tangent. There are grounds in this cace when measuring the change in length, for correcting the zero
18、 point (see figure 2). 3.3.2 Secant modulus to x 2 elongation Grsdient of the straight line going through the zero point 1) of the stress/deformation diagram and the point in this diagram which corresponds to a relative change in length of x %. 4 Designation of the method Example : In case the test
19、has been carried out with specimen type I. Description block Identity block Tensile properties EN2747-I Title description Number of the EN standard Type of specimen according to table 1 5 Apparatus 5.1 Test machine with constant tensile speed and comprising : a) A fixed or in practice fixed part, wi
20、th a suitable grip and a mobile part with a second grip. The grips shall.be designed so as to enable the axis of the test specimens to be aligned at all times with the direction of the applied force. Thh can be achieved, for example, by using centring rods in the jaws of the test: machine, 1) The ze
21、ro point being taken after possible correction according to the note to clause 3.3.1. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-b) A load indicat
22、ing mechanism. It is essential that this mechanism has no inertia at the test speeci and it shall indicate the load to an accuracy of at least 1 % of the value indicated. The fixed and mobile parts, the device mechanisni and the grips shall be constructed from materials and In sizes such that the to
23、tal elastic longitudinal deformation of these devices does not exceed 1 Z of the longitudinal deformation sustained at the time of the test compared to the reference length of the test specimen; these requirements shall be satisfied for any load whatsoever that is less or equal to the fixed capacity
24、 of the test machine. 5.2 Extensometer It shall enable determination at any time during the test of the distance between two fixed points (or reference-marks) situated on the straight portion of the test specimen, Note 1 : Also applicable are mechanical, optical or volumetrical devices, if they meas
25、ure the elongation of the test specimen to an accuracy of at least 1 %. Note 2 : test specimen not cause failures in the grips. The extensometer used shall not give rise to any damage to the The initial distance between the - two ref erence-marks, called “gauge length“, shall be known to within an a
26、ccuracy of 5 1 %. The change in length shall be recorded automatically in relation to the load or the time elapsed since the start of the test, In this latter case, one shall equally record the load in relation to time. It is essential that the extensometer has no inertia at the test speed. It shall
27、 be accurate to within at least 1 X of the elongation measured. The reference length recommended is to be taken from table 1. However, a shorter distance can be used, as long as the above tolerances are adhered to. 5.3 MicronLeter The micrometer shall have an accuracy of 5 0,Ol mm. ci 6.1 The agre T
28、est specimens Preparation types are acco .ed between user trding and ma to table 1; .nufacturer. mat er ia 1 related requirements shall be Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking per
29、mitted without license from IHS-,-,-I F Minimum total 1er.gth W Width of ends 150 20 + - 0,5 h t hi ckne s s of specimens semi-finished products 2 to 10 test panels 2 to 3,5 according to EN 2743 B Length of straight portion b Width of straight portion Lo Gauge length 60 i- - 0,5 10 + - 0,5 50 E Dist
30、ance between grips D Distance between tabs 115 2 5 - T Minimum length of tabs P Diametre of centring holes e Thickness of tabs - - - ,AECMA PREN2747 O L0123Ll O004096 4 prEN 2747 Page 6 Table 1.- Dimensions for the test specimens according to figure 1 Dimensions in millimetres I Type II Type III Typ
31、e IV I 250 164 - - 2 to 10 250 2 to 10 2 to 3,5 2 to 3,5 1 + 0,2 to I 3-+ - 0,2 - I 25 + - 0,5 25 + - 0,5 10 -i- - 0,5 1 50 or 100 50 or 100 I 25 170 + - 5 1 50 2 2 170 5 5 150 + 5 I 64 i- 1,5 50 50 + 0,25 - 0,05 + 0,25 - O,G5 + 0,25 - 0,05 0,5 i- I 0,l Especially applicable for Glass f ab reinf the
32、rm fibre 8ic med Gets Unidirect ional glass fibre reinforced thermosets Glass fibre reinforced thermo- plastics *. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license f
33、rom IHS-,-,-AECMA PREN2747 70 H LL23LL 0004077 b - prEN 2747 Page 7 E h I I f I ! F c TYPE I 2 HOLES 0 P DRILLING OF HOLES OPTIONAL) E I NPE II y fb!?g:t it is recommended that a cooling fluid he used. In this case make sure the test specimen is .ciiped dry immediately after machining. - Check that
34、the edges of the test specimei; are free of defects, 6.1.3.1 Type I test specimens The test specimens of reinforced thermoplastbc 2re usually prone to fibre misalignments, when they are moulded. It is, therefore, desirable in most cases to machine test specimens from coinpression-moulded rectangular
35、 sheets with an abrading wheel or mill of suitable naterial, using a template. 6.1.3.2 Rectangular test specimens type IS iip to and including type IV These may be cut using di.amond cr silicon carbide saws. 6.2 Number of tcst specimens Beinforced plastics are generally misotropic. It is, therefore,
36、 often worth cutting the test specimens along at least the two principal anisotropic directions cr according tc previously specified directions (for example longitudinally or crosswise to the sheet). . For each direction and property that is being considered (modirlus of ehsticity, tensile strength,
37、 etc.) at,least five valid results AK necessary. Reject and replace any test specimen tliat has broken in the jaws or nt less than 10 mm from the jaws. 7 Conditioning In case the test is carried out in the initial state, the specinens shall be conditione according to EN 2743, In case the test is car
38、ried out after immersion of the test spcdmens, the conditioning shall be according to EN 2489. In case the test is carried out after hot-wet exposure of the test specimeris, the conditioning shall be according to EN 2823. 8 Procedure 8.1 Test atrtiosphere Unless otherwise specified, carry out the te
39、stu Kt (23 + -_ 2) “C and (SO i- - 5) W relative humidity. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-8.2 kleasurerrient of the dinensions of the
40、test specimns Measure the wideli 1; to the nearest U,1 mm and the thickness h to the nerest 0,OZ mm, this beiig tc the centre of the test specimen and at a distance of 5 mm from each end of the gauge Length, in the directior; of the centre. 8.3 Eecording c?r:d calculetion of the widths and thickness
41、es I 91 Tensile stress at bs6:alc Calculate the tensile stress at break with the help of the following formula : Record the urininum und maximum values of width and thickness and make sure that for the width they are within the tol.erances given in table 1. Calculate the arithmetical mean of the wid
42、ths b ar,d thicknesses h of the respective ceasured specimen type which is to be used for calculation. - 8.4 Test techniques Place the test specimen in the grips, taking care to align the 1orgitudinal.axis of the test specimn with the mechanical axis of the test machine. When the centring rods in th
43、e grips are vsed, perfect alignment is obtained by light: tension cn the test specimen before clamping the grips together. Clamp uniformly and strongly to avoid any slipping of the test specinien. Check and, if required, calibrate the extensmeter. Fix the extensometer in the centre of the test speci
44、men. 8 Note : If a tensile load has been appliet: during clamping in the grips, reduce this to zero before measuring strain. . The testing speed for all types of test specimens shall be 2 m/miri -i- - 10 %. 9 Calculations and expression of results where : bh o is the temile stress at break in MPa F
45、is the maximum fcrce in N b is the initial average width of the test specimen, in m: h is the initial average thickness of the test specimen, in mm. Record the result to three signlficant figures. e Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under licen
46、se with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 2747 Page 12 AECMA PREN2747 90 m 1012311 0004102 b W 9.2 Strain at maximum load Calculate the strain at maximum load, as a percentage, using the formula : c . Lo LO where : a is the strain at niaxinu
47、m load in X Zr is the apparent elongation at maximum load (see note), in mm, measured on the loa.d/elongation curve (see figure 2) C is the magnification of the extensometer Lo is the gauge length of the extensometers in mm. Note : The apparent elongation at maximm load is the direct reading from th
48、e graph, in mu, without correcting for the magnification of the extensometer. Record the result to two significant figures. 9.3 1nitia.l tangent modu1u.s of elasticity Calculate the initial tangent inoddus of elasticity usin.g the following formula : 1, O . C .AF1 A . bZ, - Er - o where : Er is the
49、initial tangent rnodulus of elasticity under tension, in MPa AF, is the change in force in N (see figure 2) Lo is the gauge length of the extensometer, in mm C is the magnification of the extensmeter A dZ1 is the cross-sectional area of the straight portion of the specimen in mm2 is the change in length, 2n nun, measured on the curve for the change in load a F1 (see figure
