ISO 527-4:1997 download.Plastics — Determination of tensile properties — Part 4:
Test conditions for isotropic and orthotropic fibre-reinforced plastic composites.
1.1 This part of ISO 527 specifies the test conditions for the determination of the tensile properties of isotropc and orthotropic fibre-reinforced plashc composites, based upon the general principles given in part 1.
Unidirectionay remforced materials are covered by part 5.
1.2 See ISO 527-1, subclause 1.2.
1.3 The test method Is suitable for use with the following matenals:
— tebre-reinforced thermosetting and thermoplastic composites incorporating non-unidirectional reinforcements such as mats, woven fabrics, woven rovings, chopped strands, combinations of such reinforcements, hybrids, rovings, short or milled fibres or preimpregnated materials (prepregs) (for directly in)eclion-moulded specimens, see specimen 1A in ISO 527-2:1993);
— combinations of the above with unidirectional reinforcements and multidirechonal reinforced materials constructed from unidirectional layers, provided such laminates are symmetrical (for materials with completely, or mainly, unidirectional reinforcements, see ISO 527-5);
— finished products made from these materials.
The reinforcement fibres covered include glass fibres, carbon fibres, aramid fibres and other similar fibres.
1.4 The method is performed using specimens machined from a test panel made in accordance with ISO 1268 or by equivalent methods, or from finished and semi-finished products with suitable flat areas.
1.5 See ISO 527-1 • subclause 1.5.
2 Normative references
The ‘oowing standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 527. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO 527 are encouraged to investigate the possibility of applying the most recent edions of the standards indicated below. Members of IEC arid ISO maintain registers of currently valid International Standards.
ISO 527-2:1993. Ptastics — V mã,atior, of tensile prcrperfiss — P.42 Test oond.Wons for moukflng and astruefon ptesflca.
ISO 527-5:1997, Plastice — DeterrvWiabon of tenvA.b prcerhes — Pail i Test conthttona to, unrecficnal toreeisforc.dpfasfic conos4es.
ISO 1268:1974, Piasfioa — Preparataon of ‘Sass fb-e re*tfot’ced. ream bonded. low-pressure %amJneled piste* or penefs tar test pwpo.esISO 2818:1994, Plastics — Pr. paraflon of test specimens by inctiirWng
ISO 3534-1:1993, Statistics — Vocabufar’ and symbofo — Pan 1: Ptobeby and general statistical terms.
3 PrInciple
See ISO 527-1, dause 3.
4 DefinitIons
For the purposes of this part of ISO 527, the following definitions epply.
4.1 gauge length: See ISO 527.1. subclause 4.1
4.2 speed of testIng: See ISO 527-1, subdause 42.
4.3 lanaI). stress, a (englneeflng)t See ISO 327-1, sdxIause 4.3, except that a tot -redion specimens is defined as a, and for dlren sp.cWn.ns U o (see 4.0 tot d WWbons of these r.don.).
4.3.1 tensile strength, a4: See ISO 527-1. subdeuse 4.3.3. except that 0b4 tot “1 directIon specimens is de[n.d as and for ‘7-direction specimens as .
4.4 tensIle strain, n See ISO 327-1, subcbuse 4.4. except that £ for 1”-direction specimens is defined as , and toe 2-deection specrwns as .
Ills expressed as a dImensionless ratio or En percent.
45 tensIle strain at tensile strength; tensile failure strain. : The tensde strain at the point correeponcisig to the tensile strength of the specimen.
For r-dW.cllon specimens, a I. defined as and for ‘Tdredlori specimens as p. tile espressed as a dimensIonless ratio or En percent.
4.6 modulus of elasticity In tension; Young. modulus, E See ISO 527-1 • subc*ause 4,6. except thai E for r-dieectlon speonens clef med is t and lot ‘7-direction specimens as
The strain values used are as given in ISO 527-1. ShAcIauae 4.8, Ii. c = 0,0005 and c = 0.002 5 (see figure 1), usiees alternative values are given in the melerial or Iechrcal specifications.
4.7 PoIsson’s ratio, p: See ISO 527-1. suticlause 4.7. except that for ‘1diedion specimens pis defined as p and j as , using the ooordmales shown in figure 2. For ‘7-diradion specimens. p. is defined s end p as
6 Test specimens
6.1 Shape and dimensions
ilvee types of lest specinen are specified lot use with this part of ISO 527, as detailed and illustrated r figure 3 (type 1 B) and figure 4 (types 2 and 3).
Type lB tot testing llbre-ralrdocad th.rmopiasitcs. Type 10 spom.ns may also be used low fibre-reInforced thermosels ii they break within the gauge leng& Type lB shall not be ue.d for maitidirectional. continuous-Mxereinforced malenals.
Type 2 (rectangular without end lab.) and type 3 (radtar at with bonded arid lds) we lot testing fbe-ieiifvrced thermosets and theimoplastics. Specimens with unbonded end t,s are considered as type 2.
The preferred width of type 2 and type 3 specimens is 25 rtvn, but width, of 50 nvn ow greater may be used if the tenaile strength as low dti. In the paitlizelar type of rei*rnamant used.
The thickness ci type 2 end type 3 specimens shall be between 2 mend 10 trail.
To decide wteIher to e type 2 or type 3 specimens. first carry out tests with type 2 specimens and, lithe lest is not poesible or not satisfactory, i.e. if the specimen sl or breaks in the grips (see ISO 527-1, subdause 5,1), us type 3 specimens.
For compresaion-moulded materials, the thickness between In. end-pieces of any type of specimen shall t no poInt deviate from the mean by more then 2%.
6.2 PreparatIon of specimens
6.2.1 General
In th case of moulding and lamination rnetnals, prepare a panel in accordance with ISO 1268 or another specified/agreed procedure. Cut individusi specimens, or group. of specimens In the case of type 3 specimens (see annex A). Iron, the panel.
In the case of flnfshed products (for •xample. for quality control during mamdaclure or on delivery), take specimens from flat areas.
Parwele1s for mactwnlng specimens are specified in ISO 2816. Further gtidance on cutting specimens is gmerl ii annex A.
6.2.2 End tab. (for type 3 specImen.)
The ends of the specimen shel be reinforced, preferably with end tabs made of cross-ply or fabric glass.fibre/resrn laminate with the fre. at ± 45 to the specimen a,os. The tab thickness shall be between 1 mm and 3mm. with a tab angl. of 90 (1.. not tapered).
Alternative tabbing arrangements are pemlsal,le. brA shat be shmm, before use, to give at least equal strength and no greater oo&Ilcien( of variation (see ISO 527.1, auticlause 10.5. and ISO 3534-i) than the recommended tabs. PoesibJe ab.mativee include tab. mad. from the malarial under test, mechanically fastened tabs, unbonded tabs made of rough materials (such as emery paper or sancEeper, arid the use of roughened gnp faces).
6.2.3 Appflcatlon of end tab. (for type 3 specImens)
Bond the end tabs to the specimen with a fagh-stretch adhesiv, aa deecrt.d In annex A.
NOTE — The aena procedure can be used br Indiviclad specimens and for a group of specknens.
6.3 Gauge marks
See ISO 527-1. subclause 6.3.
64 CheckIng the specimens
See ISO 527-1, subdause 6.4.
6.5 Anlsotropy
The propertie, of ftore-r.lnlorced plastic conspoeries frequently vary with direction in me plane of the sheet (anteotropy). For this mason, if rcorrwriended that two groups of test specimens be prepared with thew malor axes parabi and perpendicular. respectively, to the direction of some feature which Is interred from a knowledg, of the stnicture of the material or its method of menrIactijre (a.. subclauee 4.8).
7 Number of specimens
See 150527-1. clause 7.
8 Condftioning
See ISO 527-1, clauseS.