BS EN 658-2-2002 Advanced technical ceramics — Mechanical properties of ceramic composites at room temperature1.pdf

BRITISH STANDARD BS EN 658-2:2002 Advanced technical ceramics Mechanical properties of ceramic composites at room temperature Part 2: Determination of compression properties The European Standard EN 658-2:2002 has the status of a British Standard ICS 81.060.30 ? Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 05:14:29 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295. -,-,- BS EN 658-2:2002 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 7 March 2003 © BSI 7 March 2003 ISBN 0 580 41372 1 National foreword This British Standard is the official English language version of EN 658-2:2002. It supersedes DD ENV 658-2:1993 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee RPI/13, Advanced technical ceramics, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “ International Standards Correspondence Index” , or by using the “ Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 18, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 05:14:29 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295. -,-,- EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 658-2 December 2002 ICS 81.060.30Supersedes ENV 658-2:1993 English version Advanced technical ceramics - Mechanical properties of ceramic composites at room temperature - Part 2: Determination of compression properties Céramiques techniques avancées - Propriétés mécaniques des céramiques composites à température ambiante - Partie 2: Détermination des propriétés en compression Hochleistungskeramik - Mechanische Eigenschaften von keramischen Verbundwerkstoffen bei Raumtemperatur - Teil 2: Bestimmung der Eigenschaften unter Druck This European Standard was approved by CEN on 16 October 2002. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels © 2002 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 658-2:2002 E Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 05:14:29 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295. -,-,- EN 658-2:2002 (E) 2 Contents page Foreword3 1Scope 4 2Normative references 4 3Principle4 4Terms, definitions and symbols.4 5Apparatus .6 5.1Test machine6 5.2Load train6 5.3Strain measurement 6 5.3.1Strain gauges .6 5.3.2Extensometry .7 5.4Data recording system7 5.5Dimension measuring devices.7 6Test specimens7 6.1Compression between platens.8 6.2Test specimen used with grips.10 7Test specimen preparation.13 7.1Machining and preparation.13 7.2Number of test specimens13 8Test procedure.13 8.1Displacement rate13 8.2Measurement of test specimen dimensions.14 8.3Buckling14 8.4Testing technique 14 8.4.1Specimen mounting.14 8.4.2Extensometers .14 8.4.3Measurements14 8.5Test validity 15 9Calculation of results 15 9.1Test specimen origin.15 9.2Compression strength.15 9.3Strain at maximum compression force .15 9.4Proportionality ratio or pseudo-elastic modulus, elastic modulus16 10Test report 17 Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 05:14:29 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295. -,-,- ? EN 658-2:2002 (E) 3 Foreword This document (EN 658-2:2002) has been prepared by Technical Committee CEN /TC 184, “Advanced technical ceramics“, the secretariat of which is held by BSI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2003, and conflicting national standards shall be withdrawn at the latest by June 2003. This document supersedes ENV 658-2 :1993. EN 658 consists of the following parts, under the general title “Advanced technical ceramics Mechanical properties of ceramic composites at room temperature“ Part 1 : Determination of tensile properties Part 2 : Determination of compressive properties Part 3 : Determination of flexural strength Part 4 : Determination of interlaminar shear strength by compression loading of notched test specimens Part 5 : Determination of interlaminar shear strength by short span bend test (three-points) Part 6 : Determination of interlaminar shear strength by double-punch shearing According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 05:14:29 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295. -,-,- ? EN 658-2:2002 (E) 4 1 Scope This part of this European Standard describes a method for determination of compression properties of ceramic matrix composite materials with continuous fibre reinforcement at room temperature. This method applies to all ceramic matrix composites with a continuous fibre reinforcement, unidirectional (1D), bidirectional (2D), and tridirectional (xD, with 2 x 3) as defined in ENV 13233, loaded along one principal axis of reinforcement. Two cases are distinguished: compression between platens; compression using grips. 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 publications 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 latest edition of the publication referred to applies (including amendments). ENV 13233:1998, Advanced technical ceramics - Ceramic composites - Notations and symbols. EN ISO 7500-1:1999, Metallic materials - Verification of static uniaxial testing machines - Part 1: Tension/compression testing machines (ISO 7500-1:1999). ISO 3611, Micrometer callipers for external measurements 3 Principle A test specimen of specified dimensions is loaded in compression. The test is performed at a constant crosshead displacement rate or at a constant deformation rate. NOTE 1Constant loading rate is only allowed in the case of linear stress strain behaviour up to failure. NOTE 2When applied, it is recommended to use constant cross head displacement rate when the test is carried out up to failure. The force and longitudinal deformation are measured and recorded simultaneously. 4 Terms, definitions and symbols For the purposes of this European Standard, the following terms and definitions and the symbols given in ENV 13233 apply. 4.1 calibrated length, l the part of the test specimen which has uniform and minimum cross-section area 4.2 gauge length, Lo initial distance between reference points on the test specimen in the calibrated length Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 05:14:29 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295. -,-,- ? EN 658-2:2002 (E) 5 4.3 initial cross-section area, Ao initial cross-section of the test specimen within calibrated length 4.4 longitudinal deformation, L decrease in the gauge length between reference points under a compression force. Its value corresponding to the maximum force shall be denoted Lc,m 4.5 compression strain, relative change in the gauge length defined as the ratio L/Lo. Its value corresponding to the maximum force shall be denoted c,m 4.6 compression stress, the compression force supported by the test specimen at any time in the test divided by the initial cross-section area 4.7 maximum compression force, Fc,m highest recorded compression force in a compression test on the test specimen when tested to failure 4.8 compression strength, c,m ratio of the maximum tensile force to the initial cross-section area 4.9 proportionality ratio or pseudo-elastic modulus Ep, elastic modulus E the slope of the linear section of the stress-strain curve, if any. Examination of the stress-strain curves for ceramic matrix composites allows definition of the following cases: a) material with a linear section in the stress-strain curve For ceramic matrix composites that have a mechanical behaviour characterised by a linear section, the proportionality ratio Ep is defined as: () 12 12 21 ? ? ?,?Ep =(1) where (1, 1) and (2, 2)lie near the lower and the upper limits of the linear section of the stress-strain curve (see Figures 1 and 2). The proportionality ratio or pseudo-elastic modulus is termed the elastic modulus, E, in the single case where the linearity starts near the origin (see Figure 2); b) material with non-linear section in the stress-strain curve In this case only stress-strain couples can be fixed. 4.10 axial strain average of the longitudinal strain measured at the surface of the test specimen at specified locations Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 05:14:29 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295. -,-,- ? EN 658-2:2002 (E) 6 4.11 bending strain the difference between the longitudinal strain at a given location on the test specimen surface and the axial strain 4.12 percent bending the bending strain times 100 divided by the axial strain 5 Apparatus 5.1 Test machine The machine shall be equiped with a system for measuring the force applied to the test specimen which shall conform to grade 1 or better according to EN ISO 7500-1:1999. 5.2 Load train The load train is composed of the moveable and fixed crosshead, the loading rods and the grips or platens. Load train couplers may additionally be used to connect the grips or platens to the loading rods. The load train shall align the specimen axis with the direction of load application without introducing bending or torsion in the specimen. The maximum percent bending shall not exceed 5 at an average strain of 6 10500 . There are two alternative means of load application: a)compression platens are connected to the load cell and on the moving cross head. The parallelism of these platens shall be better than 0,01 mm, in the loading area and they shall be perpendicular to the load direction. NOTE 1The use of platens is not recommended for compression testing of 1D and 2D materials with low thicknesses because of buckling. NOTE 2A compliant interlayer material between the test specimen and platens can be used for testing macroscopically inhomogeneous materials to ensure uniform contact pressure. When the dimensions of specimen are such that buckling may occur, it is recommended to use an antibuckling tool such as one of those which are described in EN ISO 14126. This tool should not induce parasitic stresses during loading of the specimen; b) grips are used to clamp and load the test specimen. The grip design shall prevent the test specimen from slipping. The grips must align the test specimen axis with that of the applied force. NOTEThis point should be verified and documented, according to, for example the procedure described in WI 00184136. 5.3 Strain measurement For continuous measurement of the longitudinal deformation as a function of the applied force either strain gauges or a suitable extensometer complying with EN 10002-4 may be used. Measurement of longitudinal deforma