EN 12789:2002

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Advanced technical ceramics - Mechanical properties of ceramic composites at high temperature under air at atmospheric pressure - Determination of flexural strengthHochleistungskeramik - Mechanische Eigenschaften von keramischen Verbundwerkstoffen bei hoher Temperatur au Luft bei Atmosphärendruck - Bestimmunng der BeigefestigkeitCéramiques techniques avancées - Propriétés mécaniques des céramiques composites a haute température sous air a pression atmosphérique - Détermination de la résistance en flexionAdvanced technical ceramics - Mechanical properties of ceramic composites at high temperature under air at atmospheric pressure - Determination of flexural strength81.060.30Sodobna keramikaAdvanced ceramicsICS:Ta slovenski standard je istoveten z:EN 12789:2002SIST EN 12789:2004en01-januar-2004SIST EN 12789:2004SLOVENSKI
STANDARDSIST ENV 12789:20001DGRPHãþD

EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12789October 2002ICS 81.060.30Supersedes ENV 12789:1998English versionAdvanced technical ceramics - Mechanical properties of ceramiccomposites at high temperature under air at atmosphericpressure - Determination of flexural strengthCéramiques techniques avancées - Propriétés mécaniquesdes céramiques composites à haute température sous air àpression atmosphérique - Détermination de la résistanceen flexionHochleistungskeramik - Mechanische Eigenschaften vonkeramischen Verbundwerkstoffen bei hoher Temperatur auLuft bei Atmosphärendruck - Bestimmunng derBeigefestigkeitThis European Standard was approved by CEN on 7 September 2002.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards 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 translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.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 STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2002 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12789:2002 ESIST EN 12789:2004

Alternatively, pyrometers or thermocouples whichare not covered by EN 60584-1 and EN 60584-2, but which are appropriately calibrated can be used.5.5 Data recording systemA calibrated recorder shall be used to record force-time curve. The use of a digital data recording system combinedwith an analogue recorder is recommended.5.6 MicrometersMicrometers used for the measurement of the dimensions of the test piece shall be in accordance with ISO 3611.6 Test piecesRecommended specimen dimensions are given in Table 1. These dimensions have been successfully used andtake due account of the following factors:The amount of material under load shall be representative of the nature of the material and of the reinforcementstructure. This sets minimum limits to the span and to the width and thickness of the specimen. In the case offlexural, as opposed to tensile testing, also the distribution of the longitudinal reinforcement through the thicknesshas to be considered. When this distribution is not symmetrical with respect to the neutral plane, care shall betaken to insure that it is similar between specimens.The thickness and the distance between the inner and outer roller(s) shall be chosen so as to avoid shear failure.This is achieved by setting a minimum limit to the ratio between the moment arm and the specimen thickness. Avalue of 10 is commonly used and translates into a minimum L/h ratio of 20 in three-point bending, and a minimum(L-Li)/h ratio of 20 in four-point bending with Li=L/3.Other factors affecting the size and dimensions of the specimens are the type of the heating and of the loadingsystem.Table 1 — Recommended test specimen and span dimensionsDimensions in millimetres1D, 2D & xDToleranceLt, total lengthL + 10+ 1b, width10+ 0,2h, thickness2,5+ 0,2Inner spanfour-point bending, Li25+ 0,1Outer spanfour-point bending, L75+ 0,1three-point bending, L50+ 0,1NOTEIf it is necessary to define test pieces of different dimensions, the conditions of clause 6 should be taken intoaccount.SIST EN 12789:2004
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