BS EN 1007-5-2010 Advanced technical ceramics - Ceramic composites - Methods of test for reinforcements - Determination of distribution of tensile strength and of tensile strain to.pdf

1、BS EN1007-5:2010ICS 81.060.30NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDAdvanced technicalceramics Ceramiccomposites Methods of test forreinforcementsPart 5: Determination of distributionof tensile strength and of tensilestrain to failure of filaments withi

2、na multifilament tow at ambienttemperatureThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 30 April2010. BSI 2010ISBN 978 0 580 63432 1Amendments/corrigenda issued since publicationDate CommentsBS EN 1007-5:2010National forewordThis British Standa

3、rd is the UK implementation of EN 1007-5:2010. Itsupersedes BS EN 1007-5:2003 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee RPI/13, Advanced technical ceramics.A list of organizations represented on this committee can be obtained onrequest to its secr

4、etary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.BS EN 1007-5:2010EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1007-5

5、 March 2010 ICS 81.060.30 Supersedes EN 1007-5:2003English Version Advanced technical ceramics - Ceramic composites - Methods of test for reinforcements - Part 5: Determination of distribution of tensile strength and of tensile strain to failure of filaments within a multifilament tow at ambient tem

6、perature Cramiques techniques avances - Cramiques composites - Mthodes dessais pour renforts - Partie 5: Dtermination de la distribution de la rsistance en traction et de la dformation de traction la rupture des filaments dans un fil temprature ambiante Hochleistungskeramik - Keramische Verbundwerks

7、toffe - Verfahren zur Prfung der Faserverstrkungen - Teil 5: Bestimmung der Verteilung von Zugfestigkeit und Zugdehnung von Fasern im Faserbndel bei Raumtemperatur This European Standard was approved by CEN on 13 February 2010. CEN members are bound to comply with the CEN/CENELEC Internal Regulation

8、s 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 CEN Management Centre or to any CEN member. This Europ

9、ean 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 CEN Management Centre has the same status as the official versions. CEN members are the nat

10、ional standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switze

11、rland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. E

12、N 1007-5:2010: EBS EN 1007-5:2010EN 1007-5:2010 (E) 2 Contents page Foreword 31 Scope 42 Normative references 43 Terms and definitions . 44 Principle . 65 Significance and use . 66 Apparatus . 66.1 Tensile testing equipment 66.2 Load train . 66.3 Data recording . 77 Test specimens 77.1 General . 77.

13、2 Window type specimen . 77.3 Cylindrical end type specimen . 88 Test specimen preparation . 88.1 General . 88.2 Window type specimen . 88.3 Cylindrical end type specimen . 98.4 Number of test specimens . 98.5 Determination of the initial cross sectional area . 98.6 Determination of the gauge length

14、 109 Testing technique 109.1 Test specimen mounting 109.2 Selection of strain rate 109.3 Measurement . 119.4 Determination of load train compliance 119.5 Test validity 1110 Calculation of results 1110.1 Calculation of the parasitic load train compliances 1110.2 Determination of true origin . 1210.3

15、Construction of envelope curve and determination of instantaneous compliance Ct,j1210.4 Probability of filament rupture . 1310.5 Distribution of filament strain 1310.5.1 Calculation of filament strain . 1310.5.2 Distribution of filament strain 1310.6 Distribution of filament strength 1410.6.1 Initia

16、l cross sectional area . 1410.6.2 Elastic modulus (Youngs modulus) of the tow . 1410.6.3 Calculation of filament strength and filament strength distribution 1510.7 Average filament rupture strain and average filament rupture strength . 1510.8 Overall average filament rupture strain and overall avera

17、ge filament rupture strength . 1510.9 Calculation of tow strength 1611 Test report 16Bibliography 18BS EN 1007-5:2010EN 1007-5:2010 (E) 3 Foreword This document (EN 1007-5:2010) has been prepared by Technical Committee CEN/TC 184 “Advanced technical ceramics”, the secretariat of which is held by BSI

18、. 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 September 2010, and conflicting national standards shall be withdrawn at the latest by September 2010. Attention is drawn to the possibility that

19、some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 1007-5:2003. EN 1007 Advanced technical ceramics Ceramic composites Methods of test for reinforcement

20、s has 7 parts: Part 1: Determination of size content Part 2: Determination of linear density Part 3: Determination of filament diameter and cross-section area Part 4: Determination of tensile properties of filaments at ambient temperature Part 5: Determination of distribution of tensile strength and

21、 of tensile strain to failure of filaments within a multifilament tow at ambient temperature Part 6: Determination of tensile properties of filaments at high temperature Part 7: Determination of the distribution of tensile strength and of tensile strain to failure of filaments within a multifilament

22、 tow at high temperature According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece,

23、Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 1007-5:2010EN 1007-5:2010 (E) 4 1 Scope This European Standard specifies the conditions, apparatus and

24、procedure for determining the distribution of tensile strength and tensile strain to failure of ceramic filaments in multifilament tows at ambient temperature. This European Standard applies to tows of continuous ceramic filaments, which are assumed to act freely and independently under loading, and

25、 behave linearly elastic up to failure. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendme

26、nts) applies. EN 1007-2, Advanced technical ceramics Ceramic composites Methods of test for reinforcement Part 2: Determination of linear density CEN/TR 13233:2007, Advanced technical ceramics Notations and symbols ISO 10119, Carbon fibre Determination of density 3 Terms and definitions For the purp

27、oses of this document, the terms and definitions given in CEN/TR 13233:2007 and the following apply. 3.1 gauge length L0initial distance between two reference points on the tow NOTE Usually the gauge length is taken as the distance between the gripped ends of the tow. 3.2 initial cross sectional are

28、a A0sum of the cross sectional areas of all the filaments in the tow 3.3 tow elongation L increase of the gauge length between the two reference points on the tow 3.4 tow strain ratio of the tow elongation L to the gauge length Lo3.5 tow maximum tensile force Ftow highest recorded tensile force on t

29、he test specimen when tested to failure BS EN 1007-5:2010EN 1007-5:2010 (E) 5 3.6 tow strength towratio of the tow maximum tensile force to the cross sectional area of all unbroken filaments at maximum tensile force, Ftow3.7 force at step j Fjforce applied on the test specimen at step j 3.8 filament

30、 strain jstrain at step j in the non-linear parts of the force-displacement graph 3.9 filament stress jratio of the tensile force to the cross sectional area of all unbroken filaments at step j in the non-linear parts of the force-displacement curve 3.10 average filament rupture strain rstatistical

31、average rupture strain of the filaments in the tow for each test determined from the Weibull strain distribution parameters of the filaments 3.11 overall average filament rupture strain rarithmetic mean of the average filament rupture strains 3.12 average filament strength rstatistical average stren

32、gth of the filaments in the tow for each test determined from the Weibull strength distribution parameters of the filaments 3.13 overall average filament strength rarithmetic mean of the average filament strengths 3.14 compliances 3.14.1 initial total compliance Ctinverse slope of the linear part of

33、 the force-displacement curve 3.14.2 instantaneous total compliance Ct,jinverse slope of the secant at any point j in the non-linear part of the force-displacement curve BS EN 1007-5:2010EN 1007-5:2010 (E) 6 NOTE The slope is taken from a line through any point of the force-displacement curve and th

34、e intersection point of the line of the initial total compliance with the abscissa (true origin). 3.14.3 load train compliance Clratio of the cross head displacement to the force, excluding any contribution of the test specimen to the displacement during the tensile test 3.14.4 compliance of the tow

35、 Ctowinstantaneous total compliance of the tow at maximum tensile force 4 Principle A multifilament tow is loaded in tension. The test is performed at a constant displacement rate up to failure of all fibres. Force and cross-head displacement are measured and recorded simultaneously. When required,

36、the longitudinal deformation is derived from the cross-head displacement using a compliance correction. From the force-displacement curve, the two-parameter Weibull distribution of the rupture strain and the distribution of the rupture strength of the filaments are obtained by sampling the non-linea

37、r parts of the curve at discrete intervals j, which correspond to an increasing number of failed filaments in the tow. The test duration is limited to reduce time dependent effects. 5 Significance and use The measurement of strain directly on the tow is difficult, so it is usually achieved indirectl

38、y via a compliance measurement that includes contributions of the loading train, grips, tab materials, etc. When it is possible to measure the tow elongation directly (by using a suitable extensometer system) this correction is not needed. The calculation of the results in Clause 10 also applies in

39、this case by setting the load train compliance equal to zero. The evaluation method is based on an analysis of the non-linear increasing and decreasing parts of the force-displacement curve, which are caused by progressive filament failure during the test. The occurrence of these stages is promoted

40、by a higher stiffness of the loading and gripping system. This method of evaluation is only applicable when the force-displacement curve shows these non-linear parts. The distribution of filament rupture strains does not depend on the number of filaments in the tow and is hence not affected by the n

41、umber of filaments that are broken before the test. The determination of the filament strength distribution and of the elastic modulus necessitates knowledge of the initial cross sectional area of the tow. Because the number of unbroken filaments within the tow prior to the test is usually unknown,

42、the values for the filament strength and for the elastic modulus necessarily represent lower bounds to these quantities. Also, the variation in filament diameter, which affects the strength values, is not accounted for. 6 Apparatus 6.1 Tensile testing equipment The test machine shall be equipped wit

43、h a system for measuring the force applied to the specimen and the displacement, or directly the tow elongation. Additionally, the machine shall be equipped with a system for measuring the crosshead displacement with accuracy better than 1 m. 6.2 Load train The grips shall align the test specimen wi

44、th the direction of the force. Slippage of the test specimen in the grips shall be prevented as well as avoiding pre-damage due to gripping. BS EN 1007-5:2010EN 1007-5:2010 (E) 7 NOTE The use of a displacement transducer placed at the ends of the grips (see Figure 1) should limit the contribution of

45、 different parts of the load train to the measured displacement, and hence should increase the accuracy. Key 1 displacement transducer 2 grips 3 tow Figure 1 Displacement transducer at the ends of the grips (principle sketch) 6.3 Data recording A calibrated recorder shall be used to record force-dis

46、placement curves. The use of a digital data recording system combined with an analogue recorder is recommended. 7 Test specimens 7.1 General Specimens with a gauge length of 200 mm shall be used to establish the filament strength and filament rupture strain distributions. Specimens with gauge length

47、s of 100 mm and 300 mm shall be used to determine, if necessary, the load train compliance. Examples of two types of test specimens are given below. 7.2 Window type specimen A window type specimen is shown in Figure 2. A stretched tow is fixed between two identical sheets of material (e.g. cardboard

48、 plates), each containing a central window. When the displacement is not measured directly on the tow, the height of the window defines the gauge length. NOTE This type of specimen has the advantage of easy handling. BS EN 1007-5:2010EN 1007-5:2010 (E) 8 Key 1 cardboard plates with window 2 tow 3 gl

49、ue 4 tow, glued between cardboard plates 5 tow, gauge length equals height of the window Figure 2 Window type specimen (principle sketch) 7.3 Cylindrical end type specimen A cylindrical end type specimen is shown in Figure 3. Both ends of a stretched tow are fixed (glued) in small diameter cylindrical tubes. When the displacement is not measured directl