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1、DD CEN/TS 15867:2009 ICS 81.060.30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW DRAFT FOR DEVELOPMENT Advanced technical ceramics Ceramic composites Guide to the determination of the degree of misalignment in uniaxial mechanical tests Licensed CopyChinese University of Hong
2、 Kong, 13/06/2009 08:46, Uncontrolled Copy, (c) BSI This Draft for Development was published under the authority of the Standards Policy and Strategy Committee on 30 April 2009 BSI 2009 ISBN 978 0 580 63940 1 Amendments/corrigenda issued since publication DateComments DD CEN/TS 15867:2009 National f
3、oreword This Draft for Development is the UK implementation of CEN/TS 15867:2009. This publication is not to be regarded as a British Standard. It is being issued in the Draft for Development series of publications and is of a provisional nature. It should be applied on this provisional basis, so th
4、at information and experience of its practical application can be obtained. Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the international organization responsible for its conversion to an international standard. A review of this
5、publication will be initiated not later than 3 years after its publication by the international organization so that a decision can be taken on its status. Notification of the start of the review period will be made in an announcement in the appropriate issue of Update Standards. According to the re
6、plies received by the end of the review period, the responsible BSI Committee will decide whether to support the conversion into an international Standard, to extend the life of the Technical Specification or to withdraw it. Comments should be sent to the Secretary of the responsible BSI Technical C
7、ommittee at British Standards House, 389 Chiswick High Road, London W4 4AL. The UK participation in its preparation was entrusted to Technical Committee RPI/13, Advanced technical ceramics. A list of organizations represented on this committee can be obtained on request to its secretary. This public
8、ation does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Licensed CopyChinese University of Hong Kong, 13/06/2009 08:46, Uncontrolled Copy, (c) BS
9、I DD CEN/TS 15867:2009 TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION CEN/TS 15867 March 2009 ICS 81.060.30 English Version Advanced technical ceramics - Ceramic composites - Guide to the determination of the degree of misalignment in uniaxial mechanical tests Cramiques tech
10、niques avances - Cramiques composites - Guide pour dterminer le degr de non- alignement des essais mcaniques uniaxiaux Hochleistungskeramik - Keramische Verbundwerkstoffe - Anleitung zur Bestimmung der Fluchtungsfehler bei mechanischen Prfungen mit einachsiger Beanspruchung This Technical Specificat
11、ion (CEN/TS) was approved by CEN on 3 February 2009 for provisional application. The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question whether the CEN/TS can be converted
12、into a European Standard. CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS) u
13、ntil the final decision about the possible conversion of the CEN/TS into an EN is reached. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Lux
14、embourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2009 CENAll rig
15、hts of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TS 15867:2009: E Licensed CopyChinese University of Hong Kong, 13/06/2009 08:46, Uncontrolled Copy, (c) BSI DD CEN/TS 15867:2009 CEN/TS 15867:2009 (E) 2 Contents Page Foreword 3? 1?Scope 4? 2?N
16、ormative references 4? 3?Terms and definitions .4? 4?Principle 5? 5?Apparatus .6? 5.1?Test machine 6? 5.2?Strain gauges .6? 5.3?Data recording system 7? 5.4?Micrometers 7? 6?Reference test specimens 7? 7?Reference test specimens preparation .9? 7.1?Adhesion of strain gauges 9? 7.2?Reference test spe
17、cimen validity .9? 8?Test procedure .9? 8.1?General 9? 8.2?Correction of the torsion defect .9? 8.3?Correction of the C defect 10? 8.4?Correction of the S defect 11? 8.5?Final verification before starting a series of measurements on CMCs . 12? 9?Test report . 12? Bibliography . 14? Licensed CopyChin
18、ese University of Hong Kong, 13/06/2009 08:46, Uncontrolled Copy, (c) BSI DD CEN/TS 15867:2009 CEN/TS 15867:2009 (E) 3 Foreword This document (CEN/TS 15867:2009) has been prepared by Technical Committee CEN/TC 184 “Advanced technical ceramics”, the secretariat of which is held by BSI. Attention is d
19、rawn to the possibility that 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. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the follo
20、wing countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia,
21、 Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Licensed CopyChinese University of Hong Kong, 13/06/2009 08:46, Uncontrolled Copy, (c) BSI DD CEN/TS 15867:2009 CEN/TS 15867:2009 (E) 4 1 Scope This Technical Specification provides guidance on: verifying the degree of misalignment of the
22、 load train of test machines, using a reference test specimen uniformly loaded in tension or in compression; correcting for defects caused by, e.g. torsion and bending. This document is not intended to provide a quantitative and acceptable limit before the testing of ceramic matrix composites with a
23、 fibre reinforcement: unidirectional (1D), bidirectional (2D) and tridirectional (xD, with 2 x 3) loaded along one principle axis of reinforcement. This limit depends on the sensitivity of each type of composite to the misalignment defect. NOTE 1 This limit is to be defined between the testing estab
24、lishment and the customer. NOTE 2 Monolithic ceramics are very sensitive to misalignment defects, while ceramic matrix composites (CMCs) in general are moderately sensitive to them. 2 Normative references The following referenced documents are indispensable for the application of this document. For
25、dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. CEN/TR 13233:2007, Advanced technical ceramics Notations and symbols EN ISO 7500-1, Metallic materials Verification of static uniaxial testing m
26、achines Part 1: Tension/compression testing machines Verification and calibration of the force measuring system (ISO 7500-1:2004) EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories (ISO/IEC 17025:2005) ISO 3611, Micrometer callipers for external measure
27、ment 3 Terms and definitions For the purposes of this document, the terms and definitions given in CEN/TR 13233:2007 and the following apply. 3.1 calibrated length l part of the reference test specimen which has a uniform and minimum cross section area 3.2 width b width of the reference test specime
28、n in the calibrated length 3.3 thickness h thickness of the reference test specimen in the calibrated length Licensed CopyChinese University of Hong Kong, 13/06/2009 08:46, Uncontrolled Copy, (c) BSI DD CEN/TS 15867:2009 CEN/TS 15867:2009 (E) 5 3.4 Type of defects 3.4.1 C type magnitude angle betwee
29、n the loading axis of each of the two grips (see Figure 1) 3.4.2 S type magnitude d distance between the loading axis when they are parallel (see Figure 2) 3.4.3 torsion defect magnitude angle between the gripping planes (see Figure 3) 4 Principle A rectangular cross section of a reference test spec
30、imen equipped with 10 strain gauges is loaded in tension or in compression up to a load corresponding to 10 % of the nominal load capacity of the load cell used for the tests of CMCs. The stress corresponding to this value does not exceed 50 % of the elasticity limit of the material used for the ref
31、erence test specimen. The readings obtained from the strain gauges bonded on the calibrated length of the reference test specimen allow the degree of misalignment to be determined. The positioning of strain gauges is such that it indicates the magnitude of defects. These magnitudes permit the practi
32、cal correction of the different types of defects: bending defects, either C (Figure 1) or S (Figure 2); or torsion (Figure 3). Indications for correction are obtained by comparing the experimental readings of the strain gauges to values from charts established from numerical simulations. Licensed Co
33、pyChinese University of Hong Kong, 13/06/2009 08:46, Uncontrolled Copy, (c) BSI DD CEN/TS 15867:2009 CEN/TS 15867:2009 (E) 6 Figure 1 C defect magnitude Figure 2 S defect magnitude Key 1 lower grip 2 upper grip Figure 3 Torsion defect magnitude 5 Apparatus 5.1 Test machine The configuration of the t
34、est machine, including the load train and load cell shall be identical to the test machine used for the tests on the CMCs and shall be in accordance with EN ISO 7500-1. 5.2 Strain gauges The principle of this method requires the use of strain gauges with an active surface equal to or smaller than 4
35、x 2 mm2. Furthermore, the distance between the edge of the test reference specimen and the longitudinal axis of the strain gauge shall be such as to avoid edge effects. A minimum distance of 2 mm is required. Care shall be taken to ensure that the strain gauge readings are not influenced by the surf
36、ace preparation and the adhesive used. Licensed CopyChinese University of Hong Kong, 13/06/2009 08:46, Uncontrolled Copy, (c) BSI DD CEN/TS 15867:2009 CEN/TS 15867:2009 (E) 7 5.3 Data recording system A calibrated recorder may be used to record load/strain curves. The use of a data recording system
37、combined with an analogue recorder is recommended. All strain measuring equipment and data acquisition systems shall be calibrated. They shall have an accuracy to within 0,5 % of the indicated reading or 3 microstrain, whichever is greater, and a resolution of 1 microstrain. 5.4 Micrometers Micromet
38、ers used for the measurement of the dimensions of the reference test specimen shall be in accordance with ISO 3611. 6 Reference test specimens The degree of misalignment of the load train of the test machine is verified by performing tests at room temperature with the following reference test specim
39、en: dimensions: see Figure 4; material: steel ISO reference; location of the strain gauges: see Figure 4. If another reference test specimen is used, it is necessary to establish a new series of charts. Plan parallelism of the faces 0,02 mm. Dimensions of the strain gauges, in millimetres: 2 4 Licen
40、sed CopyChinese University of Hong Kong, 13/06/2009 08:46, Uncontrolled Copy, (c) BSI DD CEN/TS 15867:2009 CEN/TS 15867:2009 (E) 8 NOTE Gauge n 5 is a rosette allowing measurements of strains parallel to 1 and to 45. Figure 4 Dimensions of the reference test specimen and location of the strain gauge
41、s Licensed CopyChinese University of Hong Kong, 13/06/2009 08:46, Uncontrolled Copy, (c) BSI DD CEN/TS 15867:2009 CEN/TS 15867:2009 (E) 9 7 Reference test specimens preparation 7.1 Adhesion of strain gauges It is essential to protect strain gauges and adhesives from effects due to moisture and other
42、 degrading contaminants. Therefore it is recommended that, after installation of the strain gauges, a layer of protective coating material such as strain-gauge-grade silicone rubber is applied. 7.2 Reference test specimen validity Periodically check the response of the strain gauges by comparing the
43、 Youngs modulus of the steel (from which the reference test specimen is made) determined for each location of the strain gauges, to the value of the Young modulus determined during the first utilization of the reference test specimen by the same method. The difference between these two values shall
44、not exceed 5 %. This value shall be indicated more accurately when more experimental results are made available. It is recommended to do this verification once a year. 8 Test procedure 8.1 General The procedure consists of the following sequence. 8.2 Correction of the torsion defect The reference te
45、st specimen is gripped while keeping the uniaxial load at 0, by using a specific mounting tool that secures a strict parallelism between the loading axis and the longitudinal axis of the reference test specimen. To check it, compare responses given by gauges 1 and 2. Record the reading of strain gau
46、ges at position 5 and calculate the distortion (+45 - -45). This value allows the torsion defect to be determined using chart 1 (see Figure 5). If this value is higher than the authorized limit, a correction of the angle between the two grips shall be made. The above procedure is repeated until the
47、value of the angle is less or equal to the authorized limit. Licensed CopyChinese University of Hong Kong, 13/06/2009 08:46, Uncontrolled Copy, (c) BSI DD CEN/TS 15867:2009 CEN/TS 15867:2009 (E) 10 NOTE is in C and the other dimensions are in millimetres. Figure 5 Chart 1: torsion defect 8.3 Correct
48、ion of the C defect Load the reference test specimen to stretch the load train. Record the longitudinal readings of the strain gauges located at position 4 (1,4) and 5 (1,5): see specimen drawing in Figure 4 given by strain gauges no. 4 and no. 5 respectively and see dimensions in Table 1. Calculate
49、 the value of (1,4 - 1,5) and determine the C defect using chart 2 (see Figure 6). If this value is higher than the authorized limit, a correction of the angle between the loading axis of each of the two grips shall be made. The above procedure is repeated until the value of the angle is less or equal to the authorized limit. Then unload the reference test specimen. Table 1 Strain gauges dimensions Dimensions mm Tolerances mm l, length with strain gauges 100 0,1 t, thickness 4 0,1 b, widt