1、 ISO 2016 Glass in building Determination of the bending strength of glass Part 5: Coaxial double ring test on flat specimens with small test surface areas Verre dans la construction Dtermination de la rsistance du verre la flexion Partie 5: Essais avec doubles anneaux concentriques sur prouvettes p
2、lanes, avec de petites surfaces de sollicitation INTERNATIONAL STANDARD ISO 1288-5 First edition 2016-02-15 Reference number ISO 1288-5:2016(E) ISO 1288-5:2016(E)ii ISO 2016 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in Switzerland All rights reserved. Unless otherwise spec
3、ified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or I
4、SOs member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org ISO 1288-5:2016(E)Foreword iv 1 Scope . 1 2 Normative references 1 3 Terms and definitions . 1
5、 4 Symbols 1 5 Principle of test method . 2 6 Apparatus . 3 6.1 Testing machine . 3 6.2 Loading device. 3 6.3 Measuring instruments . 5 7 Sample . 5 7.1 Shape and dimensions of specimens . 5 7.2 Sampling and preparation of specimens 6 7.2.1 Cutting and handling 6 7.2.2 Conditioning 6 7.2.3 Examinati
6、on . 6 7.2.4 Adhesive film . 6 7.3 Number of specimens . 6 8 Procedure. 6 8.1 Temperature 6 8.2 Humidity . 6 8.3 Thickness measurement . 6 8.4 Base plate . 6 8.5 Positioning of specimen and loading ring . 7 8.6 Load application 7 8.7 Location of the origin 7 8.8 Assessment of residual stresses . 7 9
7、 Evaluation 7 9.1 Limitation of the evaluation 7 9.2 Calculation of bending strength . 8 10 Test report . 8 Bibliography 9 ISO 2016 All rights reserved iii Contents Page ISO 1288-5:2016(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standar
8、ds bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organi
9、zations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its f
10、urther maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/direc
11、tives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the
12、 Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the meaning of ISO specific terms and expressions relat
13、ed to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsible for this document is ISO/TC 160, Glass in building, Subcommittee SC 2, Use con
14、siderations in conjunction with Technical Committee CEN/TC 129, Glass in building. ISO 1288 consists of the following parts, under the general title Glass in building Determination of the bending strength of glass: Part 1: Fundamentals of testing glass Part 2: Coaxial double-ring test on flat specim
15、ens with large test surface areas Part 3: Test with specimen supported at two points (four-point bending) Part 4: Testing of channel-shaped glass Part 5: Coaxial double-ring test on flat specimens with small test surface areas This International Standard has been based on EN 1288-5, Glass in buildin
16、g Determination of the bending strength of glass Part 5: Coaxial double-ring test on flat specimens with small test surface areas prepared by Technical Committee CEN/TC 129 “Glass in building”. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following c
17、ountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.iv ISO 2016 All rights reserved INTERNATIONAL ST
18、ANDARD ISO 1288-5:2016(E) Glass in building Determination of the bending strength of glass Part 5: Coaxial double ring test on flat specimens with small test surface areas 1 Scope This part of ISO 1288 specifies a method for determining the comparative bending strength of glass for use in buildings,
19、 excluding the effects of the edges. See ISO 1288-1, 5.1.4 for an explanation as to why this test method should only be used for comparing the strength of types of glass and not for assessing strength for design purposes. The limitations of this part of ISO 1288 are described in ISO 1288-1. ISO 1288
20、-1 should be read in conjunction with this part of ISO 1288. This test method is not suitable for patterned glass. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only th
21、e edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 48, Rubber, vulcanized or thermoplastic Determination of hardness (hardness between 10 IRHD and 100 IRHD) 3 Terms and definitions For the purposes of this document,
22、the following terms and definitions apply. 3.1 bending stress tensile bending stress induced in the surface of a specimen Note 1 to entry: For testing purposes, the bending stress should be uniform over a specified part of the surface. 4 Symbols F load N F max load at breakage, “breaking load” N h t
23、hickness of specimen m L side length of square specimens m K 1 ,K 2 constants for calculation of bending stress ISO 2016 All rights reserved 1 ISO 1288-5:2016(E) r 1 radius of loading ring m r 2 radius of supporting ring m r 3 radius of circular specimens m r 3m average specimen radius (for evaluati
24、on) m t time s stress Pa bB bending strength Pa Poisson number of specimen NOTE for soda lime silicate glass (see ISO 16293-1), a value of 0,23 is used. F/t rate of increase of load N/s /t rate of increase of stress Pa/s 5 Principle of test method A circular or square plane-parallel specimen with ra
25、dius r 3 , or length of side L, resting on a supporting ring (radius r 2 ) shall be loaded by means of a loading ring (radius r 1 ) arranged concentrically relative to the supporting ring (see Figure 1). Outside the loading ring, the radial and tangential stresses in the specimen decrease towards th
26、e edge so that the risk of failure there is small. For limited loads, F, (depending on the values of r 1 , r 2 , r 3and h) there is, in the central region of the convexly bent specimen surface, a tensile stress field (see Reference 3) extending in all directions and uniform, the area in this field b
27、eing bounded by the loading ring. By increasing the load, F, the tensile stress in the middle of the specimen is increased at a constant rate until failure occurs, the expected point of failure being in the most severely stressed surface region defined by the loading ring. The bending strength, bB ,
28、 shall be calculated from the maximum load, F max , measured when failure occurs and the specimen thickness, h, taking into account the dimensions of the square or circular specimens and the value for Poisson number, , of the specimen.2 ISO 2016 All rights reserved ISO 1288-5:2016(E) Key 1 loading r
29、ing 2 specimen 3 supporting ring Figure 1 Test arrangement (indicating the principle), illustrated for a circular specimen 6 Apparatus 6.1 Testing machine The bending test shall be carried out using a suitable bending testing machine, which shall incorporate the following features. a) The stressing
30、of the specimen shall be capable of being applied from zero up to a maximum value in a manner which minimizes shock and is stepless. b) The stressing device shall be capable of the specified rate of stressing. c) The testing machine shall incorporate a load measuring device with a limit of error of
31、2,0 % within the measuring range. 6.2 Loading device The loading device shall be arranged as illustrated in Figure 2, with dimensions conforming to Table 1 for the two combinations of loading ring and supporting ring accepted for the coaxial double-ring bending test. ISO 2016 All rights reserved 3 I
32、SO 1288-5:2016(E) Key 1 specimen 2 base plate of hardened steel provided with a supporting ring 3 spacer of silicone rubber 4 loading ring of hardened steel 5 load transmitting member with a centring feature for the loading ring 6 spacer of paper or synthetic material approximately 0,1 mm thick 7 ad
33、justing jaw for centring the specimen 8 contact circle of loading ring 9 contact circle of supporting ring Figure 2 Loading device Table 1 Dimensions of loading ring and supporting ring Dimensions in millimetres Loading device Radius of loading ring r 1 Radius of supporting ring r 2 Radius r 3or L/2
34、 of specimen as specified in Table 2 R30 R45 R60 R105 6 9 20 35 30 45 60 105 33 50 120 210 The radius of curvature of the bearing surface of the supporting ring shall be 2,5 mm. The silicone rubber shall be 3 mm thick, or alternatively a rubber section, 3 mm thick, matched to the supporting ring wit
35、h a hardness of (40 10) IRHD (according to ISO 48).4 ISO 2016 All rights reserved ISO 1288-5:2016(E) The radius of curvature of the bearing surface of the loading ring shall be 2,5 mm. 6.3 Measuring instruments The following measuring instruments are required: a measuring instrument enabling the dia
36、meter or the length of the side of the specimen to be measured to the nearest 1 mm; a measuring instrument allowing the thickness of the specimen to be measured to the nearest 0,01 mm. 7 Sample 7.1 Shape and dimensions of specimens Circular or square specimens as specified in Table 2 and Table 3 sha
37、ll be used. Table 2 Dimensions of specimens Dimensions in millimetres Loading device Diameter (= 2r 3 ) or side length L Thickness hminimum maximum R30 R45 R60 R105 66 2 100 2 240 5 420 5 see Table 3 see Table 3 see Table 3 see Table 3 6 9 12 19 Table 3 Minimum thickness of specimens as a function o
38、f bending strength Dimensions in millimetres Bending strength bB MPa Minimum thickness of specimens for loading device R45 R30 R60 R105 bB 100 2,0 1,0 2,5 4,5 100 bB 200 2,5 1,5 3,5 6,0 200 bB 300 3,0 2,0 4,5 7, 5 300 bB 400 3,5 2,5 5,0 8,5 400 bB 500 3,5 2,5 5,5 9,5 500 bB 600 4,0 3,0 6,0 10,5 In c
39、ases in which not even the approximate value of the anticipated bending strength is known beforehand, the data given in the last line of Table 3 (values for bending strength up to 600 MPa) shall be taken for the minimum thickness of the specimens. After the first tests have been evaluated, the appro
40、priate minimum thickness shall be determined from Table 3. The following tolerances shall apply to that portion of the specimen bounded by the contact circle of the supporting ring: the flatness tolerance shall be 0,1 mm; the parallelism tolerance shall be 2 % of the specimen thickness. ISO 2016 All
41、 rights reserved 5 ISO 1288-5:2016(E) 7.2 Sampling and preparation of specimens 7.2.1 Cutting and handling The greatest care shall be taken that the test surface, which will be subsequently subjected to tensile stress, does not come into contact with tools, grinding agents, glass splinters, etc. and
42、 also is not damaged during storage. NOTE 1 In order to preserve specific surface conditions, the test surface can be provided with a protective coating (glued down) during specimen preparation. NOTE 2 The method of cutting specimens is not significant and no edge processing is necessary. 7.2.2 Cond
43、itioning Protective coatings shall be removed 24 h before the test (see ISO 1288-1). The specimen shall be stored in the test environment (see 8.1 and 8.2) for at least 4 h before testing. 7.2.3 Examination Before the bending strength test, all specimens shall be examined over the test surface area
44、for any faults which are not representative of the quality characteristics of the material tested. 7.2.4 Adhesive film To hold together the fragments, an adhesive film shall be fixed to the side of the specimen facing the loading ring. This facilitates location of the fracture origin and measurement
45、 of the specimen thickness. 7.3 Number of specimens The number of specimens to be tested shall be determined depending on the confidence limits required, especially with regard to estimating the extremes of the strength distribution (see ISO 1288-1 for a discussion of numbers of specimens). 8 Proced
46、ure 8.1 Temperature The coaxial ring bending test shall be carried out at a temperature of (23 5) C. During the test, the temperature of the specimen shall be kept constant to 1 C in order to avoid the development of thermal stresses. 8.2 Humidity The coaxial ring bending test shall be carried out a
47、t a relative humidity between 40 % and 70 %. 8.3 Thickness measurement To prevent damage from being caused to the surface by measuring instruments, the thickness shall be measured at four points on the edge of the specimen. The average shall be taken from these measured values. 8.4 Base plate The ba
48、se plate is centred by moving down the force transmitting component (without the loading ring and specimen) into the adjusting cone (see Figure 2). The base plate shall be locked in this position. 6 ISO 2016 All rights reserved ISO 1288-5:2016(E) Glass splinters and other hard and sharp-edged partic
49、les shall be cleaned from the supporting ring. Damage to the supporting ring shall be eliminated. 8.5 Positioning of specimen and loading ring The silicone rubber spacer shall be positioned between the specimen and the base plate in such a way that, at each point, it protrudes beyond the bearing annulus on each side by not less than 5 mm. The specimen shall be placed in position with the surface to be tested downwards. The loading ring, which has bee
