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1、TECHNICAL REPORT ISO/TR 12735-2 First edition 1996-l 2-l 5 Mechanical testing of metals - Symbols used with their definitions - Part 2: Recommendations for the development of symbols and definitions Essais mkaniques des m - type 2, when the subject is still under technical development or where for a
2、ny other reason there is the future but not immediate possibility of an agreement on an International Standard; - type 3, when a technical committee has collected data of a different kind from that which is normally published as an International Standard (“state of the art”, for example). Technical
3、Reports of types 1 and 2 are subject to review within three years of publication, to decide whether they can be transformed into International Standards. Technical Reports of type 3 do not necessarily have to be reviewed until the data they provide are considered to be no longer valid or useful. ISO
4、/TR 12735-2, which is a Technical Report of type 2, was prepared by Technical Committee ISO/TC 164, Mechanical testing of metals. lSO/TR 12735 consists of the following parts, under the general title Mechanical testing of metals - Symbols used with their definitions: - Part 1: Symbols and definition
5、s in published standards - Part 2: Recommendations for the development of symbols and definitions 0 IS0 1996 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and mi
6、crofilm, without permission in writing from the publisher. International Organization for Standardization Case Postale 56 l CH-1211 Geneve 20 l Switzerland Printed in Switzerland ii Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technica
7、l Standards 1/9972545001 Not for Resale, 04/24/2007 23:21:51 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 ISO/TR 127352:1996(E) Introduction This part of ISO/TR 12735 has been prepared to provide the appropriate means of avoiding contradiction and misunderstanding an
8、d to standardize various kinds of symbols and their definitions generally used in ISO/TC 164 documents. Wherever possible the same symbol has been used to denote the same type of parameter in different tests but differing types of test piece, product form and test have to be taken into account. This
9、 has not been universally possible and symbols should always be considered in the context of the specific method of test being used. Symbols are attached to concepts and phenomena in order to communicate data succinctly. They must be simple to use and readily comprehensible in both speech and writin
10、g across geographical frontiers and language barriers. III Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 23:21:51 MDTNo reproduction or networking permitted without license fro
11、m IHS -,-,- TECHNICAL REPORT 0 IS0 ISO/TR 12735-2: 1996(E) Mechanical testing of metals - Symbols used with their definitions - Part 2: Recommendations for the development of symbols and definitions 1 Scope This part of ISO/TR 12735 contains recommendations on the choice of definitions and symbols t
12、o be used in IS0 International Standards for methods of mechanical testing of metallic materials which are the specific responsibility of Technical Committee lSO/TC 164. It establishes the procedure for co-ordinating the adoption of suitable symbols between WG 1 and the technical subcommittees of IS
13、OjTC 164. Furthermore, it establishes a procedure for the review of both parts of the document itself at regular intervals by ISO/TC 164 WG 1. 2 The use of definitions (See ISO/IEC Directives, Part 3, annex B.1.4.) 2.1 A definition is a statement of the precise meaning of a word or term. 2.2 The use
14、 of a definition in a standard prepared by a TC 164 subcommittee is recommended under the following conditions. 2.2.7 Where one of many widely used meanings of a word or a term is to be applied. 2.2.2 When the word or term is not widely recognized, because it is specific only to the test or type of
15、test to which the standard refers. 2.2.3 If the subcommittee believes that ambiguity may arise if a definition of the word or term is not included in the standard. 2.3 Definitions are gathered in a clause which follows immediately after “Normative references”. 2.4 It is recommended that the definiti
16、ons be listed in alphabetical order. The purpose is to ease the task of locating the definition for readers of the standard, who will generally be referring back from subsequent clauses to refresh their minds on the precise meaning of a word or a term. NOTE - In many standards however, symbols and d
17、efinitions are presented in their order of importance or order of use within the body of the standard. 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 23:21:51 MDTNo reproducti
18、on or networking permitted without license from IHS -,-,- ISO/TR 12735-2:1996(E) 0 IS0 2.5 It is recommended that each definition be given a sub-clause number to assist communication between readers. 3 The use of symbols 3.1 A symbol is a combination of marks or characters representing a concept, an
19、 object, a measurement or a process. 3.2 The purpose in using a symbol is to reduce the time and space required to transmit the concept or the data attached to the concept from person to person, visually or verbally, while simultaneously reducing the effort required on the part of the receiver to co
20、mprehend the information. 3.3 It is recommended that symbols be employed whenever this purpose can be achieved. 3.4 Symbols are built up from components in a formal structure as described in clause 5. 3.5 Mathematical symbols already widely used to represent algebraic or analytic functions such as i
21、ntegration or summation shall not be used within lSO/TC 164 to represent other concepts. 3.6 Symbols are to be first presented in tabular form, the appropriate clause and table to follow immediately after the Definitions (see 2.3). 3.7 It is recommended that the symbol table comprise one or two head
22、er rows for numbering and titling the table, followed by three vertical columns for: a) the symbols themselves; b) the units in which the data relevant to the symbol are presented; cl the designation or concept which the symbol is to represent in the rest of the document. NOTE - The word Designation
23、 is preferred to the word Definition as the heading for the 3rd column of the symbols table Part 1 of lSO/TR 12735 contains many examples. 3.8 It is recommended that the tables be presented in alphabetical order of the symbols used (see 2.4). 3.9 It is recommended that, when printed, symbols represe
24、nting variables be set in italic script to distinguish them from surrounding text. 4 Explanatory figures 4.1 Comprehension and communication of the concept behind a symbol or definition, or the application of that concept, will often be enhanced by the inclusion of a figure. 4.2 It is recommended th
25、at figures be used wherever beneficial. 4.3 Figures shall always be drafted in accordance with current IS0 rules. (See ISO/IEC Directives, Part 3, 4.3.) 4.4 If a figure is used to illustrate one or more concepts and includes the symbols used to designate those concepts, then the figure should be ref
26、erenced in the designation column of the symbol table see 3.7 a) as part of the designation for each of those symbols. 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 23:21:51
27、MDTNo reproduction or networking permitted without license from IHS -,-,- 0 IS0 ISO/TR 127352: 1996(E) 5 The components of a symbol 5.1 When preparing a standard, it is often necessary to distinguish between: a) several different states of a single parameter, or b) several different but closely rela
28、ted items from a single class of parameter. 5.2 In order to achieve clarity, symbols are built up from an essential root and three other possible elements, a suffix, a prefix and a signifier. 5.2.1 The general rule is to minimize the number of elements employed and the number of characters within ea
29、ch element. 5.2.2 Where a single parameter achieves or is measured in several different states see 5.1 a), a suffix of a single numerical character to identify each state will often be sufficient. For example: Xi where i = 1, 2, . . . . 10 5.2.3 However, where there exist numerous different states o
30、r interpretations of a class of parameters, brevity may reduce the ability to communicate with clarity (see 5.4.1). 5.3 The root This is the basic element of every symbol to be used. It consists of one or more characters that identify the single parameter or the single class of parameter (see 5.1).
31、5.3.1 The characters shall be letters from recognized alphabets. Numbers shall not be used. 5.3.2 A compound root is one consisting of several upper case characters, combined and treated as a single symbol. Each of the various hardness scales is so identified as is the Erichsen Cupping Index. The le
32、ading character in all symbols for hardness scales is H. For example: HBW, HV, HRC, HRK 5.3.3 When printed, the characters are at full size in the chosen font and they are placed on the baseline of the main text. 5.4 A suffix This is the preferred choice of identifier to distinguish between two diff
33、erent but closely related parameters having the same root. The suffix immediately follows that root both in speech and on the printed page. For example, in the symbol LR, L is the root and R is the suffix. 5.4.1 Where there are many different possible interpretations of the application of a root, th
34、e requirement for clarity of communication may be better met by using a suffix that is a word or part of a word to identify particular categories. For example, in a complex stress field with many states of stress, it may be better to identify concepts such as total and notch stresses as ototar and O
35、r,- strain (deformation/original length). 4 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 23:21:51 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0
36、 ISO/TR 12735-2:1996(E) 6.3.2 Ratios between parameters of different dimensions shall be given lower case Greek letters where a conflict with other recommendations contained herein may occur. For example, stress (force/area), for which o(sigma) may be used in preference to S, a reserved symbol (see
37、6.4). 6.3.3 Linear dimensions and combinations of linear dimensions shall be represented by letters from the Roman alphabet. 6.3.4 Where a pair of similar dimensions is to be represented, the one larger than the other, it is permissible to use for the root of the symbol the upper case letter for the
38、 greater dimension and the lower case letter for the smaller. For example, D and d for the outer and inner diameters of a tube. 6.4 In addition to the restrictions in 5.3, some characters are reserved for use in designating particular classes of parameter. These are identified in table 1 ( : ( : I (
39、 I ( I I I 1 ! I I Table 1 - Symbol roots - reserved characters Designation Symbol Irack tip opening displacement 6 jtrain 77.040.10 Descriptors: metals, metal products, tests, mechanlcal tests, ldentiflcation methods, numeric codes, designation, symbols, definitions, development (work). Price based on 6 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 23:21:51 MDTNo reproduction or networking permitted without license from IHS -,-,-