1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 1438:1998 The Europ
2、ean Standard EN 1438:1998 has the status of a British Standard ICS 01.075; 79.040 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Symbols for timber and wood-based productsBS EN 1438:1998 This British Standard, having been prepared under the direction of the Sector Committee f
3、or Building and Civil Engineering, was published under the authority of the Standards Committee and comes into effect on 15 December 1998 BSI 1998 ISBN 0 580 30445 0 Amendments issued since publication Amd. No. Date Text affected National foreword This British Standard is the English language versio
4、n of EN 1438:1998. No existing British Standard is superseded. The UK participation in its preparation was entrusted by Technical Committee B/543, Round and sawn timber, to Subcommittee B/543/1, Timber terminology and measurement, which has the responsibility to: aid enquirers to understand the text
5、; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obt
6、ained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find”
7、facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal ob
8、ligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 7 and a back cover.CEN European Committee for Standardization Comite Europe en de Normalisation Europa isches Komitee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 B
9、russels 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1438:1998 E EUROPEAN STANDARD EN 1438 NORME EUROPE ENNE EUROPA ISCHE NORM August 1998 ICS 01.075; 79.040 Descriptors: wood, sawn timber, wood products, symbols, utilizati
10、on, standards English version Symbols for timber and wood-based products Symboles pour le bois et les produits a base de bois Symbole fu r Holz und Holzwerkstoffe This European Standard was approved by CEN on 19 July 1998. CEN members are bound to comply with the CEN/CENELEC Internal Regulations whi
11、ch 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 Central Secretariat or to any CEN member. This European Sta
12、ndard 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 Central Secretariat has the same status as the official versions. CEN members are the national sta
13、ndards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Page 2 EN 1438:1998 BSI 1998 Foreword This European Standard has been prepared by Technical
14、Committee CEN/TC 175, Round and sawn timber, the Secretariat of which is held by AFNOR. 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 February 1999, and conflicting national standards shall be w
15、ithdrawn at the latest by February 1999. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, It
16、aly, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. No existing European Standard is superseded. Contents Page Foreword 2 Introduction 3 1 Scope 3 2 Normative references 3 3 Letter types 3 4 Principles 3 5 Symbols in alphabetical order 5 5.1 Latin upper
17、 case Italic letters 5 5.2 Latin lower case Italic letters 5 5.3 Greek upper case Roman letters 6 5.4 Greek lower case Italic letters 6 5.5 General subscripts and subscripts formed from abbreviations or other combinations of letters Latin lower case Roman letters 6 5.6 Examples of combined subscript
18、s 7 6 Examples of symbols with subscripts 7 7 Special symbols 7Page 3 EN 1438:1998 BSI 1998 Table 2 Letter guide for the construction of symbols Type of letter Dimensions Usage Latin upper case Force, force times length, length to a power other than 1, temperature 1. Actions and action-effects 2. Ar
19、ea, first and second moment of area 3. Elastic moduli (exception to the general rule) 4. Temperature Latin lower case Length, quotient of length and time to a power, force per unit length or area, mass, time 1. Actions and action- effects per unit of length or area 2. Linear dimensions (length, widt
20、h, thickness, etc.) 3. Strengths 4. Velocity, acceleration, frequency 5. Descriptive letters (subscripts) 6. Mass 7. Time Greek upper case Reserved for mathematics and for physical quantities excluding geometrical and mechanical quantities Greek lower case Dimensions 1. Coefficients and dimensionles
21、s ratios 2. Strains 3. Angles 4. Densities (mass density and weight density) (exception to the general rule) 5. Stresses (exception to the general rule) NOTE Concepts not included in Table 2 should comply with the nearest appropriate category listed. Introduction Acceptable uniformity between standa
22、rds on timber and wood-based materials can only be obtained if a common technical language is used. Part of such a language is a set of symbols which should be used consistently throughout all timber related standards currently being drafted. ISO 3898 defines standard notations for structural design
23、. It covers only general notations which are necessary for this field of application and excludes notations relevant to a particular material (for example steel, concrete, wood) or to a specific technical field (for example foundations). Because of their anisotropic nature and other special features
24、, timber and wood-based products have a need for a unique set of symbols. The set of symbols in this European Standard tries to fulfil this need. It follows the general principles laid down in ISO 3898, not only for use in the design of timber structures, but also for the detailed aspects necessary
25、for timber in a wide range of standards and other documents. 1 Scope This standard defines a wide range of symbols for use in documents covering solid timber and all wood-based materials. Clause 5 follows the layout of ISO 3898. All the symbols are presented as letter types in alphabetical order. 2
26、Normative references This European Standard incorporates, by dated or undated reference, provisions from another publication. These normative references are cited at the appropriate places in the text and the publication is listed hereafter. For dated references, subsequent amendments to or revision
27、s of this publication apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. ISO 3898:1987, Bases for design of structures Notations General symbols. 3 Letter types Both upper case (capi
28、tal) and lower case (small) Latin and Greek letters appear in Roman (upright) and Italic (sloping) style, as shown in Table 1. Table 1 Letter types ROMAN ITALIC LATIN Upper case A, B, C etc. A, B, C etc. Lower case a, b, c etc. a, b, c etc. GREEK Upper case A,B,G etc. A, B, G etc. Lower case a,b,g e
29、tc. a, b, g etc. 4 Principles 4.1 The principal use of letters as symbols is as given in ISO 3898, see Table 2.Page 4 EN 1438:1998 BSI 1998 Figure 1 Coordinates Table 3 Symbols for and in relation to glued, laminated timber and wood-based panels Glued, laminated timber Wood-based panels Symbol Plywo
30、od, OSB and similar Particleboard, fibre board and similar Grain direction of laminae Grain direction of face *) veneer Machine or longitudinal *) direction l or x Perpendicular to grain direction of laminae, parallel to plane of joints Perpendicular to grain direction of face veneer parallel to glu
31、e lines (rolling shear) Perpendicular to machine or longitudinal direction, parallel to face t or y Perpendicular to plane of joints Perpendicular to face (through thickness) Perpendicular to face r or z *) Not necessarily the main direction. *) Can be marked on the panel with the symbol . 4.2 For s
32、ubstantive symbols this standard uses: Latin upper case Italic; Latin lower case Italic; Greek lower case Italic letters. For subscripts this standard uses: Latin lower case Roman or Italic letters. 4.3 Digits as well as units like N, kg, m, N/mm 2 and mathematical notations like , or shall always b
33、e printed in Roman. 4.4 For subscripts the use of small format letters and numbers is preferred. They shall be printed in Italic if they represent symbols for quantities (e.g.v y ), and in Roman if they represent abbreviations (e.g. f c, 0, k ). 4.5 In subscripts a comma followed by a space is used
34、for separation of different digits, letters, symbols or abbreviations. The comma(s) and the space(s) may be omitted where no confusion is expected. 4.6 The order of the different parts of a subscript is from basic to evaluated as in f ck for the characteristic value of the basic property compressive
35、 strength. 4.7 For mechanical properties of timber and wood-based products used in the design of structures the subscript k is normally used for the fifth percentile values of strength and modulus of elasticity, if this modulus is critical for strength, e.g. in the case of buckling. They are denoted
36、 as f k and E k respectively. Where the E-modulus is used to calculate (mean) values of deformation the mean value can be used, denominated E mean . If so desired, more precise denominations can be used, e.g. f 05 , f 50 , or any other value, to make clear that a52,a5 02 , or another percentile is m
37、eant. 4.8 Free choice between two symbols for one concept has been avoided as far as possible, e.g.: only Q (not V) for variable action; only V (not Q) for shear force. 4.9 Cartesian coordinates for a timber member are defined in Figure 1a). 4.10 Cross-sectional dimensions of a timber member are def
38、ined in Figure 1b). 4.11 The symbols l, t, r,o rx ,y ,zcan be used for glued, laminated timber or for panels, as in Table 3.Page 5 EN 1438:1998 BSI 1998 1) 2) With a subscript if it is necessary to define an imposed load more precisely. 5 Symbols in alphabetical order NOTE Symbols, marked with * in
39、this clause, have corresponding symbols in ISO 3898. 5.1 Latin upper case Italic letters NOTE Latin upper case Roman letters are not used in ISO 3898. Letter(s) Meaning A * area; accidental action D * flexural rigidity of plates and shells D flexural rigidity of panels and structural floor decking E
40、 * modulus of elasticity; earthquake action F * action in general; force in general G * shear modulus; permanent action (dead load) G self load; energy release rate H * horizontal component of a force I * second moment of plane area K * any quantity but with a proper unit in the absence of a specifi
41、c symbol K stress intensity factor; foundation modulus; displacement modulus L * can be used for span; length of a member L to be avoided for length M * moment in general; bending moment N * normal force O * to be avoided as far as possible P * prestressing force; probability (or p, see ISO 3898:198
42、7, Table 3) Q * variable action (live load) 1) R * resultant force; reaction force; resistance R racking stiffness of panel S * first moment of plane area (static moment); action-effect (solicitation); snow action (load) T * torsional moment; temperature; period of time T loading time V * shear forc
43、e; volume; vertical component of a force W * section modulus; wind action load W impact energy 5.2 Latin lower case Italic letters NOTE Latin lower case Roman letters are not used in ISO 3898. Letter(s) Meaning a * distance; acceleration b * width c * void Letter(s) Meaning d * diameter; depth (for
44、example foundation) e * eccentricity f * strength (of a material); frequency g * distributed permanent action (dead load); acceleration due to gravity h * height; thickness h depth (of beams); thickness of plates, shells, panels i * radius of gyration j * number of days j relaxation coefficient k *
45、coefficient k factor l * span; length of a member l length between two points m * mass; average value of a sample; bending moment per unit of length or width m(x) mean value of the quantity x n * normal force per unit of length or width; number of o * to be avoided p * pressure; probability (or P ,
46、see ISO 3898:1997, Table 2) p pitch q * distributed variable action (live load) 2) r * radius s * standard deviation of a sample; spacing; distributed snow action (load) s(x) standard deviation of the quantity x t * time in general; thickness of thin members; torsional moment per unit of length or w
47、idth t thickness of plates, shells, panels u * perimeter u * components of the displacement of a point, corresponding to the directions x,y,z in Figure 1. v * w * v * velocity; speed w * distributed wind action (load) x * coordinates y * z * z lever armPage 6 EN 1438:1998 BSI 1998 3) As far as possi
48、ble, abbreviations which are not contained in this sub-clause should be derived from words, preferably English, having Latin roots. If there is no risk of confusion, these subscripts can be reduced to one or two letters. 4) Other than subscripts for actions and action-effects (see ISO 3898:1987, Tab
49、le 7) and subscripts formed from abbreviations (see ISO 3898:1987, Table 8). 5) As opposed to observed . 6) This subscript should never be omitted. 7) If necessary, a suitable subscript can be added or substituted in order to define the elastic limit more precisely, for example y, 0, 1 . 8) If there is a risk of confusion, “net” shall be used. 5.3 Greek upper case Roman letters delta D * difference; increment 5.4 Greek lower case Italic letters Letter(s) Meaning alpha a * angle (in timber standards
