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1、BRITISH STANDARD BS EN 12369-2:2004 Wood-based panels Characteristic values for structural design Part 2: Plywood The European Standard EN 12369-2:2004 has the status of a British Standard ICS 79.060.10 ? BS EN 12369-2:2004 This British Standard, was published under the authority of the Standards Po
2、licy and Strategy Committee on 5 August 2004 BSI 5 August 2004 ISBN 0 580 44217 9 National foreword This British Standard is the official English language version of EN 12369-2:2004. The UK participation in its preparation was entrusted to Technical Committee B/541, Wood-based panels, which has the
3、responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. BS EN 12369-2 provides information on characteristic values for use in designing timber structures incorporating plywood in a similar way to the data for OSB, particleboard and vario
4、us types of fibreboard given in BS EN 12369-1. Users should be aware that the terminology and notation used in BS EN 12369-2 is different from that previously used for plywood in BS 5268-2. The symbols used are explained in 3.2 and it should be noted that the subscripts “0” and “90” are used to indi
5、cate the major and minor axes of the panels for plywood these are the axes parallel and perpendicular to the grain of the face veneer respectively. Bending properties are for flatwise bending only and no corresponding values are given for edgewise bending. The values are given as a series of strengt
6、h and modulus classes, linked to the corresponding classes in the product standard, BS EN 636. Separate classes should be assigned for the parallel and perpendicular directions. The tension and compression properties are not given as these vary significantly with lay-up and are not part of the manuf
7、acturers quality control procedures. Reference is given to other standards for methods of derivation of in-plane tension and compression properties by testing or by calculation for a known lay-up. No procedures are given for stress perpendicular to the plane of the panel. The term “panel shear” refe
8、rs to in-plane shear that tends to distort a rectangular section into a lozenge shape, as can occur in the web of an “I” beam. Planar shear refers to the in-plane shear stress that occurs in flatwise bending and at the interface of glued components. In this case the stresses tend to cause the layers
9、 of the panel to slide over each other. In BS 5268-2 this property is referred to as “rolling shear”. Conservative shear properties are given in Table 4, or alternatively values can be derived by testing. The characteristic values given are intended for use with Eurocode 5. These values can be conve
10、rted to permissible stresses for use with BS 5268-2 using modification factors given in 4.6 of that standard. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “Inter
11、national Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a Br
12、itish Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international
13、and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 11 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issue
14、d since publication Amd. No. DateComments EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12369-2 February 2004 ICS 79.060.10 English version Wood-based panels - Characteristic values for structural design - Part 2: Plywood Panneaux base de bois - Valeurs caractristiques pour la conception stru
15、cturelle - Partie 2: Contreplaqu Holzwerkstoffe - Charakteristiche Werte fr die Berechnung un Bemessung von Holzbauwerken - Teil 2: Sperrholz This European Standard was approved by CEN on 2 January 2004. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the co
16、nditions 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 Management Centre or to any CEN member. This European Standard exists in three
17、 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 Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austri
18、a, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZA
19、TION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2004 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12369-2:2004 E EN 12369-2:2004 (E) 2 ContentsPage Forewor
20、d. 3 1Scope . 4 2Normative references . 4 3Terms and definitions and symbols . 4 3.1Terms and definitions. 4 3.2Symbols. 6 4General. 6 5Characteristic values for plywood 7 5.1Introduction. 7 5.2EN 636: Plywood: Loadbearing panels for use in bending in all conditions 7 5.3Characteristic values for te
21、nsion and compression. 8 5.4Characteristic values for both panel and planar shear. 8 Annex A (informative) Format for the presentation of characteristic values. 10 Bibliography. 11 EN 12369-2:2004 (E) 3 Foreword This document (EN 12369-2:2004) has been prepared by Technical Committee CEN/TC 112 “Woo
22、d-based panels”, the secretariat of which is held by DIN. 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 August 2004, and conflicting national standards shall be withdrawn at the latest by August
23、 2004. This standard is intended to be used in conjunction with ENV 1995-1-1. NOTEprEN 1995-1-1 is in preparation. Annex A is informative. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard:
24、 Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 12369-2:2004 (E) 4 1 Sco
25、pe This European Standard provides information on the characteristic values for use in designing structures incorporating wood based panels. The characteristic values given are as defined in ENV 1995-1-1. This standard includes the characteristic values of the mechanical properties for plywood compl
26、ying with EN 636 and the requirements of EN 13986 when used in a bending mode. Advice on obtaining the characteristic values for tension and compression for plywood by either testing or calculation is provided. Conservative values for shear are also included. Characteristic values for OSB, particleb
27、oards and fibreboards are given in EN 12369-1. A further part of the standard for characteristic values of solid wood panels is in preparation. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are
28、 cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest ed
29、ition of the publication referred to applies (including amendments). EN 636, Plywood Specifications. EN 789, Timber structures Test methods Determination of mechanical properties of wood-based panels. EN 1058, Wood-based panels Determination of characteristics values of mechanical properties and den
30、sity. ENV 1995-1-1 (Eurocode 5), Design of timber structures Part 1-1: General rules and rules for buildings. 3 Terms and definitions and symbols 3.1 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. EN 12369-2:2004 (E) 5 3.1.1 characteristi
31、c value characteristic strength values are defined as the population 5-percentile values obtained from the results of tests with a duration of 300 s at equilibrium moisture content of the test pieces relating to a temperature of 20 C and a relative humidity of 65 %. Characteristic stiffness values a
32、re defined as either the population 5-percentile or the mean values obtained under the same test conditions as defined above. The stiffness values given in the tables are mean values as these are most commonly used in design. The note in annex A explains how to calculate the 5-percentile value. The
33、characteristic density is defined as the population 5-percentile value with mass and volume corresponding to equilibrium moisture content at a temperature of 20 C and a relative humidity of 65 %. This value is used in the design of joints in association with ENV 1995-1-1 3.1.2 service class three se
34、rvice classes are defined in ENV 1995-1-1. These are: Service class 1: is characterised by a moisture content in the materials corresponding to a temperature of 20 C and the relative humidity of the surrounding air only exceeding 65 % for a few weeks per year. Service class 2: is characterised by a
35、moisture content in the materials corresponding to a temperature of 20 C and the relative humidity of the surrounding air only exceeding 85 % for a few weeks per year. Service class 3: climatic conditions leading to higher moisture contents than in service class 2 3.1.3 load duration class for stren
36、gth and stiffness calculations actions are assigned to one of the load-duration classes given in Table 1. The load-duration classes are characterised by the effect of a constant load acting for a certain period of time in the life of the structure. For a variable action the appropriate class is dete
37、rmined on the basis of an estimate of the interaction between the typical variation of the load with time and the rheological properties of the materials Table 1 Load-duration classes Load-duration class Order of accumulated duration of characteristic load Examples of loading Permanentmore than 10 y
38、earsself weight Long-term6 months to 10 yearsstorage Medium-term1 week to 6 monthsimposed load Short-termless than one weeksnowa and wind Instantaneousaccidental load a In areas which have a heavy snow load for a prolonged period of time, part of the load should be regarded as medium-term EN 12369-2
39、:2004 (E) 6 3.2 Symbols In the Tables the following symbols are used: 3.2.1main symbols fStrength EModulus of elasticity (defined as stiffness in ENV 1995-1-1) GModulus of rigidity kRetention in strength (kmod) or stiffness (kdef) after a period of time relative to initial values. Values are include
40、d in ENV 1995-1-1 0In the direction of the grain of the outer layers of plywood 90Perpendicular to the direction of the grain of the outer layers of plywood 3.2.2subscripts mBending tTension cCompression vPanel shear rPlanar shear kCharacteristic mean Mean modStrength defDeflection 4 General The cha
41、racteristic values given in this standard are the minimum values applicable to products conforming to EN 636. Suppliers may present these values in a format similar to that in annex A. Alternatively, characteristic values other than those contained in this standard shall be determined using sampling
42、 techniques set out in EN 1058 and testing procedures given in EN 789, and declared in a format similar to that in annex A. EN 12369-2:2004 (E) 7 The characteristic values shall be supported by the following information: product description product specification service class or classes in which the
43、 panel can be used details of the veneer species and grade, and of the lay-up. 5 Characteristic values for plywood 5.1 Introduction This part of this European Standard gives information on the characteristic values of the mechanical properties for plywood in bending, the values of which correspond t
44、o a series of strength classes and modulus classes. Advice is given on the determination of the characteristic values in tension and compression by the combination of testing and calculation. Conservative values for shear are presented. 5.2 EN 636: Plywood: Loadbearing panels for use in bending in a
45、ll conditions Plywood should comply with the requirements of EN 636 for a specific service class or classes. When used structurally under service class 1 conditions, the characteristic values of the mechanical properties given in Tables 2 and 3 shall apply: these require to be modified according to
46、ENV 1995-1-1 for duration of load (kmod, kdef). When used structurally under service classes 2 and 3 conditions, the characteristic values of the mechanical properties given in Tables 2 and 3 shall be modified according to ENV 1995-1-1 for both service class and duration of load (kmod, kdef). Table
47、2 Characteristic bending strength values fm, k for a series of strength classes for plywood complying with EN 636 Class Minimum value fm, k characteristic bending strength (N/mm2) F 3 3 F 5 5 F 1010 F 1515 F 2020 F 2525 F 3030 F 4040 F 5050 F 6060 F 7070 F 8080 EN 12369-2:2004 (E) 8 Table 3 Mean ben
48、ding modulus values Em, mean for a series of modulus classes for plywood complying with EN 636 Class Minimum value Em, mean mean bending modulus (N/mm2) E 5 500 E 10 1 000 E 15 1 500 E 20 2 000 E 25 2 500 E 30 3 000 E 40 4 000 E 50 5 000 E 60 6 000 E 70 7 000 E 80 8 000 E 90 9 000 E 10010 000 E 1201
49、2 000 E 14014 000 The 5 % characteristic values for bending modulus (stiffness) should be taken as 0,8 times the mean values given in Table 3. A load bearing plywood is characterised by a set of four classes, two of which relate to its bending strength along and across the panel, while the other two classes relate to its bending modulus (stiffness) in the same two directions. The classes referred to in Tables 2 and 3 are the same as those defined in EN 636, th