DIN EN 14081-2-2013 Timber structures - Strength graded structural timber with rectangular cross section - Part 2 Machine grading additional requirements for initial type testing G.pdf

1、March 2013 Translation by DIN-Sprachendienst.English price group 12No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS

2、79.040!$0“1961393www.din.deDDIN EN 14081-2Timber structures Strength graded structural timber with rectangular cross section Part 2: Machine grading; additional requirements for initial type testing;English version EN 14081-2:2010+A1:2012,English translation of DIN EN 14081-2:2013-03Holzbauwerke Nac

3、h Festigkeit sortiertes Bauholz fr tragende Zwecke mit rechteckigem Querschnitt Teil 2: Maschinelle Sortierung; zustzliche Anforderungen an die Erstprfung;Englische Fassung EN 14081-2:2010+A1:2012,Englische bersetzung von DIN EN 14081-2:2013-03Structures en bois Bois de structure de section rectangu

4、laire class selon la rsistance Partie 2: Classement mcanique Exigences supplmentaires concernant les essais detype initiaux;Version anglaise EN 14081-2:2010+A1:2012,Traduction anglaise de DIN EN 14081-2:2013-03SupersedesDIN EN 14081-2:2010-11www.beuth.deIn case of doubt, the German-language original

5、 shall be considered authoritative.Document comprises 23 pages 02.13 DIN EN 14081-2:2013-03 2 A comma is used as the decimal marker. National foreword This document (EN 14081-2:2010+A1:2012) has been prepared by Technical Committee CEN/TC 124 “Timber structures” (Secretariat: AFNOR, France). The res

6、ponsible German body involved in its preparation was the Normenausschuss Bauwesen (Building and Civil Engineering Standards Committee), Working Committee NA 005-04-01 AA Holzbau (SpA CEN/TC 124, CEN/TC 250/SC 5). Amendments This standard differs from DIN EN 14081-2:2010-11 as follows: a) in Clauses

7、2 and 3, the references to DIN EN 14081-1 are now undated. Previous editions DIN EN 518: 1996-07 DIN EN 519: 1996-07 DIN EN 14081-2: 2006-03, 2010-11 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 14081-2:2010+A1 November 2012 ICS 79.040 Supersedes EN 14081-2:2010English Version Timber structu

8、res - Strength graded structural timber with rectangular cross section - Part 2: Machine grading; additional requirements for initial type testing Structures en bois - Bois de structure de section rectangulaire class selon la rsistance - Partie 2: Classement mcanique - Exigences supplmentaires conce

9、rnant les essais de type initiaux Holzbauwerke - Nach Festigkeit sortiertes Bauholz fr tragende Zwecke mit rechteckigem Querschnitt - Teil 2: Maschinelle Sortierung; zustzliche Anforderungen an die Erstprfung This European Standard was approved by CEN on 5 May 2010 and includes Amendment 1 approved

10、by CEN on 8 October 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which 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 stan

11、dards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard 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 n

12、otified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary,

13、 Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management C

14、entre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14081-2:2010+A1:2012: EEN 14081-2:2010+A1:2012 (E) 2 Contents Page Foreword 3Introduction .41 Scope 52 Normative references 53 Terms and

15、definitions .54 Symbols 65 Requirements for strength grading machines 76 Additional requirements for initial type testing for machine controlled systems 86.1 General 86.2 Requirements for the derivation and verification of machine settings86.3 Machine installation check 147 Additional requirements f

16、or initial type testing for output controlled systems . 157.1 General . 157.2 Requirements for the assessment of initial settings 15Annex A (normative) Calculation of elementary cost matrix values for 6.2.4.8 . 17A.1 General . 17A.2 Factors for wrongly upgraded pieces. 17A.3 Factors for wrongly down

17、graded pieces . 17Annex B (informative) Guidance on the procedure of initial type testing for machine controlled systems 19B.1 Introduction . 19B.2 Guidance 19Bibliography . 21DIN EN 14081-2:2013-03EN 14081-2:2010+A1:2012 (E) 3 Foreword This document (EN 14081-2:2010+A1:2012) has been prepared by Te

18、chnical Committee CEN/TC 124 “Timber structures”, 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 May 2013, and conflicting national standards shall be w

19、ithdrawn at the latest by May 2013. Attention is drawn 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. This document supersedes !EN 14081-2:2010.“ This d

20、ocument includes Amendment 1 approved by CEN on 8 October 2012. The start and finish of text introduced or altered by amendment is indicated in the text by tags !“. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and su

21、pports essential requirements of EU Directive(s). Other parts of the EN 14081 series are: EN 14081-1, Timber structures Strength graded structural timber with rectangular cross section Part 1: General requirements; EN 14081-3, Timber structures Strength graded structural timber with rectangular cros

22、s section Part 3: Machine grading; additional requirements for factory production control EN 14081-4, Timber structures Strength graded structural timber with rectangular cross section Part 4: Machine grading Grading machine settings for machine controlled systems According to the CEN/CENELEC Intern

23、al Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ire

24、land, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. DIN EN 14081-2:2013-03EN 14081-2:2010+A1:2012 (E) 4 Introduction Machine grading is in common use in a number of countries

25、. The countries use two basic systems, referred to as “output controlled“ and “machine controlled“. Both systems require a visual override inspection to cater for strength-reducing characteristics that are not automatically sensed by the machine. The output-controlled system is suitable for use wher

26、e the grading machines are situated in sawmills grading limited sizes, species and grades in repeated production runs of around one working shift or more. This enables the system to be controlled by testing timber specimens from the daily output. These tests together with statistical procedures are

27、used to monitor and adjust the machine settings to maintain the required strength properties for each strength class. With this system it is permissible for machine approval requirements to be less demanding and for machines of the same type to have non-identical performance. The machine controlled

28、system was developed in Europe. Because of the large number of sizes, species and grades used it was not possible to carry out quality control tests on timber specimens drawn from production. The system relies therefore on the machines being strictly assessed and controlled, and on considerable rese

29、arch effort to derive the machines settings, which remain constant for all machines of the same type. The acceptability of grading machines and the derivation of settings rely on statistical procedures and the results will therefore depend on the method used. For this reason this document gives appr

30、opriate statistical procedures. The requirements in this European Standard are based on machines in current use and on future types of machines as far as these can be foreseen. It is recognised that additional clauses or standards may be required if unforeseen developments take place. DIN EN 14081-2

31、:2013-03EN 14081-2:2010+A1:2012 (E) 5 1 Scope This European Standard specifies requirements, additional to those in EN 14081-1, for initial type testing of machine graded structural timber with rectangular cross sections shaped by sawing, planing or other methods, and having deviations from the targ

32、et sizes corresponding to EN 336. This includes requirements for strength grading machines and test equipment for proof loading graded material. 2 Normative references The following referenced documents are indispensable for the application of this European Standard. For dated references, only the e

33、dition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 338, Structural timber Strength classes EN 384, Structural timber Determination of characteristic values of mechanical properties and density EN 408:2003, Timber structu

34、res Structural timber and glued laminated timber Determination of some physical and mechanical properties !EN 14081-1, Timber structures Strength graded structural timber with rectangular cross section Part 1: General requirements“ EN 14081-3, Timber structures Strength graded structural timber with

35、 rectangular cross section Part 3: Machine grading; additional requirements for factory production control EN 14081-4, Timber structures Strength graded structural timber with rectangular cross section Part 4: Machine grading Grading machine settings for machine controlled systems 3 Terms and defini

36、tions For the purposes of this document, the terms and definitions given !in EN 14081-1 and the following apply.“ 3.1 characteristic strength population 5-percentile value obtained from the results of tests with a duration of (300 120) s using test pieces at an equilibrium moisture content resulting

37、 from a temperature of 20 C and a relative humidity of 65 % 3.2 characteristic stiffness population mean value obtained under the same test conditions as defined in 3.1 3.3 critical feed speed speed within the intended usable range at which the grading machine is least accurate in measuring its indi

38、cating property 3.4 depth dimension perpendicular to the longitudinal axis of a timber beam, in the plane of the bending forces DIN EN 14081-2:2013-03EN 14081-2:2010+A1:2012 (E) 6 3.5 grade determining property mechanical or physical property for which a particular value of that property should be a

39、chieved for the material to be assigned to that grade, e.g. bending strength, mean modulus of elasticity and density for the strength classes of EN 338 3.6 indicating property IP measurement or combination of measurements made by the grading machine, which are closely related to one or more of the g

40、rade determining properties NOTE For grading machines which compute and predict values of the grade determining properties directly from numerous measuring devices, the indicating property may be a predicted value of a grade determining property. 3.7 optimum grade highest grade, of those for which s

41、ettings are required, to which a piece of timber can be assigned, such that the grade determining properties of the graded sample will meet the values required for the grade 3.8 settings values of the parameters used to set the machine to grade timber, which are mathematically related to the indicat

42、ing property 3.9 sub-sample number of specimens of timber of one species or species combination, from one growth area or source of production 3.10 thickness lesser dimension perpendicular to the longitudinal axis of a piece of timber 4 Symbols b width of cross section (in millimetres) E theoretical

43、modulus of elasticity (in newtons per square millimetre) Epactual modulus of elasticity measured in a proof load test (in newtons per square millimetre) Eassignedmean modulus of elasticity for assigned grade (in newtons per square millimetre) Eoptimummean modulus of elasticity for optimum grade (in

44、newtons per square millimetre) E0,meancharacteristic mean modulus of elasticity parallel to grain (in newtons per square millimetre) F applied force (in newtons) Fpproof load (in newtons) fm,kcharacteristic bending strength (in newtons per square millimetre) fpproof stress (in newtons per square mil

45、limetre) h depth of cross section (in millimetres) DIN EN 14081-2:2013-03EN 14081-2:2010+A1:2012 (E) 7 khsize factor l span (in millimetres) t thickness (in millimetres) w deflection or deformation (in millimetres) achachieved safety index tartarget safety index deflection (in millimetres) mean valu

46、e of bending strength for the optimum or assigned strength classes (in newtons per square millimetre) 5 Requirements for strength grading machines 5.1 The machine shall be of a type that meets the requirements given in Clauses 5 and 6 if it is part of a machine-controlled system, or Clauses 5 and 7

47、if it is part of an output controlled system. It shall be installed and set up according to the manufacturers specification and to any additional requirements resulting from the tests given here. In addition, except when a grading machine operates by measuring the bending stiffness of timber, the in

48、stallation and calibration shall be checked by the use of control planks, using the procedures given in EN 14081-3 under requirements for the use of control planks. 5.2 The following information shall be provided in the manufacturers specification for the machine: a) specification and description of the mechanical and electrical operation of the machine, and the software (this includes information on data process