EN 384:2010
(Main)Structural timber - Determination of characteristic values of mechanical properties and density
Structural timber - Determination of characteristic values of mechanical properties and density
This European Standard gives a method for determining characteristic values of mechanical properties and density, for defined populations of visual and/or mechanical strength grades of sawn timber.
A method is also given for checking the strength of a timber sample against its designated value.
The values determined in accordance with this standard for mechanical properties and density are suitable for assigning grades and species to the strength classes of EN 338.
NOTE 1 For assigning grades and species to the strength classes in EN 338 only three characteristic values, i.e. bending strength, mean modulus of elasticity parallel to grain and density, need to be determined, other properties may be taken from the table in EN 338.
NOTE 2 EN 1912 gives examples of assignment to strength classes of established national or regional visual grades.
Bauholz für tragende Zwecke - Bestimmung charakteristischer Werte für mechanische Eigenschaften und Rohdichte
Diese Europäische Norm legt fest, wie charakteristische Werte für mechanische Eigenschaften und Rohdichtewerte von Schnittholz definierter Grundgesamtheiten von visuell und/oder maschinell nach der Festigkeit sortierte Sortierklassen zu bestimmen sind.
Außerdem wird ein Verfahren zur Überprüfung der Festigkeitswerte einer Probe zum Vergleich mit genormten Festigkeitswerten angegeben.
Die nach dieser Norm bestimmten mechanischen Eigenschaften und Rohdichtewerte sind für die Zuordnung der Holzarten und -klassen in die Festigkeitsklassen nach EN 338 geeignet.
ANMERKUNG 1 Für die Zuordnung der Holzarten und -klassen in die Festigkeitsklassen nach EN 338 ist die Bestimmung von nur drei charakteristischen Werten, d. h. Biegefestigkeit, Mittelwert des Elastizitätsmoduls, parallel zur Faserrichtung, und Rohdichte, erforderlich. Die übrigen Eigenschaften dürfen der in EN 338 angegebenen Tabelle entnommen werden.
ANMERKUNG 2 EN 1912 gibt Beispiele für die Zuordnung von Festigkeitsklassen von bewährten nationalen und regionalen visuellen Sortiergraden.
Structures en bois - Détermination des valeurs caractéristiques des propriétés mécaniques et de la masse volumique
La présente norme fournit une méthode permettant de déterminer des valeurs caractéristiques des propriétés
mécaniques et de la masse volumique, pour des populations de bois sciés définies, classées visuellement
et/ou mécaniquement.
Une méthode permettant de vérifier la résistance d’un échantillon de bois par rapport à une valeur spécifiée
est également fournie.
Les valeurs des propriétés mécaniques et de la masse volumique déterminées conformément à la présente
norme permettent d’affecter des classes et des essences aux classes de résistance de l'EN 338.
NOTE 1 Pour l’affectation des classes et des essences aux classes de résistance de l’EN 338, il suffit de déterminer
trois valeurs caractéristiques : à savoir la résistance à la flexion, le module d’élasticité moyen axial, ainsi que la masse
volumique ; d’autres propriétés peuvent être extraites du tableau de l’EN 338.
NOTE 2 L’EN 1912 fournit des exemples d’affectation de classes de résistance aux classements visuels nationaux ou
régionaux.
Konstrukcijski les - Ugotavljanje značilnih vrednosti mehanskih lastnosti in gostote
Ta evropski standard podaja metodo za določevanje značilnih vrednostih mehanskih lastnosti in gostote za določeno populacijo razredov na podlagi vizualnega in/ali mehanskega razvrščanja v razrede trdnosti rezanega lesa. Metoda je prav tako podana za preverjanje trdnosti vzorca lesa z njegovo določeno vrednostjo. Vrednosti, določene v skladu s tem standardom za mehanske lastnosti in gostoto, so primerne za označevanje razredov in vrst za razrede trdnosti iz EN 338.
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.JRVWRWHBauholz für tragende Zwecke - Bestimmung charakteristischen festigkeits-, Steifigkeits- und RohdichtewerteStructures en bois - Détermination des valeurs caractéristiques des propriétés mécaniques et de la masse volumiqueTimber structures - Determination of characteristic values of mechanical properties and density91.080.20Lesene konstrukcijeTimber structuresICS:Ta slovenski standard je istoveten z:EN 384:2010SIST EN 384:2010en,fr,de01-september-2010SIST EN 384:2010SLOVENSKI
STANDARDSIST EN 384:20041DGRPHãþD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 384
April 2010 ICS 79.040 Supersedes EN 384:2004English Version
Structural timber - Determination of characteristic values of mechanical properties and density
Structures en bois - Détermination des valeurs caractéristiques des propriétés mécaniques et de la masse volumique
Bauholz für tragende Zwecke - Bestimmung charakteristischer Werte für mechanische Eigenschaften und Rohdichte This European Standard was approved by CEN on 4 March 2010.
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 standards may be obtained on application to the CEN 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 notified to the CEN 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 384:2010: ESIST EN 384:2010
Form for declaring characteristic values . 17Bibliography . 19 SIST EN 384:2010
Structural codes can only function effectively if standard methods of determining the mechanical and physical properties exist.
Whilst total accuracy of characteristic values for any defined population is an aim, it is recognized that this is not achievable. A major aim of the procedures given in this standard is to produce characteristic values that are comparable in terms of the populations they represent. It is also important that the standard permits the use of as much existing test data as possible from various sampling and testing techniques.
Where methods are given to permit characteristic values to be determined from a less than ideal amount of structural size test data or from small, clear, defect-free specimen test data, reduction factors to reflect a lower degree of confidence are employed.
This standard covers the stages of population definition, sampling, testing and analysis and presentation of data in the determination of characteristic values. SIST EN 384:2010
A method is also given for checking the strength of a timber sample against its designated value.
The values determined in accordance with this standard for mechanical properties and density are suitable for assigning grades and species to the strength classes of EN 338. NOTE 1 For assigning grades and species to the strength classes in EN 338 only three characteristic values, i.e. bending strength, mean modulus of elasticity parallel to grain and density, need to be determined, other properties may be taken from the table in EN 338. NOTE 2 EN 1912 gives examples of assignment to strength classes of established national or regional visual grades. 2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 338, Structural timber — Strength classes EN 408, Timber structures — Structural timber and glued laminated timber — Determination of some physical and mechanical properties EN 1912, Structural timber
Strength classes
Assignment of visual grades and species EN 14081-1, Timber structures — Strength graded structural timber with rectangular cross section — Part 1: General requirements EN 14081-2, Timber structures — Strength graded structural timber with rectangular cross section — Part 2: Machine grading, additional requirements for initial type testing ISO 3131:1975, Wood — Determination of density for physical and mechanical tests 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 characteristic value generally, value that corresponds to a fractile of the statistical distribution of a timber property
NOTE For strength properties, modulus of elasticity and density the fractile is the 5-percentile. For modulus of elasticity, the mean value is also a characteristic value. 3.2 p-percentile value for which the probability of getting lower values is p % 3.3 population material for which the associated characteristic values are relevant SIST EN 384:2010
NOTE See 5.1. 3.5 small clear test test to determine mechanical properties of small defect-free specimens 3.6 specimen piece of timber for testing 3.7 thickness lesser dimension perpendicular to the longitudinal axis of a piece of timber 3.8 width greater dimension perpendicular to the longitudinal axis of a piece of timber 3.9 depth dimension perpendicular to the longitudinal axis of a timber beam, in the plane of the bending forces 4 Symbols and abbreviations
af
distance between the inner load points of the bending test (in millimetres)
COV coefficient of variation
E
mean modulus of elasticity for one sample (in newtons per square millimetre)
E0,mean
mean characteristic value of modulus of elasticity parallel to grain (in newtons per square millimetre)
E0,05
5-percentile characteristic value of modulus of elasticity parallel to grain (in newtons per square millimetre)
E90,mean
mean characteristic value of modulus of elasticity perpendicular to grain (in newtons per square millimetre)
Emean,acc
mean modulus of elasticity for an acceptable quality lot (in newtons per square millimetre)
Emean,unacc
mean modulus of elasticity for an unacceptable quality lot (in newtons per square millimetre)
f strength property
fc,0,k
characteristic value of compression strength parallel to grain (in newtons per square millimetre)
fc,90,k
characteristic value of compression strength perpendicular to grain (in newtons per square millimetre)
fk
characteristic value of strength (in newtons per square millimetre) SIST EN 384:2010
fm,k
characteristic value of bending strength (in newtons per square millimetre)
ft,0,k
characteristic value of tensile strength parallel to grain (in newtons per sq
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