BS EN 310-1993 Wood-based panels Determination of modulus of elasticity in bending and of bending strength《木基板 弯曲弹性模量和弯曲强度的测定》.pdf

1、BRITISH STANDARD BS EN 310:1993 Wood-based panels Determination of modulus of elasticity in bending and of bending strength The European Standard EN 310:1993 has the status of a British Standard UDC 674.03:620.172.225:620.174BSEN 310:1993 This British Standard, having been prepared under the directi

2、onof the Technical Sector Board for Building and Civil Engineering (B/-), was publishedunder the authorityofthe Standards Boardand comes into effect on 15 April 1993 BSI 03-1999 The following BSI references relate to the work on this standard: Committee reference B/541 Draft for comment 90/15587 DC

3、ISBN 0 580 21056 1 Cooperating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries. Austria Oesterreichisches Normungsinstitut Belgium Institut belge de

4、normalisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y. France Association franaise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland Ireland National Standards Au

5、thority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Asociacin Espaola de Normalizacin y Certificacin Sweden St

6、andardiseringskommissionen i Sverige Switzerland Association suisse de normalisation United Kingdom British Standards Institution Amendments issued since publication Amd. No. Date CommentsBSEN 310:1993 BSI 03-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii Fore

7、word 2 Text of EN 310 3 National annex NA (informative) Committees responsible Inside back cover National annex NB (informative) Cross-reference Inside back coverBSEN 310:1993 ii BSI 03-1999 National foreword This British Standard has been prepared under the direction of the Technical Sector Board f

8、or Building and Civil Engineering and is the English language version of EN310:1993 Wood-based panels Determination of modulus of elasticity in bending and of bending strength, published by the European Committee for Standardization (CEN). EN310 was produced as a result of international discussion i

9、n which the UK took an active part. The principle of this method is technically equivalent to A.10 and A.12 of BS1142:1989 Specification for fibre building boards and to clauses10 and 11.1 of BS5669 Particleboard Part1:1989 Methods of sampling, conditioning and test, both of which will be withdrawn

10、in due course. 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 obligations. Summary of pages This docu

11、ment comprises a front cover, an inside front cover, pages i and ii, theEN title page, pages2to8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on theinside front cove

12、r.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 310 February 1993 UDC 674.03:620.172.225:620.174 Descriptors: Wood-based panel, particleboard, plywood, fibreboard, OSB, cement-bonded particleboard, test method, modulus of elasticity, bending strength English version Wood-based panels Determin

13、ation of modulus of elasticity in bending and of bending strength Panneaux base de bois Dterminationdumodule dlasticit en flexionet de la rsistance la flexion Holzwerkstoffe BestimmungdesElastizittsmoduls und der Biegefestigkeit This European Standard was approved by CEN on 1992-12-15. CEN members a

14、re 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

15、 the Central Secretariat 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 Central Secretariat has the same s

16、tatus as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization

17、Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1993 Copyright reserved to CEN members Ref. No. EN310:1993 EEN 310:1993 BSI 03-1999 2 Foreword This European Standard was prepared by Working Group 4 “Common test methods” (Secretar

18、iat: United Kingdom) of Technical Committee CEN/TC112 “Wood-based panels” (Secretariat: Germany). The text is based on ISO9429 (at present ISO/DIS) which has been elaborated with European participation. This standard is one of a series of standards specifying methods of test for determining dimensio

19、ns and properties of wood-based panels. No existing European Standard is superseded. 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 August1993, and conflicting national standards shall be withdra

20、wn at the latest by December1994. In accordance with the CEN/CENELEC Internal Regulations the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Swe

21、den, Switzerland, United Kingdom. Contents Page 1 Scope 3 2 Normative references 3 3 Principle 3 4 Apparatus 3 5 Test pieces 3 6 Procedure 5 7 Expression of results 5 8 Test report 5 Annex A (informative) Bibliography 7 Figure 1 Arrangement of the binding apparatus 4 Figure 2 Cross section of tubula

22、r boards 4 Figure 3 Load-deflection curve within the range of elastic deformation 6EN 310:1993 BSI 03-1999 3 1 Scope This European Standard specifies a method of determining the apparent modulus of elasticity in flatwise bending and bending strength of wood-based panels of nominal thickness equal to

23、 or greater than3mm. NOTEStructural design values shall be determined according to methods according to EN789. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places

24、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 edition of the publication referre

25、d to applies. EN 325, Wood-based panels Determination of dimensions of test pieces. EN 326-1, Wood-based panels Sampling, cutting and inspection Part1: Sampling and cutting of test pieces and expression of test results 1) . 3 Principle The modulus of elasticity in bending and bending strength are de

26、termined by applying a load to the centre of a test piece supported at two points. The modulus of elasticity is calculated by using the slope of the linear region of the load-deflection curve; the value calculated is the apparent modulus, not the true modulus, because the test method includes shear

27、as well as bending. The bending strength of each test piece is calculated by determining the ratio of the bending moment M, at the maximum load F max , to the moment of its full cross section. 4 Apparatus 4.1 Measuring instruments, as specified in EN325. 4.2 Testing apparatus (Figure 1), having the

28、following essential components. 4.2.1 Two parallel, cylindrical, roller-bearing supports of length exceeding the width of the test piece and of (15 0,5)mm diameter. The distance between the supports shall be adjustable. A cylindrical loading head, of the same length and(30 0,5)mm in diameter, placed

29、 parallel to the supports and equidistant from them. 4.2.2 A suitable instrument capable of measuring the deflection of the test piece in the middle of the span with an accuracy of0,1mm. 4.2.3 A suitable load measurement system capable of measuring the load applied to the test piece with an accuracy

30、 of1% of the measured value. 5 Test pieces 5.1 Sampling and cutting Sampling and cutting of the test pieces shall be carried out according to EN326-1. Series of both transverse and longitudinal test pieces are required. 5.2 Dimensions of test pieces The test pieces shall be rectangular, and of the f

31、ollowing dimensions: The width b shall be (50 1)mm. In the case of extruded panels, cellular panels, or panels of similar structure with cavities parallel to the length of the test piece, the width of the test piece shall be at least twice the width of an individual core element (e.g.two tube diamet

32、ers plus two web thicknesses) and the test pieces shall have a symmetrical cross-sectional area as shown in Figure 2. In test pieces with cavities perpendicular to the length, the loading head shall be located directly above a web. The length l 2shall be20 times the nominal thickness plus50mm, with

33、a maximum length of1050mm and a minimum length of150mm. If the deflection of the test piece is large but rupture (failure) does not occur, the distance between supports shall be reduced for testing the bending strength. The test report shall include the distance between supports at which failing tes

34、ts were conducted. If this procedure needs to be adopted, a new set of test pieces shall be used. Plywood test pieces shall be free of visible strength-reducing characteristics. 5.3 Conditioning The test pieces shall be conditioned to constant mass in an atmosphere with a relative humidity of(65 5)%

35、 and a temperature of (20 2)C. Constant mass is considered to be reached when the results of two successive weighing operations, carried out at an interval of24 h, do not differ by more than0,1% of the mass of the test piece. 1) At present at the draft stage.EN 310:1993 4 BSI 03-1999 Figure 1 Arrang

36、ement of the bending apparatus Figure 2 Cross section of tubular boardsEN 310:1993 BSI 03-1999 5 6 Procedure 6.1 Measure the width and thickness of each test piece according to EN325 at the following points: the thickness at the intersection of the diagonals; the width at the mid-length. 6.2 Adjust

37、the distance between the centres of the supports, to within1mm of20times the nominal thickness of the panel, but not less than100mm and not more than1000mm. Measure the distance between the centres of the supports to the nearest0,5mm. 6.3 Place the test piece flat on the supports, with its longitudi

38、nal axis at right angles to those of the supports with the centre point under the load (Figure 1). 6.4 The load shall be applied at a constant rate of cross-head movement throughout the test. The rate of loading shall be adjusted so that the maximum load is reached within (60 30)s. Measure the defle

39、ction in the middle of the test piece (below the loading head) to an accuracy of0,1mm and plot these values against the corresponding loads measured to an accuracy of1% of the measured value. If deflection is determined by incremental readings, at least6pairs of readings shall be used. 6.5 Record th

40、e maximum load to an accuracy of1% of the measured value. 6.6 Carry out tests on two groups of test pieces according to the two directions of the board, i.e.in the longitudinal and transverse directions. Within each group, test half of the test pieces with the “top face” upwards and half with the “b

41、ottom face” upwards. 7 Expression of results 7.1 Modulus of elasticity 7.1.1 The modulus of elasticity E m(in N/mm 2 ), of each test piece, is calculated from the formula: where The modulus of elasticity for each test piece shall be expressed to three significant figures. 7.1.2 The modulus of elasti

42、city for each group of test pieces taken from the same board (6.6) is the arithmetic mean of the moduli of elasticity of the appropriate test pieces, expressed to three significant figures. 7.2 Bending strength 7.2.1 The bending strength f m(in N/mm 2 ), of each test piece, is calculated from the fo

43、rmula: where F maxis the maximum load, in newtons l 1 , b, and t are in millimetres as defined in 7.1.1 The bending strength of each test piece shall be expressed to three significant figures. 7.2.2 The bending strength for each group of test pieces taken from the same board (6.6) is the arithmetic

44、mean of the bending strengths of the appropriate test pieces, expressed to three significant figures. 8 Test report As described in EN326-1. E m l 1 3 F 2 F 1 () 4 bt 3 a 2 a 1 () - = l 1 is the distance between the centres of the supports, in millimetres b is the width of the test piece, in millime

45、tres t is the thickness of the test piece, in millimetres F 2 F 1 is the increment of load on the straight line portion of the load-deflection curve, (Figure 3) in N. F 1shall be approximately10% and F 2shall be approximately40% of the maximum load a 2 a 1 is the increment of deflection at the mid-l

46、ength of the test piece (corresponding to F 2 F 1 ) f m 3 F max l 1 2 bt 2 - =EN 310:1993 6 BSI 03-1999 Figure 3 Load-deflection curve within the range of elastic deformationEN 310:1993 BSI 03-1999 7 Annex A (informative) Bibliography EN 789, Timber structures Testing of wood-based panels for the de

47、termination of mechanical properties for structural purposes 2) . ISO 9429:1987, Wood-based panels Determination of apparent modulus of elasticity in bending and of bending strength. 2) At present at the draft stage.8 blankBSEN310:1993 BSI 03-1999 National annex NA (informative) Committees responsib

48、le The United Kingdom participation in the preparation of this European Standard was entrusted by the Technical Sector Board for Building and Civil Engineering (B/-) to Technical Committee B/541, upon which the following bodies were represented: American Plywood Association Association of British Pl

49、ywood and Veneer Manufacturers British Woodworking Federation Chartered Institute of Building Coordinator for Timber and Timber Products Council of the Forest Industries of British Columbia Department of the Environment (Timber Division, Building Research Establishment) Fibre Building Board Organisation (FIDOR) Finnish Plywood International Flat Roofing Contractors Advisory Board Forestry Commission Furniture Industry Research Asso