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1、 W - - - - - - - - - - - 7- - - 7- - $ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - W W D - w - - - - EN 15737:2009 (E) 2 Contents Page Foreword 3 1Scope 4 2Normative references 4 3Terms and definitions .4 4Symbols 4 5Material requirements .4 5.1Fasteners 4 6Test Methods 5 6.1
2、General 5 6.2Conditioning .5 6.3Sampling .5 6.4Test piece dimensions 5 7Test 6 7.1Test setup .6 7.2Procedure .6 7.3Results 7 8Test report 7 8.1Test piece .7 8.2Test method 7 8.3Test results .7 EN 15737:2009 (E) 3 Foreword This document (EN 15737:2009) has been prepared by Technical Committee CEN/TC
3、124, “Timber Structures”, the secretariat of which is held by SFS. 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of an identical text or by endorsement, at the latest by February 2010, and conflicting national standards shall be withdrawn at the lates
4、t by February 2010. 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 test standard provides information how to determine the torsi
5、onal resistance to insertion of screws into timber with a reference to requirements specified in EN 14592. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyp
6、rus, 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 the United Kingdom. EN 15737:2009 (E) 4 1 Scope This sta
7、ndard specifies a test method to determine the torsional resistance to driving of screws in solid timber or glued laminated timber or other wood based materials. 2 Normative references The following referenced documents are essential to the use of this document. For dated references, only the editio
8、n cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 14592:2008, Timber Structures Dowel type fasteners - Requirements ISO 3130, Wood Determination of moisture content for physical and mechanical tests ISO 3131, Wood Determinat
9、ion 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 Moment cell device that records the torque applied 3.2 Test piece element or part of an element that will include the driven screw after the test
10、 made of solid timber, glued laminated timber or wood based materials or combinations of these materials 4 Symbols P Penetration ratio; Rtor,max maximum screw insertion moment, in Newton millimetre; Rtor,r screw insertion resistance, in Newton millimetre; Rtor,s screw insertion strength, in Newton m
11、illimetre; d nominal diameter, in millimetre; l is total length of the screw, in millimetre. 5 Material requirements 5.1 Fasteners The screws shall comply with the requirements given in 6.3 of EN 14592:2008 EN 15737:2009 (E) 5 6 Test Methods 6.1 General The moisture content and density of the test p
12、iece shall be determined according to ISO 3130 and ISO 3131. 6.2 Conditioning The test pieces shall be manufactured at an equilibrium moisture content corresponding to (20 2) C and (65 5) % relative humidity. The material is conditioned when it attains constant mass. Constant mass is considered to b
13、e attained when the results of successive weightings, carried out at an interval of 6 h, do not differ, by more than 0,1 % of the mass of the material. For further investigations other moisture conditioning can be appropriate, and shall be reported. 6.3 Sampling The density of the test pieces or com
14、ponents of the test piece shall comply with the density of the grade used in practise. The upper surface (receiving the point) shall predominantly be radial or tangential. 6.4 Test piece dimensions For solid timber and glued laminated timber test pieces the minimum dimensions are given in Figure 1.
15、For test pieces made of wood based materials or combinations of wood based materials and solid timber or glued laminated timber the dimensions in the direction perpendicular to penetration shall be as minimum 20 d, where d is the nominal diameter of the screw. The test piece dimension in penetration
16、 direction shall always allow full penetration of the screw. Key d screw nominal diameter l total length of the screw grain direction Figure 1 Test piece of solid wood (left) and wood based materials (right) EN 15737:2009 (E) 6 7 Test 7.1 Test setup The test piece is mounted on the base plate of a f
17、rame and fixed in such a way as to prevent any movement during the test. The test rig should allow fixing a moment cell to the screwing device capable of moving in a vertical axis and mounting displacement transducers on either side of the screwing device to measure vertical displacement. An example
18、 is given in Figure 2. The moment cell used shall be capable of measuring the torque to an accuracy of 1 % of the torque applied to the screw. The equipment for measuring displacement shall be capable of measuring to an accuracy of 1 % of the measured value. 7.2 Procedure Fix a drive bit into the mo
19、ment cell and mount a screw into the bit. The screw should be installed according to the manufacturers instructions, including any advice on pre-drilling requirements. Move the cross-head/screw assembly into a position where the screw tip is resting on the top of the test specimen. Drive the screw i
20、nto the test specimen, either by using a mechanical drill or screwing machine, or by using a hand screw wrench ( 100 revolutions per minute), until the screw is fully embedded along its entire length in the specimen. For countersunk screws this includes the thickness of the head. Key 1 Mechanical dr
21、ill, screwing machine, or hand screw wrench, screwing device 2 Drill chuck/bit 3 Moment cell 4 Screw 5 Displacement transducers 6 Timber Figure 2 Example of a test arrangement for screw insertion in timber EN 15737:2009 (E) 7 The vertical displacement of the cross-head to screw assembly shall be rec
22、orded via the displacement transducers, and the screw insertion moment shall be recorded via the moment cell. 7.3 Results Determine for each specimen the maximum value of the screw insertion moment, Rtor,max prior to the point at which the screw head comes into contact with the test piece surface gi
23、ven by the moment cell. 8 Test report 8.1 Test piece The following information shall be given: a) technical specification of the screw and relevant information on their sampling; b) description of the test piece, specification of the material, species or type, grade, density, moisture content, devia
24、tions from specifications, characteristics near the insertion point that might affect the result; c) sizes of the test pieces; d) method of conditioning; e) position and orientation of the screw; f) details of predrilling (including any countersink); g) any other information, which may have influenc
25、ed the test results. 8.2 Test method The following information shall be given: a) reference to this test standard; b) test method applied - insertion method and speed; c) temperature and relative humidity at the time of test; d) description of the testing device, the test equipment and the measuring
26、 instruments; e) any other information which may have influenced the test results. 8.3 Test results The following information for each test piece shall be given: a) maximum value of the screw insertion moment; b) moisture content of the test piece material; c) actual dimensions, position of the insertion point; d) location of failure if any in the test piece or screw; e) plot of the moment to penetration depth for each specimen; f) any other information, which may have influenced the test results.