BS EN 409-2009 pdf download.Timber structures Test methods Determination of the yield moment of dowel type fasteners.
This BS EN 409 specifies a method for determining the yield moment of dowel type fasteners.
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 14592, Timber structures — Dowel-type fasteners — Requirements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
dowel type fastener
fasteners specified in EN 14592
3.2
yield moment
bending moment when the specimen is deformed through a prescribed rotation angle
4 Symbols and abbreviations
For the purposes of this document, the following symbols and abbreviations apply.
d nominal dowel type diameter according to EN 14592, in millimetres F,, F1 maximum support loads on the dowel type fastener, in newtons
F2, F4 test loads applied to the dowel type fastener, in newtons
distances between loading points and the nearest support, in millimetres, see Figure 1
free length of the nail in millimetres, see Figure 1
yield moment of the dowel type fastener, in newton millimetres
a, a1, a2 rotation angle, in degrees
Ph is the characteristic density of the timber, in kglm3
is the tensile strength of the fastener, NJmm2
5 Requirements
The requirements for dowel type fasteners as given in EN 14592 apply.
BS EN 409:2009
EN 409:2009 (E)
6.3 Apparatus
The apparatus used for the test snaH be sucn mai me ioaas t2 ana t4 see 1-igures 1 ano Go flOl aeviate oy more than 5 % from each other. The bending moment diagram for the resulting yield moment M is shown in Figure 3.
NOTE A test apparatus, which has been found to be suitable for this test, is shown in Annex A.
6.4 Preparation of the specimen
The nail shall be tested about its weakest axis.
6.5 Loading procedure
6.5.1 General
The load shall be applied to the dowel type fastener as shown in Figure 1, and shall be increased at such a rate that at least the rotation angle according to 6.5.2 is reached in 10 s ± 5 s. Record the loads and the corresponding values of the rotation angle during the test.
The load shall be determined to an accuracy of 1 %.
6.5.2 Rotation angle
For nails and staples the rotation angle shall be 450
For screws, dowels or bolts used in wood based products the rotation angle is 11OfI degree.
For screws, dowels or bolts with a tensile strength of 1 000 N/mm2 used in timber with a characteristic density of 360 kg/rn3 the rotation angle is given in Figure 4.
For different tensile strength values or/and different characteristic timber density the rotation angle is:
a is the rotation angle to be used in the determination of the yield moment, in degrees:
a is the rotation angle according to Figure 4, in degrees;
a2 S 1O for nails, staples and screws and O for dowels and bolts;
pi is the characteristic density of the timber where fastener is to be applied. kglm3
J Is the tensile strength of the fastener. N/mm2.
6.6 Results
Determine the load. F1 and F1, at the rotation angle a according to 65.2.
The yield moment, Al,,, shall be calculated as given by.
6.7 Test report
The test repoct shall include the following information:
a) description of the dowel type fastener:
b) description of the test apparatus:
BS EN 409:2009
EN 409:2009 (E)
c) locat,on of the free length, i. along the shank of the dowel type fastener in the test;
d) tensile strength of the steel;
e) characteristic wood density;
f) graphs plotting the values of the rotation angle and load;
g) rotation angle used for calculating the yield moment:
h) value of the yield moment:
i) failure mode of the fastener at the rotation given by Equation (1).
j) reference to this European Standard, e. EN 409:2009.BS EN 409-2009 pdf download.