EN 310-1993 pdf download.Wood-based panels – Determination of modulus of elasticity in bending and of bending strength.
This EN 310 specifies a method of detersining the apparent modulus of elasticity i, flatwise bending and bending strength of wood-based panels of nominsI thickness equal to or greater than 3 .
NOTE: Structurel design values shall b determined according to methods according to EN 159.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references ire cited it the appropriate places 1r the text end the publicetions are listed hereafter. For dated references, subsequent amendeents 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 referred to applies. V
EN 325 Wood-based panels – Oeterwination of dimensions of test pieces
•1
EN 326-1 Wood-based panels — Saapling, cutting and inspection — Part la Sampling and cutting of test pieces and expression of test re*ults ‘)
3 Principle
The modulus of .lasticfey in bending mod bending strength are determined by applying a load to the centre of a test piece siported at ti.o poists. The modulus of elasticity Is calculated y using the slope of the linear r.gion of the lod-deflection curvj the vlue calculated is the apparent modulus, not the true modulus, becaus, the test method includes shear as mmli as bending. The bendfrig strength of each test piece ii calculated by determining th. ratio of the bending moment N, at the maxi.ue load Fmax, tO the moment of its full cws.ctioe
4 Apparatus
4.1 Neasuring instrueents, as sp.cifi,d in EN 32S.
4.2 Testing apparatus (figure 1). havIng the following essential eonsnts.
4.2.1 Two parallel, cylindrical, roller-bearing s..çports of length exceeding the width of the test piece
and of (15 * 0,5) am diameter.
The distance b.t’.een the stçports shall be adjustable.
A cylindrical loading head, of the same length end (30 t OS) am In dIameter, pl.c,d parallel to the Supports and equidistant from tham.
4.2.2 A suitable instrint cble of ne.swing (ha del lection of tha test p4.c. n the .iddle of th. span with an accuracy of 0.1 .
4.2.3 A suItable load .euurenent syste. caple of neasuring the load applied to the test piec, with en ccuracy of I * of the .‘..sured value.
5 Test pieces –
5.1 5Hng nd cutting
S.)ing and cutting of the test pieces shall be carried out according to EN 325-1. SerIes of both
traneverse end longitudinal test pieces are required.
5.2 Diaensi of test pieces
The test pieces shall be rectangular1 and of the following di..nsioni
The width b shall be (SO t 1) es
In the case of estruded panels, cellular pnel, or panels of si.ilat •tructixq with cavities parallel to the length of the test piece, the width of the test piece shall be at least tw1 the width of an Individual co.’e elesent (e. g. tt te dters plus two .b thicknesses) and the test pieces shall have a res.trical cross-sectional area as sha.n in figure 2.
In test pieces with cavities perpendicular to ‘the length, the ‘loading heed shall be located directly above a Web.
The length 12 ;hall be 20 times the n.ina1 thicknes.s plus 50 , with • sai.um length of 1050 — and a animt length of ISO mo
If the deflection of the test piece is large but rupture (failur. does not .pccur, the distance between supports shall be reduced for testing the bending strength. The test report shall include the distance between sports at which tailing tests were conducted. If this procedure needs to be adopted, a new set of test pieces shall be used.
Pl,i.ood test pieces shall be free of visible strength-reducing characteristics.
5.3 Conditioning
The test pieces shall be conditioned to constant sass in an ateospher. with a relative hueidtty of
(65 t 5) ; and a temperature of (20 t 2) •C. Constant sass is considered to be reached when the results of two successive weighing Operations, carried out at an interval of 24 h, do not differ by onr• than 0,1 of the mass of the test piece.
6 ProCedure
Li Neasure the Width md thickness of each test piece according to EN 325 •t the following points:
the thickness at the intersection of the diagonals,
– the width at th, mid-length.
6.2 Mjust the distance between the centres of th. supports, to within 1 — of 20 times the nominal thick— ness of the panel, but not less than 100 an and flOt moie than 1000 —- $easure the distance between the centres of the supports to the nearest OS an
1.3 Place the test piece flat on the supports, with tt longitudinal axis at right •ngles to those of the supports with the cntre point tider th, load (figure 1). –
6.4 The load shall be applied at p constant rat. of cross—head movement throughout the test. The rate of loading shall be adjusted so that the maximue load is reached within (60 f 30) s.
leasure the deflection in the middle of the test piece (below th. loading head) to in accuracy of 01 an and plot this valu. against the corresponding loads measured to an accuracy of 1 * of the .easured value. If deflection is determined by incremental readings. at least I pairs of readings shall be used.EN 310-1993 pdf download.