Lvl

For bending edgewise; tension and stress distribution:

r/300v 1

In the apex zone of a double tapered, curved and pitched cambered beam with all veneers parallel to the beam axis: kvol = 1 — J

In the apex zone of double tapered, curved beams and pitched cambered beams, the values for kas are as for glued-laminated beams.

For the evaluation ofkh

(i) The size effect exponent s is obtained from EN 14374: s = 2(cov) — 0.25, where cov is the coefficient of variation of the test results.

(ii) Bending: reference depth h = 300 mm. For the evaluation ofk£

(i) Tension: reference length t = 3000 mm and s is as defined as for kh. For the evaluation of kY01 (i) Tension: reference volume Vo = 0.01 m3. The stressed volume of the apex zone (in m3) as defined in EC5, Figure 6.9, is V (see Figure 6.7). (NB: the value used for V should not be greater than 2Vb/3 where is the volume of the beam.)

(i) Tensile strength along the grain:

(i) Tensile strength perpendicular to the grain: = £dis£„oi /t,90,d

Where there is a requirement to have to verify that the load distribution system is strong enough to transfer the loading between the members, the loading shall be assumed to be of short-term duration.

If laminated timber flooring is to be used in the structure, the value of ksys will be dependent on the number of loaded laminations being used and whether the floor will be nailed/screwed or pre-stressed/glued. Values for the system strength factor for laminated floor plates made from solid timber or glued-laminated timber are given in EC5, Figure 6.12.

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