Qmm

2. Material strength properties

Table 1.3, strength class C24 (BS EN 338:2003, Table 1)

Characteristic bending strength, fm k fm k = 24 N/mm2 Characteristic shear strength, fv k

Mean modulus of elasticity parallel to the grain, E0.mean Mean shear modulus, G0.mean Table 1.12, plywood - 12.5 mm Canadian Douglas fir (5 ply) Characteristic compression strength, f 1p.c0k = 20.4 N/mm2

Characteristic tensile strength, f 1p.t0.k Characteristic rolling shear strength, f 1p.r.k

Mean modulus of elasticity, f 1p.t.0.k = 13.5 N/mm2 f 1k = 1.25 N/mm2

Table 1.12, plywood - 15.5 mm Canadian Douglas fir (4 ply) Characteristic compression strength, f 2p.c 0 k = 19.7 N/mm2

Characteristic tensile strength, f2p.t.0.k Characteristic rolling shear strength, f2p.r.k

Mean modulus of elasticity,

E2p.c.0.mean

In the following analysis, the transformed section is based on the use of the web material throughout the section.

3. Partial safety factors

Table 2.8 (UKNA to BS EN 1990:2002, Table NA.A1.2(B))) for the ULS

Permanent actions, yG

Variable actions, yq

Material factor for solid timber, ym

Material factor for plywood, YpM

4. Actions

Characteristic permanent action on the panel, Gk

Characteristic variable (imposed) medium-term action on the panel, Qk

Design load due to the critical load combination, Fd

(Table 2.8, equation (c) using the unfavourable condition)

Design load due to permanent loading, FPd

Design moment on the panel due to the critical load combination, Md

Design shear force on the panel due to the critical load combination, Vd

The critical design load case at the ULS will be due to the combination of permanent and unfavourable medium-duration variable action.

perm

Modification factors

Factor for permanent duration kmod action and service class 2, kmod.perm (Table 2.4 (EC5, Table 3.1))

Factor for medium-duration action and service class 2, kmod.med (Table 2.4 (EC5, Table 3.1))

Load sharing factor - ksys (2.3.7 (EC5, 6.6)) (1.1 can be used for web if required)

Depth factor for solid timber in bending, kh kh = min

150 mm h w

0 0

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