Minimum thickness of outer member, to = 2.25 he to (equation (11.1) (EC5, 8.10.3))

i.e. actual bolt spacing is equal to the minimum permitted spacing, therefore OK

Minimum thickness of inner member, t; (equation (11.2) (EC5, 8.10.3))

Cross-sectional area of the side members - taking account of loss of area due to the bolt hole plus a tolerance of 1 mm, As Cross-sectional area of the inner members, with same tolerance allowance, Ain

Number of toothed-plate connectors, per shear plane per row, ntp

Number of bolts per shear plane per row, n

Number of effective bolts per shear plane per row, nefjb (equation (10.45); EC5, equation (8.34))

Each member thickness exceeds the minimum value, therefore OK

2. Timber and bolt properties

Table 1.3, strength class C22 (BS EN 338:2003(E), Table 1)

Characteristic tension strength parallel /t.o.k = 13 N/mm2 to the grain, /t 0 k

Characteristic bearing strength perpendicular to the grain, /c.90.k

Mean modulus of elasticity parallel to the grain, Fo.mean

Mean density of the timber, pm

Tensile strength of each bolt, /u.k

Characteristic density of the timber, pk pk = 340 kg/m3

Eo.mean = 10kN/mm2

3. Partial safety factors

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

Permanent actions, kg.uls Variable actions, yg.ULs

Table 2.6 (UKNA to EC5, Table NA.3) Material factor for timber, KM.timber Material factor for connections,


4. Actions

(i) Ultimate limit states (ULS)

Characteristic permanent tensile action, Gk

Characteristic variable tensile action, Qk

Design value of the tensile force in the central member at the ULS, Fd (Table 2.8, equation (c) using the unfavourable condition variable action)

(ii) Serviceability limit states (SLS)

Design value of the tensile force in the central member at the SLS, Fd SLS Based on the characteristic combination (equation (2.24); EC0, equation (6.14b))

5. Modification factors

Factor for medium-duration loading and service class 2, (Table 2.4 (EC5, Table 3.1))

Size factor for width less than 150 mm, kh,

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