Bsp

Emean,fin = t , T*" (EC5, equation (2.10)) (8.43)

where:

• Emean is the mean value of the modulus of elasticity of the material;

• kdef is the creep deformation factor given in Table 2.10 (Table 3.2 of EC5) at the relevant service class the material will function in;

• f 2 is the factor for the quasi-permanent value of the action causing the largest stress in relation to the strength (see Table 2.2). If this is a permanent action a value of 1 should be used.

(b) Mechanical fasteners,

where the symbols are as described above and Kser is the slip modulus of the fastener per shear plane at the SLS.

Where a fastener is used for the connection, as stated in 2.3.2, if the connection is constituted of elements with the same creep behaviour, the value used for kdef is to be twice the value given in Table 2.10 and if the connection comprises two wood-based elements with different creep behaviour, kdefj1 and kdef>2, the value will be:

Based on the above the connection efficiency factor, y;, referred to in equation (8.3) will become:

where the symbols are as previously defined and:

• kdef,c0nnecti0n,i is the deformation factor for the fastener at connection i, and if the connection comprises two wood-based elements with different creep behaviours, kdef, 1 and kdef,2, then kdef, connection = y/kdef, 1 kdef, 2 ;

• kdefji is the deformation factor for member i ;

• Kser is the slip modulus for the fastener type being used.

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