4. STRUCTURAL DESIGN OF LVL STRUCTURES Figure 4.20. Bending at a notch A) with tensile stresses at the notch B) with compressive stresses at the notch (EC5 Figure 6.10 and 6.11). When the taper at the notch at tensile side is steeper than 1:10, it can be located only at the support. For beams with rectangular cross sections and where the grain runs essentially parallel to the length of the member, the shear stress τd at the notched support should be calculated using the effective (reduced) depth hef, see Figure 4.20 b). It should be verified that τ_d=(1,5 V_d)/(b ∙ h_ef )≤k_v∙f_(v,d) (4.46) (EC5 6.60) where Vd is design value of the shear force [N]; b is the beams thickness [mm]; hef is the effective beam depth [mm]; kv is a reduction factor [-]; and fv,d is the design value of the shear strength [N/mm2]. The reduction factor kv is defined as follows: − For beams notched at the opposite side to the support, see Figure 4.20 B), kv = 1,0. − For beams notched on the same side as the support, see Figure 4.20 A) k_v=min(1 ; (k_n (1 + (1,1 i^1,5)/√h) (4.47) (EC5 6.62) where i is the notch inclination, see Figure 4.20 a); h is the beam depth in mm; x is the distance from line of action of the support reaction to the corner of the notch, in mm; and α=h_ef/h (4.48) kn is 4,5 for LVL in general in edgewise direction. Note: manufacturers provide product-specific information on the kn values of their products, especially where the advantages of LVL-C are evident. d =1,5 d ∙ ℎef ≤ v ∙ v,d (4.46) (EC5 6.60) v =min�1 ; n�1 + 1,1 1, √ℎ 5� √ℎ �� (1 − ) + 0,8 ℎ �1 − 2�� (4.47) (EC5 6.62) =ℎefℎ (4.48) d =1,5 d ∙ ℎef ≤ v ∙ v,d (4.46) (EC5 6.60) v =min�1 ; n�1 + 1,1 1, √ℎ 5� √ℎ �� (1 − ) + 0,8 ℎ �1 − 2�� (4.47) (EC5 6.62) d =1,5 d ∙ ℎef ≤ v ∙ v,d (4 v =min�1 ; n�1 + 1,1 1, √ℎ 5� √ℎ �� (1 − ) + 0,8 ℎ �1 − 2�� (4 =ℎefℎ A B LVL Handbook Europe 131
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