Wpk

35bW 1+

where the symbols are as previously described and/or shown in Figure 7.3 and ^v,w,Ed is the design shear force acting on each web, /v,0,d is the design panel shear strength of the web, /v k is the characteristic panel shear strength of the web, and values for different materials are given in Chapter 1.

(c) Horizontal shear stresses in the glued joints between the web and the flanges. The horizontal shear stresses generated in the flange area are transferred between the web and the flanges through the glued interface connection. The glue in the connection will be able to take these stresses and the limiting design condition will be the rolling shear strength of the web. This type of shear stress is referred to in 4.5.2.2. The design shear stress is as follows:

At the instantaneous condition:

Ief,mst(nhf)

At the final mean value condition

Ief,fin(nhf)

where:

• 7inst,mean,d,Tfin,mean,d is the design horizontal shear stress at the instantaneous (and final) deformation condition at the glued interface between the flange and the web;

• Vd is the design shear force at the position of maximum shear;

• inst, Sf,fin is the first moment of area of the flange (excluding the web area) about the neutral axis at the instantaneous (and final) deformation conditions;

• hf is the height of the flange, i.e. hf,c or hf,t, as appropriate;

• n is the number of glue line interfaces between the flange and the web.

EC5 takes into account the effect of stress concentrations at the web/flange interface in the vicinity of position 2 (see Figure 7.3(a) and (b)) when the height of the flange is greater than 4-ef and the design strength requirements are:

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