k9o sin2 a + cos2 a with k90 = 1.3 + 0.001dc (EC5, equation (8.68)) (11.22)

where Fv, 0, Rk is defined in equation (11.16), and dc is as previously defined.

The minimum spacings, edge and end distances for ring and shear-plate connectors will be as given in Table 11.2 with the symbols being the same as those in Figures 10.11 and 11.3.

Where ring or shear-plate connectors are staggered, as for toothed-plate connectors, the minimum spacings parallel and perpendicular to the grain can be reduced by complying with the following rules:

(ka1)2 + (ka2)2 > 1 with |0 " ka1 " 1 (EC5, equation (8.69)) (11.23)

where ka1 and ka2 are reduction factors applied to the minimum distance a1 parallel to the grain and a2 perpendicular to the grain, respectively, as shown in Figure 11.4.

If required, the spacing parallel to the grain, ka1 a1 can be further reduced by multiplying by a factor ks red , provided 0.5 < ks,red < 1.0 and the load-carrying capacity of each connector, Fv 0 Rk connector, is also reduced as follows:

Fv , 0 , Rk, connector = kr, red X Fv , 0 , Rk (11.24)

where kr,red = 0.2 + 0.8ks,red (EC5, equation (8.70))

Using the largest permitted reduction, i.e. ks,red = 0.5, the strength of each connector will be reduced to 60% of its full strength.

Should the factor ka1 be reduced by ks,red, the minimum spacings parallel and perpendicular to the grain must satisfy

(ks,redka1)2 + fe)2 > 1 with {0 < < 1 (11.23a)

Where there is a row of split-ring or shear-plate connectors parallel to the grain and more than two connectors are in the row, the strength of the connectors per shear plane when loaded parallel to the grain will be reduced. For this condition, the effective number of connectors, nef, should be taken to be as follows:

Table 11.3 Requirements for the size of bolts used with ring and shear-plate connectors (as referenced in BS EN912)*
0 0

Post a comment