Pa p p

The characteristic lateral resistance per shear plane per nail will be Fv.Rk = min(Fv.Rk.a, Fv.Rk.b, Fv.Rk.c, Fv.Rk.d, Fv.Rk.e, Fv.Rk.f, Fv.Rk.dd) Fv.Rk = 764 N

The design resistance per nail per Fv Rd = shear plane, Fv Rd

Number of nails for member 1 connection per shear plane:

Number of nails required per Mnaiis = side, Mnails

KM. connection

Fd,1

For a symmetrical nailing pattern N1nails = ceil(N1nails) adopt 2 nails per side

Mnails = 1.06 N1nails 2

Number of nails for member 2 connection per shear plane:

Number of nails required per side, N2naUs

Fv.Rd 2

For a symmetrical nailing pattern N2naiis = ceil(N2nails) adopt six nails per side

10. Check strength of plywood gusset plates

Strength of gusset plates at connection with member 1: (can ignore the loss of area due to nail holes)

Tension force taken by gusset Fd1 = 1 x 103 N

plates, Fd1

Design tensile stress in gusset ap1t.90.d =

plates - assuming a conservative tensile stress area = 2(tp x h 1), a p 1t.90.d

Design tensile strength of gusset fp 1t 90 d = plates, fp 1t.9o.d

Fd.1

^mod.med ■ fp.t.90.k KM. plywood fP 1t.90.d = 23.33 N/mm2

i.e. stress is less than strength; OK

Strength of gusset plates at connection with member 2: (can ignore the loss of area due to nail holes)

Compression force taken by gusset F2d = Fd 2 ■ cos(33°) F2d = 4.19 x 103 N plates, Fd 2 cos(33°)

Design compressive stress in gusset plates - assuming a conservative stress area = 2(ip x h2), a2t.90.d

Design compressive strength of gusset plates, fpc.a.d (equation (5.14); EC5, equation (6.16))

KM.plywood kmod.med ' fp.c.0.k KM.plywood fp 2c

kc.90" fp2c.90.d fp2c.90.d = 16.2 N/mm2 fp2c.o.d = 18.47 N/mm2 fpc.a.d = 17.73 N/mm2

i.e. stress is less than strength, OK

11. Nail spacing (see Figure 10.13.2(b))

Table 10.8 (EC5, Table 8.2) incorporating the requirements of EC5, 8.3.1.3(1) and (2) for nailed panel connections:

Angle to timber grain

Angle to plywood face grain relative to timber grain

Minimum spacing parallel to grain for d < 5 mm and pk < 420 kg/m3, a11

To eliminate the effect of nail spacing in a row (i.e. to make kef = 1 in equation (10.43) (EC5, equation (8.17))), from Table 10.12 (EC5, Table 8.1), a1

Minimum spacing perpendicular to a2 = 0.85.5 ■ d the timber grain and the plywood grain, a2

a = 0 ■ deg ap = 33 ■ deg a11 = 0.85 ■ (5 + 5| cos(a)|) ■ d a11 = 25.5 mm a1 = 14 ■ d a1 = 42 mm a2 = 12.75 mm

Minimum loaded end distance for timber, a3.t

Minimum unloaded end distance for a3.c = 10 ■ d timber, a3.c a3.t = (10 + 5 cos(a)) ■ d a3.t = 45 mm

Minimum unloaded edge distance a4.c = 5 ■ d for timber, a4.c a3.c = 30 mm a4.c = 15 mm

Minimum loaded end and edge distance for plywood, ap3 t ap3t = (3 + 4 sin(ap)) ■ d ap3t = 15.54 mm

Minimum loaded edge distance for ap 13 t = (3 + 4sin(90°)) ■ d ap13 t = 21mm plywood when loaded at 90° to the grain, ap3x

Minimum unloaded end and edge ap4 t = 3 ■ d distance for plywood, ap4 t ap4t = 9 mm

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