EWPAA Structural Plywood and LVL Design Manual - Engineered ...

5. Diaphragm Deflection∆ (diaphragm) = ∑(bending deflection,∆b + shear deflection,∆ s + nail slip,∆ ns + chordsplice,∆ c )= 5 v L 3 /(96EAd) + v L/(4Gt) +0.188e n L +∑(∆ c X)/(2d)where v = unit shear kN/mL = diaphragm length (m)d = diaphragm width (m)A = area of chord cross-section (mm 2 )E = Modulus of Elasticity of the chord material (MPa)G = Modulus of Rigidity of the diaphragm material (MPa)t = Effective plywood thickness for shear (mm)e n= nail deformation (mm) from TABLE 9.2 at calculated load per nail onperimeter of interior panels, based on shear per meter divided bynumber of nails per meter. If the nailing is not the same in bothdirections, use the greater spacing.∑(∆cX) = sum of individual chord-splice slip values on both sides of thediaphragm, each multiplied by the distance (v) of the splices to thenearest support.∆ = Half the allowable hole tolerance in excess of the bolt diameter M12 AS1720 cl 4.4.1cbolts : Permitted hole tolerance of + 10% of bolt diameterDiaphragm deflection in the N-S direction:v = 7.5 kN/mL = 36 mb = 12 mA2= 11700 mmE = 13200 MPaG = 660 MPat = 7.2 mmV (3.75) = 7.5/8 = 0.94 kN/nail (8 nails per metre)e n = 1.194 mmTable 9.2∆ c = 0.6 mmM12 bolts => 10% of 12 mm = 1.2mm Half of this = 0.6mmX = 12 m for chord splice slip∆ (diaphragm)= 5 v L 3 /(96EAd) + v L/(4Gt) + 0.188 e n L + ∑(∆cX)/(2d)∆ (bending) = 5 v L 3 /(96 EAd)= (5 x 7.5 x 36000 3 )/(96 x 13200 x 11700 x 12000)= 9.8 mm∆ (shear)= v L/(4Gt)= (7.5 x 36000)/(4 x 660 x 7.2)= 14.2 mm∆ (nail slip) = 0.188 e n L= 0.188.1.194.36= 8.1 mm∆ (chord splice)= ∑(∆cX)/(2d)= (4 x 0.6mm x 12m)/(2 x 12)= 1.2 mm∆ (diaphragm) = 9.8 + 14.2 + 8.1 + 1.2= 33.3 mm102