Calculate necessary pitch and efficiency of the joint:
A single riveted double covered butt joint is used for connecting two plates 12 mm thick. The power driven field rivets are 24 mm nominal diameter. Tensile strength of the plate fy = 150 MPa
Calculate necessary pitch and efficiency of the joint.
Figure
Solution
Gross diameter = 24 + 1.5 = 25.5 mm
Considering a pitch length of p mm
Taking the maximum permissible stresses in power-driven field rivets from
Table 2, we have double shear value of rivet
= π/4 × (25.5)2 × 90 × 2 = 91, 927 N
Bearing value of rivet = 12 × 25.5 × 270 = 82,620 N
Tearing strength of plate = (p - 25.5) × 12 × 150
Equating the plate tearing strength to the smaller of the two rivet values
we have (p - 25.5) × 1800 = 82620
giving p = 71.4 mm
Minimum pitch = 2.5 × 25.5 = 63.75 ∴ Adopt 75 mm pitch
Fact tearing strength of plate per pitch (without holes)
= 12 × 75 × 150 = 135,000 N
∴ Efficiency of the joint = 82620/135000 ×100 = 61.2 %