From the Specification, the allowable stresses are as follows: Tensile stress in connect-
ed member, 22,000 lb/in^2 (151,690.0 kPa); shearing stress in rivet, 15,000 lb/in^2
(103,425.0 kPa); bearing stress on projected area of rivet, 48,500 lb/in^2 (334,408.0 kPa);
stress on throat of fillet weld, 13,600 lb/in^2 (93,772.0 kPa).
Let n denote the number of sixteenths included in the size of a fillet weld. For exam-
ple, for a^3 /s-in (9.53-mm) weld, n = 6. Then weld size = «/16. And throat area per linear
inch of weld - 0.707«/16 - 0.0442« in^2. Also, capacity of weld = 13,600(0.0442«) = 600«
Ib/lin in (108.0/1 N/mm).
As shown in Fig. 54, a rivet is said to be in single shear if the opposing forces tend to
shear the shank along one plane and in double shear if they tend to shear it along two
planes. The symbols Rss, Rds, and Rb are used here to designate the shearing capacity of a
rivet in single shear, the shearing capacity of a rivet in double shear, and the bearing ca-
pacity of a rivet, respectively, expressed in pounds (newtons).
CAPACITY OFA RIVET
Determine the values of Rss, Rds, and Rb for a %-in (19.05-mm) and 78-in (22.23-mm)
rivet.
Calculation Procedure:
- Compute the cross-sectional area of the rivet
For the^3 / 4 -in (19.05-mm) rivet, area = A = 0.785(0.75)^2 = 0.4418 in^2 (2.8505 cm^2 ). Like-
wise, for the^7 / 8 -in (22.23-mm) rivet, A = 0.785(0.875)^2 = 0.6013 in^2 (3.8796 cm^2 ).
- Compute the single and double shearing capacity of the rivet
Let t denote the thickness, in inches (millimeters) of the connected member, as shown in
Fig. 54. Multiply the stressed area by the allowable stress to determine the shearing ca-
pacity of the rivet. Thus, for the 34-in (19.05-mm) rivet, Rss, = 0.4418(15,000) - 6630 Ib
(29,490.2 N); R^ = 2(0.4418)(15,000) = 13,250 Ib (58,936.0 N). Note that the factor of 2
is used for a rivet in double shear.
Likewise, for the %-in (22.23-mm) rivet, ^ 55 , = 0.6013(15,000) - 9020 Ib (40,121.0
N); Rds = 2(0.6013)(15,000) = 18,040 Ib (80,242.0 N).
- Compute the rivet bearing capacity
The effective bearing area of a rivet of diameter d in (mm) = dt. Thus, for the %-in (19.05-
mm) rivet, Rb = 0.75^(48,500) = 36,38Or Ib (161,709 N). For the^7 / 8 -in (22.23-mm) rivet,
Rb = 0.875^(48,500) = 42,44Or Ib (188,733 N). By substituting the value of tin either re-
lation, the numerical value of the bearing capacity could be obtained.
(o) Rivet in single shear (b) Rivet in double shear
FIGURE 54
