Question : 1
A double riveted double cover butt joint in plates 20 mm thick is made with 25 mm diameter
rivets at 100 mm pitch. The permissible stresses are:
σt =120MPa Ʈ=100MPa
σc = 150 MPa
Find the efficiency of joint, taking the strength of the rivet in double shear as twice than that
of single shear.
t 20mm
=
·d 25mm
=
p 100mm
H
=
- - - -
·Ot MPa
=
120
- - -
c 150
=
MPa
=100 MPa
S
Pt (p-d) t. 0= (100-25).20-120 =180000 N ->
plate tearing resis.
=
=
.
·Ps n.2.2.d
=
2 2
=
+
2
x
25
+
100
x
196375 N
=
- rivert shearing resis.
W
Pc n.dot. &, rivert
2 25x20x150 150000N
crushing
=
=
x =
resis
Joint
strength min(Pt, Ps, Pc)
=
150000N
=
Unriveted (solid plate) strength p.t.O
=
100 20 x120
=
x 240000N
=
min(Pt,Ps,Pc) 150000
62.5%
Efficiency (n) 0.625
= = - =
p. t. Ot 240000
-
, Riveted Joint for Structural Applications
-
For structural applications, such as roof, bridge work or girders, Lozenge joint type reveted
joints are used.
In such a joint, diamond riveting is employed so that the joint is made of uniform strength.
:
I 10
H
P< >P
Triple riveted double strap butt joint
S
.
.
. -
Steps in riveted joint calculations for structural applications
For this types of questions we get informations about plate width, thickness and permissible stresses.
W
According to those details we have to calculate other things.
1). Diameter of rivet hole 2). Number of rivets
3). Revert arrangement (diamond shape) 4). Thickness of the butt straps
5). Efficiency of the joint 6). Pitch of the rivets
7). Marginal pitch 8). Distance between the rows
Diameter of revert
d = hole diameter
Revert hole diameter can calculate by, d = 6 t t = plate thickness
.
-
After calculating revert hole diameter, according to following table, revert diameter can be select.
Number of reverts
To determine number of reverts required, we should consider maximun pulling force (Pt) on joint and minimun
...i
amoung shear (Ps) and crushing(Pc) forces.
d
↑
b
Maximum pull acting on the joint is the tearing resistance of the plate at the outer row which has only one rivet.
A double riveted double cover butt joint in plates 20 mm thick is made with 25 mm diameter
rivets at 100 mm pitch. The permissible stresses are:
σt =120MPa Ʈ=100MPa
σc = 150 MPa
Find the efficiency of joint, taking the strength of the rivet in double shear as twice than that
of single shear.
t 20mm
=
·d 25mm
=
p 100mm
H
=
- - - -
·Ot MPa
=
120
- - -
c 150
=
MPa
=100 MPa
S
Pt (p-d) t. 0= (100-25).20-120 =180000 N ->
plate tearing resis.
=
=
.
·Ps n.2.2.d
=
2 2
=
+
2
x
25
+
100
x
196375 N
=
- rivert shearing resis.
W
Pc n.dot. &, rivert
2 25x20x150 150000N
crushing
=
=
x =
resis
Joint
strength min(Pt, Ps, Pc)
=
150000N
=
Unriveted (solid plate) strength p.t.O
=
100 20 x120
=
x 240000N
=
min(Pt,Ps,Pc) 150000
62.5%
Efficiency (n) 0.625
= = - =
p. t. Ot 240000
-
, Riveted Joint for Structural Applications
-
For structural applications, such as roof, bridge work or girders, Lozenge joint type reveted
joints are used.
In such a joint, diamond riveting is employed so that the joint is made of uniform strength.
:
I 10
H
P< >P
Triple riveted double strap butt joint
S
.
.
. -
Steps in riveted joint calculations for structural applications
For this types of questions we get informations about plate width, thickness and permissible stresses.
W
According to those details we have to calculate other things.
1). Diameter of rivet hole 2). Number of rivets
3). Revert arrangement (diamond shape) 4). Thickness of the butt straps
5). Efficiency of the joint 6). Pitch of the rivets
7). Marginal pitch 8). Distance between the rows
Diameter of revert
d = hole diameter
Revert hole diameter can calculate by, d = 6 t t = plate thickness
.
-
After calculating revert hole diameter, according to following table, revert diameter can be select.
Number of reverts
To determine number of reverts required, we should consider maximun pulling force (Pt) on joint and minimun
...i
amoung shear (Ps) and crushing(Pc) forces.
d
↑
b
Maximum pull acting on the joint is the tearing resistance of the plate at the outer row which has only one rivet.
