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Timber and Steel DesignTimber and Steel Design
Riveted Connections
Types of Joints
Failure of Joints
Bearing & Friction connections
Truss Joints Shear and Tension on Bolt
Mongkol JIRAVACHARADET
S U R A N A R E E INSTITUTE OF ENGINEERING
UNIVERSITY OF TECHNOLOGY SCHOOL OF CIVIL ENGINEERING
LectureLecture 1111 BoltedBolted ConnectionsConnections
Riveted Connections
rivet = round ductile steel bar (shank) with a head at one end
Snap
d
Pan Flat
countersunk
Round
countersunk
d= Shank diameter
= Nominal diameter
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Riveting Procedure
Rivets are heated before driving
hot rivet = hole
Head is formed by
- Hand hammer
- Hydraulic pressure
- Pneumatic pressure
On cooling, the rivet shrinks both length
and diameter
Connected parts become tighter:
- Tension in rivet
- Compression in plates
Friction between plates called
clamping action
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Forms of riveted joints
Lap Joint P
P
P
P
Rivet in single shear
fv= P/ A
P
P
e
Eccentricity in lap joint
PP
Undesired bending causes tension in rivetsDouble riveted lap joint
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Butt JointP
P
- F
Butt joint v.s. Lap joint:
P
P/2
P/2
Rivet in double shear
fv= P/2A
P/2P/2
- FF
- F F
Bolted ConnectionsBolted Connections
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FFFF
P
P/2
P/2
W section
(a) F (b)F
(d)F(c)F
(e)F (f)F
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Failure of Joints
PP
Single shear in lap joint
P/2P
Double-shear in butt joint
P/2
Case 1: Shear failure of rivets
Shear stress in rivet exceed the limit
Case 2: Shear failure of plates
Shearing out
Insufficient edge distance
P P
Case 3: Tension or Tearing failure of plates
Tensile stress at net cross section exceeds tensile strength
Case 4: Bearing failure of plate
P P
Plate may be crushed when bearing stress in plate exceeds the limit
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Bolted Connections
Beam splice moment connection
P
P/2
P/2
Friction from clamping pressure
using high strength bolt
BearingBearing--type Connectionstype Connectionsd
F
Ft (../.2)
FFv (../.2)
Shearing Strength: vFd2)4/(
Friction-type Bearing-type
A307 1,400 - 700
A325 (F) 3,100 1,200 1,480
A325 (FF) 3,100 1,200 2,100
A490 (F) 3,800 1,480 1,970
A490 (FF) 3,800 1,480 2,800
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Threads Excluded from Shear Plane or not ?Threads Excluded from Shear Plane or not ?
Bearing
stress
2P
P
P
Diameter = dShear
planes
Bearing StrengthBearing Strength
For long-slotted holes perpendicular to the load Fp = 1.0 Fu
1.22
e up u
L FF F
d= forLe < 1.5d
d
t
Bearing area = dx t
Excessive bearing results in shear tear-out failure mode.
Failure surface
Failure surface
Ra
Ra/2
Ra/2
Le
ppa FtdFR == areabearing
Allowable bearing strength Ra :
For standard or short-slotted holes Fp = 1.2 Fu
uuea FtdFtLR 2.15.0 =
uuca FtdFtLR 2.16.0Or =
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Spacing and EdgeSpacing and Edge--Distances RequirementsDistances Requirements
Pitch: center-to-center of bolts parallel to axis of member
Gage: center-to-center of bolts lines perpendicular to axis of member
Edge distance: shortest distance from center of bolt to edge
min Le = 1.5-2 diameter
Distance between bolts: shortest distance between bolts
min distance = 3 diameter A490
A325
Marking for Bolt
A307
P Pg
s s
Spacing and EdgeSpacing and Edge--Distances RequirementsDistances Requirements
12
Lc2 Lc1
Le s
Lc= clear distance, in the direction
parallel to the applied load.
Le = edge-distance to center of the hole
s = center-to-center spacing of holes
h = d+ 2 mm = hole diameter
For edge bolts(2), use Lc= Le h/2
For other bolts(1), use Lc= s h
)2-(1.5J3.4TableAISCfromvalue
)3y(preferabl2 32
ddL
dds
e
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F 11-1F P A36, A325 22 .., , , 1.5d, 3d
PP
22 mm. bolts
1.0 cm1.0 cm
P P30 cm
F:
Ag = 1.0 (30) = 30.2
An = 30 2 (2.5) (1.0) = 25 .2 = AeP = 0.60 (2.5) (30.0) = 45
P = 0.50 (4.0) (25.0) = 50
F:
: P = 0.25 (2.2) 2 (2.1) (4) = 31.93
: P = (1.0) (2.2) (1.2) (4.0) (4) = 42.24
FP = 31.93
8 9 (F)
F 11-2 FF A325 19 .. ? F A36 FF
P/2= 40 tonP= 80 ton
19 mm. bolts (A = 2.84 cm2)
2.0 cm1.0 cm
P/2= 40 ton
1.0 cm
F:
= 2(2.84)(2.1) = 11.93 ()
= (2.0)(1.9)(1.2)(4.0) = 18.24
F = 80/11.93 = 7+
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F 11-3 F V 80 F A325 22 .. (A=3.8 .2) F F A36
2 cm
W500x128
Ix = 71000
tf= 1.8
2 cm
48.8cm
45.2cm
PL2x40
PL2x40
s
I = 71,000 + 2(240)(25.4)2
= 174,226 .4
q = VQ/I
= (80)(240)(25.4)/174,226
= 0.93 /.
F = (2)(2.2)(1.8)(1.2)(4.0) = 38.02
s = 15.96/0.93 = 17 . ( 15 . c-c)
F = (2)(3.8)(2.100) = 15.96 ()
F S:
24 = 24(1.8) = 43.2 . > 15 . OK
478 478(1.8)
2,500
f
y
t
F= = 17.2 . > 15 . OK
Smax = 30 . > 15 . OK
AISC smax :
30 . FF
478/ yF 24
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Slip-critical(Friction-type) Connections
F A325 A490
F ()
A490A325 (..)
15.912.71922.317.72229.123.22546.432.332
PP
P
P
N
N
F
F
AISC360-05 Specification for Structural Steel Buildings
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d+ 2 ..d+ 8 ..
(d+ 2 ..) (d+ 10 ..)
(d+ 2 ..) 2.5 d
(F)
(F)
(F)
(F)
d+ 2 mm
(a) Standard
d+ 8 mm
(b) Oversized
d+ 10 mm
(c) Short slot
d+ 2 mm
2.5 d
(d) Long slot
d+ 2 mm
Gusset plate
F- F
- F Gusset plate
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Truss Joint
Double member with a single connector piece, called a gusset plate.
Members must have sufficient "bite" into the plate for bolts or weld contact.
Converging centerlines enable equilibrium without member moments.
F F B A325 19 .. F F 12 ..
B
2Ls 75x75x10 2Ls 90x90x1028 ton
C20 ton
A
1L
50x5
0x8
D
8 ton
1L50x5
0x8
7 ton
E
A325 F
: Fv = 2,100 ./.2
: Fp
= 1.2(4,000) = 4,800 ./.2
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Control2 22 2 1.9 2.1 11.91 ton4 4
vP d F = = =
AB: P = 20
2Ls 75x75x10 FF A325 19 .. 1
2 1.9 2(1.0) 4.8 18.24 tonpP d t F = = =
= 20/11.91 = 1.68 2
Control
BC: P = 28 2Ls 90x90x10 F
2 22 2 1.9 2.1 11.91 ton4 4
vP d F = = =F
2 1.9 2(1.0) 4.8 18.24 tonpP d t F = = =
= 28/11.91 = 2.53 3
Control
BD: P = 8 1Ls 50x50x8
2 21.9 2.1 5.95 ton4 4
vP d F
= = =F
1.9 0.8 4.8 7.30 tonpP d t F = = =
= 8/5.95 = 1.35 2
Control
BE: P = 7 1Ls 50x50x8
2 21.9 2.1 5.95 ton4 4
vP d F
= = =F
1.9 0.8 4.8 7.30 tonpP d t F = = =
= 7/5.95 = 1.18 2
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B
D
CA
E
Gusset plate 20 mm
More ckeck for:
- Effective area of tension members (0.5FuAe)
- Block shear failure of tension members
2Ls 75x75x10 2Ls 90x90x10
1L
50x50x8
1L50x5
0x8
Bolt A32519 mm
Detail Drawing
Timber and Steel DesignTimber and Steel Design
Riveted Connections
Types of Joints
Failure of Joints
Bearing & Friction connections
Truss Joints
Shear and Tension on Bolt
Mongkol JIRAVACHARADET
S U R A N A R E E INSTITUTE OF ENGINEERING
UNIVERSITY OF TECHNOLOGY SCHOOL OF CIVIL ENGINEERING
LectureLecture 1111 BoltedBolted ConnectionsConnections
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Riveted Connections
rivet = round ductile steel bar (shank) with a head at one end
Snap
d
Pan Flat
countersunk
Round
countersunk
d= Shank diameter= Nominal diameter
Riveting Procedure
Rivets are heated before driving
hot rivet = hole
Head is formed by
- Hand hammer
- Hydraulic pressure
- Pneumatic pressure
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On cooling, the rivet shrinks both length
and diameter
Connected parts become tighter:
- Tension in rivet
- Compression in plates
Friction between plates calledclamping action
Forms of riveted joints
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Lap Joint P
P
P
P
Rivet in single shear
fv= P/ A
P
P
e
Eccentricity in lap joint
P
P
Undesired bending causes tension in rivetsDouble riveted lap joint
Butt JointP
P
- F
Butt joint v.s. Lap joint:
P
P/2
P/2
Rivet in double shear
fv= P/2A
P/2P/2
- FF- F F
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Bolted ConnectionsBolted Connections
FFFF
P
P/2
P/2
W section
(a) F (b)F
(d)F(c)F
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(e)F (f)F
Failure of Joints
PP
Single shear in lap joint
P/2P
Double-shear in butt joint
P/2
Case 1: Shear failure of rivets
Shear stress in rivet exceed the limit
Case 2: Shear failure of plates
Shearing out
Insufficient edge distance
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P P
Case 3: Tension or Tearing failure of plates
Tensile stress at net cross section exceeds tensile strength
Case 4: Bearing failure of plate
P P
Plate may be crushed when bearing stress in plate exceeds the limit
Bolted Connections
Beam splice moment connection
P
P/2
P/2
Friction from clamping pressure
using high strength bolt
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BearingBearing--type Connectionstype Connectionsd
FFt (../.2)
FFv (../.2)
Shearing Strength: vFd2)4/(
Friction-type Bearing-type
A307 1,400 - 700
A325 (F) 3,100 1,200 1,480
A325 (FF) 3,100 1,200 2,100
A490 (F) 3,800 1,480 1,970
A490 (FF) 3,800 1,480 2,800
Threads Excluded from Shear Plane or not ?Threads Excluded from Shear Plane or not ?
Bearing
stress
2P
P
P
Diameter = dShear
planes
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Bearing StrengthBearing Strength
For long-slotted holes perpendicular to the load Fp = 1.0 Fu
1.22
e up u
L FF F
d= forLe < 1.5d
d
t
Bearing area = dx t
Excessive bearing results in shear tear-out failure mode.
Failure surface
Failure surface
Ra
Ra/2
Ra/2
Le
ppa FtdFR == areabearing
Allowable bearing strength Ra :
For standard or short-slotted holes Fp = 1.2 Fu
uuea FtdFtLR 2.15.0=
uuca FtdFtLR 2.16.0Or =
Spacing and EdgeSpacing and Edge--Distances RequirementsDistances Requirements
Pitch: center-to-center of bolts parallel to axis of member
Gage: center-to-center of bolts lines perpendicular to axis of member
Edge distance: shortest distance from center of bolt to edge
min Le = 1.5-2 diameter
Distance between bolts: shortest distance between bolts
min distance = 3 diameter A490
A325
Marking for Bolt
A307
P Pg
s s
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Spacing and EdgeSpacing and Edge--Distances RequirementsDistances Requirements
12
Lc2 Lc1
Le s
Lc= clear distance, in the direction
parallel to the applied load.
Le = edge-distance to center of the hole
s = center-to-center spacing of holes
h = d+ 2 mm = hole diameter
For edge bolts(2), use Lc= Le h/2
For other bolts(1), use Lc= s h
)2-(1.5J3.4TableAISCfromvalue
)3y(preferabl2 32
ddL
dds
e
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F 11-1F P A36, A325 22 .., , , 1.5d, 3d
PP
22 mm. bolts
1.0 cm1.0 cm
P P30 cm
F:
Ag = 1.0 (30) = 30.2
An = 30 2 (2.5) (1.0) = 25 .2 = AeP = 0.60 (2.5) (30.0) = 45
P = 0.50 (4.0) (25.0) = 50
F:
: P = 0.25 (2.2) 2 (2.1) (4) = 31.93
: P = (1.0) (2.2) (1.2) (4.0) (4) = 42.24 FP = 31.93
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8 9 (F)
F 11-2 FF A325 19 .. ? F A36 FF
P/2= 40 tonP= 80 ton
19 mm. bolts (A = 2.84 cm2)
2.0 cm1.0 cm
P/2= 40 ton
1.0 cm
F:
= 2(2.84)(2.1) = 11.93 ()
= (2.0)(1.9)(1.2)(4.0) = 18.24 F = 80/11.93 = 7+
F 11-3 F V 80 F A325 22 .. (A=3.8 .2) F F A36
2 cm
W500x128
Ix = 71000
tf= 1.8
2 cm
48.8cm
45.2cm
PL2x40
PL2x40
s
I = 71,000 + 2(240)(25.4)2
= 174,226 .4
q = VQ/I
= (80)(240)(25.4)/174,226
= 0.93 /.
F = (2)(2.2)(1.8)(1.2)(4.0) = 38.02
s = 15.96/0.93 = 17 . ( 15 . c-c)
F = (2)(3.8)(2.100) = 15.96 ()
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F S:
24 = 24(1.8) = 43.2 . > 15 . OK
478 478(1.8)
2,500
f
y
t
F= = 17.2 . > 15 . OK
Smax
= 30 . > 15 . OK
AISC smax :
30 . FF
478/ yF 24
Slip-critical(Friction-type) Connections
F A325 A490
F ()
A490A325 (..)
15.912.71922.317.722
29.123.22546.432.332
P
P
P
P
N
N
F
F
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AISC360-05 Specification for Structural Steel Buildings
d+ 2 ..d+ 8 ..
(d+ 2 ..) (d+ 10 ..)
(d+ 2 ..) 2.5 d
(F)(F)
(F)
(F)
d+ 2 mm
(a) Standard
d+ 8 mm
(b) Oversized
d+ 10 mm
(c) Short slot
d+ 2 mm
2.5 d
(d) Long slot
d+ 2 mm
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Gusset plate
F
- F
- F Gusset plate
Truss Joint
Double member with a single connector piece, called a gusset plate.
Members must have sufficient "bite" into the plate for bolts or weld contact.
Converging centerlines enable equilibrium without member moments.
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F F B A325 19 .. F F 12 ..
B
2Ls 75x75x10 2Ls 90x90x1028 ton
C20 ton
A
1L
50x50x8
D
8 ton
1L50x5
0x8
7 ton
E
A325 F
: Fv= 2,100 ./.2
: Fp
= 1.2(4,000) = 4,800 ./.2
Control2 22 2 1.9 2.1 11.91 ton4 4
vP d F
= = =
AB: P = 20
2Ls 75x75x10 FF A325 19 .. 1
2 1.9 2(1.0) 4.8 18.24 tonpP d t F = = =
= 20/11.91 = 1.68 2
Control
BC: P = 28 2Ls 90x90x10 F
2 22 2 1.9 2.1 11.91 ton4 4
vP d F
= = =F
2 1.9 2(1.0) 4.8 18.24 tonpP d t F = = =
= 28/11.91 = 2.53 3
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Control
BD: P = 8 1Ls 50x50x8
2 21.9 2.1 5.95 ton4 4
vP d F
= = =F
1.9 0.8 4.8 7.30 tonpP d t F
= = =
= 8/5.95 = 1.35 2
Control
BE: P = 7 1Ls 50x50x8
2 21.9 2.1 5.95 ton4 4
vP d F
= = =F
1.9 0.8 4.8 7.30 tonpP d t F = = =
= 7/5.95 = 1.18 2
B
D
CA
E
Gusset plate 20 mm
More ckeck for:
- Effective area of tension members (0 5F A )
2Ls 75x75x10 2Ls 90x90x10
1L
50x50x8
1L50x50
x8Bolt A32519 mm
Detail Drawing