Riveted Connections rivet = round ductile steel bar (shank) with a head at one
end. Snap d. Pan. Flat countersunk. Round countersunk d = Shank diameter.
Timber and Steel Design Lecture 11
Bolted Connections Riveted Connections Types of Joints Failure of Joints Bearing & Friction connections Truss Joints Shear and Tension on Bolt Mongkol JIRAVACHARADET
SURANAREE UNIVERSITY OF TECHNOLOGY
INSTITUTE OF ENGINEERING SCHOOL OF CIVIL ENGINEERING
Riveted Connections rivet = round ductile steel bar (shank) with a head at one end
d Snap
Pan
Flat countersunk
d = Shank diameter = Nominal diameter Round countersunk
Riveting Procedure
Rivets are heated before driving
φ hot rivet = φ hole
φ
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”
Forms of riveted joints
P
Lap Joint
P P
Rivet in single shear fv = P / A
P Eccentricity in lap joint
P P e P P Undesired bending causes tension in rivets
Double riveted lap joint
Butt Joint
P
P/2 P P/2
P/2 Rivet in double shear
P
fv = P/2A Butt joint v.s. Lap joint:
- - !"#!! $ - %"! & ! '( !
P/2
P/2 W section
P
P/2 (a)
(c)
(b)
(d)
(e)
!
(f)
Failure of Joints Case 1: Shear failure of rivets P/2
P
P
Single shear in lap joint
P P/2
Double-shear in butt joint
Shear stress in rivet exceed the limit Case 2: Shear failure of plates
Insufficient edge distance
Shearing out
Case 3: Tension or Tearing failure of plates
P
P
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
P/2 P P/2
Friction from clamping pressure using high strength bolt Beam splice moment connection
Spacing and edge distances of bolts Marking for Bolt P
g
s
P
s
A307
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
A325
min Le = 1.5-2 diameter Distance between bolts: shortest distance between bolts min distance = 3 diameter
A490
Bearing-type connections Shearing Strength:
d
π d2 Fv 4
' "
A307 A325 ( C D ) A325 ( ! C D ) A490 ( C D ) A490 ( ! C D )
! ((Ft) ./-!.2
! ((Fv) ./-!.2 Friction-type Bearing-type
1400
-
700
3100
1200
1480
3100
1200
2100
3800
1480
1970
3800
1480
2800
(t × d ) Fp
Bearing Strength:
Bearing area =dxt
t d
Fp = 1.2 Fu for standard or short-slotted holes Fp = 1.0 Fu for long-slotted holes perpendicular to the load
Fp =
Le Fu ≤ 1.2Fu 2d
for Le < 1.5d
11-1 P ! " # A36, "
( A325 22 .., ", - , "
( , "./ , ,, ( 1.5d, ,,,,( "
(( 3d
1 :
22 mm. bolts P P 1.0 cm
P
1.0 cm
30 cm
Ag = 1.0 (30) = 30
3.2
An = 30 – 2 (2.5) (1.0) = 25 3.2 = Ae P = 0.60 (2.5) (30.0) = 45
P
P = 0.50 (4.0) (25.0) = 50
"
(4"./ , " (: "./ :
P = 0.25π (2.2) 2 (2.1) (4) = 31.93
:
P = (1.0) (2.2) (1.2) (4.0) (4) = 42.24
!! " P
= 31.93
11-2 ,5 "
( A325 19 .. ", - 31"
( , "./ ( ( ? 5" # A36 , ,, ,,,,( "
(" 8 9 1.0 cm P/2 = 40 ton P/2 = 40 ton
19 mm. bolts (A = 2.84 cm2) 2.0 cm P = 80 ton
1.0 cm
"
( 4"./ ,: : "./ "
( 1 ( = 2(2.84)(2.100) = 11.93 "
( 1 ( = (2.0)(1.9)(1.2)(4.0) = 18.24 ( "
( = 80/11.93 = 7+ 8 $" 9 ('() * !+ , )
( ! /0)
11-3 1: , ! " # "./ V , 80 ,, "
( A325 22 .. (A=3.8 3.2) " 8 ,, ,,, "
( D" 8 9 , "
( , "./ 5" # A36 , E
PL2x40
48.8 cm
W500x128 Ix = 71000 tf = 1.8
2 cm
45.2 cm
PL2x40
s
I = 71,000 + 2(2×40)(25.4)2 = 174,226 3.4 q = VQ/I = (80)(2×40)(25.4)/174,226
2 cm
= 0.93 /3.
"./ "
( ( = (2)(3.8)(2.100) = 15.96
( ! /0)
"
( ( = (2)(2.2)(1.8)(1.2)(4.0) = 38.02 s = 15.96/0.93 = 17 3.
( 15 20. c-c)
- AISC smax "
( :M: , " : 478 / Fy
/ 24 " :(
/ 30 3. N5: ( 0 /,' S 0$ : 24 " :( = 24(1.8) = 43.2 3. > 15 3.
478 t f Fy
=
478(1.8) = 17.2 3. > 15 3. 2,500
Smax = 30 3. > 15 3.
OK OK OK
Slip-critical(Friction-type) Connections
5"., "
( :/ A325 , A490 P N
F
P P
N
F P
1 "
( ( ) ', (0.0.)
A325
A490
19 22 25 32
12.7 17.7 23.2 32.3
15.9 22.3 29.1 46.4
5 ", d + 2 mm
d + 2 .. ",- (" !O M ) d + 8 .. ",P"OQ (" !O M ) (d + 2 ..) × (d + 10 ..) D (( × () (d + 2 ..) × 2.5 d ( (( × () d + 10 mm
(a) Standard d + 2 mm 2.5 d
d + 8 mm (c) Short slot
d + 2 mm
(b) Oversized
(d) Long slot
+/, 9 : - :M:, N9 "/DO M - /D 9" ,5 Gusset plate 5(
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. STEEL13_02
B #G CH # '( A325 ! 19 !.!. C D!I C D J
KHD 12 !.!. 2Ls 75x75x10 A 1L
E 7 ton
5
5 x 0
8 x 0
2Ls 90x90x10 B
28 ton C
1L 50x50x8
20 ton
D 8 ton
L A325 C D
L :
Fv = 2,100 ./-!.2
L : Fp = 1.2(4,000) = 4,800 ./-!.2 STEEL13_03
AB: P = 20 '( ( 2Ls 75x75x10 & C L C A325 19 !.!. 1 P = 2×
L
π 4
× d 2 × Fv = 2 ×
π 4
× 1.92 × 2.1 = 11.91 ton Control
P = d × 2t × Fp = 1.9 × 2(1.0) × 4.8 = 18.24 ton
L ( = 20/11.91 = 1.68 2 BC: P = 28 '( ( 2Ls 90x90x10 C π
π
L C
P = 2×
L
P = d × 2t × Fp = 1.9 × 2(1.0) × 4.8 = 18.24 ton
4
× d × Fv = 2 × 2
4
× 1.92 × 2.1 = 11.91 ton Control
L ( = 28/11.91 = 2.53 3 STEEL13_04
BD: P = 8 π
'( ( 1Ls 50x50x8 π
L C
P=
L
P = d × t × Fp = 1.9 × 0.8 × 4.8 = 7.30 ton
4
× d 2 × Fv =
4
× 1.92 × 2.1 = 5.95 ton
Control
L ( = 8/5.95 = 1.35 2 BE: P = 7 π
'( ( 1Ls 50x50x8 π
L C
P=
L
P = d × t × Fp = 1.9 × 0.8 × 4.8 = 7.30 ton
4
× d 2 × Fv =
4
× 1.92 × 2.1 = 5.95 ton
Control
L ( = 7/5.95 = 1.18 2
STEEL13_05
Detail Drawing A
2Ls 75x75x10
B
2Ls 90x90x10
C
E
1L 50x50x8
1L
50 x5 0
x8
Bolt A325×19 mm Gusset plate 20 mm
D More ckeck for: - Effective area of tension members (0.5Fu Ae) - Block shear failure of tension members STEEL13_06
Bolts Subjected to Shear and Tension ft
35.8 ton
80 ton
2L150x90x12
1 2 71.6 ton
Ft
Eight 22 mm. bolts
Structural Tee Fv
fv
!" Ft # $#%&'&% () " & Type of Bolt A307
'&% *+$',-
'&% ."*+$',-
1820 − 1.8 f v ≤ 1400
A325
(3080)2 − 4.39 f v2
(3080)2 − 2.15 f v2
A490
(3780 )2 − 3.75 f v2
(3780 )2 − 1.82 f v2
