timber and steel design lecture 11 bolted connectionseng.sut.ac.th/ce/oldce/courseonline/430432/l11...
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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
Lecture Lecture 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
Riveting Procedure
Rivets are heated before driving
φ
φ hot rivet = φ 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”
Forms of riveted joints
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
- �������� ���� ��� � �����������������������
Butt joint v.s. Lap joint:
P
P/2
P/2
Rivet in double shear
fv = P/2A
P/2P/2
- ���������������� !���"�#!�!�$���
- ����������%"�!��& !���'(���������������!��
������������� ������������������������� ������������
P
P/2
P/2
W section
(a) ���������� (b) ������ �� ���
(d) ��������������(c) �����������
(e) ����������������� ����� !�� (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
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
Spacing and edge distances of bolts
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
Shearing Strength: vFd
4
2π
'"���� ���� ��� ��������������!��((Ft) ��������������!��((F
v)
��./-!.2 ��./-!.2
Friction-type Bearing-type
A307 1400 - 700A325(�� ����C���D�����) 3100 1200 1480A325(�� ��� !��C���D�����) 3100 1200 2100A490 (�� ����C���D�����) 3800 1480 1970A490 (�� ��� !��C���D�����) 3800 1480 2800
Bearing-type connectionsd
Bearing Strength: ( ) pFdt×
Fp = 1.2 Fu for standard or short-slotted holes
Fp = 1.0 Fu for long-slotted holes perpendicular to the load
1.22
e up u
L FF F
d= ≤ for Le < 1.5d
d
t
Bearing area
= d x t
� �������� 11-1 �������������� ������� P �������������������������� �!��"�#� A36, ���"� �( A325 ���� 22 �.�., ��"��,��������-��, "� �(��������,������"./��, �,�,�������(�� 1.5d, �,�,�,�,�(������"� �(����(�� 3d
PP
22 mm. bolts
1.0 cm1.0 cm
P P30 cm
������ ����1�� �������:
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 = 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 ��
���������� 8 $�"� 9 � ('()���*��!���+,����)
� �������� 11-2 �,�����5����"� �( A325 ���� 19 �.�. ����"��,��������-��31��"� �(��������,������"./�����(�� ���(������������ ������������ ? �5�"�#� A36 �,����������,�,����,�,�,�����,�(������"� �(" 8�9 �����������
P/2 = 40 tonP = 80 ton
19 mm. bolts (A = 2.84 cm2)
2.0 cm1.0 cm
P/2 = 40 ton
1.0 cm
������ ���"� �(����4��������"./���,�����:��:
����������"./��������"� �(��1����( = 2(2.84)(2.100) = 11.93 ��� (� !�/0)
������������������"� �(��1����( = (2.0)(1.9)(1.2)(4.0) = 18.24 ���
���(����"� �(� �������� = 80/11.93 = 7+
� �������� 11-3 � ����������1�����:�� �,����!��"�#����� ���"./�� V ��,�� 80 ��� ��������,�,����� ��������������"� �( A325 ���� 22 �.�. (A=3.8 3�.2) " 8����������� ����� �������,�,����,�,�,�������"� �(��D����" 8�9 ������������,"� �(��������,������"./�� �5�"�#� A36 �,��� E����������������
2 cm
W500x128
Ix = 71000
tf = 1.8
2 cm
48.8
cm
45.2
cm
PL2x40
PL2x40
s
������I = 71,000 + 2(2×40)(25.4)2
= 174,226 3�.4
q = VQ/I
= (80)(2×40)(25.4)/174,226
= 0.93 ���/3�.
���������� ����������������"� �(�����( = (2)(2.2)(1.8)(1.2)(4.0) = 38.02 ���
s = 15.96/0.93 = 17 3�. (��� 15 20. c-c)
���"./��� ����������������"� �(�����( = (2)(3.8)(2.100) = 15.96 ��� (� !�/0)
���0������/,'�� S �����0�$�:
24 "������:(����� = 24(1.8) = 43.2 3�. > 15 3�. OK
478 478(1.8)
2,500
f
y
t
F= = 17.2 3�. > 15 3�. OK
Smax = 30 3�. > 15 3�. OK
����-�� AISC ����� smax ������"� �(����:M��:�� �,���"������:
��/� 30 3�. N���5�:��� ������(��
478/ yF ��/� 24 "������:(�����
Slip-critical(Friction-type) Connections
�5�".��,������"� �(�������:/� A325 �, A490
����1�� �������������"� �(������������ (���)
A490A325'��,������� (0.0.)
15.912.71922.317.72229.123.22546.432.332
P
P
P
P
N
N
F
F
5��������"��,5��������"��, d + 2 �.�.
d + 8 �.�.
(d + 2 �.�.) × (d + 10 �.�.)
(d + 2 �.�.) × 2.5 d
��"��,����-�� ("���!��O���M���)
��"��,��P���"OQ ("���!��O���M���)
�����D� (�(��� × ��()�����( (�(��� × ��()
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
+/,���������� ��9���:�
- �������:M��:���,������������� �������N��9��� ���"�/D��O���M
- �/D�� ������������9��"� �����,�5� Gusset plate 5�(�
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��� K�H�D����� 12 !.!.
B
2Ls 75x75x10 2Ls 90x90x1028 ton
C20 ton
A
1L
50x50x8
D
8 ton
1L50
x50x
8
7 ton
E
��� �� �L� ����� ���� ��� A325 �� ����C���D�����
�L� �����: Fv= 2,100 ��./-!.2
�L� �������: Fp= 1.2(4,000) = 4,800 ��./-!.2
STEEL13_03
Control2 22 2 1.9 2.1 11.91 ton4 4
vP d Fπ π
= × × × = × × × =
��������� AB: P = 20 ���
�'(�(���� 2Ls 75x75x10 ����&� ���� �������������C��L� ������C���� ���� ��� A325 ��� 19 !.!. 1 ���
�L� ������� 2 1.9 2(1.0) 4.8 18.24 tonpP d t F= × × = × × =
�L��� ���� �������(���� = 20/11.91 = 1.68 ��� 2 ���
Control
��������� BC: P = 28 ��� �'(�(���� 2Ls 90x90x10 � ���� �������������C�
2 22 2 1.9 2.1 11.91 ton4 4
vP d Fπ π
= × × × = × × × =�L� ������C�
�L� ������� 2 1.9 2(1.0) 4.8 18.24 tonpP d t F= × × = × × =
�L��� ���� �������(���� = 28/11.91 = 2.53 ��� 3 ���
STEEL13_04
Control
��������� BD: P = 8 ��� �'(�(���� 1Ls 50x50x8 � ���� ������������������
2 21.9 2.1 5.95 ton4 4
vP d Fπ π
= × × = × × =�L� ������C�
�L� ������� 1.9 0.8 4.8 7.30 tonpP d t F= × × = × × =
�L��� ���� �������(���� = 8/5.95 = 1.35 ��� 2 ���
Control
��������� BE: P = 7 ��� �'(�(���� 1Ls 50x50x8 � ���� ������������������
2 21.9 2.1 5.95 ton4 4
vP d Fπ π
= × × = × × =�L� ������C�
�L� ������� 1.9 0.8 4.8 7.30 tonpP d t F= × × = × × =
�L��� ���� �������(���� = 7/5.95 = 1.18 ��� 2 ���
STEEL13_05
B
D
CA
E
Gusset plate 20 mm
More ckeck for:
- Effective area of tension members (0.5Fu Ae)
- Block shear failure of tension members
2Ls 75x75x10 2Ls 90x90x10
1L
50x50x8
1L50
x50x
8
Bolt A325×19 mm
Detail Drawing
STEEL13_06
Bolts Subjected to Shear and Tension
80 ton
12
71.6 ton
35.8 ton
Structural Tee
2L150x90x12
Eight 22 mm. bolts
ft
Fv
Ft
fv
��������� � �!��"��� Ft #�����$#%�&'&%�����()�������"����&�
Type of Bolt '&%�����*����+��$',-�� '&%���."���*����+��$',-��
A307
A325
A490
14008.11820 ≤− vf
( ) 2239.43080 vf− ( ) 22
15.23080 vf−
( ) 2275.33780 vf− ( ) 22
82.13780 vf−