Timber and Steel Design Lecture 12 Bolted Connections...

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Eccentric Bolts Bolts Subjected to Shear and Tension Tension Loads on Bolted Joints Prying Action Timber and Steel Design Timber and Steel Design Lecture Lecture 1 1 2 2 Bolted Connections II Bolted Connections II Mongkol JIRAVACHARADET S U R A N A R E E INSTITUTE OF ENGINEERING UNIVERSITY OF TECHNOLOGY SCHOOL OF CIVIL ENGINEERING

Transcript of Timber and Steel Design Lecture 12 Bolted Connections...

Page 1: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

� Eccentric Bolts

� Bolts Subjected to Shear and Tension

� Tension Loads on Bolted Joints

� Prying Action

Timber and Steel DesignTimber and Steel Design

Lecture Lecture 1122 Bolted Connections IIBolted Connections II

Mongkol JIRAVACHARADET

S U R A N A R E E INSTITUTE OF ENGINEERING

UNIVERSITY OF TECHNOLOGY SCHOOL OF CIVIL ENGINEERING

Page 2: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

Bolts Subjected to Eccentric Shear

(a) (b)

Elastic Analysis

c.g.

e P

c.g.

e P

P

P c.g. c.g.

e P

P

P

Page 3: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

e P

d4d1

d3d2

r4

r1

r3

r2

44332211c.g. drdrdrdrPeM +++==

4

4

3

3

2

2

1

1

d

r

d

r

d

r

d

r===

∑∑∑∑====

2

442

332

222

11 ,,,

d

Mdr

d

Mdr

d

Mdr

d

Mdr

Moment Resistant of Bolt Group

Forces on bolts proportions to C.G. distance

Page 4: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

1 1

1 1

sin

sin

r r H

d d v

θθ

= =

1 1

2 2

1 1

r v Md v MvH

d dd d

= = = ∑ ∑

2

MhV

d=∑

Vertical and Horizontal Components

h

v

V

H

r1

c.g.

d1

θ

θ

Page 5: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

��������� 12-1 ������������� ���� ����������������� ����������������� ������� �������!��"#$%%�� ��&��

15 cm P=12 ton

10 cm

10 cm

10 cm

10 cm

P/8

P/8 P/8

P/8P/8

P/8

P/8

V

V

V

V

V

V

V

H2

H1H1

H1H1

H2H2

P/8

V

H2

C.G.

15 cm

5 cm

Page 6: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

������� ����������������� ����� ������������ ���������������������

�� �� !"�����#$�������������������%��&��'�����!��������'�����#���� ��������'�

���������

2 2 2d h v= +∑ ∑ ∑2 2 2 28(5) 4(5 15 ) 1,200d = + + =∑

2

2

240(15)3.0 ton

1200

240(5)1.0 ton

1200

/8 12 /8 1.5 ton

MvH

d

MhV

d

P

= = =

= = =

= =

���(����������������%�������'�(������&��%��&��'�)��������&

2 23.0 2.5 3.9 tonr = + =

e = 15 + 5 = 20 cm

M = Pe = (12)(20) = 240 t-cm

C.G.

P/8

V

H

15 cm

5 cm

Page 7: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

��������� 12-2 ����������� P �������������'�#�����������������(�����%)�� ��� "�'�#������*������# +� A36 ��� ���� ��� A325 1��� 22 �.�. ������"��&�3�� �� ���������"��%�45�� ������� �������!��"#$%%�� ��&��

5 @ 8 cm

e = 40 cm P

16 cm

Critical bolts

�����

1. �������: M = Pe = 40P &��-;�.

2. ���������������������� !"#���$���2 2 212(8) 768 cmhΣ = =

2 2 2 2 24(4) 4(12) 4(20) 2,240 cmvΣ = + + =

2 2 2 2768 2,240 3,008 cmd h vΣ = Σ + Σ = + =

3. ��&�'����()���������������*� �������&�� ������ "%�����������1��

2

40 (20)0.266

3,008

Mv PH P

d= = =Σ 2

40 (8)0.106

3,008

Mh PV P

d= = =Σ

P/12 = 0.083P &��

Page 8: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

4. )����,��-�������������*�

2 2 2 2( /12) 0.266 (0.106 0.083) 0.326r H V P P P= + + = + + =

���&���� �.1 � ���� ��� A325 1��� 22 �.�. �����"��&�3�� �� ���������"��%�45�� ��%����45��������)��&�� " 5.63 &�� �����?�

0.326P = 5.63 &��

�?*�#������������ P = 17.3 ��� �

Page 9: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

���������0��-�1)���23��)��)��!4���35��"#���

Pe

N.A.

P

10 cm

8 cm

8 cm

8 cm

v

Pf

nA=

t

Mc Pecf

I I= =

Shear stress in each bolt:

Tensile stress from moment:

Page 10: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

��������� 12-3 &�����%���&��#���������*�����# +� A36 (��&�������� ���� ��� A325-N 1��� 22 �.�. &����%�A���� #�������%�?*�#���%����� 12 &�� #�������A���� 30 ;�. �"�"#�����������"#����� ���� ��� 8 ;�. "�"�"#��������% 10 ;�.

P

10 cm

8 cm

8 cm

8 cm

����� 1. ����������������6�7�����������

I = 3.8 [4(4)2 + 4(12)2] = 2,432 ;�.4

#�������B�������1�� A325-N = 3,100 ��./;�.2

2. 8����)��!4�����!745�-�������������(�� !

(12,000)(30)(12)1,776 ksc < 3,100 ksc

2,432t

Pecf

I= = = OK

3. 8����)���23������-81 A325-N: Fv = 1,480 ��./;�.2 #�������45���� ���� ���!5�

12,000395 ksc < 1,480 ksc

(8)(3.8)vf = = OK

Page 11: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

&�����%#�������B�������#������������D������� $ (���&������� 11.5):

Type of Bolt ���� ������������ � ������� ������������ �

A307

A325

A490

14008.11820 ≤− vf

( ) 2239.43080 vf− ( ) 22

15.23080 vf−

( ) 2275.33780 vf− ( ) 22

82.13780 vf−

2 23,080 4.39t vF f= −

2 23,080 4.39 395 2,967 ksc > 1,776 ksc = − × = OK

Page 12: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

� !���&�� Moment

Rotation

����� ����� (Rigid connection)��%�����&$)��������� 90%

�������� (Simple connection) ��%�����&$)�� 0 - 20%

����#$%�� ����� (Semirigid connection)��%�����&$)�� 20 - 90%

- Beam-to-Column Connections- Beam-to-Beam Connections

Page 13: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

Coping

(a) Framed connection

Erection

seat

(c) Framed connection with seat

(b) Seated connection

(d) Seated connectionFiller

PL

(e) Seated connection with

stiffened seat

������ 12.7 ��������� ���������������

Page 14: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

� !���&��)((�&��Framed Connections

'()�*+%,�*-./01�/�23(�� (Net shear area) 1��#���&��4����#�������45��������#� 0.3Fu "1��������"������"������%����I��J���$� ��� ���� ���%�� 3 �.�.

- ����45��1��� ���� ���

- ��%����%�I���# +�

- % +�����45��1�����!��

���&�����%��������1B?�!5�

Page 15: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

�������� 12-4 !*�����?*�#���%�����������&��%%�!�������%)�� ���# +� A36 � ���� ��� A325-N 1��� 19 �.�.

7.5 cm

7.5 cm

5 cm cope

Beam

W450x76

(tw = 9 mm)

Lh = 4 cm1.25 cm clear

Girder

W600x175

(tw = 14 mm)

2Ls 100 x 75 x 7 mm x 22 cm long

3.5 cm

3.5 cm

4 cm

����� �������� ���� ���������!�� W450×76 ;B�������%���45��!��

1. �������23��&#�7����������� A325-N 1��� 19 �.�. �����"��&�3��

���&���� �.1 ��%���45��!��)�� = 8.39 &��

�������� 3 &�� �*� ���45��!��1��� ���� ��� = 3(8.39) = 25.2 ���

Page 16: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

2. ������)(���(����&�� �"�"#���� ���� ��� 7.5 ;�. = 3.95d ( > 3d ) OK

�"�"1�% 3.5 ;�. = 1.84d ( > 1.5d ) OK

��#������%����������#�������% 1.2Fu!���#�����!�� = 9 �.�.

!���#���# +�4��!�� = 7 + 7 = 14 �.�.

←←←← Control

�*� ��%�������� ���� ��� 3 &�� = 3 (1.2) (4.0) (0.9) (1.9) = 24.6 ���

3. �������23��(�,35��� ���8�K�2�� ( Fv = 0.30 Fu ) ������1��� ���

Shear

area

3.5 ;�.

7.5 ;�.

7.5 ;�.

3.5 ;�.

1��������" = 19 + 3 = 22 �.�.

�5?������� � Av = 2 (0.7) ( 22 O 3 (2.2) ) = 21.6 ;�.2

�*� ���45���# +�4�� = 0.30 (4.0) (21.6) = 25.9 ���

Page 17: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

4. �*� ��% +�����45��1�����!�� ������1��� ���

7.5 cm

7.5 cm

5 cm cope

Beam

W450x76

(tw = 9 mm)

3.5 cm

4 cm

1��������" = 19 + 3 = 22 �.�.

Av = (0.9) ( 18.5 O 2.5 (2.2) ) = 11.7 ;�.2

At = (0.9) ( 4 O 0.5 (2.2) ) = 2.61 ;�.2

Pt = 0.3 (4.0) (11.7) + 0.5 (4.0) (2.61)

= 19.3 ��� &�(& �

&�����%�*� �����&��%� Girder W600x175 �%���������� 19.3 &��

!����5�������� !���&3� 19.3 ���

Page 18: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

Seated Connections

Seat angle

Beam

Clip angle

ColumnR

b/2

N

Set back = 1 cmb/2

b + 2.5k

k

1) ,����N����&���-����&��:

0.66( 2.5 )

y

w

RF

t b k=

+��5�� b = !������%���� ≤ N

12.5

(0.66 ) 2 (0.66 )w y w y

R Rb k

t F t F

= − ≥

Page 19: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

�����&$���: M = R e

#���������: 1

2 / 6b

ReMf

S Lt= =

0.75b yF F=

Angle thickness:

= =1 16 8

(0.75 )y y

Re Ret

L F LF

R

b/2

e

N

ta

1 cm

b/2

b + 2.5k

9 mm

k

Critical section

2) ,����N����!�!-��8�K�2��

�"�"��5?��J���$ e = b/2 + 2 – ta – 0.9

�"�" Setback = 1 ;�. &�����!*������ 2 ;�.

��J��!����!���"���"�" ta + 9 �.�.

Page 20: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

Length of seat angle = width of beam flange

= 175 mm

Bearing length, b1

2.50.66 2 0.66y w y w

R Rk

F t F t

= − ≥

1 1 8

2 0.66 2 0.66 2.5 0.7

1(6.93) 3.46 cm

2

y w

R

F t

= × ×

= =

Bearing length required is 3.46 cm

��������� 12-5 �����%%���&��%%3����� ���D�������� ��!�� 8 &�� #���&��!�� W250×44.1 (tw = 7 �.�., k = tf + r = 27 �.�., bf = 175 �.�.) &����%�A���� W200×49.9 (tw = 8 �.�., bf = 200 �.�.)

W250x44.1W200x49.9

Try angle section L 150 x 90 x 15 mm

Page 21: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

R

b/2

e

ta = Thickness of

seat angle

1 cmTry angle section L 150 x 90 x 15 mm

8 8 8 1.33

17.5 2.5

1.40 cm 1.5 cm

a

y

Ret

LF

× ×= =

×

= < OK

Try bolt A325-N φφφφ 19 mm:

Shear strength = 2(1.9) (1.48) 4.20 ton/bolt4

π=

Bearing strength = × × =(1.9 1.5)(1.2 4.0) 13.7 ton/bolt

Control

number of bolts, n = 8.0/4.2 = 1.91 use 2 A325-N φ 19 mm

e = b/2 + 2 – ta – 0.9 = 3.46/2 + 2 – 1.5 – 0.9

= 1.33 ;�.

Page 22: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

��������� 12-6 ����������?*�#���%����������%)��1�����&��%%3�������� �# +������!5� A36 "� ���� ��� A325-N 1��� 19 �.�. ������"��&�3��

W250x44.1

Column: W250x72.4

L150x100x15mm

x 20cm long

L = 20 cm

����� !�������# +�4�� L = 20 ;�.

!*����!������%���� b:

2.5(2.7)0.7(0.66)(2.5)

2(0.7)(0.66)(2.5)

Rb

R

= −

6.75 ( )1.16 2.32

R Rb a= − ≥ …………

�"�"��5?��J���$ e = b/2 + 2 – ta – 0.9 = b/2 – 0.4

2.98 0.4 ( )2.32 4.64

R Rb= − ≥ − ………………………

Page 23: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

8a

y

Ret

LF=�������� ������#����5��#�!�� e:

2 20.75 0.75(2.5) 20(1.5) 14.06( )

6 6

y aF L t

e cR R R

= = =

……………

�*�#��#������ (b) " (c) ������� �")�����������*� �������5���������!�� R !5�

214.62.98 6.91 33.87 0 10.2 ton

2.32

RR R R

R− = → − − = → =

214.60.4 18.56 67.74 0 9.47 ton

4.64

RR R R

R− = → − − = → =

� 5��!������������� �����?�� 5�� R = 9 ��� �����?�&�����% b :

�������� (a), 6.751.16 2.32

R Rb = − ≥

9 96.75 1.01 3.88

1.16 2.32

= − = < =

-6� b = 3.88 Q�.

Page 24: Timber and Steel Design Lecture 12 Bolted Connections IIeng.sut.ac.th/ce/oldce/CourseOnline/430432/L12 Bolt Connection2.pdf · Tension Loads on Bolted Joints Prying Action Timber

�"�"��5?��J���$ e = 3.88/2 – 0.4 = 1.54 ;�.

!���#���# +�4�����&������:

8 8 (9)(1.54)1.49 cm < 1.5 cm

(20)(2.5)a

y

R et

L F= = = OK