This document discusses the flexibility method for analyzing structures. It provides the definitions of flexibility and stiffness influence coefficients and describes how to develop flexibility matrices for truss, beam, and frame elements using the physical and energy approaches. It then shows how to assemble the total flexibility matrix of a structure and use it to analyze simple structures like plane trusses, continuous beams, and plane frames. The document includes an example problem of a two-member structure to illustrate the flexibility method steps, such as determining static indeterminacy, developing member and system flexibility matrices, evaluating joint displacements and member end actions.
1. Structural Analysis IIIStructural Analysis - III
Fl ibilit M th d 2Flexibility Method -2
ProblemsProblems
Dr. Rajesh K. N.
Assistant Professor in Civil EngineeringAssistant Professor in Civil Engineering
Govt. College of Engineering, Kannur
Dept. of CE, GCE Kannur Dr.RajeshKN
1
2. Module I
Matrix analysis of structures
Module I
• Definition of flexibility and stiffness influence coefficients –
d l t f fl ibilit t i b h i l h &
Matrix analysis of structures
development of flexibility matrices by physical approach &
energy principle.
Flexibility method
• Flexibility matrices for truss beam and frame elements –• Flexibility matrices for truss, beam and frame elements –
load transformation matrix-development of total flexibility
matrix of the structure –analysis of simple structures –
l t ti b d l f d l l dplane truss, continuous beam and plane frame- nodal loads
and element loads – lack of fit and temperature effects.
Dept. of CE, GCE Kannur Dr.RajeshKN
2
3. •Problem 1:
Static indeterminacy = 2
Choose reactions at B and C as redundants
Static indeterminacy = 2
Dept. of CE, GCE Kannur Dr.RajeshKN
3
Released structure
4. 1JA 2JA
1QA 2QA1QD 2QD
Joint actions & corresponding displacementsJoint actions & corresponding displacements
Redundants & corresponding displacements
Reactions other than redundants
Dept. of CE, GCE Kannur Dr.RajeshKN
6. Member end actions consideredMember end actions considered
2MA 4MA
1MA L
A B
3MA L
B C
Hence member flexibility matrix,
L L−⎡ ⎤
[ ] 11 12
21 22
3 6M M
Mi
L L
F F EI EI
F
F F L L
⎡ ⎤
⎢ ⎥⎡ ⎤
= = ⎢ ⎥⎢ ⎥ −⎣ ⎦ ⎢ ⎥21 22
6 3
M MF F L L
EI EI
⎣ ⎦ ⎢ ⎥
⎢ ⎥⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
6
7. L L−⎡ ⎤
[ ]1
6 12
;M
EI EI
F
L L
⎡ ⎤
⎢ ⎥
= ⎢ ⎥
−⎢ ⎥
⎢ ⎥
Member1:
12 6EI EI
⎢ ⎥
⎢ ⎥⎣ ⎦
L L⎡ ⎤
[ ]2
3 6
M
L L
EI EI
F
L L
−⎡ ⎤
⎢ ⎥
= ⎢ ⎥
⎢ ⎥
Member2: [ ]
6 3
L L
EI EI
−⎢ ⎥
⎢ ⎥⎣ ⎦
Unassembled flexibility matrix 2 1 0 0−⎡ ⎤
⎢ ⎥
[ ]
1 2 0 0
0 0 4 212
M
L
F
EI
⎢ ⎥−
⎢ ⎥=
−⎢ ⎥
⎢ ⎥
Dept. of CE, GCE Kannur Dr.RajeshKN
0 0 2 4
⎢ ⎥
−⎣ ⎦
8. To find [BMS] and [BRS] matrices:
[BMS] and [BRS] are found from the released structure when
it is subjected to 1 2 1 21, 1, 1, 1J J Q QA A A A= = = = separately.
1 1JA =
Q Q
2 1JA =2J
1 1QA =
Dept. of CE, GCE Kannur Dr.RajeshKN
2 1QA =
9. 1 1JA =
A B C
1
1− 1 0 0
A B C
0
1A 2 1JA =
1
1− 1 1− 1
A B C
0
1− 1 1− 1
Dept. of CE, GCE Kannur Dr.RajeshKN
10. A B CL
1 1QA =
A B C
1
L
L− 0 0 0
A B C2L
2 1QA =
1
2L− L L− 0
Dept. of CE, GCE Kannur Dr.RajeshKN
12. [ ] [ ] [ ][ ]
T
S MS M MSF B F B=[ ] [ ] [ ][ ]S MS M MSF B F B
1 1 0 0 2 1 0 0 1 1 2L L⎡ ⎤⎡ ⎤ ⎡ ⎤1 1 0 0 2 1 0 0 1 1 2
1 1 1 1 1 2 0 0 1 1 0
L L
LL
− − − − − −⎡ ⎤⎡ ⎤ ⎡ ⎤
⎢ ⎥⎢ ⎥ ⎢ ⎥− − − ⎢ ⎥⎢ ⎥ ⎢ ⎥=
⎢ ⎥⎢ ⎥ ⎢ ⎥0 0 0 0 0 4 2 0 1 012
2 0 0 0 2 4 0 1 0 0
L LEI
L L L
⎢ ⎥− − − −⎢ ⎥ ⎢ ⎥
⎢ ⎥⎢ ⎥ ⎢ ⎥
− − −⎣ ⎦ ⎣ ⎦ ⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
13. 1 1 0 0 3 3 2 5
1 1 1 1 3 3 4
L L
L LL
− − − − −⎡ ⎤ ⎡ ⎤
⎢ ⎥ ⎢ ⎥− −
⎢ ⎥ ⎢ ⎥
0 0 0 0 6 0 412
2 0 0 6 0 2
L LEI
L L L L
⎢ ⎥ ⎢ ⎥=
− − −⎢ ⎥ ⎢ ⎥
⎢ ⎥ ⎢ ⎥
− −⎣ ⎦ ⎣ ⎦⎣ ⎦ ⎣ ⎦
6 6 3 9L L⎡ ⎤
[ ]
6 6 3 9
6 18 3 15 JJ JQ
L L
F FL LL
⎡ ⎤
⎢ ⎥ ⎡ ⎤⎡ ⎤⎣ ⎦⎢ ⎥ ⎢ ⎥2 2
2 2
3 3 2 512
9 15 5 18
QJ QQ
L L L LEI F F
L L L L
⎢ ⎥ ⎢ ⎥= =
⎢ ⎥ ⎢ ⎥⎡ ⎤ ⎡ ⎤⎣ ⎦ ⎣ ⎦⎣ ⎦⎢ ⎥
⎣ ⎦9 15 5 18L L L L⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
13
14. R d d t
{ } { }
1−
⎡ ⎤⎡ ⎤ ⎡ ⎤
Redundants:
{ } { } { }
1
Q QQ Q QJ JA F D F A
−
⎡ ⎤⎡ ⎤ ⎡ ⎤= −⎣ ⎦ ⎣ ⎦⎣ ⎦ { }QD
is a null matrix1
1
is a null matrix
{ } { }
1
Q QQ QJ JA F F A
−
⎡ ⎤ ⎡ ⎤∴ = − ⎣ ⎦ ⎣ ⎦
{ }
13 3 2 2
2 5 3 3
112 12 12 12
L L L L
PLEI EI EI EI
A
−
⎡ ⎤ ⎡ ⎤
⎢ ⎥ ⎢ ⎥ ⎧ ⎫
⎢ ⎥ ⎢ ⎥ ⎨ ⎬{ } 3 3 2 2
295 18 9 15
12 12 12 12
QA
L L L L
EI EI EI EI
⎢ ⎥ ⎢ ⎥= − ⎨ ⎬
⎢ ⎥ ⎢ ⎥ ⎩ ⎭
⎢ ⎥ ⎢ ⎥⎣ ⎦ ⎣ ⎦12 12 12 12EI EI EI EI⎢ ⎥ ⎢ ⎥⎣ ⎦ ⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
14
15. 18 5 1 1 1PL ⎡ ⎤ ⎡ ⎤ ⎧ ⎫ 18 5 3P −⎡ ⎤ ⎧ ⎫
{ }
18 5 1 1 1
5 2 3 5 233
Q
PL
A
L
−⎡ ⎤ ⎡ ⎤ ⎧ ⎫−
= ⎨ ⎬⎢ ⎥ ⎢ ⎥−⎣ ⎦ ⎣ ⎦ ⎩ ⎭
18 5 3
5 2 1333
P ⎡ ⎤ ⎧ ⎫−
= ⎨ ⎬⎢ ⎥−⎣ ⎦ ⎩ ⎭
3
3
P
P
⎧
=
⎫
⎨ ⎬
⎩ ⎭3P−⎩ ⎭
In the subsequent calculations, the above values of {AQ}
H h fi l l f d d b i d b
q , { Q}
should be used.
However, the final values of redundants are obtained by
including actual or equivalent joint loads applied directly
to the supportsto the supports.
{ } { } { }
33 10 3P P
A A A
P−⎧ ⎫ ⎧ ⎫
+ +⎨ ⎬ ⎨ ⎬
⎧ ⎫
⎨ ⎬Thus
Dept. of CE, GCE Kannur Dr.RajeshKN
{ } { } { } 3 2 3Q QC QFINAL
A A A
P P P
= − + = − + =⎨ ⎬ ⎨ ⎬
−⎩ ⎭
⎨
⎩ ⎭ ⎩
⎬
− ⎭
Thus,
16. Joint displacements:
{ } [ ]{ } { }J JJ J JQ QD F A F A⎡ ⎤= + ⎣ ⎦
Joint displacements:
{ } [ ]{ } { }J JJ J JQ QD F A F A⎡ ⎤+ ⎣ ⎦
6 6 1 3 9 3L L P⎧ ⎫⎡ ⎤ ⎡ ⎤ ⎧ ⎫6 6 1 3 9
6 18 2 3 1512 9 1
3
2 3
L LL PL L
L LEI EI
P
P
⎧ ⎫⎡ ⎤ ⎡ ⎤
= +⎨ ⎬⎢ ⎥ ⎢ ⎥
⎩ ⎭⎣ ⎦ ⎣ −⎦
⎧ ⎫
⎨ ⎬
⎩ ⎭
2 2
3 2PL PL⎧ ⎫ ⎧ ⎫3 2
7 418 12
PL PL
EI EI
⎧ ⎫ ⎧ ⎫
= −⎨ ⎬ ⎨ ⎬
⎩ ⎭ ⎩ ⎭
2
0PL ⎧ ⎫
⎨= ⎬
Dept. of CE, GCE Kannur Dr.RajeshKN
118EI
⎨
⎩
= ⎬
⎭
18. Reactions other than redundants:
{ } { } [ ]{ } { }R RC RJ J RQ QA A B A B A⎡ ⎤= − + + ⎣ ⎦
Reactions other than redundants:
{ }A represents combined joint loads (actual and
{ }RCA represents combined joint loads (actual and
equivalent) applied directly to the supports.
{ }
2
0 0 1 1 1
1 1 2 29
3
3
R
P
PL
A PL
L L
P
P
−⎧ ⎫
− −⎧ ⎫⎡ ⎤ ⎡ ⎤⎪ ⎪
= − + +⎨ ⎬ ⎨ ⎬⎢ ⎥ ⎢ ⎥
⎩ ⎭⎣ ⎦ ⎣ ⎦⎪
⎧ ⎫
⎨
⎪
⎬
⎩ ⎭
{ }
1 1 2 29
3
3L L P⎢ ⎥ ⎢ ⎥− − − −− ⎩ ⎭⎣ ⎦ ⎣ ⎦⎪ ⎪⎩ ⎭
−⎩ ⎭
22 0 0P
PL PL PL
P
PL
⎧ ⎫ ⎧ ⎫ ⎧ ⎫
⎪ ⎪ ⎪ ⎪ ⎪ ⎪
= + + =⎨ ⎬ ⎨ ⎬ ⎨ ⎬
⎪ ⎪ ⎪ ⎪
⎧ ⎫
⎪ ⎪
⎨ ⎬
⎪ ⎪⎪ ⎪
Dept. of CE, GCE Kannur Dr.RajeshKN
18
3 3 3 3
−⎪ ⎪ ⎪ ⎪ ⎪ ⎪⎩⎪ ⎪⎩ ⎩ ⎭ ⎩ ⎭ ⎭⎭
19. •Problem 2: (Same problem as above, with a different
choice of member end actions)
Choose reactions at B and C as redundants
Static indeterminacy = 2
Choose reactions at B and C as redundants
Dept. of CE, GCE Kannur Dr.RajeshKN
19Released structure
21. 2MA
A B
4MA
L
B C
1MA
L
B
3MA
L
Member end actions considered
Hence member flexibility matrix,
3 2
L L
F F
⎡ ⎤
⎢ ⎥⎡ ⎤
[ ] 11 12
2
21 22
3 2M M
Mi
M M
F F EI EI
F
F F L L
⎢ ⎥⎡ ⎤
⎢ ⎥= =⎢ ⎥
⎢ ⎥⎣ ⎦
⎢ ⎥
Dept. of CE, GCE Kannur Dr.RajeshKN
2EI EI⎢ ⎥⎣ ⎦
22. 3 2
L L⎡ ⎤
[ ]1 2
6 4
;M
L L
EI EI
F
L L
⎡ ⎤
⎢ ⎥
= ⎢ ⎥
⎢ ⎥
⎢ ⎥
Member1:
4 2EI EI⎢ ⎥⎣ ⎦
⎡ ⎤
[ ]
3 2
2 2
3 2
M
L L
EI EI
F
L L
⎡ ⎤
⎢ ⎥
= ⎢ ⎥
⎢ ⎥
Member2: [ ]2 2
2
M
L L
EI EI
⎢ ⎥
⎢ ⎥⎣ ⎦
Unassembled flexibility matrix 2
2 3 0 0L L⎡ ⎤
⎢ ⎥
[ ] 2
3 6 0 0
12 0 0 4 6
M
LL
F
EI L L
⎢ ⎥
⎢ ⎥=
⎢ ⎥
⎢ ⎥
Dept. of CE, GCE Kannur Dr.RajeshKN
0 0 6 12L
⎢ ⎥
⎣ ⎦
23. To find [BMS] and [BRS] matrices:
[ ] [ ]B b d i d
To find [BMS] and [BRS] matrices:
[ ]MSB [ ]RSBand are member end actions and support
reactions in the released structure when it is subjected to
unit loads corresponding to joint actions and redundantsunit loads corresponding to joint actions and redundants
separately.
are found from the released structure
when it is subjected to
[ ]MSB [ ]RSB
1 2 1 21, 1, 1, 1J J Q QA A A A= = = =
i.e., and
when it is subjected to 1 2 1 2, , ,J J Q Q
separately.
Dept. of CE, GCE Kannur Dr.RajeshKN
23
24. 1 1JA =
A B C
1
A B C
0
2 1MLA =1
4 0MLA =
1
0 1 0MLA = 3 0MLA =
2 1JA =
1
1ML
A B C
1
0
1 1
0
1
Dept. of CE, GCE Kannur Dr.RajeshKN
0
00
25. L A B C
1
L
L L
1 1QA =
A B C
0 0
L
1 01
A B C2L
2 1QA =
1
L 0L 0
1
2L
Dept. of CE, GCE Kannur Dr.RajeshKN
1 11
26. AJ1 AJ2 AQ1 AQ2
=1 =1 =1 =1
0 0 1 1
1 1 0 L
⎡ ⎤
⎢ ⎥
⎢ ⎥
=1 =1 =1 =1
[ ] [ ]
1 1 0
0 0 0 1
0 1 0 0
MS MJ MQ
L
B B B ⎢ ⎥⎡ ⎤⎡ ⎤= =⎣ ⎦⎣ ⎦ ⎢ ⎥
⎢ ⎥
⎣ ⎦0 1 0 0⎣ ⎦
[ ] [ ]
0 0 1 1
B B B
− −⎡ ⎤
⎡ ⎤⎡ ⎤= = ⎢ ⎥⎣ ⎦⎣ ⎦[ ] [ ] 1 1 2RS RJ RQB B B
L L
⎡ ⎤⎡ ⎤= = ⎢ ⎥⎣ ⎦⎣ ⎦ − − − −⎣ ⎦
[ ] [ ] [ ][ ]
T
S MS M MSF B F B=[ ] [ ] [ ][ ]S MS M MS
2
0 1 0 0 0 0 1 12 3 0 0L L⎡ ⎤⎡ ⎤ ⎡ ⎤
⎢ ⎥⎢ ⎥ ⎢ ⎥
2
0 1 0 1 1 1 03 6 0 0
1 0 0 0 0 0 0 112 0 0 4 6
LLL
EI L L
⎢ ⎥⎢ ⎥ ⎢ ⎥
⎢ ⎥⎢ ⎥ ⎢ ⎥=
⎢ ⎥⎢ ⎥ ⎢ ⎥
⎢ ⎥⎢ ⎥ ⎢ ⎥
Dept. of CE, GCE Kannur Dr.RajeshKN
26
1 1 0 0 1 0 00 0 6 12L L
⎢ ⎥⎢ ⎥ ⎢ ⎥
⎣ ⎦ ⎣ ⎦⎣ ⎦
27. 2 2
0 1 0 0 3 3 2 5
0 1 0 1 6 6 3 9
L L L L
L LL
⎡ ⎤⎡ ⎤
⎢ ⎥⎢ ⎥
⎢ ⎥⎢ ⎥
2
1 0 0 0 12 0 6 0 4
1 1 0 0 12 0 6
EI L L
L L
⎢ ⎥⎢ ⎥=
⎢ ⎥⎢ ⎥
⎢ ⎥⎢ ⎥
⎣ ⎦ ⎣ ⎦⎣ ⎦ ⎣ ⎦
6 6 3 9L L⎡ ⎤
⎢ ⎥ [ ]F F⎡ ⎤⎡ ⎤⎣ ⎦
2 2
6 18 3 15
3 3 2 512
L LL
L L L LEI
⎢ ⎥
⎢ ⎥=
⎢ ⎥
⎢ ⎥
[ ]JJ JQ
QJ QQ
F F
F F
⎡ ⎤⎡ ⎤⎣ ⎦⎢ ⎥=
⎢ ⎥⎡ ⎤ ⎡ ⎤⎣ ⎦ ⎣ ⎦⎣ ⎦
2 2
9 15 5 18L L L L
⎢ ⎥
⎣ ⎦
⎣ ⎦ ⎣ ⎦⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
28. Redundants
{ } { } { }
1
Q QQ Q QJ JA F D F A
−
⎡ ⎤⎡ ⎤ ⎡ ⎤= −⎣ ⎦ ⎣ ⎦⎣ ⎦{ } { } { }Q QQ Q QJ J⎣ ⎦ ⎣ ⎦⎣ ⎦
{ }QD is a null matrix
{ } { }
1−
⎡ ⎤ ⎡ ⎤
{ }
1−
⎡ ⎤ ⎡ ⎤
{ } { }Q QQ QJ JA F F A⎡ ⎤ ⎡ ⎤∴ = −⎣ ⎦ ⎣ ⎦
13 3 2 2
3 3 2 2
2 5 3 3
112 12 12 12
29
L L L L
PLEI EI EI EI
−
⎡ ⎤ ⎡ ⎤
⎢ ⎥ ⎢ ⎥ ⎧ ⎫
⎢ ⎥ ⎢ ⎥= − ⎨ ⎬
⎢ ⎥ ⎢ ⎥ ⎩ ⎭
3 3 2 2
295 18 9 15
12 12 12 12
L L L L
EI EI EI EI
⎨ ⎬
⎢ ⎥ ⎢ ⎥ ⎩ ⎭
⎢ ⎥ ⎢ ⎥⎣ ⎦ ⎣ ⎦
18 5 1 1 1 18 5 3PL P− −⎡ ⎤ ⎡ ⎤ ⎧ ⎫ ⎡ ⎤ ⎧ ⎫− −
= =⎨ ⎬ ⎨ ⎬⎢ ⎥ ⎢ ⎥ ⎢ ⎥
Dept. of CE, GCE Kannur Dr.RajeshKN
28
5 2 3 5 2 5 2 1333 33L
⎨ ⎬ ⎨ ⎬⎢ ⎥ ⎢ ⎥ ⎢ ⎥− −⎣ ⎦ ⎣ ⎦ ⎩ ⎭ ⎣ ⎦ ⎩ ⎭
29. 3P⎧ ⎫
{ }
3
3Q
P
P
A
⎧
−
=
⎫
⎨ ⎬
⎩ ⎭
The final values of redundants are obtained by includingy g
actual or equivalent joint loads applied directly to the
supports.
Th { } { } { }
3 10 33P P P
A A A
⎧ ⎫ ⎧ ⎫
⎨ ⎬ ⎨ ⎬
⎧ ⎫
⎨ ⎬Thus,{ } { } { } 3 2 3Q QC QFINAL
A A A
P P P
⎧ ⎫ ⎧ ⎫
= − + = + =⎨ ⎬ ⎨ ⎬
⎩ ⎭
⎧ ⎫
⎨ ⎬
−⎩ ⎩⎭ ⎭
Dept. of CE, GCE Kannur Dr.RajeshKN
29
30. Joint displacements
{ } [ ]{ } { }J JJ J JQ QD F A F A⎡ ⎤= + ⎣ ⎦
Joint displacements
{ } [ ]{ } { }J JJ J JQ Q⎣ ⎦
{ }
6 6 1 3 9
6 18 2 3 1512 9 12
3
3J
L LL PL L
D
L LEI E
P
I P
⎡ ⎤ ⎧ ⎫ ⎡ ⎤
= +⎨
⎧ ⎫
⎨ ⎬
−
⎬⎢ ⎥ ⎢ ⎥
⎣ ⎦ ⎩ ⎦ ⎩⎭ ⎣ ⎭⎣ ⎦ ⎩ ⎦ ⎩⎭ ⎣ ⎭
{ }
2 2 2
0
11
3 2
7 41 12 88
J
PL PL
D
EI EI
PL
EI
⎧ ⎫ ⎧ ⎫
= − =⎨ ⎬
⎧
⎨ ⎬
⎩ ⎭ ⎩ ⎭
⎫
⎨ ⎬
⎩ ⎭117 41 12 88EI EI EI⎩ ⎭ ⎩ ⎭ ⎩ ⎭
Dept. of CE, GCE Kannur Dr.RajeshKN
30
32. Reactions other than redundants
{ } { } [ ]{ } { }A A B A B A⎡ ⎤= − + + ⎣ ⎦{ } { } [ ]{ } { }R RC RJ J RQ QA A B A B A⎡ ⎤= + + ⎣ ⎦
{ }A represents combined joint loads (actual and{ }RCA represents combined joint loads (actual and
equivalent) applied directly to the supports.
{ }
2 0 0 1 1 1 3P PL
A
P− − −⎧ ⎫ ⎡ ⎤ ⎧ ⎫ ⎡ ⎤
= − + +⎨ ⎬ ⎨ ⎬⎢ ⎥ ⎢ ⎥
⎧ ⎫
⎨ ⎬{ }
3 1 1 2 29 3RA
PL L L P
= + +⎨ ⎬ ⎨ ⎬⎢ ⎥ ⎢ ⎥− − − − −⎩ ⎭ ⎣ ⎦ ⎩ ⎭ ⎣ −⎦
⎨ ⎬
⎩ ⎭
{ }
2
3
2 0 0
3 3 3R
P
P
P
A
PL PL PL L
⎧ ⎫ ⎧ ⎫ ⎧ ⎫
= + + =⎨ ⎬ ⎨ ⎬ ⎨ ⎬
−⎩ ⎭
⎧ ⎫
⎨
⎩ ⎩ ⎭ ⎩⎭
⎬
⎭
Dept. of CE, GCE Kannur Dr.RajeshKN
32
33 3 3 PPL PL PL L⎩ ⎭ ⎩ ⎩ ⎭ ⎩⎭ ⎭
33. •Problem 3:
A D
120 kN40 kN/m 20 kN/m
A
B C D4 m
12 m 12 m 12 m
Static indeterminacy = 2
Choose reactions at C and D as redundants
A D
120 kN40 kN/m 20 kN/m
A
B C D4 m
12 m 12 m 12 m
Dept. of CE, GCE Kannur Dr.RajeshKN
33
Released structure
34. 120 kN40 kN/m 20 kN/m
A
B C D
/ 20 kN/m
4 m
12 m 12 m 12 m
2
wl
480
12
wl
= 480 240 240
wl 240 120 120
240
2
wl
= 240 120 120
213.33 106 673.33 106.67
Fixed end actions
Dept. of CE, GCE Kannur Dr.RajeshKN
3488.89 31.11
Fixed end actions
35. 480 266 67 133.33 240
A B C D
480 266.67
240
240 88.89
328 89
+
=
120 31.11
151 11
+
120
328.89= 151.11=
Equivalent joint loads
A
1JA 2JA
3JA
4JA
A
B C
D
A AA A
Structure with redundants and other reactions
1QA 2QA1RA 2RA
Dept. of CE, GCE Kannur Dr.RajeshKN
35
and joint actions
36. Member flexibility matrix
11 12 3 6M M
L L
F F EI EI
−⎡ ⎤
⎢ ⎥⎡ ⎤
[ ] 11 12
21 22
3 6
6 3
M M
Mi
M M
F F EI EI
F
F F L L
EI EI
⎢ ⎥⎡ ⎤
= = ⎢ ⎥⎢ ⎥ −⎣ ⎦ ⎢ ⎥
⎢ ⎥⎣ ⎦6 3EI EI⎢ ⎥⎣ ⎦
Unassembled flexibility matrix
2 1 0 0 0 0
1 2 0 0 0 0
−⎡ ⎤
⎢ ⎥
⎢ ⎥
[ ]
1 2 0 0 0 0
0 0 2 1 0 02
0 0 1 2 0 0MF
EI
−
⎢ ⎥
−⎢ ⎥
= ⎢ ⎥
⎢ ⎥0 0 1 2 0 0
0 0 0 0 2 1
0 0 0 0 1 2
EI −⎢ ⎥
⎢ ⎥−
⎢ ⎥
⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
36
0 0 0 0 1 2−⎣ ⎦
37. To find [BMS] and [BRS] matrices:
are found from the released structure when[ ]MSB [ ]RSB
1 1 1 1 1 1A A A A A A
and
it is subjected to 1 2 3 4 1 21, 1, 1, 1, 1, 1J J J J Q QA A A A A A= = = = = =
separately.p y
Dept. of CE, GCE Kannur Dr.RajeshKN
37
38. 1 1JA =
1
A B
C
D
1
12
1 0 0 0 0 0
1212
2 1JA =
A B
C
D
1
12
1
12
0 1 0 0 0 0
Dept. of CE, GCE Kannur Dr.RajeshKN
38
39. 3 1JA =
A B
C
D
1
12
1
12
0 1 1− 1 0 0
1212
1A 4 1JA =
A B DA B
C
D
1
12
1
12
0 1 1− 1 1− 1
Dept. of CE, GCE Kannur Dr.RajeshKN
40. 1 1QA =
A B C D
21
0 12 12− 0 0 0
1 1QA
A B C D
2 32
2 1QA =
0 24 24− 12 12− 0
Dept. of CE, GCE Kannur Dr.RajeshKN
52. 1RA 1R
2RA 3RA
Redundants [AQ] and reactions other than redundants [AR]
3R
Dept. of CE, GCE Kannur Dr.RajeshKN
Redundants [AQ] and reactions other than redundants [AR]
55. Member flexibility matrix
3 6
L L
F F EI EI
−⎡ ⎤
⎢ ⎥⎡ ⎤
[ ] 11 12
21 22
3 6
6 3
M M
Mi
M M
F F EI EI
F
F F L L
EI EI
⎢ ⎥⎡ ⎤
= = ⎢ ⎥⎢ ⎥ −⎣ ⎦ ⎢ ⎥
⎢ ⎥⎣ ⎦6 3EI EI⎢ ⎥⎣ ⎦
Unassembled flexibility matrix
2 1 0 0 0 0
1 2 0 0 0 0
−⎡ ⎤
⎢ ⎥−
⎢ ⎥
[ ]
1 2 0 0 0 0
0 0 4 2 0 0
0 0 2 4 0 012
M
L
F
EI
⎢ ⎥
−⎢ ⎥
= ⎢ ⎥
⎢ ⎥
[ ]
0 0 2 4 0 012
0 0 0 0 2 1
EI −⎢ ⎥
⎢ ⎥−
⎢ ⎥
Dept. of CE, GCE Kannur Dr.RajeshKN
55
0 0 0 0 1 2
⎢ ⎥
−⎣ ⎦
56. Joint displacements
R d d tRedundants
Reactions other than redundants
are member end actions found from the released
structure when it is subjected to
[ ]MSB [ ]RSBand
Dept. of CE, GCE Kannur Dr.RajeshKN
56
structure when it is subjected to
1 2 3 4 5 11, 1, 1, 1, 1, 1J J J J J QA A A A A A= = = = = = separately.
60. AJ1 AJ2 AJ3 AJ4 AJ5 AQ1
=1 =1 =1 =1 =1 =1
1 0 0 0 0 0
1 2 0 0 0 2L L
⎡ ⎤
⎢ ⎥
⎢ ⎥
=1 =1 =1 =1 =1 =1
[ ] [ ]
1 2 0 0 0 2
1 2 1 0 0 2
L L
L L
B B B
⎢ ⎥
−⎢ ⎥
⎢ ⎥− −
⎡ ⎤⎡ ⎤= = ⎢ ⎥⎣ ⎦⎣ ⎦[ ] [ ]
0 0 0 1 1 2
0 0 0 0 1 2
MS MJ MQB B B
L
L
⎡ ⎤⎡ ⎤= = ⎢ ⎥⎣ ⎦⎣ ⎦
⎢ ⎥
⎢ ⎥− −
⎢ ⎥
0 0 0 0 1 0
⎢ ⎥
⎢ ⎥⎣ ⎦
⎡ ⎤
AJ1 AJ2 AJ3 AJ4 AJ5 AQ1
=1 =1 =1 =1 =1 =1
[ ] [ ]
0 1 0 0 0 1
1 1 2 1 1 1 0RS RJ RQB B B L L L L
− −⎡ ⎤
⎢ ⎥⎡ ⎤⎡ ⎤= = −⎣ ⎦⎣ ⎦ ⎢ ⎥
⎢ ⎥
Dept. of CE, GCE Kannur Dr.RajeshKN
1 1 2 1 1 1 0L L L L⎢ ⎥− − − −⎣ ⎦
61. Redundants:
{ }QD∵ is a null matrix{ } { }
1
Q QQ QJ JA F F A
−
⎡ ⎤ ⎡ ⎤= − ⎣ ⎦ ⎣ ⎦
T
3
L
[ ]
T
QQ MQ M MQF B F B⎡ ⎤ ⎡ ⎤ ⎡ ⎤=⎣ ⎦ ⎣ ⎦ ⎣ ⎦ 3
L
E I
=
[ ][ ]
T
QJ MQ M MJF B F B⎡ ⎤ ⎡ ⎤=⎣ ⎦ ⎣ ⎦
2
9 2 2 3 3 9 2
L
L L L L L⎡ ⎤= − −⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
9 2 2 3 3 9 2
12
L L L L L
EI
⎡ ⎤⎣ ⎦
62. 0⎧ ⎫
{ } 2
0
2
3
9 2 2 3 3 9 2 4 27
P
EI L
A L L L L L PL
⎧ ⎫
⎪ ⎪
⎪ ⎪− ⎪ ⎪
⎡ ⎤∴ = ⎨ ⎬⎣ ⎦{ } 3
9 2 2 3 3 9 2 4 27
12
2 27
0
QA L L L L L PL
L EI
PL
⎡ ⎤∴ = − − −⎨ ⎬⎣ ⎦
⎪ ⎪
⎪ ⎪
⎪ ⎪⎩ ⎭0⎪ ⎪⎩ ⎭
5
12
P−
=
12
{ } { } { } 5 5
0Q QC Q
P
A A A
P⎛ ⎞
= − + = + =⎟
−
−⎜
⎝ ⎠
{ } { } { } 12
0
12
Q QC QFINAL
A A A+ + ⎟⎜
⎝ ⎠
Dept. of CE, GCE Kannur Dr.RajeshKN
63. Member end actions
{ } { } [ ]{ } { }A A B A B A⎡ ⎤= + + ⎣ ⎦
Member end actions
{ } { } [ ]{ } { }M MF MJ J MQ QA A B A B A⎡ ⎤= + + ⎣ ⎦
0 1 0 0 0 0 0
0
0 1 2 0 0 0 2
2
L L
P
⎧ ⎫ ⎡ ⎤ ⎡ ⎤
⎧ ⎫⎪ ⎪ ⎢ ⎥ ⎢ ⎥− ⎪ ⎪⎪ ⎪ ⎢ ⎥ ⎢ ⎥
⎪ ⎪
2
4 27 1 2 1 0 0 2 5
4 27
2 27 0 0 0 1 1 2 12
2 27
P
PL L L P
PL
PL L
PL
⎪ ⎪ ⎢ ⎥ ⎢ ⎥
⎪ ⎪− −⎪ ⎪ ⎢ ⎥ ⎢ ⎥ −⎪ ⎪ ⎛ ⎞
= + +−⎨ ⎬ ⎨ ⎬⎢ ⎥ ⎢ ⎥⎜ ⎟− ⎝ ⎠⎪ ⎪ ⎪ ⎪⎢ ⎥ ⎢ ⎥
⎪ ⎪ ⎪ ⎪
2 27
0 0 0 0 0 1 2
0
0 0 0 0 0 1 0
PL
L
⎪ ⎪ ⎪ ⎪⎢ ⎥ ⎢ ⎥
⎪ ⎪ ⎪ ⎪⎢ ⎥ ⎢ ⎥− −
⎪ ⎪ ⎪ ⎪⎢ ⎥ ⎢ ⎥⎩ ⎭
⎩ ⎭ ⎣ ⎦ ⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
63
65. Reactions other than redundants
{ } { } [ ]{ } { }R RC RJ J RQ QA A B A B A⎡ ⎤= − + + ⎣ ⎦
Reactions other than redundants
{ } { } [ ]{ } { }R RC RJ J RQ QA A B A B A⎡ ⎤+ + ⎣ ⎦
0
0 0 1 0 0 0 12P
⎧ ⎫
⎪ ⎪
⎧ ⎫ ⎧ ⎫⎡ ⎤0 0 1 0 0 0 12
5
20 1 1 2 1 1 1 04 27
27 12
7 1 1 2 1 1 1 02 27
P
P P
L L L L PL
L L L L PL
⎪ ⎪− −⎧ ⎫ ⎧ ⎫⎡ ⎤⎪ ⎪− −⎪ ⎪ ⎪ ⎪ ⎪ ⎪⎛ ⎞⎢ ⎥= − + − +−⎨ ⎬ ⎨ ⎬ ⎨ ⎬⎜ ⎟⎢ ⎥ ⎝ ⎠⎪ ⎪ ⎪ ⎪ ⎪ ⎪⎢ ⎥⎩ ⎭ ⎩ ⎭⎣ ⎦7 1 1 2 1 1 1 02 27
0
L L L L PL⎪ ⎪ ⎪ ⎪ ⎪ ⎪− − − − −⎢ ⎥⎩ ⎭ ⎩ ⎭⎣ ⎦⎪ ⎪
⎪ ⎪⎩ ⎭
1
5
12
P
−⎧ ⎫
⎪ ⎪
⎨ ⎬=
12
7
⎨ ⎬
⎪
⎩
⎪
⎭
Dept. of CE, GCE Kannur Dr.RajeshKN
65
66. { } [ ]{ } { }J JJ J JQ QD F A F A⎡ ⎤= + ⎣ ⎦Joint displacements { } [ ]{ } { }J JJ J JQ QD F A F A⎡ ⎤+ ⎣ ⎦Joint displacements
10 7 2 4 2 2L− − −⎡ ⎤
[ ] [ ] [ ][ ]T
JJ MJ M MJF B F B=
2
10 7 2 4 2 2
7 2 3 2 2
4 2 4 2 2
L
L L L L L
L
L
⎡ ⎤
⎢ ⎥− −
⎢ ⎥
= − − −⎢ ⎥[ ] [ ] [ ][ ]JJ MJ M MJF B F B 4 2 4 2 2
12
2 2 4 4
2 2 4 10
L
EI
L
L
= ⎢ ⎥
⎢ ⎥
− −⎢ ⎥
⎢ ⎥⎣ ⎦2 2 4 10L⎢ ⎥− −⎣ ⎦
9 2L⎧ ⎫
T
⎡ ⎤ ⎡ ⎤
2
9 2
2
L
L
L
−⎧ ⎫
⎪ ⎪
⎪ ⎪⎪ ⎪
[ ] [ ]T
JQ MJ M MQF B F B⎡ ⎤ ⎡ ⎤=⎣ ⎦ ⎣ ⎦ 3
12
3
L
L
EI
L
⎪ ⎪
= −⎨ ⎬
⎪ ⎪
⎪ ⎪
Dept. of CE, GCE Kannur Dr.RajeshKN
66
9 2L
⎪ ⎪
⎪ ⎪⎩ ⎭
67. { } [ ]{ } { }D F A F A⎡ ⎤∴ = + ⎣ ⎦{ } [ ]{ } { }J JJ J JQ QD F A F A⎡ ⎤∴ = + ⎣ ⎦
2 2
10 7 2 4 2 2 0 9 2
7 2 3 2 2 2 2
5
L L
L L L L L P L
L L P
− − − −⎧ ⎫ ⎧ ⎫⎡ ⎤
⎪ ⎪ ⎪ ⎪⎢ ⎥− −
⎪ ⎪ ⎪ ⎪⎢ ⎥⎪ ⎪ ⎪ ⎪⎛ ⎞5
4 2 4 2 2 4 27 3
12 12 12
2 2 4 4 2 27 3
L L P
L PL L
EI EI
L PL L
⎪ ⎪ ⎪ ⎪⎢ ⎥ −⎪ ⎪ ⎪ ⎪⎛ ⎞
= +− − − − −⎢ ⎥⎨ ⎬ ⎨ ⎬⎜ ⎟
⎝ ⎠⎢ ⎥⎪ ⎪ ⎪ ⎪− −⎢ ⎥⎪ ⎪ ⎪ ⎪
2 2 4 10 0 9 2L L
⎢ ⎥⎪ ⎪ ⎪ ⎪
⎢ ⎥− − ⎪ ⎪ ⎪ ⎪⎩ ⎭ ⎩ ⎭⎣ ⎦
2
133
62L
PL
−⎧ ⎫
⎪ ⎪
⎪ ⎪⎪ ⎪
{ }
2
106
2592
34
JD
PL
EI
⎪ ⎪⎪ ⎪
−⎨ ⎬
⎪ ⎪−
=
⎪ ⎪
Dept. of CE, GCE Kannur Dr.RajeshKN
169−⎪⎩
⎪ ⎪
⎪⎭
68. Alternatively, if the entire [Fs] matrix is assembled at a time,
[ ] [ ] [ ][ ]
T
S MS M MSF B F B=
y [ ]
1 0 0 0 0 0 2 1 0 0 0 0 1 0 0 0 0 0
1 2 0 0 0 2 1 2 0 0 0 0 1 2 0 0 0 2
T
L L L L
−⎡ ⎤ ⎡ ⎤⎡ ⎤
⎢ ⎥ ⎢ ⎥⎢ ⎥− − −⎢ ⎥ ⎢ ⎥⎢ ⎥
1 2 0 0 0 2 1 2 0 0 0 0 1 2 0 0 0 2
1 2 1 0 0 2 0 0 4 2 0 0 1 2 1 0 0 2
0 0 0 1 1 2 0 0 2 4 0 0 0 0 0 1 1 212
0 0 0 0 1 2 0 0 0 0 2 1 0 0 0 0 1 2
L L L L
L L L LL
L LEI
L L
⎢ ⎥ ⎢ ⎥⎢ ⎥
⎢ ⎥ ⎢ ⎥− − − − −⎢ ⎥
= ⎢ ⎥ ⎢ ⎥⎢ ⎥
−⎢ ⎥ ⎢ ⎥⎢ ⎥
⎢ ⎥ ⎢ ⎥⎢ ⎥− − − − −0 0 0 0 1 2 0 0 0 0 2 1 0 0 0 0 1 2
0 0 0 0 1 0 0 0 0 0 1 2 0 0 0 0 1 0
L L⎢ ⎥ ⎢ ⎥⎢ ⎥
⎢ ⎥ ⎢ ⎥⎢ ⎥
−⎢ ⎥ ⎢⎣ ⎦⎣ ⎦ ⎣ ⎦⎥
1 1 1 0 0 0 3 2 0 0 0 2
0 2 2 0 0 0 3 0 0 0
L L
L L L L
− − −⎡ ⎤ ⎡ ⎤
⎢ ⎥ ⎢ ⎥− −
⎢ ⎥ ⎢ ⎥
⎢ ⎥ ⎢ ⎥0 0 1 0 0 0 4 2 4 2 2 3
0 0 0 1 0 0 2 2 4 4 312
0 0 0 1 1 1 0 0 0 0 3
L LL
L LE I
L
− − − −⎢ ⎥ ⎢ ⎥
= ⎢ ⎥ ⎢ ⎥
− −⎢ ⎥ ⎢ ⎥
⎢ ⎥ ⎢ ⎥− − −
⎢ ⎥ ⎢ ⎥
Dept. of CE, GCE Kannur Dr.RajeshKN
0 2 2 2 2 0 0 0 0 0 3 2L L L L L
⎢ ⎥ ⎢ ⎥
− −⎣ ⎦ ⎣ ⎦
69. 2 2
10 7 2 4 2 2 9 2
7 2 3 2 2 2
L L
L L L L L L
− − − −⎡ ⎤
⎢ ⎥− −
⎢ ⎥
[ ]
7 2 3 2 2 2
4 2 4 2 2 3
2 2 4 4 312
JJ JQ
L L L L L L
F FL LL
L LEI F F
⎢ ⎥
⎡ ⎤⎡ ⎤− − − −⎢ ⎥ ⎣ ⎦⎢ ⎥= =⎢ ⎥
− − ⎢ ⎥⎡ ⎤ ⎡ ⎤⎢ ⎥ ⎣ ⎦ ⎣ ⎦⎣ ⎦
2 2
2 2 4 4 312
2 2 4 10 9 2
9 2 2 3 3 9 2 4
QJ QQ
L LEI F F
L L
L L L L L L
− − ⎢ ⎥⎡ ⎤ ⎡ ⎤⎢ ⎥ ⎣ ⎦ ⎣ ⎦⎣ ⎦
⎢ ⎥− −
⎢ ⎥
− −⎣ ⎦9 2 2 3 3 9 2 4L L L L L L− −⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
70. •Problem 5: 30 kN/m
50 kN
30 kN/m
4m
B C
4
2m
4m
D
A
Static indeterminacy = 3
Dept. of CE, GCE Kannur Dr.RajeshKN
70
Choose 3 reactions at D as redundants
73. Member flexibility matrix
11 12 3 6M M
L L
F F EI EI
−⎡ ⎤
⎢ ⎥⎡ ⎤
[ ] 11 12
21 22
3 6
6 3
M M
Mi
M M
F F EI EI
F
F F L L
EI EI
⎢ ⎥⎡ ⎤
= = ⎢ ⎥⎢ ⎥ −⎣ ⎦ ⎢ ⎥
⎢ ⎥⎣ ⎦6 3EI EI⎢ ⎥⎣ ⎦
U bl d fl ibilit
4 2 0 0 0 0
2 4 0 0 0 0
−⎡ ⎤
⎢ ⎥
Unassembled flexibility
matrix
[ ]
2 4 0 0 0 0
0 0 4 2 0 02
0 0 2 4 0 06
MF
EI
⎢ ⎥−
⎢ ⎥
−⎢ ⎥
= ⎢ ⎥[ ]
0 0 2 4 0 06
0 0 0 0 2 1
0 0 0 0 1 2
M
EI
⎢ ⎥
−⎢ ⎥
⎢ ⎥−
⎢ ⎥
⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
73
0 0 0 0 1 2
⎢ ⎥
−⎣ ⎦
74. 40A = 40A =2 40JA = 3 40JA =
1 50JA =
2JD 3JD
1 50JA
1JD
Joint displacements and
di j i t l dcorresponding joint loads
are found from the released structure when
it is subjected to 1 2 3 1 2 31, 1, 1, 1, 1, 1J J J Q Q QA A A A A A= = = = = =
t l
[ ]MSB [ ]RSBand
Dept. of CE, GCE Kannur Dr.RajeshKN
74
separately.
86. •Problem 6 (Support settlement)
Analyse the beam. Support B has a downward settlement of
30mm. EI=5.6×103 kNm2×
Static indeterminacy = 3
Dept. of CE, GCE Kannur Dr.RajeshKN
Choose reactions at B,C,D as redundants
87. [ ] 3 6
Mi
L L
EI EI
F
−⎡ ⎤
⎢ ⎥
= ⎢ ⎥Member flexibility matrix [ ]
6 3
MiF
L L
EI EI
⎢ ⎥
−⎢ ⎥
⎢ ⎥⎣ ⎦
2 1 0 0 0 0
1 2 0 0 0 0
−⎡ ⎤
⎢ ⎥
Unassembled flexibility matrix
[ ]
1 2 0 0 0 0
0 0 4 2 0 03
0 0 2 4 0 06
MF
EI
⎢ ⎥−
⎢ ⎥
−⎢ ⎥
= ⎢ ⎥[ ]
0 0 2 4 0 06
0 0 0 0 2 1
0 0 0 0 1 2
M
EI
⎢ ⎥
−⎢ ⎥
⎢ ⎥−
⎢ ⎥
⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
87
0 0 0 0 1 2−⎣ ⎦
88. 2525
Fixed end actions 50 50
2525 2525
Equivalent joint loads 50 50
1JD 2JD
3JD
Joint displacements{ }JD
A C D30mm 1QD
Dept. of CE, GCE Kannur Dr.RajeshKN
Support settlements { }QD
B
96. •Problem 6a ( Same problem as above, with a differentProblem 6a ( Same problem as above, with a different
approach)
25 28
A D
25 25
6 03EI
28
B
C2
6 .03
112
3
EI ×
=
2
6 .03
28
6
EI ×
=
112
12 .03EI ×
74.667
3
12 .03
6
EI ×
9.333 50 50
3
3
74.667=
6
9.333=
Fixed end actions
Dept. of CE, GCE Kannur Dr.RajeshKN
96
105. •Problem 7:
Static indeterminacy = 2 ( 1 internal + 1 external )
Dept. of CE, GCE Kannur Dr.RajeshKN
105
Choose reaction at B and force in AD as redundants
107. Dept. of CE, GCE Kannur Dr.RajeshKN
Redundants [AQ] and reactions other than redundants [AR]
108. Member flexibility matrix of truss member
⎡ ⎤
[ ]Mi
L
F
EA
⎡ ⎤
= ⎢ ⎥⎣ ⎦
Unassembled flexibility matrix
1 0 0 0 0 0
0 1.414 0 0 0 0
⎡ ⎤
⎢ ⎥
⎢ ⎥
[ ]
0 0 1.414 0 0 0
0 0 0 1 0 0M
L
F
EA
⎢ ⎥
⎢ ⎥
= ⎢ ⎥
⎢ ⎥
0 0 0 0 1 0
0 0 0 0 0 1
⎢ ⎥
⎢ ⎥
⎢ ⎥
⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
108
⎣ ⎦
109. To find [BMS] and [BRS] matrices:
are found from the released structure when it[ ]MSB [ ]RSBand
is subjected to 1 2 3 4 1 21, 1, 1, 1, 1, 1J J J J Q QA A A A A A= = = = = =
separately.
3JDD 3JD
2JD
1JD 5
2 3
D
1 4
4JD
6
Dept. of CE, GCE Kannur Dr.RajeshKN
109Joint displacements
112. •Each column in the submatrix consists of member[ ]MJB
forces caused by a unit value of a joint load applied to the
released structure.
[ ]
•Each column in the submatrix consists of member
forces caused by a unit value of a redundant applied to the
MQB⎡ ⎤⎣ ⎦
released structure.
AJ1 AJ2 AJ3 AJ4 AQ1 AQ2
=1 =1 =1 =1 =1 =1
0 1 0 0 0 0.707
0 0 0 0 0 1
−⎡ ⎤
⎢ ⎥
⎢ ⎥
=1 =1 =1 =1 =1 =1
0 0 0 0 0 1
1.414 0 0 0 1.414 1
⎢ ⎥
⎢ ⎥
⎢ ⎥
= ⎢ ⎥[ ] [ ]MS MJ MQB B B⎡ ⎤⎡ ⎤= ⎣ ⎦⎣ ⎦
1 0 1 0 1 0.707
1 0 0 0 0 0.707
= ⎢ ⎥
− − −⎢ ⎥
⎢ ⎥− −
⎢ ⎥
[ ] [ ]MS MJ MQ⎣ ⎦⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
0 0 0 1 0 0.707
⎢ ⎥
−⎢ ⎥⎣ ⎦
113. •Each column in the submatrix consists of support[ ]RJB•Each column in the submatrix consists of support
reactions caused by a unit value of a joint load applied to
the released structure.
[ ]RJ
RQB⎡ ⎤⎣ ⎦•Each column in the submatrix consists ofQ⎣ ⎦
support reactions caused by a unit value of a redundant
applied to the released structure.
AJ1 AJ2 AJ3 AJ4 AQ1 AQ2
1 0 0 1 1 0− − −⎡ ⎤
AJ1 AJ2 AJ3 AJ4 AQ1 AQ2
=1 =1 =1 =1 =1 =1
[ ] [ ]
1 0 0 1 1 0
1 1 0 0 1 0
1 0 1 0 1 0
RS RJ RQB B B
⎡ ⎤
⎢ ⎥⎡ ⎤⎡ ⎤= = − − −⎣ ⎦⎣ ⎦ ⎢ ⎥
⎢ ⎥
Dept. of CE, GCE Kannur Dr.RajeshKN
113
1 0 1 0 1 0⎢ ⎥−⎣ ⎦
114. Redundants
{ }QD∵ is a null matrix{ } { }
1
Q QQ QJ JA F F A
−
⎡ ⎤ ⎡ ⎤= − ⎣ ⎦ ⎣ ⎦ { }Q{ } { }Q QQ QJ J⎡ ⎤ ⎡ ⎤⎣ ⎦ ⎣ ⎦
3 828 2 707⎡ ⎤
[ ]
T
QQ MQ M MQF B F B⎡ ⎤ ⎡ ⎤ ⎡ ⎤=⎣ ⎦ ⎣ ⎦ ⎣ ⎦
3.828 2.707
2.707 4.828
L
EA
⎡ ⎤
= ⎢ ⎥
⎣ ⎦
[ ][ ]
T
QJ MQ M MJF B F B⎡ ⎤ ⎡ ⎤=⎣ ⎦ ⎣ ⎦⎣ ⎦ ⎣ ⎦
3.828 0 1 0L −⎡ ⎤
⎢ ⎥3.414 0.707 0.707 0.707EA
= ⎢ ⎥− − −⎣ ⎦
Dept. of CE, GCE Kannur Dr.RajeshKN
115. 1−⎧ ⎫
⎪ ⎪
{ }
1
3.828 2.707 3.828 0 1 0 2
2.707 4.828 3.414 0.707 0.707 0.707 0
Q
EA PL
A
L EA
− ⎪ ⎪− −⎡ ⎤ ⎡ ⎤− ⎪ ⎪
∴ = ⎨ ⎬⎢ ⎥ ⎢ ⎥− − −⎣ ⎦ ⎣ ⎦ ⎪ ⎪
0
⎪ ⎪
⎪ ⎪⎩ ⎭
⎧ ⎫1.172
0.243
P
⎧
=
⎫
⎨ ⎬
−⎩ ⎭
(There are no loads applied directly to the
supports.)
Dept. of CE, GCE Kannur Dr.RajeshKN
122. 1JA =
1JD
2JA =
2JD
2JA
DJ1 and DJ2
: Joint displacements
M b fl ibilit
Released structure with loads
Member flexibility
matrix of truss member: [ ]Mi
L
F
EA
=
5 0 0⎡ ⎤
[ ]
5 0 0
1
0 2 0MF
EA
⎡ ⎤
⎢ ⎥=
⎢ ⎥
Unassembled flexibility matrix:
Dept. of CE, GCE Kannur Dr.RajeshKN
122
0 0 5
EA ⎢ ⎥
⎢ ⎥⎣ ⎦
123. are found from the released structure when[ ]MSB [ ]RSBand are found from the released structure when
it is subjected to separately.1 2 11, 1, 1J J QA A A= = =
[ ]MSB [ ]RSBand
1 1JA =
2 1JA =
Dept. of CE, GCE Kannur Dr.RajeshKN
123
125. •Each column in the submatrix consists of member[ ]MJB
forces caused by a unit value of a joint load applied to the
released structure.
[ ]MJ
•Each column in the submatrix consists of member
forces caused by a unit value of a redundant applied to
MQB⎡ ⎤⎣ ⎦
forces caused by a unit value of a redundant applied to
the released structure.
[ ] [ ]
0.833 0.625 0.625
0 0 1MS MJ MQB B B
−⎡ ⎤
⎢ ⎥⎡ ⎤⎡ ⎤= =⎣ ⎦⎣ ⎦ ⎢ ⎥[ ] [ ]
0.833 0.625 0.625
MS MJ MQ⎣ ⎦⎣ ⎦ ⎢ ⎥
− −⎢ ⎥⎣ ⎦
•In this problem, since support reactions can be easily
found out once the forces in members are obtained,
Dept. of CE, GCE Kannur Dr.RajeshKN
matrix need not be assembled.[ ]RSB
126. Redundants:
{ }QD∵ is a null matrix{ } { }
1
Q QQ QJ JA F F A
−
⎡ ⎤ ⎡ ⎤= − ⎣ ⎦ ⎣ ⎦
[ ]
T
F B F B⎡ ⎤ ⎡ ⎤ ⎡ ⎤=⎣ ⎦ ⎣ ⎦ ⎣ ⎦[ ]QQ MQ M MQF B F B⎡ ⎤ ⎡ ⎤ ⎡ ⎤=⎣ ⎦ ⎣ ⎦ ⎣ ⎦
5 0 0 0.625⎡ ⎤⎡ ⎤
[ ]
1
0 2 00.625 1 0.625 1
0 0 5 0 625
EA
⎡ ⎤⎡ ⎤
⎢ ⎥⎢ ⎥=
⎢ ⎥⎢ ⎥
⎢ ⎥⎢ ⎥⎣ ⎦⎣ ⎦
5.906
EA
=
0 0 5 0.625⎢ ⎥⎢ ⎥⎣ ⎦⎣ ⎦
0⎧ ⎫
[ ][ ]
T
QJ MQ M MJF B F B⎡ ⎤ ⎡ ⎤=⎣ ⎦ ⎣ ⎦
01
3.906EA
⎧ ⎫
= ⎨ ⎬
−⎩ ⎭
Dept. of CE, GCE Kannur Dr.RajeshKN
127. 1
{ } { }
1
Q QQ QJ JA F F A
−
⎡ ⎤ ⎡ ⎤∴ = −⎣ ⎦ ⎣ ⎦
[ ]
151
0 3.906
105.906
EA
EA
⎧ ⎫−
= − ⎨ ⎬
⎩ ⎭⎩ ⎭
6.614 kN=
Dept. of CE, GCE Kannur Dr.RajeshKN
131. Lack of fit and temperature change problems:
{ } { }
1 T−
⎡ ⎤ ⎡ ⎤
ac o t a d te pe atu e c a ge p ob e s:
{ } { }
1 T
QT QQ MQ TA F B D⎡ ⎤ ⎡ ⎤= − ⎣ ⎦ ⎣ ⎦Redundants:
{ }TD are the displacements (change in length in the case
of trusses) due to lack of fit or temperature changes.) p g
MQB⎡ ⎤⎣ ⎦ are the member forces when unit load is appliedMQB⎡ ⎤⎣ ⎦ are the member forces when unit load is applied
corresponding to the redundants separately.
{ } { }MT MQ QTA B A⎡ ⎤= ⎣ ⎦Member forces:
Dept. of CE, GCE Kannur Dr.RajeshKN
132. •Problem 9:
Member AB is too short by 1 mm.
(i.e., AB is 1 mm shorter than C( ,
required, hence it has to be
pulled to fit in the frame). All
b h i lmembers have cross sectional
areas 35 cm2 and E=2.1x103 t/cm2
D
A B
D
300
300
300
300
A B
10m
300 300
Internal indeterminacy = 1
Dept. of CE, GCE Kannur Dr.RajeshKN
132
Choose the force in AB as redundant
134. ⎡ ⎤ are the member forces when a unit load is
MQB⎡ ⎤⎣ ⎦
are the member forces when a unit load is
applied corresponding to the redundant.
CC
1 2
4
3 5
D
A B
1 1QA =
6
Dept. of CE, GCE Kannur Dr.RajeshKN
1Q
138. SummarySummary
Fl ibilit th dFlexibility method
• Analysis of simple structures – plane truss, continuous
beam and plane frame- nodal loads and element loads –
lack of fit and temperature effectslack of fit and temperature effects.
Dept. of CE, GCE Kannur Dr.RajeshKN
138