background image

Przykład 5

Wyznaczyć wykresy sił wewnętrznych

2l

l

l

l

EJ=const

q

P

M

background image

dane

2l

l

l

l

EJ=const

q

P

M

P=10kN

M=10kNm

q=3kN/m

l =10m

EJ=10000kNm

2

background image

dyskretyzacja

x

x

x

x

y

y

y

y

1

1

2

3

4

5

2

3

4

2l

l

l

l

EJ=const

węzły

elementy

background image

Wektor przemieszczeń

1

2

3

4

q

2

q

3

q

4

q

5

q

1

[

]

1

2

3

4

5

T

q

q

q

q

q

q

=

background image

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....1

6

4

6

2

.....2

....0

12

6

12

6

....3

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....1

6

4

6

2

.....2

....0

12

6

12

6

....3

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

Macierze sztywności elementów

1

2

3

4

q

2

q

3

q

4

q

5

q

1

1

v

a

ϕ

a

ϕ

b

v

b

2

v

a

ϕ

a

ϕ

b

v

b

3

v

a

ϕ

a

ϕ

b

v

b

4

v

a

ϕ

a

ϕ

b

v

b

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....0

6

4

6

2

.....0

....1

12

6

12

6

....2

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....0

6

4

6

2

.....0

....1

12

6

12

6

....2

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....0

6

4

6

2

.....3
....0

12

6

12

6

....4

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....0

6

4

6

2

.....3
....0

12

6

12

6

....4

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....0

6

4

6

2

.....4

....0

12

6

12

6

....5

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....0

6

4

6

2

.....4

....0

12

6

12

6

....5

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

modyfikacja

0      0       1       2

1       2        0       3

0       3        0       4

0        4        0       5

background image

Agregacja globalnej

Macierzy sztywnosci

1

2

3

4

q

2

q

3

q

4

q

5

q

1

3

2

3

2

22

3232

22

.....0

6

4

6

2

.....0

....1

1261

2

6

....2

62

64

aa

bb

llllv

E

J

E

J

E

J

E

J

llll

v

E

JE

JE

JE

J

llll

E

JE

JE

JE

J

llll

ϕ

ϕ

⎢⎥

⎢⎥⎡⎤

⎢⎥

⎢⎥

⎢⎥⎢⎥

⎢⎥⎢⎥

⎢⎥

−−

−⎢

⎢⎥⎣⎦

⎢⎥

⎢⎥

⎣⎦

3

2

3

2

22

3232

22

.....

6

4

6

2

.....

....0

126126

....

6264

aa

bb

llll

v

E

J

E

J

E

J

E

J

llll

v

E

JE

JE

JE

J

llll

E

JE

JE

JE

J

llll

ϕ

ϕ

⎢⎥

⎢⎥⎡

⎢⎥

⎢⎥

⎢⎥⎢⎥

⎢⎥⎢⎥

⎢⎥

−−

⎢⎥

⎢⎥⎣

⎢⎥

⎢⎥

⎣⎦

3232

22

323

2

22

126126

...

6462

...

...

126126

...

6264

a

abb

E

JE

JE

JE

J

llll

v

E

JE

JE

JE

J

llll

v

EJEJEJEJ

llll

E

JE

JE

JE

J

llll

ϕ

ϕ

⎡⎤

⎢⎥

⎢⎥⎡

⎢⎥

⎢⎥

⎢⎥

⎢⎥

⎢⎥⎢⎥

⎢⎥

−−

⎢⎥

⎢⎥⎣

⎢⎥

⎢⎥

⎣⎦

3232

22

3232

22

126126

.....

0

6

4

6

2

....

.4

....

0

12612

6

....

5

6264

a

abb

E

JE

JE

JE

J

llllv

E

JE

JE

JE

J

llllv

E

JE

JE

JE

J

llll

E

JE

JE

JE

J

llll

ϕ

ϕ

⎡⎤

⎢⎥

⎢⎥⎡⎤

⎢⎥

−⎢

⎢⎥

⎢⎥

⎢⎥⎢⎥

⎢⎥

−−

−⎢

⎢⎥⎣⎦

⎢⎥

⎢⎥

⎣⎦

3

2

3

2

22

3232

22

.....0

6

4

6

2

.....0

....1

1261

2

6

....2

62

64

aa

bb

llllv

E

J

E

J

E

J

E

J

llll

v

E

JE

JE

JE

J

llll

E

JE

JE

JE

J

llll

ϕ

ϕ

⎢⎥

⎢⎥⎡⎤

⎢⎥

⎢⎥

⎢⎥⎢⎥

⎢⎥⎢⎥

⎢⎥

−−

−⎢

⎢⎥⎣⎦

⎢⎥

⎢⎥

⎣⎦

3

2

3

2

22

3232

22

.....

6

4

6

2

.....

....0

126126

....

6264

aa

bb

llll

v

E

J

E

J

E

J

E

J

llll

v

E

JE

JE

JE

J

llll

E

JE

JE

JE

J

llll

ϕ

ϕ

⎢⎥

⎢⎥⎡

⎢⎥

⎢⎥

⎢⎥⎢⎥

⎢⎥⎢⎥

⎢⎥

−−

⎢⎥

⎢⎥⎣

⎢⎥

⎢⎥

⎣⎦

3232

22

323

2

22

126126

...

6462

...

...

126126

...

6264

a

abb

E

JE

JE

JE

J

llll

v

E

JE

JE

JE

J

llll

v

EJEJEJEJ

llll

E

JE

JE

JE

J

llll

ϕ

ϕ

⎡⎤

⎢⎥

⎢⎥⎡

⎢⎥

⎢⎥

⎢⎥

⎢⎥

⎢⎥⎢⎥

⎢⎥

−−

⎢⎥

⎢⎥⎣

⎢⎥

⎢⎥

⎣⎦

3232

22

3232

22

126126

.....

0

6

4

6

2

....

.4

....

0

12612

6

....

5

6264

a

abb

E

JE

JE

JE

J

llllv

E

JE

JE

JE

J

llllv

E

JE

JE

JE

J

llll

E

JE

JE

JE

J

llll

ϕ

ϕ

⎡⎤

⎢⎥

⎢⎥⎡⎤

⎢⎥

−⎢

⎢⎥

⎢⎥

⎢⎥⎢⎥

⎢⎥

−−

−⎢

⎢⎥⎣⎦

⎢⎥

⎢⎥

⎣⎦

1

2

3

4

5

1234

5

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....0

6

4

6

2

.....0

....1

12

6

12

6

....2

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....1

6

4

6

2

.....2

....0

12

6

12

6

....3

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....0

6

4

6

2

.....3
....0

12

6

12

6

....4

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....0

6

4

6

2

.....4
....0

12

6

12

6

....5

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....0

6

4

6

2

.....0

....1

12

6

12

6

....2

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....1

6

4

6

2

.....2

....0

12

6

12

6

....3

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....0

6

4

6

2

.....3
....0

12

6

12

6

....4

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

.....0

6

4

6

2

.....4
....0

12

6

12

6

....5

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

v

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

EJ

l

l

l

l

ϕ

ϕ

⎥ ⎡

⎥ ⎢

⎥ ⎢

⎥ ⎣

1

0

0

1

0

0

0

1

0

2

0

4

2

3

0

4

2

3

3

1

0

0

0

1

0

0

0

4

2

5

3

4

2

5

3

4

5

1

2

3

4

5

background image

Macierz sztywności układu

1

2

3

4

q

2

q

3

q

4

q

5

q

1

3

2

2

24

6

0

0

0

8

2

0

0

0

6

2

8

2

0

2

8

2

0

0

2

4

0

0

0

EJ

EJ

l

l

EJ

EJ

l

l

EJ

EJ

EJ

EJ

l

l

l

l

EJ

EJ

EJ

l

l

l

EJ

EJ

l

l

background image

Wyznaczenie wektora obciążenia

2l

l

l

l

EJ=const

q

P

M

2

2

2

12

2

12

ql

ql

ql

ql

0

3

0

4

2

2

0

,

,0,

,0

2

12

12

T

ql

ql

ql

= −

R

[

]

, ,0,0,0,0

T

P M

=

R

2

0

2

2

25
35

12

0

0

0

0

25

0

0

12

0

ql

P

ql

M

ql

⎡ ⎤

⎢ ⎥

⎢ ⎥

⎢ ⎥

=

=

=

⎢ ⎥

⎢ ⎥

⎢ ⎥

⎣ ⎦

P

R

R

P=10kN

M=10kNm

q=3kN/m

l =10m

EJ=10000kNm

2

2

2

2

12

2

12

ql

ql

ql

ql

1

2

0

3

background image

Obliczenie sił w elemencie nr 1

2l

l

l

l

EJ=const

q

P

M

    

0.1337

0.0073

   q= -0.0118

-0.0002

0.0001

   

   

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

0

0

-11.6464

6

4

6

2

0

0

 -65.5592

 

12

6

12

6

0.1337

0

11.6464

0.0073

0

-5

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

T

EJ

EJ

EJ

EJ

M

l

l

l

l

T

EJ

EJ

EJ

EJ

l

l

l

l

M

EJ

EJ

EJ

EJ

l

l

l

l

⎤ ⎡ ⎤

⎥ ⎢ ⎥

⎥ ⎢ ⎥

=

+

=

⎥ ⎢ ⎥

⎥ ⎢ ⎥

⎥ ⎣

⎦ ⎣ ⎦

0.9046

 
   
  

Wektor 
przemieszczeń:

Siły w 1 
elemencie:

background image

Obliczenie sił w elemencie 2, 3

    

0.1337

0.0073

   q= -0.0118

-0.0002

0.0001

   
    

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

0.13370

15

-1.6464

6

4

6

2

0.0073

25

60.9

  

12

6

12

6

0

15

-0.0118

25

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

T

EJ

EJ

EJ

EJ

M

l

l

l

l

T

EJ

EJ

EJ

EJ

l

l

l

l

M

EJ

EJ

EJ

EJ

l

l

l

l

=

+

=

⎥ ⎣

046

-28.3536

72.6316

   
  
   

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

0

15

-22.2039

6

4

6

2

-0.0118

25

-72.6316

 

12

6

12

6

0

15

-

-0.0002

25

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

T

EJ

EJ

EJ

EJ

M

l

l

l

l

T

EJ

EJ

EJ

EJ

l

l

l

l

M

EJ

EJ

EJ

EJ

l

l

l

l

=

+

=

⎥ ⎣

7.7961

0.5921

  
   
    

2l

l

l

l

EJ=const

q

P

M

Siły w 2 
elemencie:

Siły w 3 
elemencie:

background image

Obliczenie sił w elemencie 4

    

0.1337

0.0073

   q= -0.0118

-0.0002

0.0001

   
    

3

2

3

2

2

2

3

2

3

2

2

2

12

6

12

6

0

0

-0.0592

6

4

6

2

-0.0002

0

-0.5921

12

6

12

6

0

0

0.0592

0.0001

0

0

6

2

6

4

a

a

b

b

EJ

EJ

EJ

EJ

l

l

l

l

T

EJ

EJ

EJ

EJ

M

l

l

l

l

T

EJ

EJ

EJ

EJ

l

l

l

l

M

EJ

EJ

EJ

EJ

l

l

l

l

⎤ ⎡ ⎤ ⎡

⎥ ⎢ ⎥ ⎢

⎥ ⎢ ⎥ ⎢

=

+

=

⎥ ⎢ ⎥ ⎢

⎥ ⎢ ⎥

⎥ ⎣

⎦ ⎣ ⎦ ⎣

   
    

        

2l

l

l

l

EJ=const

q

P

M

Siły w 4 
elemencie:

background image

Wykresy sił wewnętrznych

-0.0592

-0.5921

 

0.0592

0

   
    

        

a

a

b

b

T

M

T

M

⎤ ⎡

⎥ ⎢

⎥ ⎢

=

⎥ ⎢

⎥ ⎢

2l

l

l

l

EJ=const

q

P

M

-11.6464

-65.5592

 

11.6464

-50.9046

 
   
  

a

a

b

b

T

M

T

M

=

-1.6464

60.9046

 

-28.3536

72.6316

   
  
   

a

a

b

b

T

M

T

M

⎤ ⎡

⎥ ⎢

⎥ ⎢

=

⎥ ⎢

⎥ ⎢

-22.2039
-72.6316

-7.7961

0.5921

  
   

   

a

a

b

b

T

M

T

M

⎤ ⎡

⎥ ⎢

⎥ ⎢

=

⎥ ⎢

⎥ ⎢

1

2

3

4