Advanced Methods of Structural Analysis

Problems 419

11.10.Calculate the displacement of the joints and internal forces in all member of
the truss;EA= constant for all elements,dD 1 m (Fig. P11.10).

F 1 =4kN

F 2 =2kN

d

d

1

2

3

4

5

6

Fig. P11.10

Ans.S 1 D0:6212IS 2 DS 5 DS 6 D1:3788IS 3 D1:9503IS 4 D3:7074

11.11.The externally and internally statically indeterminate truss is subjected to
two groups of external loads. The first group isF 1 D 12 kN andF 2 D 5 kN; the
second group isN 1 D 16 kN andN 2 D 4 kN as shown in Fig.P11.11. For each set
of load calculate internal forces in each element. Knowing internal forces compute
the reactions of supports.EADconstant for all elements.

4m

3m

a

1

2

3

7

4

5

6 8

12

9

10

11 13

15

14

B D F

ACE

L G

F 1

F 2

N 1 N 2

Fig. P11.11

Ans. Set FWS 1 D6:2910I S 2 D 10:0328I:::; S 15 D0:4672: RD D
8:57606kN

11.12.Construct the influence lines for internal force in each member of the in-
ternally statically indeterminate truss shown in Fig.P11.12.EADconstant for all
elements.

4m

3m

a

1

2

3

7

4

5

6 8

12

9

10

11 13

15

14

BDF

Fig. P11.12