CE 311-Structural Analysis & Design I

1. M.S MAHAFUZ SHAWON FAKIR
B.Sc. In Civil Engineering
ID. 050 07732
Stamford University Bangladesh

2. FRAME
CHAPTER: 2
Stability & Determinacy

3. INTRODUCE DIFFERENT PART OF THE FRAME.
Not Frame
Frame
 Here, Colum
n= Total Number of Frame
r = Minimum Number of Reactive Components
required for External Stability/Determinacy. Beam Reaction
 One face open ,it’s frame
 r=3n

4. ESSENTIAL FORMULA FOR FRAME.
 STABILITY
 r < 3n The Frame is Stable.
 r ≥ 3n The Frame is Unstable.
 DETERMINACY:
r = 3n The Frame is Determinate.
r > 3n The Frame is Indeterminate.
 If Frame is Indeterminate, then
Degree of Indeterminacy (I) = r-3n

5. Determine the stability and determinacy condition for the following
structure as shown in the figure.
 Here,
n = 3
r = 6+3*3 =15
3n= 3*3
= 9
Since, r > 3n The Frame is Stable.
Since, r> 3n The Frame is Indeterminate.
I = r-3n
= 19-14 = 5°

6. Determine the stability and determinacy condition for the following
structure as shown in the figure.
 Here,
n = 2
r = 6+1*3 =9
3n= 3*2
= 6
Since, r > 3n The Frame is Stable.
Since, r> 3n The Frame is Indeterminate.
I = r-3n
= 9-6 = 3°

7. Determine the stability and determinacy condition for the following
structure as shown in the figure.
 Here,
n = 7
r = 12+7*3 =33
3n= 3*7
= 21
Since, r > 3n The Frame is Stable.
Since, r> 3n The Frame is Indeterminate.
I = r-3n
=33-21 = 12°

8. Determine the stability and determinacy condition for the following
structure as shown in the figure.
 Here,
n =3
r = 9+5*3 = 21
3n= 3*3
= 9
Since, r > 3n The Frame is Stable.
Since, r> 3n The Frame is Indeterminate.
I = r-3n
=21-9 = 15°

9. Determine the stability and determinacy condition for the following
structure as shown in the figure.
 Here,
n =2
r = 9+3*3 = 18
3n= 3*2
= 6
Since, r > 3n The Frame is Stable.
Since, r> 3n The Frame is Indeterminate.
I = r-3n
=18-6 = 12°

10. Determine the stability and determinacy condition for the following
structure as shown in the figure.
 Here,
n =4
r = 6+4*3 = 18
3n= 3*4
= 12
Since, r > 3n The Frame is Stable.
Since, r> 3n The Frame is Indeterminate.
I = r-3n
=18-12 = 6°

11. Determine the stability and determinacy condition for the following
structure as shown in the figure.
 Here,
n =8
r = 15+8*3 = 39
3n= 3*8
= 24
Since, r > 3n The Frame is Stable.
Since, r> 3n The Frame is Indeterminate.
I = r-3n
=39-24 = 15°

12. Determine the stability and determinacy condition for the following
structure as shown in the figure.
 Here,
n =6
r = 9+6*3 = 27
3n= 3*6
= 18
Since, r > 3n The Frame is Stable.
Since, r> 3n The Frame is Indeterminate.
I = r-3n
=27-18 = 9°

13. Determine the stability and determinacy condition for the following
structure as shown in the figure.
 Here,
n =6
r = 9+6*3 = 27
3n= 3*6
= 18
Since, r > 3n The Frame is Stable.
Since, r> 3n The Frame is Indeterminate.
I = r-3n
=27-18 = 9°

14. SLAIDE MADE BY MSF
END