Civil Engineering - Strength of Materials - Discussion

Discussion Forum : Strength of Materials - Section 5 (Q.No. 11)
11.
If the depth of a simply supported beam carrying an isolated load at its centre, is doubled, the deflection of the beam at the centre will be changed by a factor of
2
1/2
8
1/8
4
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
10 comments Page 1 of 1.

Niraj Adhikari said:   6 years ago
No @Shweta.

You can't assume L=2L.

And you are correct @Ravana.

d= wl^3/48EI
I= bd^3/12.

Assume x= wl^3/48E ( constant).

d= X*12/bd^3.
d=2d ( given).
Hence deflection is inversely proportional to the cube of depth.

Deflection decreases with increase in depth with respect to previous.
(1)

Shweta puri said:   9 years ago
Deflection at the center of S. S is WL^3/48Ei if depth is double it mean L = 2L then the formula become W (2L) ^3/48EI. The divided first term which is WL^3/48EI to W (2L) ^3/48EI. It becomes 1/8.

Ashish said:   7 years ago
No, @Shweta Puri.

Your concept is right @Pv Ramana.

Deflection is inversely proportional to MOMENT OF INERTIA i.e. also inversely proportional to the depth.

Pv ramana said:   9 years ago
Substitute I = b (2d) ^3/12 you will get 1/8th of S. S deflection at center.

Aamir said:   9 years ago
Deflection is inversely proportional to the cube of depth.

Shiva said:   8 years ago
For cantilever it is 8.

For simply supported it is 1/8.
(1)

Gourav saha said:   6 years ago
Thanks for giving a proper method @Shweta Puri.

Reshu agrawal said:   9 years ago
Can anyone give the solution of this question?

Rajesh Yadav said:   6 years ago
You are right, Thanks @Pv Ramana.

Gandhari pradhan said:   5 years ago
Thanks all for explaining.
(1)

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