Civil Engineering - Strength of Materials - Discussion


A cast iron T section beam is subjected to pure bending. For maximum compressive stress to be three times the maximum tensile stress, centre of gravity of the section from flange side is

[A]. h/4
[B]. h/3
[C]. h/2
[D]. 2/3 h.

Answer: Option A


No answer description available for this question.

Bahaa said: (Jul 20, 2016)  
I think the correct answer should be 3/4 h. But it is not given in the option.

Rahul said: (Apr 9, 2017)  
How? Explain in detail.

Rohit said: (Apr 26, 2017)  
Here, x=h/4 from the bottom side of t- beam.
And x=3h/4 from the flange (top side) of the beam.

T. Suresh Babu said: (Aug 19, 2017)  
Yes, (3h/4) is correct when the applied moment is Sagging. Otherwise i.e., if the applied moment is Hogging it is (h/4). As in the options both are not given means we have to take the moment is Hog. If both are given there will be an ambiguity. So, in that case the type of moment have to given in the question.

Naveen Kallan said: (Dec 22, 2017)  
3/x = 1/h-x
X= 3h/4 from top.

Sanju said: (Jul 25, 2018)  
Thanks @Naveen.

Nilraj said: (Nov 20, 2018)  
Answer is correct. Because C.G. is moving towards more area and towards flange area is more.

Srikanth said: (Jan 28, 2019)  
1/x = 3/(h-x).
x = h/4.

Giraq said: (Jun 13, 2019)  
From top x=3/4h.
From bottom x=1/4h.

Krishna said: (Jan 11, 2020)  
See here the beam is under hogging i.e. top fiber under tension and bottom fiber under compression. Therefore the answer given is correct.

If it is under sagging, It would be given as 3h/4 in the options along with h/4.

Sandya said: (Apr 30, 2020)  
Explain with diagram?

Sandya said: (Apr 30, 2020)  
Explain it.

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