Fexural Modulus of Elasticity of Steel Pipe

[marty494]

Hi all

I am looking at a buried gas pipeline to determine if it is strong enough to support a load at ground level. To do this i am using BS EN 1295 and I need to determine the flexural modulusof elasticity for a 18 inch diameter steel pipe.

Is there a standard formula for this as I can't seem to find standard values as are available for the young's modulus of elasticity.

Regards

 

[frv]

Modulus of elasticity is a material property, independent of shape. And the vast majority of steels are around 29,000 ksi. Is that really what you are looking for?

 

[marty494]

I agree Young's Modulus of Elasticity is a material property that doesnt change due to shape. However the Flexural Modulus of Elasticity is not the same parameter.

 

[rb1957]

it could be I/R = pi/4*(R^4-r^4)/R

if t (= R-r) is small compared to R then you can simplify to pi*R^2*t

 

[frv]

Young's Modulus is commonly referred to as Modulus of Elasticity.

I've never heard of Flexural Modulus of Elasticity. Are you referring to section modulus (S) or plastic section modulus (Z)?

 

[drawoh]

Could the OP be twisting the pipe and looking for the shear modulus of steel? Typically, this is around 11.5[×]10⁶psi.

Is this a good idea when the pipe is pressurized?

--
JHG

 

[rb1957]

maybe this is something to do with the BS ... maybe the BS is referring to a flexural equivalent to young's modulus (ie a modulus of elasticity derived from bending loads, as opposed to tension) ?

 

[BAretired]

I have never heard of the term Flexural Modulus, but Wikipedia has. Check this link and you find that it has the same value as Young's Modulus. Why anyone would invent such a useless term is beyond me.

BA

 

[rb1957]

to confuse people ?

 

[hokie66]

rb1957, I think the BS means British Standard, but it means something else to me.