Bending Stress = M/Z

M = Bending Moment = F*d

Z = Section Modulus

For calculating Section Modulus, I took this link as a refrence and am trying to work out Section Modulus for last figure where
W= Sl^2/6
where S = tube thickness
l = length of weld

http://www.engineersedge.com/weld/butt_ ... odulus.htm

I cannot understand that why has he take tube thickness as breadth when actually it should be the width of a bracket for the moment.

Please HELP .. any ideas greatly appreciated.

Thnks and apologoze for posting in ASME VIII forums, its just that understanding the reason helps with application of formulas in ASME VIII

Hi,

In the explanation s could be the tube or Plate thickness. This is simply the moment of resistance for a rectangular section.

Michael

Thanks Frohnert,

From the way I understand it, I think it's a plate welded to a shell (do correct me if I am wrong).

I was trying to work out the Bending Stress on a bracket and thix os how I have tried

B.S. = B.M./Section Modulus

B.M. = Force * Prependicular distance
where Prependicular distance = breadth of the plate (and not the
thickness of the plate)


Section Modulus = W= Sl^2/6
where S = tube thickness
l = length of weld


Even though it is for moment resistance, than why has he taken prependicular distance as width of a plate in B.M. (instead of taking it as a thickness of a plate)

Please let me know If I need to expalin it more

Thanks
Materialboy