Stress in Rectangular Fastening Holding Cylindrical Pipe

[mosahed]

I have a problem in which a worn rectangular fastening is supporting a vertical steel pipe from the side of the pipe.
I must calculate the stresses within the fastening in order to determine whether the pipe is able to withstand further loading or not.

Would I be correct in assuming that the shear stress takes primacy in the causation of failure in this circumstance?

Also, would the calculation of said shear stress be as simple as Load/Contact area of fasting ?


Apologies for the lack of technical language I am a recent graduate with little experience (Also I am currently on a short vacation, so no access to codes, textbooks, mentors etc. The questions are simply to help ease my stress for returning to the problem.)

 

[paddingtongreen]

Depending on the length and way the other end of the rectangular piece is fixed or simply supported, there might also be a bending moment. If it is fixed against rotation and is short, your assumption is close to being correct but if it is long and/or is simply supported there will be a bending moment.

Draw the center lines of the pipe and the rectangular support with load and reactions shown and then visualize the deflections, they will tell you where the moments are.

Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin

 

[mosahed]

The rectangular fastening is fully fixed to a stable structure. The support is very small and the pipe quite long, although much of the weight is reduced due to it being almost fulled submerged in water.

Is my assumption of the calculation of shear stress in the fastening an over simplification?

I guess I really need access to my eurocodes right about now...

 

[dhengr]

In light of the fact that you didn’t seem to get the drift of Paddington’s comments, and because you are welding a stiff support to a large dia. pipe, probably of fairly light wall thickness, a sketch with loads and sizes and dimensions might really be helpful. Given that the pipe is submerged in water can you ever have any bouncy or lifting issues. Your approach to the shear may be about right, it’s a shear flow over the length of the weld. But, you have to protect the terminations of those welds if they have the potential of tensile forces or prying forces or if the pipe wall can flex due to this support. These types of forces can just unzip the welds from the tension end.