Maximum Allowable Load

[schretta]

I am trying to find formulas to calculate the maximum allowable load for a 304 Stainless Steel round bar that is formed into a u-shape.

 

[desertfox]

Hi Schretta

How is the U shape loaded ie where does the force act and how is the U supported.I may be able to help but it will depend on what other information you can give.

regards
desertfox

 

[schretta]

The U-shape acts as a pipe support in a hanger assembly. This hanger supports the pipe. The force applied to the U is acting downward.

 

[ugwuegbuchima]

I believe if you know the maximum amount of stress(internal force) that is to act on the U-shaped bar and also the area of the bar,you can be able to calculate the max. allowable load for the material.
That is since

Ss= P/A where Ss is the max. allowable stress on the material,P=? is the max. allowable load on the material which is to be determined,A= area of the material.
Making P subject of formula we can be able to obtain the max. allowable load on the material. That is,

A= P/Ss.

 

[NickE]

To continue:

pipe weight = X
# of hangers = n

X/n=X(h)

X(h) = weight per hanger

X(h)/2 = weight per leg of hanger



Nick
I love materials science!

 

[NickE]

Edit on above....

X(h)/2 = P

giving you the substitution for Ugwuegbuchima's equations...

you can calculate a rough approximation for the static stress on the U-bolt this way.

304 -- hmmmm... how corrosive is the environment?

cold finished wire: 90ksi UTS, 45ksi .2%Yield
Annealed: 75ksi UTS, 30ksi .2%Yield

The above only gives you the results for static even load. If you have forces in other directions you may need to factor them in to the above.

nick

 

[ugwuegbuchima]

In continuation,
P= A.Ss
where P is the allowable load you are looking for,A= cross-sectional area of the material and Ss the allowable stress on the material which you must know before you can be able to get P.I believe you can be able to calculate the area and get it on your own.

 

[IFRs]

The stress needs to be a factor-of-safety away from the yield strength.

Other factors:
fatigue loads
dynamic loads
reduced area at threads
heat affected zone if welded
stress riser at thread root
corrosion
what is at risk (human life / water presure)
expected lifetime