Strength of formed angle

[IFRs]

I have to make a formed steel angle, one leg up one leg horizontal, the vertical leg anchored into a concrete wall. The angle has to support 2000 pounds 6" from the wall. The angle can be made from almost any thickness and length although I would like it to be about 12" long and about 1/4" thick. How would I calculate the stress and deflection?


| <--vertical leg
|
| |2000 pound load
| |
| |
| V
+---------- <--horizontal leg

 

[corus]

With the vertical leg anchored, the horizontal beam acts as a cantilever. Look in Roark's formulas for Stress and Strain for a beam built in at one end. The deflection may depend on whether or not the leg is tapered.

corus

 

[IFRs]

Cantileverd beam formulas I am familiar with. That will check the flat plate, but what about the bend itself?

 

[desertfox]

Hi IFRs

Remember also to stress the anchor bolts that hold the angle
to the wall. The anchor bolts will be in tension, assuming of course that the vertical leg is in contact with concrete all along its length the angle will try to pivot off the concrete at the intersection of the horizontal and vertical
leg. I can provide formula's for the above but it will depend on how many fasteners and there position within the vertical leg. If you can provide details of how you are holding the angle to the concrete I can possibly help more.

regards desertfox

 

[flamby]

IFRs,

Is the 2000 lb load concentrated or distributed along the entire length?

I think, the cantilever formula is okay for the plate as well as the bend you describe.

 

[IFRs]

The load is distributed along the length of the angle.

 

[IFRs]

I used 12000 in pounds for the Moment and 12 * Thickness^2 /12 for S to calculate the stress, and 18,000 psi for the allowable stress.

 

[haynewp]

f=12000/(12*0.25^2/6)=96ksi

I would use a thicker plate

 

[IFRs]

Yes, that's what I got. Is this too conservative an analysis? What about the bend?

 

[corus]

The bend is a stress concentration that will give rise to a peak stress. Normally you only consider this for fatigue purposes. You could consider the bend as part of a U shaped member. Again look in Roark for stress concentration factors for a U shaped member with a nominal bending stress.

corus