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Eyebolt proper analysis

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mickAA

Mechanical
Joined
Dec 4, 2010
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3
Location
CA
I have been asked to perform an analysis on this particular eyebolt. I want to find out the force it takes to yield the eye at the critical points. I am not worried about the bolt pulling out of the concrete because the bolt length (under the eye is 24") and is been tested (in pure tension) to handle over 30 tons of tension force.

When the eyebolt is loaded in pure shear (as in the diagram) it will create the most stress under the 2" base in the discontinuity (where the 1.125" rod meets the 2" shoulder). I have done prelimary calcs resulting in a yielding force of around F=25000 lbs (by resolving the horizontal force into an equivalent moment and shear located just under the shoulder.

I am interested in a method to analyze the stresses in the eye part (0.9")?
 
Approach it as a curved beam problem.

Ted
 
Curved beam problem only if eyebolt is cut on one side just as you would have with punch press frames. There are analysis and if I find one in my library, I'll let you know the source; check the web though. Personally, I get a Crosby catalog for selection. Note that there are two types of eyebolts, shoulder and shoulderless types. Shoulder type can sustain side loading in addition to straight pulls; shoulderless types should only sustain straight pulls.
 
For a 2.5 ID X 4.5OD forged eye bolt, Crosby has a working load of 15,200 lbs. Factor of safety is 5. Ultimate load will be 5X working load.
 
Found ore info in my archive about shoulder type forged eyebolts. The above value is for direct pull. For side pull at 45 and 90 degrees from vertical reduce working load by 30 and 25 percent respectively.
 
Be very careful in permitting bending moments on eyebolts.
 
The take the bending component out of the equation you need to use a swivel head type lifting ring. Her is a very good cross section of what's available along with a good sling calculator.

 
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