Bending of eye bolts and eye hooks

[Jc67roch]

I have a situation where we are trying to apply a tension load of approximately 13 kips to a rod bent into the shape of an "eye". However, the tension load is at a low angle (18 degrees) relative to the concrete surface in which the eye is embedded. Thus, the load is being applied at the side of the eye, rather than as an upward tensile load at the top of the eye. Should I be worried and checking the bent rod/eyebolt for bending about the circular secton of the rod? When I check this, using eccentricity equal to the eye diameter, the rod will fail in bending at the base of the eye or the concrete surface.

 

[Ron]

Based on your description, I agree with your analytical approach. As bending in the rod occurs at the concrete interface, the angle of attack on the eye will change which will then cause it to open up (if your calcs are correct on the bending at the other location).

 

[unclesyd]

Look at he table on the bottom of the page for correction factors for off angle eye bolts, you will also find essentially the same information if using wire rope. Even with swivel heads eye bolts don't like to operate at less than 45°.

Can you embed your eye bolt at the desired angle where every thing is in tension?

 

[Jc67roch]

Thank you both for the input. unclesyd - I can't seem to find the table you are referring to attached. But it sounds like what I am looking for. Unfortunatey, these eyebolt are being pulled at 18 degrees off the horizontal (well below 45 degrees). And to embed them at that angle will be difficult drilling (they are to be installed in existing concrete deadmen, underwater).

 

[unclesyd]

Another senior moment. Here is the link. This is for eye bolts but

there is not much difference between a one piece eye bolt and a

coupling nut on a bent rod. You can find this guidance, reduction

in capacity, associated with almost any lifting device.
Also look at the "User Information Sheet" listed on this page.

http://www.jwwinco.com/products/section11/gn581/

Here is the RUD site with a little more information. I was looking the through bolt types to see if you could gain a little by getting the rod in shear. None listed have the capacity you require.

http://rud.sdzecom.de/productgroup.php?pgsn=1&chash=1a06a0

 

[unclesyd]

Here are two approaches to using the existing bolts without bending. Though this isn't the best in puts the bolt in shear. Now it depends on the shear strength of the bolt.
These are just conceptual sketches with no consideration on sizes or material. the lug style would be far less complicated that one with the gusset.
Excuse my drawing as I haven't ran this program in about 10 years.

http://my.engineering.com/pg/file/unclesyd/read/337308/18-degrees