Lift eye design/evaluation

[osw]

I have a u-shaped lift eye made of round bar (both ends welded). What approach should one follow in computing the maximum stress on the lift eye: the flexure formula, the curved beam flexure formula, (used on crane hooks) or a different approach? Thank you.

 

[sdz]

Finite element analysis?

 

[Bribyk]

Can you change the eye design? I don't use this type of feature in my below-the-hook designs because the material properties are too difficult to predict and it's not worth the time involved. Once you bend steel the mill test report or nominal material properties are no longer valid. You've also got more complex geometry to figure out. I figure out how thick of plate I need, cut a hole it in and weld to whatever's being hoisted - much easier to design and probably equally cost-effective to fabricate (you need more stringent fabrication procedures for the bent version to ensure your estimated/tested material properties are met and that fabrication hasn't introduced any stress raisers). My $0.02...