# Calculating Stress in a Hook

1. Oct 3, 2011

### mjgarrin

Hello everyone,

I am curious about calculating the stress that acts on a hook.

I apologize I could not make a small enough image to upload, but the hook is "J" shaped. The top of the "J" is held in place to prevent movement.

The geometry of the hook is similar to a bar, whose cross sectional area is 10.0mm by 5.0mm
The thickness of the hook is 5.0mm throughout the hook
The bend radius of the hook is 8.0mm
The radius where the base of the "J" meets the top is 8.5mm

The hook began to bend when a torque of 400,000 N-mm was applied to the very bottom of the "J".

Can someone please help me determine the moment that is applied to this hook?

Thank you,
Mike

2. Oct 10, 2011

### nvn

mjgarrin: Did you mean to say a force, or load, of 400 000 N is being applied to the very bottom of the hook? Or are you truly applying a torque? If you really are applying a torque, then the bending moment on the hook would be M1 = 400 000 N*mm.