Reverse Loads

[Renslekee]

I have a consultant telling me that an equal and opposite load will produce identical von mises results. I'm holding fast to the point that non-symmetric geometry will create deflections that will slightly alter the stresses.
I don't have an FEA software license. Is anyone willing to pull a standard crane hook model from the internet and run a + and - vertical load and share the results?

Thanks!

 

[rickfischer51]

You dont need FEA. Do hand calculations at some point on a horizontal cantileaver beam, with a vertical end load up and then down. What you will see is that that all the stress components are squared, summed and then square rooted. The squaring operation removes negative signs, leaving identical summed magnitudes.

Rick Fischer
Principal Engineer
Argonne National Laboratory