Inventor 2014 Stress Analysis bug/defect?

[cyberider]

Look at the Safety Factor results. The only thing I have changed between the two simulations is adding a lot more load points. All Force vectors you see are exactly the same force value (5000N).

The more load (stress) I add the "safer" this same design gets... how is that possible?

Note: I have all the latest updates for Inventor 2014. I have SP2 and Update 3 installed and inventor says my software is up to date. However Inventor replies back to my crash reports that I should install SP2 to solve my crashes even though the crash reports say I have SP2 installed.

This forum restricts file uploads to <5MB. So I cannot use the upload. Instead I put the 19MB zip file in my public dropbox folder:

Zipped 19MB files

[raviburla · Accepted solution]

Hi,

I looked into the model you had attached. Here are my observations:

Simulation3:

This has 3 active forces each with magnitude of 5000 N along -ve y direction => Net load of 15000 N .

Simulation5:

This has 1 active force with a magnitude of 6000N along -ve y direction. Net load is 6000 N. 

Since the net load applied in Simulation3 is more than that of Simulation5, the safety factor is lower. Also, please note that when a force P is applied on N-number of faces, then the load will be distributed on these faces based on their areas and the net force applied will be P.

Please let us know if you have more questions/concerns.

Thanks!

Ravi Burla (Autodesk)

[cyberider]

Right you are! I didn't realize it was dividing my force by how many vectors load points I had. I thought it was my force times the number of load points. So I have re-run the simulation at 35000N (7 steps x 5000N) and get a result I would expect.