FEA beginner help

[aldumoul]

Hello, haven’t used FEA in quite some time.

Not sure how to interpret the results. I found in my hand calc, the max stress the broached shaft will see is 2830 psi. And the max/yield to be 4026 psi. Which matches the Von Mises result. The analysis is for torsion in the cross section of the id/keyway. How should I interpret the von mises and principal results?

 

[FEA way]

So your question is what do those quantities mean ? You will need some theory to understand this. It's typically discussed in mechanics of materials textbooks, in chapters about analysis of stress but I can also recommend "Building Better Products with Finite Element Analysis" by V. Adams. In that book you will find a short description related to practical application in FEA.

 

[Andries]

Hi aldomoul,

As FEA way alluded to you must have a thorough grasp of basic mechanics of materials. Also read up on basic elasticity theory.
You must be able to do rough "sanity" checks on your results using hand calculations on a simplified representation of the part in question.
Another essential check is the displacements of the part or structure: do they make physical sense? Are the boundary conditions correct?

This way of working requires experience but is the only way.

All the best.

Andries

 

[rb1957]

First, please change your pdf, so that the header of each pic is on the same page as the pic !

Linear FEA ? if so, pretty meaningless if you're trying to detect the stress concentration in the keyway.

Element stresses ... also pretty meaningless if you're trying to detect the Kt; use nodal stress.

Many shafts/keyways are critical in fatigue.

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.