I'd like to analyse torque and thrust on a vertical shaft at the same time. I've set up the problem for torque-only using an "on cylindrical faces" fixture to simulate the bearings (see attached; torque at 1 is equal and opposite to total torque at 2 & 3) and gotten good results. What I'd like to do is apply (in addition to the torque force) a thrust force located at points 2 & 3 as indicated in the image.
The problem I'm running in to is that the "on cylindrical faces" fixture won't transmit the bending moment through the fixture, and a bearing fixture won't transmit the torque unless I know the axial and radial stiffness values of the bearings.
I might be able to get axial stiffness values from the bearing manufacturer, but radial stiffness seems very non-trivial (it is based on the bearing/lubrication itself, RPM, angle of the deflected shaft running through it, etc.). Simulation will allow me to define a flexible bearing with just axial stiffness, but I don't feel comfortable leaving radial stiffness out of the equation altogether. Any suggestions?
I should also note that I'm not set on using the SW Sim bearing fixture if there's a better way to do this. Any and all input is appreciated!
so the shaft is supported by bearings at the 2 split lines that you're restraining
and then you want to apply torque and a downward force on both other locations?
what's the end goal for the analysis? where are the torque and thrust forces coming from?
if you were going to look at this in a test or hand calculations, how would you set it up?
the biggest challenge you're going to have with bearing forces or on cylindrical face restraints is that you'll have instability in your model. sure you can turn on "stabilize' but if you look through posts on this, you'll see why that may not be a good idea
so my first suggestion would be to come up with:
1. what the problem would look like as a static problem with hand calculations.
2. what you know about the problem or what additional features you want to include that you can't easily do in a hand calc. in the end if you want to include that bearing stiffness, you don't have much choice but to get the information or do testing to get the information. but if you're looking to compare designs relative to each other. make a good estimate and then run simulations and compare them udner the same assumptions.