Simulation Bearing Forces

[champeau24]

I'm running a static analysis on a shaft supported by two bearings with several loads on it. After running the simulation, when I look at the bearing reaction forces, everything comes up zeroes. Everything else in the analysis results look good, deflection, von mises stress, etc. But I can't get the results to display the proper bearing reactions. Any advice?

 

[carson32]

How do you have the bearings defined in the simulation? If you have them as fixed then they will not show the reaction because the simulator sees them as unmovable objects. You will have to explain more about how the simulation is defined before I could give any more advice.

 

[champeau24]

I'm running a static analysis on a shaft supported by two bearings with several loads on it. After running the simulation, when I look at the bearing reaction forces, everything comes up zeroes. Everything else in the analysis results look good, deflection, von mises stress, etc. But I can't get the results to display the proper bearing reactions. Any advice?

I'm using the bearing fixture function. On both bearings, I have the rigid button selected and self alignment allowed. On one of the bearings I have the "stabilize shaft rotation" box checked.

 

[champeau24]

Bearing Details

Both bearings are set up as rigid. Both bearings are set up as self-aligning. One of the bearings has the "stabilize shaft rotation" box checked.

I've also tried setting up the bearings as flexible vs. rigid and still get all zeroes for bearing reaction forces.

 

[carson32]

I got it to work. Hopefully I can remember the steps I took.
- the bearing housings must be fixed in some way
- delete the global contact in the component contacts subsection of the tree
I think the previous one was causing the problem
- I used the same bearing settings, so that wasn't a problem.
- when getting the resultant force, check the free body force radio button, then select the face of the shaft that is going through the bearing. I assume you have steps in your shaft close to the bearing, if not, you might have to add them in order to avoid the error message.

 

[carson32]

I thought I replied to this a couple days ago, but it must have failed to save. I had to recreate the situation that you explained to find a solution. I had the same issues as you did, but after several steps I was able to find the reaction forces.

When doing the simulation there is an automatic constraint that is created. It is called global contact under component contacts. Delete this contact.

Under the results tab select "List Results Force". Select the radio button Free body force. This will show the reaction in the x,y, and z as well as the magnitude.

Im really glad I tried figuring this one out, I learned a lot in the process.