Reaction Forces with Beams

[MEGears10]

Hello All,

I am currently using WF5 Mechanica and I am having an issue with a reaction force analysis. Basically, I am trying to find the forces on bolt holes due to a moment from a motor. I have a baseplate that the holes are in. I have the baseplate model, and I created a datum point where the motor CG is located and applied a moment load on that point. I then created datum points where the bolt holes are located and created beams between the motor CG datum and the 4 bolt datums. When I try to run the analysis, I get an error saying "he model is insufficiently constrained for the analysis. Please review the element connections, properties, and constraints in highlighted entities." I have the baseplate constrained at the mounting holes, but I do not know what to do about the datum points. I am concerned that they are not recognized as part of the model, but I do not know how to do this.

Does anyone have any suggestions?

Thanks,

 

[jvian]

You are right that the datum points are not recognized as part of the model. You need to constrain the datum points to the baseplate but use caution as there are multiple ways of doing this and they can each provide dramatically different results and/or singularities depending on the results of interest. It may help to describe your situation with a little more detail about how you are constraining the baseplate and what you are interested in. When you say reaction forces on the bolt holes at the datum points then you may be able to get away with "spider bolts" between the datum point and the edges of the bolt holes or even simple rigid links although as I stated before these methods can produce very irregular results.

http://www.tsdengineering.com/

under the tips and tricks section has some decent information about joints and assemblies and may help you get started in a direction to solving your problem.

Hope that helps and good luck,

- J -