Mechanism Dynamics Connections

[rework]

Hi--I am perplexed by the method PTC uses in the MDO program for handling connections. Yes, I see their formula for DOF and redundancies, but cannot seem to make it give the correct asnwers. I set-up a simple problem consisting of an overhung load on the end of a rod that is supported by two bearings. I think I should constrain each bearing in the x & y directions, but of course that causes 2 redundancies. If one uses their suggestion of a planer joint + a bearing joint (which doesn't work for me either), it would seem to me the planer joint would absorb all the moment. I have tried both the static force analysis & the dynamic. No luck with either. I get answers, but they are incorrect.

I have been searching for a good tutorial or manual on this subject, but am unsuccessful. Any help would be appreciated.

Thanks

 

[TDPROE]

the only mechanica tutorial i've been able to find is: https://amzn.to/2ROnA3H

it works for very basic things.

for more "advanced" topics you could try https://amzn.to/2TRhm5Q

but as youll see its a very expensive book.



For the bearings, I would recommend placing a cylindrical coor sys and using it to constrain, leave it free in theta and fix Z and R.

good luck and let me know how it goes