Problem in bolted connection

[3JC]

Dear collages,

Firstly, I want you a happy new year, and I wish this forum would continue as good as the moment.

I'm performing a bolted connection calculation, and in the model I have this error:

If significant clearance/overclosure exists between surface pair (assembly__t0_plate-1_s,assembly__t0_plate-1_m) and the master surface does not have rotational degrees of freedom, adjustment is recommended for correct enforcement of the tie constraint

I think it is referenced because I'm modelling the clearance between the bolt shank and the hole. Could you please help to me? Thank you very much.

Best regards,

jJ

 

[IceBreakerSours]

Is the message a warning or an error? In other words, does the model converge to a solution or not? If the model runs, do the results (displacements, and then, stresses/forces etc.) make sense to you? If the results make sense, in all probability, you can ignore the warning message. If this was an error message, upload a few pictures.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[3JC]

Dear Ice...,

Thank you for the replay. Sorry for the mistake, but it is a warning. The model converge to a solution, but it is something similar that it doesn't take into account the contact between surfaces (at least between bolt-shank and hole surfaces). I send to you the *.jnl and some screenshots.

https://dl.dropbox.com/u/8161370/Btb_03_15_24.jnl

https://dl.dropbox.com/u/8161370/Btb-problem.PNG

Regards,

jJ

 

[IceBreakerSours]

Upload either your INP OR CAE and JNL files.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[3JC]

Sorry, I I send in attach the file *.cae. In this moment I don't know if it corresponds the samen *.jnl and *.cae files, but the *.cae is the last one.

https://dl.dropbox.com/u/8161370/Btb_03_15_24.cae

Thank you.

 

[IceBreakerSours]

By the way, you realize that the displacement solution in the picture you uploaded is scaled by a large number (of the order of 1e9). If you scale it back to 1, displacements look absolutely fine. You might also want to look in to incorrect DoFs and overconstraints. Your model has those warnings as well.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[3JC]

Ok, thank you very much. I have modified the scale, and the moment applied. I'm going to calculate the model this night, I will tell you something about results.

Regards,

jJ

 

[3JC]

I have modified the model. But I have some questions:
1) Do you think that step properties are good? Wit by defect properties, it couldn't converge
2) How about the moment applied? Do you think that is good to apply the load, as a constraint? How do you think is the best way to apply the load? I have obtained results very stanges.

Thank you very much.

 

[3JC]

Sorry, one more question: how I can visualizate the WarnNodeBCIncorrectDof set ? And how can I identify nodes with problems? Thank you.

 

[IceBreakerSours]

Go to Create display group -> select Nodes -> check the option below for highlighting. You'll notice the warning node sets in there.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[3JC]

Ok, thank you very much. And how do you think is the best way to apply a moment load in the extrem o the model I sent to you in attanch?

Thank you very much.

jJ