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How to apply Coupling Constrain, and Rotation of 3D Model?

How to apply Coupling Constrain, and Rotation of 3D Model?

How to apply Coupling Constrain, and Rotation of 3D Model?

(OP)
Hello Abaqus Users,

I am very new to Abaqus, and trying to rotate one gear related to other. When I try using the normal cylindrical constrain, I found that it rotates but it also expands the model. So, is there anyway I can rotate the model and other model rotates with that. Also, I feel that coupling constrain can actually help me, but I don't know how to apply coupling constrain. I tried using the abaqus manual but it's not too clear to me. Can anyone please help me to sort this problem out. I will appreciate if someone can upload very simple file having coupling constrain in it.

Thank you
Bhav

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Check out OptiEng's topics.  I helped him with a similar problem with rotating disks in edge contact.  Start with his oldest posts and work forward.  I hope this helps.

Rob Stupplebeen

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

(OP)
I really don't understand when you have explained about the coupling thing. And I think he didn't reply back after your answer so I am sure what he has done. Can you please explain me bit more about the same rotation. I am having similar rotation and trying to find contact stresses in the gear tooth. Thanks in advance.

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Hi bhavbhuti302,

I hope I can help on this, I have conducted a similar problem, expect one of my surfaces is a rotating analytical rigid surface and the other is pad with a pressure applied to one side, see the cae file attached.  Please take a look to see if this helps and we can discuss.

Kind Regards

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

(OP)
Hi OptiEng

I really appreciate for your file sharing, it gave me some hint, but I have both 3D models to rotate with respect to one another. I have 2 gear models to rotate as one is driver and other is driven and want to analyse the contact pattern of the tooth surface.

I will still try to use this trick, but I wonder if it works for 3D. Can you please help me for 3d models.

Thank you for reply.

Please check out the file attached. (I just usded normal boundary conditions, I am sorry but it takes ages to solve the analysis. I can attach .odb file if you want.) Can we talk on some messanger about this. Thank you.

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

I would create a reference point at the center of rotation of each gear.  Tie all DOFs of the inner surfaces of the gear to these points.  Constrain all DOFs of the reference points except for the rotation on the axis.  Apply a torque to the one reference point.  You probably need to define some more contact surfaces in your contact definition.  Define all potential surfaces otherwise penetration could occur.  I hope this helps.

Rob Stupplebeen

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

(OP)
Thank you Rob,

But when I use tie constraint, it asks me to define Master surface and slave surface, do I need to select my interacted master and slave surface or the RP that I have defined for this feature. I selected RP as master and all the nodes as slave in Tie constraint. I have some warnings like 1 node is not tied because it is out side the distance tolerance.

Bhav

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

(OP)
Thank you Rob,

I actually tried the same way, and now trying to see how coupling constraint works and i found really weird results on this simple ring. Please check this file I am uploading, I simply give rotation and coupling constrain, and in analysis result if you magnify it, and see the deformed and undeformed shape together then you will see it is getting expanded. I am not sure this should be the result. Can you please check this for me.

Thanks a lot...
Bhav

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

(OP)
See this is how it looks like after rotating with 11X magnification. I presume that the magnification should magnify deformed and undeformed shape and not just undeformed.
Also it does not give rotation step wise but gives all at once. I think I am missing something at this stage.

Thank you

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Hello Abaqus Users,

I am trying to rotate one disc (Elstic material) related to other (the same material) in 2D. When I put angular velocity (U6), I found that it rotates but it also expands the model. I was reading all messages and i did everything but in 2D but nothing, any one can help me? or have an example with file.inp?

Thank you

Mosab2

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

(OP)
Hi Mosab2,

I dont know if it is bug or if we are doing something wrong, but its frustrating how magnification shows expanded model. I hope someone has clue for us. Finger Crossed.

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Hi bhavbhuti302:

I don´t know why.. but really it is a little bit rare.

I will wait, becuase i don´t know what can i do..

Finger Crossed.

Thanx

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Hi bhavbhuti302:

can you send me all files but in version 6.5 o 6.7
Becuase i can not open them,

Thank you  

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

(OP)
Well actually I dont have older version, and I can't create old version files, I am afraid. But as long as I know, I tried all possible way that I know, but nothing worked so far. All I see is expanded thing after rotation. I never tried Explicit though, I am not sure it is a good idea in that, and I don't know how to work on that either. So, again I will wait for some more time as you said.

Good luck.

Bhavbhuti

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

(OP)
Hi amubashar,

Thank you for your effort and suggestion, It looks perfact in the 1:1 sale, but further magnification shows the expanded view, I am not too sure if it has to be like that, and also the value of U(displacement) also changes with the iterations of the step. So I am not too sure if it has to be like that, but 1:1 looks perfect though.

I will try to do that same thing on my gear model and see if it works or not. Do you have any suggestion for, if I have to rotate two gears one related to other, how can correlate them?

I really appreciate for your help.

Regards,
 

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

If a deformation scale factor greater than one is applied, the deformed shape would look like its increased in diameter compared to the original geometry. If you measure the diameter between any two points on the disk, it remains same before and after deformation (the base distance and the deformed distance unscaled).

I don't really understand what you mean by "if I have to rotate two gears one related to other, how can correlate them?"

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

(OP)
Hi Amubashar,

Please check the attached file, in that, I have fixed the gear to find out the stress at contact, but I am thinking to give rotation to both instead of just pinion. In first step they just come into contact, and then I applied the torque. But instead of fixing the gear in all step, is that possible to make it rotate with the help of torque that we apply on pinion.

I hope it make sense now.

please see the attached file.

Thank you for your help and interest.

Regards,
Bhav  

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Dear bhavbhuti302 and Amubashar

Can yyou send me the file not in .cae sino in .inp
so i can see how you did it.

Thank you

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Thank you bhavbhuti302

Thank you a lot

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Hi again,

I have one question:
I am trying to rotate one disc (Elstic material) related to other (the same material) in 2D, and i have to put angular velocity rad/sec (U6). The analysis is: static or dynamic?

Thank you

 

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Hi bhavbhuti302 and amubashar  
Untill now with a deformation scale one, i have the expand results, it is very rare, do you know why? do you have mejor results? please help

Thank you

 

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

It is qasi-static (standard) if you ignore inertia or else it is dynamic (explicit)

Rob Stupplebeen

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Hi everybody,

Please help, i ignored inertia, and i did it with standard, but untill now the model expands..... i don´t know why...

my problem is:

I have two discs in 2D, and each one has its angular velocity, it´s about 40rad/sec.

I draw the mesh and i put that each one has its velocity like: BOUNDARY
Refpoint, 6,6, 40

but it´s not work well, because the two discs expand.

Anyone know why? anyone have the same problem? if the problem is like this, is it better analysis it by dynamic?

If anyone have the same problem and ya know the solution, pleaase send me the model as .inp no as .cae

Thank you
   

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

When a cylinder spins at a constant velocity it's diameter should expand.  Depending on the exact problem this could be a trivial expansion or a significant increase in diameter.  If you clearly explain what your current model is including materials, boundary conditions and expansion we may be able to help more.  Posting your current model would also help.

Rob Stupplebeen

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

I am unable to open the RAR file and the input file looks incomplete.  Could you post just your CAE file not zipped?

Rob Stupplebeen

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Hi mosab2,

Your analysis aborts during running the job "too many increments", do you have this problem on your system?

Hope I can help somehow

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

My understanding of your model is that you have 2 rotating rods that are rotating in the same direction at slightly different speeds.  So at the contact location the 2 surfaces are going opposite directions.

One rod is being forced into the other with a static load.

The ID and OD are slightly off of concentric.

Since there is no inertia and no friction I would just look at the specific angles that you are interested in and mesh accordingly at the contact location.

I hope this helps.

 

Rob Stupplebeen

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Dear Rob Stupplebeen:

The angular velocity that i hace is: 400 rpm for the two discs. The mesh is not very good, i will try to do it better. About the fricction: i put it 0.0 just for test, untill now i don´t have its value.

I was looking in the abaqus manual and i found that for this problem it is better to use the steady state transport, but really i don´t know how...

if you have any idea about this, and how can i do it.

Thnak you

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Dear OptiEng:

Yes i have the same problem, but when i use small angular velocity value, it is not appear.

Something else: i was using the small sliding and the model was expanding, but when i used finite sliding it is better.

I hope this help.

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

I see you have a constraint (coupling) to the inner hole circumference surface. Are you also using the same point to apply your boundary conditions. Can you do this, without problems?

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

mosab2,
I believe that the confusion is over what your desired output of the problem is.  Physically what are you trying to model?

OptiEng,
The coupling with the inner diameter is a convenient way to apply rotations or torques to a model.

Rob Stupplebeen

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Also is there any reason why you have used contact controls?

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Thanks Rob, I just wasnt sure if mosab2 had applied the the boundary conditions to the same reference point as his reference point for his coupling. I was wondering if this would cause any issue with his his/her analysis.

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Dear rstupplebeen,

I want to model two discs with its angular velocity, and have the tangentail forces between the two discs as a function of the angular velocity.

The model that i attached before, it is just a model to understand the problem, but the model was expanding with the angular velocity (40 rad/sec), so i don´t know if i was doing it well or that i have to do it as steady state transport.

Dear OptiEng:
I have a constraint (coupling) to the inner hole circumference surface. I  used the same point to apply my boundary conditions, and i don´t have any problems

Thank you

 

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

I had a quick go trying to recreate a similar model to yours mosab2, but seem to have come across some problem of my own along the way.  In response to your comment,

"I have a constraint (coupling) to the inner hole circumference surface. I  used the same point to apply my boundary conditions, and i don´t have any problemsThank you"

The error message I obtain when I do apply my coupling and rotation to the same reference point is,

"1 nodes have dof on which velocity/displacement/acceleration/base motion etc contraints are specified simultaneosuly. The nodes have been identified in node set ErrNodeBCRedundantDof".

Not sure how I get past this one at the moment?  Any feedback would be much appreciated.

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Dear OptiEng

Can you send your file as .inp for see it.

thank you

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Please find my Input file and CAE file located at:

http://my.engineering.com/pg/file/OptiEng

Its titled "Twin Disc Rotation Model - Input File" and "Twin Disc Rotation - CAE file"

I look forward to hearing from the group

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

I can't open the file it is only 132KB.  Try uploading again.

Rob Stupplebeen

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

(OP)
Hi OptiEng,

I have same problem, couldn't open any of those 2 files. Can you please upload both again.

Regards,
Bhav

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Dear all,

i was trying to model the two discs by:
Symmetric model generation, reflect
The problem is that when i do this a can´t generate set for master , sclave surface between the discs.

anyone know how can i do it?

Thank you

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Hi OptiEng,

i was looking your .inp

i found that you have the RF has the node number=1, and your disc has also the same node number.

I think that if you change the node number of RF it will work.
My model is the same but the RF for each disc have the node number 400000 and 300000.

Good luck

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Thats strange, I downloaded the two files and tried both into a new Abaqus 6.9-1 file and seemed to work ok? Sorry I am not sure what I am doing wrong?

Thank-you for your feedback,
I really need to become more familiar with the making adjustments via the input files, I also seem to go through the CAE instead. I tried changing the node number but it failed during the import? Do I just change the number once in the input file and where do I change this?

I am not familiar with the Symmetric model generation, but I will have a look into this, and if I come up with anything to help I will let you know.

Thanks everyone.

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Thanks Mosab, please ignore my question above..

Can you explain a little more about your Symmetric model generation problem please?

Are you reflecting a specific portion?

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Am I right in saying the only section of the input file that has changed is the 200000 and 300000 node numbers:

*Node
      200000,  -6.12303177e-16,  3.74927567e-32,           0.
*Node
      300000,  -6.12303177e-16,         -60.,           0.
*Nset, nset=_PickedSet30, internal
300000,
*Nset, nset=_PickedSet41, internal
200000,

Thanks

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

The CAE file is still coming in as empty.  Can you try posting with "Step 3 Attachemnt" when replying?

Rob Stupplebeen

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Dear OptiEng,
Yes, as you put before.

I´m sorry, but, can you send the ROTATING_DISC_FE.cae in format ROTATING_DISC_FE.inp

About my Symmetric model generation problem:
I did what the abaqus manual explained, and now i have the one disc, but the Symmetric model generation transport permit one model. So i used the Symmetric model generation, reflect, and i have the two discs, but the problem is:
As the second model is the reflected model the two discs have the same name set, and i don´t know how can i change this.

Thank you

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Dear OptiEng,

I did it as the Abaqus manual explained (reflect model), and i had two same discs, but the problem was that: the set of the inner circle of the original model, after de reflect the set has the inner circle of the original model and the inner circle of the reflect model.

Maybe i can´t simulate the two discs as the Symmetric model generation.

Any help?????

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Are you able to post the input/cae file? hope I can help.

RE: How to apply Coupling Constrain, and Rotation of 3D Model?


Dear all.

Any one, can help me?

I want a model of two discs that each one has angular velocity 43 rad/sec.

Can you do it and send me the model?

Thank you
 

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Lets pretend this is a new post and start over.  Please post your model and/or a detailed picture or pictures of what you need.  What are your inputs and end goals of the model.   

Rob Stupplebeen

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Good call there Rob. This thread is fraying like mad. I can't even follow who where had the original problem anymore. haha

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Dear all,

I attached the model in format .inp.
The goal is:

I want to calculate the tangential stress in the contact zone.

The problem is:
Two discs with the same material, The angular velocity of the first disc is 410 rpm and the second is 381 rpm. So i thought that i could do it as a static problem, with time increment 0.0001. is it true?

I tried to do it as, steady state trasport, but the problem is that the Abaqus program don´t permit more than one body revolution. so i can make a model for one disc, how can i make the model for two discs?

Now, if anyone has any idea or he/she did something like that, please i want help.

Thank you

 

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

With regards to the static question.  I believe that you can do this however the 0.0001 will have to be empirically derived.  You will also need to have a much more refined mesh where contact will occur at the end of the analysis.  I would have a very coarse mesh where contact will not occur and a refined mesh that gets progressively more refined near the end of the analysis.  I hope this helps.
 

Rob Stupplebeen

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Sorry I can't add any suggestions for you at this stage, have you looked up any analytical solutions (i.e. hand calcs) to you problem?

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

(OP)
Nelio2005, you are right...I have started the thread, but actually I got some what answer after doing trial and error, I am not too sure that I have got right, although I haven't have dynamic model which I wanted to have that initially, but I am just currently working with statically rotated model.

I have attached file here. may be if someone is interested to see that. But I still be interested if someone comes up with idea that how can I rotate one gear and another gear rotates along with the first one, and get results in dynamic condition.

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Dear bhavbhuti302

I was looking your model, but it has a problem, i think..

Because when the disc start to rotate the size of the disc has been changed.

untill now, i don´t have any solution for my problem, any help?

Thank you

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

hello house
i am having problem with my simulation. i want to reel a pipe around the reel and check for residual twist when i unreel but my step of rotation is not going round. i dont kw how to resolve this. can someone give me any head way thank you.

attached is a copy of my work

RE: How to apply Coupling Constrain, and Rotation of 3D Model?

Please start a new thread.

Rob Stupplebeen

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