How to apply Coupling Constrain, and Rotation of 3D Model? 1

[bhavbhuti302]

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

 

[bhavbhuti302]

Hi Mosab2

I hope it works with you, though I don't have older version. Good luck.

Bhavbhuti

 

[mosab2]

Thank you bhavbhuti302

Thank you a lot

 

[mosab2]

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

 

[mosab2]

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

 

[rstupplebeen]

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

Rob Stupplebeen

 

[mosab2]

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

 

[rstupplebeen]

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

 

[mosab2]

Dear Rob Stupplebeen.

I attached you my model in format FEM.inp

I hope that you ca help me.

Thank you

 

[mosab2]

Dear Rob Stupplebeen.

I forgot the another needed files, like sets, XY, TOP, etc.

Now i attached you everything,

Thank you

 

[rstupplebeen]

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

 

[mosab2]

Dear Rob Stupplebeen,

I don´t have the model with CAE, i have it with .inp

Becuase i do the mesh but after that i use abaqus interactive.

I prepared you the file with everything (now is a complete).

Thank you

 

[OptiEng]

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

 

[rstupplebeen]

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

 

[mosab2]

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

 

[mosab2]

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.

 

[OptiEng]

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?

 

[rstupplebeen]

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

 

[OptiEng]

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

 

[OptiEng]

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.

 

[mosab2]

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