Rotation boundary condition on a rigid body about a moving coordinate

[ab110]

Dear All,

I have posted a question about rotation of a local coordinate system but I did not get any reply. Today I thought to make the problem clearer and post it again. Hope this time I can get some replies.

In the attached picture I want to make the rigid cylinder rotate about the Z axis of the local coordinate which is at the center of the cylinder. How can I make the cylinder rotate with a constant speed about the local X-axis which changes its direction due to rotation about Z-axis? The rotation of cylinder is similar to the rotation of the wheel in an automobile (rotation about Z axis due to steering while the wheel always rotates about X-axis that changes its direction).

I have tried to find the solution using connector elements. I think this should be the right way but unfortunately I have not been able to get the required rotation (the file is attached). The cylinder always rotates about the global X axis with constant direction and I cannot define for the software to change the direction of X-axis due to rotation of coordinate about Z-axis!

I appreciate if someone pleas help me fix this issue.

C,
A

 

[ab110]

Abaqus input file is attached.

 

[akabarten]

Hi,

Please check attached model. I think the motion is what you described. I used HINGE connector.
If you have any questions about the model please let me know.

Regards,
Bartosz

 

[ab110]

Hi,

Thanks Bartosz for the reply. Unfortunately I cannot read the attached file in Abaqus CAE. When I read the file it is nothing and empty. I opened the file with notepad and saved it again as an *.inp file but again nothing! Do you have any idea what is happening? I am using Abaqus 6.13.1 .

And Finally, I think the HINGE connector has rotation only about one axis while in my problem I want to have rotation about two axises and please pay attention that the second axis changes its direction due to rotation about the first axis. Not sure how a HINGE connector can work here. I also need to add displacement as well in the next step (to consider the movement of wheel beside rotation).

Thanks again for your help.
Regards,
Armin

 

[akabarten]

Hi Armin,

I cannot read the attached file in Abaqus CAE

I checked and I have the same. I see it is because of *ORIENTATION definition.
It looks Abaqus/CAE is not able handle definition base on nodes (DEFINITION=NODES). I did not know that, I do not work with Abaqus/CAE.
I changed *ORIENTATION to use coordinates (DEFINITION=COORDINATES) and it works with Abaqus/CAE now, the results will be the same.
You still can get some warning messages during importing since there is more not supported options in the model.

I think the HINGE connector has rotation only about one axis

Yes, you are right.

I want to have rotation about two axises

One rotation I make with hinge (*CONNECTOR MOTION) and for second I do not use connector degree of freedoms
but I rotate whole hinge element with boundary condition (*BOUNDARY).

I also need to add displacement as well in the next step

No problem, you can do it in the same way as 2nd rotation with boundary condition.

Best,
Bartosz

 

[ab110]

Thanks a lot Bartosz for your help.

 

[ab110]

Hi Bartosz,

Thanks again in advance for your help. I have tried to open your model and understand it but unfortunately I cannot read it correctly. When I import the model in Abaqus-CAE, it gives me many error for instance missing reference point and etc! I your model I do not know what exactly you did as it has some extra points and various boundary conditions.

So I decided to update my model based on your comments. I exactly understand the concept now and I have created the model. I have the reference point of wheel and the ground which is the point for hinge connection at the same location. I have tried various boundary conditions but the movement is not the one that I am looking for! Now I have a hinge which rotate about X-axis and I am trying to rotate one end of the hinge (or both points) about Z-axis but the movement is not correct!

I appreciate if you please have a look at the attached file and let me know what is wrong. Or please send me a file (probably CAE file) so that I can run it with Abaqus CAE 6.13.1.

Regards,
Armin

 

[ab110]

The CAE file is attached.

 

[akabarten]

Hi Armin,

I updated my model in the way it for sure works with Abaqus/CAE now.
Please let mw know how it works on your side.

Regards,
Bartosz

 

[ab110]

Thanks Bartosz,

I think you selected a point at the surface of the wheel and a point at the center of the wheel (not the reference point) to create a hinge in between. I am not sure what is the difference between that point in the center and the reference point. Is the location exactly the same? Then you have applied the boundary conditions to the point in the center which is not the reference point. In your model I can see the road in which we have the coordinate for hinge is fixed. I cannot understand how does the hinge coordinate rotate in your model. I think the coordinate is belong to the road which is fixed.

I apologize for my too many questions but it is still confusing to me how did you define the hinge and boundary conditions.

Regards,
Armin

 

[ab110]

Hi Bartosz,

I should confess that the structure of a hinge joint was not correct in my mind and it had made me confused. Finally I was able to fix the issue and get the model running. It seems everything is all right now. Thank you very much for your kind attention. I will let you know if I encounter a new issue in this regard.

Regards,
Armin