Extract Rotation Z and Contact Normal Force

General Questions
1

I want to extract the Rotation in z axis from a gear 2d plane stress simulation and the contact normal force of a set of nodes.

I did not find a way to extract the Rotation Z, so what I do is to extract displacement in X and Y directions and calculate it from there.

Regarding the Contact Normal force, I am not sure of the values I am obtaining, since regardless of the position of the gears (single contact or double contact) the values i am obtaining are the same… so I think that perhaps I am not getting the contact normal force of only those nodes in the set I want, and all the contact surface nodes are taken into account or i am not getting the right value…

Could you help me or gide me with that?

I am using this commands to get that information in my .inp file

*Contact print, Nset=Contact_P_flanc_3
CF

Thank you vey much!

2

You can get the rotation directly if your gear is driven by rigid body constraints - its ROT NODE has rotational DOFs.

There’s no such parameter for this keyword in CalculiX, only Abaqus has it. You should use SLAVE and MASTER parameters to identify the contact pair instead.

3

Ok. But when I define the slave and master I have all the 3 teeth in the contact pair surfaces.
Thus, how could I do to only extract the contact normal force of only a single tooth??

4

You would have to split this contact pair into separate pairs involving smaller regions (e.g. individual teeth). Just avoid overconstraints.

5

Ok right.
In that case this is what I defined:

*Surface interaction, Name=Contacto
*Surface behavior, Pressure-overclosure=Linear
*Surface interaction, Name=Contacto1
*Surface behavior, Pressure-overclosure=Linear
*Surface interaction, Name=Contacto2
*Surface behavior, Pressure-overclosure=Linear

*Contact pair, Interaction=Contacto, Type=Surface to surface
Contact_P_flanc_2, Contact_G_flanc_2
*Contact pair, Interaction=Contacto1, Type=Surface to surface
Contact_P_flanc_3, Contact_G_flanc_3
*Contact pair, Interaction=Contacto2, Type=Surface to surface
Contact_P_flanc_4, Contact_G_flanc_4

And then if I only extract this , it should work right???

*Contact print, Slave=Contact_G_flanc_3, Master=Contact_P_flanc_3
CF

I have a problem now loading this file in PrePoMax … .that is why I am asking in the definition is correct??? I think there is an error

6

You don’t have to define it via keyword editor, PrePoMax supports *CONTACT PRINT in GUI (History Outputs → Contact Output).