Learning Forum

[Vitaliy_Degtyarev]

Is it possible to specify a piecewise relationship between frictional stresses and slip using the USERFRIC subroutine? If so, could someone provide guidance on how that could be done please? An example would be helpful and greatly appreciated. I have read the ANSYS help documentation on the topic but could not figure out how to do that. 

Thanks,

Vitaliy 

[Sandeep Medikonda]

Hi Vitaliy,

Yes, When using USERFRIC, the frictional stresses can be defined as a function of variables such as slip increments, sliding rate, temperature, and other input arguments. 

Please see this section from the help and here is some additional info on the subroutine itself.

Regards,
Sandeep

[Vitaliy_Degtyarev]

Hello Sandeep,

Thank you for your response. I have read the information available in the ANSYS help documentation (which you referenced), but it is not clear enough for me. I still have a hard time understanding of how a piecewise relationship between the frictional stresses and the total slip can be specified (if it can be specified at all) and need more specific help with that.

Regards,

Vitaliy

 

[manu87]

Hi Vitaliy,

I've noticed you are working on the USERFRIC subroutine of ANSYS. So am I. I'm a starter, so could you offer some help on this part? Any example or help can be OK.

Regards,

manu

[Vitaliy_Degtyarev]

Hello Manu,

I have not used USERFRIC yet because I have not been able to find any guidelines nor examples on the use of it in addition to those in the ANSYS help documentation referenced by Sandeep above. 

You may try to use a coefficient of friction that is dependent on sliding distance to describe the same behavior as I was trying to describe with USERFRIC. Please see this link. You may also try to use the nonlinear spring element COMBIN39.

Regards,

Vitaliy