Learning Forum

[Mukesh Murugan]

Hello,

I am trying to incorporate lugre friction model in Ansys mechanical in bolt untightenig analysis. I have found some help in ansys how to give the varying friction coefficient vs velocity using command snippets, but this will be helpful only if we have the experimental data. Can anyone help in this issue. The reason I want to incorporate lugre friction model is to predict the stick slip behavior when the bolt is corroded. Is there any other option / model that can predict the same? Thanks.

[Ashish Khemka]

 

Hi,

I did not find any relevant information in database. One approach that you might know already, in case you have the data is to use command objects and define friciton coefficients.

Regards,

Ashish Khemka

 

[Mukesh Murugan]

Hi Ashish,

Thanks for the reply. Yes, I have started with the basic model(One plate is fixed to the ground and the other one is sliding on the bottom plate with constant velocity) and by giving velocity vs friction coefficients using command snippet. But the problem is I couldnt get the continuosu stick slip behaviour as shown in the image below. The below image is taken from the link ANSYS Application Stick & Slip ---- Velocity-Dependent Friction Coefficient (youtube.com)

 

The deformation pattern for my model is stick and continuous sliding as shown in the image below.

 

 

The output friction coefficient I got from expression CONTNMISC 29 and my input friction coefficient vs the velociy in command snippet as shown below

 

Can you help me in understand this behavior and how to get the stick slip output as mentioned in the link?. Thanks.

Regards,

Mukesh