Contact using lagrange multiplier method

[xwwvr]

Hi everyone,
I am now dealing with a frictional contact problem (one square plate with hole has contact with a circle plate inside the hole), I used partition to mesh the two parts symmetrically and defined the contact as surface to surface with lagrange multiplier as tangential behavior and Default "hard" contact as normal contact, but Abaqus said "Too many attempts made for this increment" . I only got such error before when boundary condition has problems. But in this case, outside square plate's left edge is fixed (suffering a unilateral pressure on right edge), has no rigid body motion. The inside circle plate only has contact constraints, it's stiffness matrix is singularity.

Also when using penalty method, Abaqus completed successfully. So I am just wondering is it because lagrange multiplier method can not handle the singularity of stiffness matrix?

Please help, I've struggling this for several days.

Kind Regards,
Weiwei

 

[xwwvr]

This is the pic of my problem, for your convenience

 

[Mustaine3]

Can you attach the model?

 

[xwwvr]

Hi Mustaine3,
Thank you for replying, I've attached the model, it aborted when use lagrange multiplier method as tangential behavior, but completed if you change it to penalty.

 

[Mustaine3]

The .msg file reports singularities, which means that your inner part has rigid body motions.
Add contact stabilization and the job should run. Check afterwards that the stabilization energy is small compared to the internal energy.