Abaqus problem-contact pair

[Tinni1]

Hi,

I am conducting a static risk analysis for a cold-formed steel stud and track assembly. Please see the screenshot of my model, in the attachment. The stud is held by the track at the top and bottom. I have defined the contact pair between the stud and track assembly as below:

1. Surface to surface contact between stud flange and track flange-front and back at top and bottom (Master surface: stud flange, slave surface -track flange.
2. Node to surface contact between stud web and track web-top and bottom (master surface-track web, slave nodes-stud end nodes).

The contact property for both the contact pair is defined as below:
1. Normal-"Hard".
2. Tangential-"Penalty", friction coff-0.35

I have applied a concentrated load at the CG of the stud section at the top.
When I ran the analysis, I got the below warning:
"Solver problem. Zero pivots when processing a contact constraint for slave node STUD-1.6298 D.O.F. 1."

And after 5 iterations the analysis was aborted with the below error:
"Too many attempts made for this increment"
Can anyone provide any direction here?
Looking forward!

 

[Tinni1]

Sorry, Missed attaching the snaps of my model:
Additional information:
In addition to contact pair definition,
I have also defined a planer wire connected between the stud flange and track flange.

Really appreciate if anyone can help!

 

[FEA way]

Before proceeding to post-buckling analysis, make sure that all parts are properly connected and constrained. There might be some underconstraints in the model that should be resolved first. Contact sometimes needs help to work properly (stabilization, displacement control, even initial interference).

 

[Tinni1]

Thanks for your response,

1. Is there any way by which I can make sure that all the parts are connected properly or I should check that manually?
2. What do you mean by, stabilization, displacement control, even initial interference?

Thanks in advance.

 

[FEA way]

Check this research paper from the Abaqus conference: "Simulation of a Parking Pawl Mechanism with ABAQUS/Standard and ABAQUS/Explicit" written by D. Ramnath and P. Andrade. It discusses various ways of handling contact convergence issues. Of course, Abaqus documentation will also help with particular functionalities (like automatic stabilization). Apart from that, a modal analysis will let you identify part connection issues. I suggest you start with a simplified model with contact and see how it behaves in different conditions. Contact is one of the hardest things to model in FEA and often requires quite a lot of effort to obtain a converged and accurate solution.

 

[Tinni1]

Many thanks! I will look into the paper.