Overclosure message doesn't match with the results in CAE

[xiazhn]

Hello, everyone.
I am modeling a forming problem. But the calculation diverged at the increment 545.

At increment 534, the difficulty of convergence appeared, and from msg file, it readed:
***WARNING: CONTACT SURFACES ASSEMBLY_METSURF2 and ASSEMBLY_CERASURF22 NODE
NUMBER 1 INSTANCE TUBE-1 IS OVERCLOSED BY 0.18470 WHICH IS TOO
SEVERE--CUTBACK WILL RESULT. YOU MAY WANT TO CHANGE THE VALUE OF
HCRIT (4.22951E-02) ON THE *CONTACT PAIR OPTION.

***WARNING: CONTACT SURFACES ASSEMBLY_METSURF2 and ASSEMBLY_CERASURF21 NODE
NUMBER 37 INSTANCE TUBE-1 IS OVERCLOSED BY 4.88247E-02 WHICH IS
TOO SEVERE--CUTBACK WILL RESULT. YOU MAY WANT TO CHANGE THE VALUE
OF HCRIT (4.22951E-02) ON THE *CONTACT PAIR OPTION.

But indeed these two nodes didn't contact with the master surfaces, which is shown in the diagram.

Here it is clear that the node 1 and 37 have openings with the master surface indicatd by the red line.

Is this the fact that wrong judgement of contact caused the convergence problem in calculation?
I tried in changing the value of HCRIT, but it seemed to help little.

Thanks a lot for any tips.

 

[mrgoldthorpe]

Do your pictures refer to the previous increment (544?), since inc 545 did not converge. If so, the pictures might be showing the real contact state before the problem arose.
MRG

http://www.analysis.demon.co.uk

 

[potf]

Hi,

I had this type of warning when rigid body motion occured.
I guess that this can happen some way when a part isn't constrained anymore due to too big deformation.

So make sure that none of the parts can move freely in space during the forming process.

G