Learning Forum

[Afrah]

Hello,

I have a 3D DCB specimen and am modeling the delamination using the Bi-linear CZM Law. I am trying to match the load-displacement graph obtained from ANSYS with that from experiment. In trying to do so, I am trying to find the correct cohesive zone parameters. When I use a high value of the "normal displacement jump at the completion of debonding" (C2), which is anything greater than or equal to .1 mm, the solution converges, but the load-displacement curve is all wrong. However, when I lower the value to something like .095 mm or lower, the solution doesn't converge. I do, however, get partial results that looks much better. Here are the errors I receive:

I have tried the following things to make my solution converge:

-increased the sub-steps, here are my settings:

 

-Refined the mesh at contact regions using contact sizing (I'm not really sure how much I should refine my mesh, it's possible I just haven't done it enough)

- lowered the stiffness of the contacts 

- reduced the penetration tolerance

-used the normal lagrange formulation

What else can I do?

Note: I've tried to find the "contact destabilization factor" option under the Advanced contact settings, but haven't been able to find it. Is this option no longer available in ANSYS 19.2?

 

 

 

 

 

[Afrah]

Would it help to attach my workbench file? I would really appreciate the help. 

[TAPTAPTAP]

yeah you should attract your model so people can help you find the solution easier.

[Afrah]

I've attached my v19.2 file. I've attached a simulation that has a simulation time of 60 s and it converges, anything more than and it doesn't. I actually need to run it for 600 s. I had to clear generated data off modeler cause the file size was too big. 

 

 

[Afrah]

Hey,

I've tried some more things to get the solution to converge;

-use MPC formulation

-enabled weak springs 

-increased number of iterations per substeps using the NEQIT command

any other suggestions?

[Flatter97xD]

did you find a solution? Having the exact same problemn

[sk_cheah]

Try do a google search for Adhesive CZM ANSYS for some tips. Also, never update contact stiffness and use fracture object.n