Learning Forum

[jdo60]

I am working with a simulation involving the lifespan of a semiconductor, and I am using Bilinear CZM in Contact Debonding to evaulate this. Within the CZM sub-model (transient structural), I have used a cut boundary constraint to import displacements and a symmetry region to help reduce simulation time. I have applied the cut boundary constraint to every side face except for the symmetry region section. Also, after the wire bond on the semiconductor has reached failure, it seems that the area along the symmetry region splits into 2 parts. In models without the symmetry boundary condition, the splitting does not happen. 

1) Would it be appropriate to apply the cut boundary constraint to the symmetry region? (Image 3 & 4)
2) Is the wire bond splitting along the symmetry region a consequence of using the symmetry boundary condition? (Image 1 & 2)

Before:

After: 

Symmetry Region:

Cut Boundary Constraint:

[dlooman]

The symmetry boundary condition should have prevented the splitting you are getting.  The symmetry boundary condition is just setting the normal displacement to that surface to zero.  You should be able to confirm this by displaying the UZ displacements on those faces.  Apparently you have turned on graphical symmetry as well, which displays the full model.