Two material interface problem- not converging

[joyful24]

I am trying to look at the edge of an interface been steel and adhesive with a negative pressure on the top. (I've tried different values of this, it's not the problem.)

I'm doing a quarter sized model with y symmetry on the vertical and x symm applied to the horizontal. On the left side right at the interface I have a very small square of elements. Then I have a larger square with diagonals connecting to the corners of the smaller square and the mesh is biased out. (This is similar to what is done for crack tip modeling.

I am getting the error "too many attempts for this increment", and the answer is not converging. I'm also getting errors of negative eigenvalues and numerical singularities along the way.

Any help will be greatly appreciated!

 

[rstupplebeen]

Is the Z direction constrained from RBM?

Rob Stupplebeen

 

[joyful24]

It is a 2-D shell. (Sorry I forgot to specify that) So do I need to constrain the z direction?

 

[rstupplebeen]

Unless you are dealing with plane strain or axisymmetry you need to constrain all 6DOF.

Rob Stupplebeen

 

[joyful24]

It is plain strain.

I figured it out. (Well kind of) I re-partitioned, re-seeded, and re-meshed and it worked!

Thanks for your help though.