Hi all,
I have a problem with periodic boundary conditions using contact elements with a cohesive zone law in Ansys.
In my micromechanical simulations of an RVE with periodic boundary conditions I would like to have a predefined fracture path. My aim is to realize the fracture path with voronoi cells. There I get problems at the boundary of the periodic domain.
A picture of the simplified problem is attached here:
http://dl.dropbox.com/u/4920002/PBC_CZM.png
The domain here is periodic and square. The red lines symbolize the cohesive zone law which connects the coincident nodes. I have no problem with the red nodes.
But how can I couple the green points with periodic boundary connections. In previous simulations I did this with constraint equations but there I did not have fracture path so I had well defined pairs of nodes on each side of the domain. But now I have two nodes on the right side an one on´the left. I can not figure out how to define constraint equations between these three points that are physically correct.
Anybody any idea.
Thanks for help.
Andreas