Ansys ACT piezo matching layer interlayer error
 

Dear friends,
right now I am working with a piezo element by using ACT for piezo and acoustics. I am trying to add (glued) matching layer of foam. How can I describe acoustic contact between these two elements? I had tried all type of bonding but not lucky. Any ideas?

https://www.youtube.com/watch?v=3xQNnkDrAFc