Constraint definition in Weak form PDE in v4.3

Hi,

I am trying to convert a Comsol 3.5 model that used the 'Weak form:Subdomain' mode into Weak form PDE in v4.3. I have the following two questions:

1. In v3.5, certain subdomains were defined with 'Constraint Type' as 'Ideal' under the 'constrf' tab. This was to implement stress free boundaries. What would be the equivalent definition in v4.3? The default seems to be 'Zero Flux'. is that equivalent of stress free boundaries?

2. Should I use 'Pointwise constraint' or 'Weak Constraint' to constrain the displacements of certain boundaries along certain axes?

Any help would be appreciated.

Thanks.