physically crosslinked elastomer

[sony020244]

hi,Jorgen

I am interested in some physically crosslinked (such as hydrophobic interaction/hydrogen bonding/crystalline as crosslinks) elastomers. based on my understanding, when i do tensile test with this kind of elastomer, it will present hyperelastic as usual chemical crosslinked elastomer. When chain stretched to certain extent the weak crosslink will break and cause plastic flow. I plan to use 8 or 3 chain model to simulate the initial elastic part and for the 'plastic part' do you have any suggestion?
thank you very much

[Jorgen]

Sounds like an interesting project. I think a good first-order approach is to follow the theory of the Bergstrom-Boyce model (http://polymerfem.com/forums/forumdisplay.php?f=4). That is, use the same hyperelastic representation for the initial response and the final response, and then use a separate flow equation to capture the "viscoplastic" part.

- Jorgen

[sony020244]

thanks a lot, Jorgen.

For the specific material I am working with, when the weak bonding is broken by external force, it can rebond later. When the bond is broken the limiting stretch increases as the segment number increases and when later it rebond again the limiting stretch decreases as the segment number decreases. So I guess for the flow part I need a special bond-debond governing equation to control both limiting stretch and viscosity. Do you have any comment on this idea because I think I might considered it too complicated.

[Jorgen]

I think your idea of bonding and later rebonding is fine.
It should definitely be possible to implement such an idea into a user-material model.

- Jorgen