Nano-composite model for semicrystalline polymer?

[Dilwyn]

Does anyone have a view on whether it is feasible to construct an FE model of a semicrystalline polymer to predict the mechanical and thermomechanical properties from those of the amorphous phase, crystals (fully anisotropic) and possibly some oriented or constrained amorphous phase? The distribution of crystal orientations is another input, along with the volume fraction of each phase and, probably, crystal sizes.
My feeling is that it would be very difficult to make the mesh with enough crystals and have them randomly distributed, and then specify the crystal properties and directions.
If it can be done, please point me at some relevant references.

Thanks,

Dilwyn

[Jorgen]

I think it can be done. I know some people who have created micromechanical FE models polycrystalline metals. The challange with semicrystalline polymers is that the constitutive equations for each phase, their interactions, and evolution of local behavior are still ongoing research topics that are not necessarily well understood or characterized. Then adding these components together will make the situation even more challenging. It could be an interesting Ph.D. thesis topic for one or more students...

-Jorgen

[Dilwyn]

Thank you Jorgen,

I think initially I would use linear elastic models for each phase, definitely anisotropic for the crystals, with principal directions the same for thermal expansivity tensor and elasticity tensor. The amorphous phase could be isotropic and uniform, at least to begin with.

Do you have any references or author names for the polycrystalline work?

Dilwyn

[Jorgen]

OK, sounds like a start.

You can check out Prof. Lallit Anand's (http://meche.mit.edu/people/faculty/index.html?id=3) work on polycrystalline plasticity.