Thank you very much for the answers, and of course I'm interested!
Suffice to say, this is a little outside my area of expertise, hence the reason for my question.
Out of curiosity, I actually made some compression measurements of these spheres, made up of the exact same material, but with varying diameters. In a plot of compression force as a function of volume, they did indeed fall in a linear line. Note that this (seemingly) linear plot was also at quite high levels of deformation (60 % strain)
- I guess anisotropy would be less significant than for soil samples/wood etc. (?). As the sphere material is made up, pretty much like this:
(More material concentrated around edges, but otherwise I guess there's no directional structures).
