hollow glass sphere modeling using pfacet as a filler in cement paste

Created by hanzj on on 2016-11-30

Dear all,
I am new in YADE, I have installed YADE from source code and learned the basic knowledge about YADE. After reading the paper of prof.Bruno Chareyre, named ''Modelling of deformable structures in the general framework of the discrete element method'', the job of Bruno's motivates me a lot. I am now doing the simulation as follows :
Hollow glass sphere, whose d(0.5) is about 40μm, acts as a filler in the cement paste.the cement's d(0.5) is about 20μm.The fresh cement paste is made up of cement and water, and the ratio of water to cement is ranging from certain values, for example,0.3,0.4,0.5. after the cement paste formed, the hollow glass spheres are mixed into the paste. After the cement paste hardened, there exist bonds between the cement paste and the hollow glass sphere.
I was thinking about regard it as a two-phase system, so the interfacial properties between hollow glass spheres and cement paste would play a key role. and I was going to use a REV (a cube whose size supposes to be 100μm),which first contains one hollow glass sphere, whose radii suppose to be 40μm and cement paste around it. any ideas about how to decide the size of the REV cube? and then, the cube would be uniaxial compressed.
So,question 1: I was wondering if I can use the pfacet to modelling the hollow glass sphere, whose properties are more similar with a hollow deformable shell but can break down in a brittle mode. To model its failure mode, which material do you recommend? whether the cohesive friction mat or cpm mat? can i use them?
question 2 : the cement paste i was thinking about modelling it using spheres and cohesive-friction mat. can I? and there exists a bond between the glass sphere and the cement paste. so if i can use the pfacet to model the glass sphere,I have to use the sphere-pfacet geometry like Ig2_Sphere_PFacet_ScGridCoGeom(),right?
question 3: whether i can use 'matchMaker' to define the specific cohesive force or something else determine the interfacial properties between the pfacet and the spheres? i would appreciate it that if you can recommend me something to learn about this.
Looking forwards to your advise and thanks a lot.

best regards