yade-users team mailing list archive

[Václav Šmilauer <eudoxos@xxxxxxxx>]

> 1- Uniaxial Strain Test is not a good test for verification of contact
> law?
No, not for the very first check. First you need to verify that the
contact law really obeys formulas you have on paper and which you can
solve (plot, whatever) by hand. Triaxial will give you macroscopic
numbers, which are made up from interaction of hundreds or thousands
particles and interaction. How do you check that by hand??
> 2- why the uniaxial starin test give bad results (even with contact
> law in YADE)? 
What do you mean, bad? The program does exactly what you told it to do.
(BTW if you have the non-equality of Material::young and macroscopic
stiffness in mind: they are not the same, and that is OK. If you wrote
your own Ip2 functor, you should understand how E maps to contact
stiffness, which in turn influences (but is not equal to) macroscopis
stiffness.
> 3- In my law (written for a continuum case and its fracture) there are
> tention, cohesion, compression, shear ,
>       there are two kinds of stiffness for the contact, before
> fracture and after fracture,
>       with a simple case (a sphere-sphere interaction) I can check it?
Yes you can, of course. Put 2 spheres in interaction and make them move
in such way that each feature of your contact law is isolated (pure
tension, pure shear etc); check with hand-computed results.

v