makeCloud question

Hi,

1. rMean = -1 in your [2] is just a default value (search on the internet some reference stuff about Python functions).
Obviously radii will never be negative (even though I doubt there always are 0.2 mm), and this negative default value is to trigger some other determination of mean radius in the cloud when mean radius is not user-imposed (and then still equal to the default value)

2. I'm not sure I understand what you tried with porosity = 0.4 or the error you obtained.
Anyway, the best here again is to search on the internet some reference stuff about Python functions to increase your confidence using Python / Yade. For instance, obeying the order of attributes is not necessary if you adopt the "function(attribute = value)" syntax, as opposed to just "function(value)"

3. In your [1] targetPorosity is defined at [*] and used at [**] (a complete sample preparation requires to uncomment some stuff in your [1]). I thus disagree with your comment that it is never used.

4. As said many many times on this mailing list, and in the doc at your [2] makeCloud alone can not reach "solid-like" porosities of 0.4. It's only intended to make an initial "gas" (something like the clouds in the sky !) that should afterwards be compressed to make a solid particle.
See" Create random very loose packing [..] a gas-like state (see Cloud denomination) with no contacts between particles. Usually used as a first step for packing generation, before subsequent mechanical loading that will confer a solid-like nature to the packing." in your [2].

Hoping this answer constitutes some favor to you, please do us (all members of yade-users mailing lists) a favor and avoid multiple mispostings like https://answers.launchpad.net/yade/+question/687972 or https://answers.launchpad.net/yade/+question/687970.....

[*] https://gitlab.com/yade-dev/trunk/blob/master/examples/triax-tutorial/script-session1.py#L39
[**] https://gitlab.com/yade-dev/trunk/blob/master/examples/triax-tutorial/script-session1.py#L150

Thank you very much for your answers.

About those rejected posts, I asekd questions and then realized I can merged them in one and that is why I tried to remove them. sorry if that bothered you and anybody else and thank you for letting me know. The only reason was that I could not find the remove or delete option because sometimes we want to delete our questions for any possible reason. Rejection was the only choice I found.

1- I want to define particles with radius between 0.1 mm and 0.3 mm. that is why in makecloud function I used like the following
sp.makeCloud(mn,mx,0.2,0.5,num_spheres,False, 0.95,seed=1)
which this line comes from [2]. I just realized 0.2 should be rMean and 0.5 should be RelFuzz which leads to partitcles' radius between 0.1mm and 0.3mm.

2- when I use it like "function(attribute = value)" I get error in this line and by "function( value)" it works so that's way I was wondering about the order of "values" .

3- Oh tahnk you. I searched it by ctrl+f but strangely couldn't find it.

4- This is my main question actually and my goal. If this command
 sp.makeCloud(mn,mx,rMean=0.2,rRelFuzz=0.5,periodic=False,num=num_spheres,porosity=targetPorosity,seed=1)
is just a cloud, and liek an initial guess. then how should we get our target sample? I am using the reaching porosity section of [2] by the following line for define the packing
sp.makeCloud(mn,mx,0.2,0.5,num_spheres,False, 0.95,seed=1)
but It seems cannot be converged and it seems like to change the frictional angle to reach the porosity which is not ok. Still I am wondering how to define a packing with 30 degree for frictional angle, "20mm*20mm*20mm" dimensions, initial porosity of 0.4, 2e4 number of particles, minimum radius=0.1, and maximum radius=0.3 because this is the sample I want to study.

Hello,

2)
> got an error.
> I get error

please provide more information (ideally copy-paset the error message here) [1]

4)
> it seems like to change the frictional angle to reach the porosity which is not ok

why it is not OK?
I think it is a standard method. The material parameters for packing preparation are (can be) completely independent on actual simulation.

cheers
Jan

[1] https://www.yade-dem.org/wiki/Howtoask

Thanks Robert Caulk, that solved my question.