what are the differences of YADE with PFC version 6 in simulating?

Asked by Mahdeyeh on 2018-12-01

Hi there

I know that PFC version 6 has the capability of simulating angular rigid blocks. This is a step forward in being able to model tightly interlocked, low porosity assemblies and it prepare conditions to study in a more efficient and robust way. Rigid, convex {polyhedral in 3D; polygonal in 2D} blocks are now available in PFC 6. We can easily create a zero porosity initial specimen, bond and cut the material, and allow for failure and flow. I believe that there are several benefits to the rigid blocks in PFC, including: 1) ability to couple with FLAC3D, 2) robustness of the contact detection and resolution, 3) efficiency especially during flow, 4) block rounding, 5) ability to model in 2D and 3D with nearly the same data files, 6) Python bindings to the rigid block data structures.
Please compare capabilities of YADE with PFC version 6 in the above cases. Does YADE software have those abilities and capabilities which I mentioned in previous paragraph? which one of them is in YADE? what is the disadvantages of YADE compared to PFC (6)?

The previuos version of PFC (version 5) approach has a key shortcoming which is the inability to specify very low initial porosities for the choke blasted blasted ring material due to the spherical or clump shape of the particles.

I wait for your useful comment and analogies

Question information

Language:
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Status:
Solved
For:
Yade Edit question
Assignee:
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Solved by:
Bruno Chareyre
Solved:
2018-12-05
Last query:
2018-12-05
Last reply:
2018-12-03
Mahdeyeh (mahdiye.sky) said : #1

AND for YADE, will it scale to extremely large problem sizes? for example Yade can simulate model in 100*50*20 m dimensions? with regarding above items that I want ...

Robert Caulk (rcaulk) said : #2

Hello,

I have a question for you, it seems PFC is providing the exact functionality you need, so why are seeking a replacement? Anyways, it's always a good exercise to find out which functionalities are "sorely" missing from one code or another, so let's discuss!

>>1) ability to couple with FLAC3D,
Depends on the FLAC3D interface. Yade was coupled with Escript [1]

>>2) robustness of the contact detection and resolution,
Please elaborate. Yade's contact detection is quite robust.

>>3) efficiency especially during flow,
What kind of flow? CFD? Does PFC have a 3D PFV model like Yade?

>>4) block rounding,
What is that?

>>5) ability to model in 2D and 3D with nearly the same data files,
What is that?

 >>6) Python bindings to the rigid block data structures.
Yade is fully wrapped in Python. Every object can be exposed to Python.

>>Yade can simulate model in 100*50*20 m dimensions?
Sure.

[1]https://yade-dem.org/doc/FEMxDEM.html

Robert Caulk (rcaulk) said : #3

>This is a step forward in being able to model tightly interlocked, low porosity assemblies and it prepare conditions to study in a more efficient and robust way.

As for this comment, it is very hard to make any kind of comparisons. What length scale are you using angular rigid blocks for? If you use angular rigid blocks as a discretization of space, I see no difference compared to spheres. At that scale we aren't modeling anything directly. I added a functionality to Yade's PFV to consider this type of scenario [1].

As for interlocking, could you comment on how blocks might provide a more accurate representation of reality compared to an increase of contact detection radius for a body [2]?

[1]https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.FlowEngine.desiredPorosity
[2]https://www.sciencedirect.com/science/article/pii/S0022509612002268

Mahdeyeh (mahdiye.sky) said : #4

Dear Robert Caulk
Thanks a lot for your comments and help.
At first as you asked, because of some reason I have to search for a replacement of PFC for my study. Anyway I study on rock mass in underground mine. I dont work on fluid at all. Actually I want to simulate a rock mass before it is broken with blasting and in the following simulate process of material flow from above to down (same as material flow in silo or bunker: [1]). So in the first stage for unbroken rock, particle should have very low porosity(zero or near to zero) then after breaking and befor moving again their porosity should be very low and at this stage the rock is broken to wide size distribution of particles (e.g. from 1cm to 1m) with different shape (angular rigid particle),afterward material flow in that column starts toward down as the broken rock is drawn from outflow at the bottom (in this stage porosity gradually increase to some extent). So YADE could do this for me? I mean having different shape of particle (e.g. polyhedral because I heard shape of particle in YADE is sphere) with zero porosity at first (no voids between particles, so it seems like a solid with a little joint or fracture) and then moving them with having all the characteristics and contact band (stress and strain and shear and .... )? and all these things in a 100m*50m*50 m model?

Thank you for your time.

[1] https://yade-dem.org/wiki/Outflows#Rectangular_outflow

Mahdeyeh (mahdiye.sky) said : #5

I want to simulate flow material of rock similar to below movies with YADE. Can I?

You can find some text and movies on this work (The use of 3DEC as an material flow simulator for having an tightly interlocked, low porosity assembly) here:

https://www.dropbox.com/sh/t7f0pxt5awxum46/AABrkXAGNjQKDXulbiGFF6Sta?dl=0

The approach used in 3DEC was based on the methodology presented here:
https://www.dropbox.com/s/mburox48c61na4c/TaghaviPierce_3DECFlow.pdf?dl=0

Robert Caulk (rcaulk) said : #6

Currently, I don't believe there is a cohesive angular block package in Yade as you describe. But Yade is designed in a way that enables the addition of such a package without reinvention of the wheel :-)

Robert Caulk (rcaulk) said : #7

Please do not "rewrite history" by editing thread titles and question descriptions.

Hi, I believe PFacets would work with cohesive interactions and paving a volume with tetrahedra as in Taghavi & Pierce implies no special difficulty. Of course it would require to read yade's documentation and practice examples before achieving anything.

A more general answer to the original question (now erased, please don't do that) is that yade can do everything - even prepare coffee - and it is more efficient than any software from the past, present, and future. :)

Bruno

Mahdeyeh (mahdiye.sky) said : #9

I am sorry but I was n`t convinced. I hope to find a little light.

What is this? :
https://yade-dem.org/doc/yade.polyhedra_utils.html?highlight=polyhedra#module-yade._polyhedra_utils

and

https://yade-dem.org/doc/yade.polyhedra_utils.html?highlight=polyhedral#yade.polyhedra_utils.polyhedralBall

and

Boon,C.W., Houlsby, G.T., Utili, S. (2012), A new algorithm for contact detection between convex polygonal and polyhedral particles in the discrete element method. Computers and Geotechnics (44), pages 73 - 82. DOI 10.1016/j.compgeo.2012.03.012 (fulltext)

> What is this?

The first is an hyperlink to yade's documentation.
The second alike.
The third suggests a journal paper.

What was your question?

The PFacets I was mentionning are explained here: https://www.sciencedirect.com/science/article/abs/pii/S0266114415001235

Mahdeyeh (mahdiye.sky) said : #11

Hi Bruno
thank you, I hadn`t seen your first message.

   > do not "rewrite history" by editing thread titles and question descriptions.
    > the original question (now erased, please don't do that)
    I don`t know that I shouldn`t edit my subject and question, I apologize and if it is necessary I can rewrite the original question?

    > What is this? :
     That meant if in YADE we don`t have polyhedral particles, what is described in these links?

As you said with PFacets I can simulate angular rigid particles (Rigid and convex blocks {polyhedral}) for being able to model tightly interlocked, low porosity assemblies? I wish this. I have n`t read your article yet.

   > yade can do everything - even prepare coffee - and it is more efficient than any software from the past, present, and future. :)

    I hope your saying is correct because I like to do my PhD thesis with YADE. ;)

Mahdeyeh

> That meant if in YADE we don`t have polyhedral particles, what is described in these links?

I don't understand why you claim there are no polyhedral particles in Yade. That's definitely some of the most confusing thread I've seen.
Bruno

Mahdeyeh (mahdiye.sky) said : #13

Thanks Bruno Chareyre, that solved my question.