yade-dev team mailing list archive

[Janek Kozicki <janek_listy@xxxxx>]

Hello everyone,

I am going back to work on yade, and I have some interesting plans.
This also entails one question :)

Sorry for goofy subject, I hope it catches your attention.

In super-short I will tell you my history: since I left Grenoble in
2009 I attended a full 5-year course in physics at University of
Gdańsk and I defended in 2015 master thesis in quantum mechanics.
I was quiet here on yade-dev, because apart from full-time studies
I was also working as associate professor at Gdańsk University
of Technology. In 2014 I defended my habilitation on civil
engineering/numerical modelling. Next week I will obtain a professor
position at GUT in civil engineering department. Since 2015 I needed
nearly 2-years to complete my physics education by self studying and
individual talks with other physics professors. This evolved into my
plans to implement quantum mechanics into yade in an elegant and
documented way. As currently it only works for me and is not
documented.

Currently I got involved in a funded research that treats shale gas
extraction. So I am paid a little to implement rock fracking, and
I decided that this is a good opportunity for me to get quickly up to
speed with current yade development process & methods. Implementing
rock fracking will make easier for me to work on quantum mechanics
later, and easier for *you* to watch me.

During years 2009-2017 all other people in my department were using
some older version of yade. And they lost touch with latest yade
releases. This was my fault, since due to my full-time 5-year studies
of physics I did not have time to keep them updated about latest yade
versions. I think that I stopped updating yade for them around year 2012.
Most of the time they were calculating concrete, and despite my
encouragement to contact this mailing list and commit their changes,
they didn't want to do so. Perhaps I didn't push them hard enough.

Currently I will update yade for them, since some of them will now
also want to calculate rock fracking. This means that I need to merge
some of their changes into latest yade trunk. But actually when
looking closer at this I see that there is only one simple change,
which perhaps is already implemented in yade, and we just don't know
about it. So there would be no need to port it, just use the
different name for this feature.


Now, here comes the question:

To calculate concrete the sample made of spheres has some of these
spheres overlapping. Since it is difficult to generate a sample where
none of the spheres overlap. And with some overlapping the spheres
want to "explode" until there is no overlap, sometimes cohesion prevents
this, but we start calculations with non-zero forces between spheres.
To mitigate this problem, the initial overlap between spheres is
stored (on first iteration) and is treated as "zero" penetration
depth during tension & compression.

So the question is whether this feature is already implemented in
yade under some name that you can give me, or whether I need to port
this to yade.

best regards
-- 
Janek Kozicki                               http://janek.kozicki.pl/  |