yade-users team mailing list archive

[Anton Gladky <gladky.anton@xxxxxxxxx>]

Hi, Chiara
verecently I realized, that when I do uniaxial tests and have friction
between "press" and spheres, results are very unstable.
When friction between spheres and press is 0, all is ok.

http://www.mail-archive.com/yade-users@xxxxxxxxxxxxxxxxxxx/msg01656.html

Maybe, it is your case also.

Anton


2010/8/20 chiara modenese <c.modenese@xxxxxxxxx>

> Hi,
>
> OK I found where is the problem. Please see the two attached figures (for
> people interested in the topic see the previous post in this thread). In one
> case I include friction between balls and boxes, in the other only between
> balls. Energy is conserved even if the simulation is _dynamic_ (good news),
> the problem is present only if there is friction between balls and boxes.
> Please I need your help to understand if this is a bug.
>
> So question for everyone:
> What is the difference in terms of computation of the shear behavior
> between a box-sphere interaction and a sphere-sphere interaction?
>
> Thanks a lot.
>
> Chiara
>
>
>
> On 12 July 2010 17:26, Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx> wrote:
>
>>
>> Chiara, I found a problem in the script you use for comparing energies in
>> bouncing spheres.
>> The line O.materials[0].frictionAngle=radians(25) is changing value in the
>> material but it is not reflecting everything automaticaly in interactions
>> (tangent of friction is still 0 in the contact law, but radians(25) is used
>> for computing energy, so...).
>> By using TriaxialCompressionEngine().setContactProperties(radians(25))
>> instead, I get something better. Total energy is still increasing, but at
>> least it will stagnate at a point.
>>
>> Bruno
>>
>>
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