← Back to team overview

yade-users team mailing list archive

Re : Triaxial Test


Janek Kozicki   said :

Another way could be to compute the forces inside the DeusEx Engine itself, by retrieving all sphere-box interactions and summing the corresponding forces. In that case, is there a way to get a list of all interactions on a box (more generally, considering a Body b0, is there a quick way to get all interactions which have b0 as body?) ? or does it need to go through all interactions and see which belong to the box ?

there is an InteractionContainer MetaBody::volatileInteractions, and all
interactions used by ElasticContactLaw are there. And currently the only
way to see which belong to the wall, is to iterate all of them and
compare id1 and id2 with wall's id. I have some idea how to make it
simpler and faster, so I'll improve it at some point in the future.

But since you already have your total force - you don't need to scan all
interactions :)

Oh! I forgot to mention one thing : Each wall (ok, I will use 6 walls rather than one box...) must know the total stiffness K, where K is the sum of stiffnesses over all interactions of type wall-something. Based on K, I can assign the wall a displacement such that the force on it reaches the presribed value in only one time-step (I hope this explanation is clear...).

So : I will have to iterate over all interactions in the engines (6 walls => 6 iterations over all interactions!) or modify something somewhere to increment K. From your previous answer, I realized that ElasticContactLaw is not the best place for this since it does not check the type of bodies. However, highest level functions (functions that know if one body is a wall) are not supposed to know the stiffness of elastic contacts... are they?

Few questions on SVN :

Recently, I tried to run Yade compiled from the repository sources, and for the first time, I had problems with permissions of opengl files :
"Error: Could not open /dev/nvidiactl because the permissions
are too resticitive.  Please see the FREQUENTLY ASKED QUESTIONS
section of /usr/share/doc/NVIDIA_GLX-1.0/README for steps
to correct.
Segmentation fault"

I know how to solve it temporarily (chmod on OGL files each time I start a KDE session). Do you have an idea if this may be due to Yade?!

More generally, do you recommend installing Yade after a complete checkout; or is it better to install it from the "official" (but very old ;)) version of Yade-all and update specific parts one by one? Is the trunk version stable currently?

Chareyre Bruno
     Maître de conférence
     Institut National Polytechnique de Grenoble
     Tél :
________________________________________ bureau I 08 Laboratoire 3S (Soils Solids Structures) BP 53 - 38041, Grenoble cedex 9 - France _______________

Follow ups