yade-users team mailing list archive

[Rohit John <question692956@xxxxxxxxxxxxxxxxxxxxx>]

Question #692956 on Yade changed:
https://answers.launchpad.net/yade/+question/692956

    Status: Needs information => Open

Rohit John gave more information on the question:
Hello,

Thanks for your answers

reply to  Robert's comments.
> Even if what you say is true (which seems odd to me), why should that prevent you from using CentralGravityEngine? There are plenty of ways to "see" motion without physically observing it in a window.

I want to observe the interaction between the debris and the cylinders.
Viewing the motion, compared to tracking states of the bodies, will
offer additional insights into the dynamics. I will read the document
Janek suggested [1].

--------------------------------------------------------------------------------------------------------------------------------------------
>You can change/turn off the applied force at any time step you like.

>From what I understood, the forceEngine applies the same force to all
bodies in the simulation.  I would like to have a force which depends on
the position of the bodies. The equations are given here [2].

--------------------------------------------------------------------------------------------------------------------------------------------
> I don't think FieldApplier should be used directly. But I really don't know why you believe it looks promising. Please provide links to everything you reference. What are you reading? Where are you reading it? 

I read the YADE documentation about fieldApplier [3]. I understood that the gravity fields use FieldApplier. Since there are engines for creating forces directed to an axis(AxialGravityEngine) or a body (CentralGravityEngine), I assumed that the forces are dependent on the position of the body they act on. I do not know how exactly the engine works. I then assumed it would be possible to create a function capable of exerting a position dependent force on a body
--------------------------------------------------------------------------------------------------------------------------------------------

reply to Janek's comments
> CentralGravityEngine does not depend on distance
That's too bad. I thought it used Newton's gravitational law. If this is the case, I cannot use it. 
--------------------------------------------------------------------------------------------------------------------------------------------


I do not know how to code a new engine or use c++. Please correct me if I am wrong. Can I add a new function for defining a the forces using the equations from [2] in the GravityEngines.cpp [4], based on the other functions in the file? Are there other files I must modify in addition to this?

Kind regards,
Rohit John

[1] https://yade-dem.org/doc/yade.qt.html#yade.qt._GLViewer.center
[2] https://en.wikipedia.org/wiki/Clohessy%E2%80%93Wiltshire_equations
[3] https://yade-dem.org/doc/yade.wrapper.html#fieldapplier
[4] https://gitlab.com/yade-dev/trunk/-/blob/master/pkg/common/GravityEngines.cpp#L51

-- 
You received this question notification because your team yade-users is
an answer contact for Yade.