increase the time step

[TP]

Hi Granooers,

I Have a question. How do I do to increase the time step in the programming?. For example I have this:

<GranOO Version="2.0" TotIteration="10000" TimeStep=“1e-5”   OutDir="Brazilian-TEST"> 

    <PlugIn Id="_ComputeOptimalTimeStep" Ratio="0.14" />

I increase the TimeStep and the programming keep the timestep 2e-8 s and not 1e-5 s that I wrote. Why?

Also, I increase the ratio from 0.14 to 1  and the timestep increase but the programme do not advance and say the message:

“The problem was detected...saving domain and place element in inconsistent”

I appreciate your answer

[Damien André]

Hello, in fact the PlugIn "_ComputeOptimalTimeStep" overwrite the timeStep that you put in the header (equal to 1e-5). The  "_ComputeOptimalTimeStep" plugin automatically computes the maximal time step that you can put in your simulation. This value depends on the local stiffness and masses of the discrete elements of your simulation.

If you put a time step larger than the value given by the   "_ComputeOptimalTimeStep" plugin your simulation may diverge. It is probably the case when GranOO says to you "The problem was detected...saving domain and place element in inconsistent..."

You can easily  document yourself about this timestep problem. This is a common and well known problem in DEM and numerical methods.

kind regards, Damien.