Metafor

ULiege - Aerospace & Mechanical Engineering

User Tools

Site Tools


doc:user:remeshing:remeshing

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
Last revision Both sides next revision
doc:user:remeshing:remeshing [2016/06/13 17:19]
joris [File 2 : script]
doc:user:remeshing:remeshing [2016/06/14 18:15]
joris [Options]
Line 547: Line 547:
  
 Since we conserve the inertial forces and correct the internal ones, this post-remeshing algorithm works quite well for quasi-static and low speed dynamic computations. For high speed dynamic computations, it is best not to use it and simply let the simulation continue. Since we conserve the inertial forces and correct the internal ones, this post-remeshing algorithm works quite well for quasi-static and low speed dynamic computations. For high speed dynamic computations, it is best not to use it and simply let the simulation continue.
 +
 +==== Options ====
 +
 +The complete ''setBalancing'' command is actually
 +
 +  setBalancing(executeBalancing, velocitiesExtrapolation=True, maxItes=7, balancingTolerance=0.001)
 +  
 +The first argument has already been described and indicates whether balancing should be done or not. 
 +
 +For the advanced user, a few options can be played with by changing the three of arguments. 
 +
 +First of all, it is possible to deactivate the ''stepPredictor()''. If you do not know what it is, do not touch it. If you do, well sometimes, when transfer errors are significant, the balancing can go better if executed without this predictor, so without extrapolating the next step based on velocities and accelerations. This is fine only in quasi-static, because in dynamic computations velocities and accelerations also intervene in the computation of forces. To do so, simply set the second argument to ''False''. If have not investigated this greatly, but I believe that this could be a sign that the mesh of the computation was not fine enough, so activating this option could hide the real problem. I believe it should be reserved for battery tests, because we want to have tests with rather coarse meshes there. 
 +
 +Second, the number of iterations for each step of the balancing can be changed. By default, seven iterations are tried before increasing the fraction of the unbalanced forces and starting again.
 +
 +Finally, the tolerance can also be changed. The parameter $\alpha$, used to ponder the unbalanced forces, starts at 1 and is progressively divided by 2 when a step fails. Once $\alpha$ becomes smaller than the tolerance, the algo stops itself, returns an error, and the temporal integrationdoes not restart. The default value of 0.001 can be changed if needed. 
 +
 + --- //[[pjoris@ulg.ac.be|Pierre Joris]] 2016/06/13 //
doc/user/remeshing/remeshing.txt · Last modified: 2018/05/04 15:47 by boman