hi everyone
I am new user to damask. I am running crystal plasticity simulation on it. Actually I have a 3d cube geometry composed of 300 grains. I am applying compression on one direction by specifying strain rate of 0.001 /s. In the case of final compression to 0.3 it works well on total increments equal to 600 and total time is 300. The step size is 0.5. On these loading parameters it is converged to 0.3 final compression without any error. The problem which i am facing is that when i have to compress to 0.4 final compression. In that case i am reducing the step size to 0.2 by giving total increments 2000 and total time 400. but still it is not converging leaves me error message when it reaches to increment number 1719 that " max number of cut backs exceeded,terminating" . what will be the possible solution to this problem? your help will be appreciated.
I faced the above problem and now i have solved the problem. So I consider it suitable to share the solution could help others. however i have included numeric file with all other input files in my directory where i was running damask simulation. what i have added in numeric file is i have increased the limit of relative error divergence. Default was 0.0001 and i have increases to 0.1. So changing this criteria now my simulation is converged even with smaller number of increments. But i am not sure whether it will affect my results or not? if anyone has information please share
This is due to mesh distortion, see: Article Large-deformation crystal plasticity simulation of microstru...
currently, the approach is available on the branch: regridMultiPhase.
In order to solve grid distortion problem can we carry the similar procedure as in mesh distortion? if yes then is there any possible material for help how can we regrid the deform geometry and then apply the load. As far as my information damask2 and 3 version has no regridding functionality yet.
Greetings Tariq Ali
I am using DAMASK2. I have also the same error as "max number of cut back exceeded, terminating ". I have solved the issue by increasing the number of increments till the simulation ran without an error. I suggest you to double the increments and try.
Dear Tejanath Reddy Sureddy
Actually this deformation is large as I am trying to carry deformation upto 0.8 final compression. So to achieve these deformation on 3D geometry i have increased the number of increments into 10000 means each step size is 0.06 but still convergence issue is not resolving.Mr. Karo Sedighiani's shared a paper about adoptive re-meshing I have read the paper that is very informative for solving convergence issue. but how to re-mesh using two method the mesh replacement method and the mesh distortion control method is challenging. At this moment we have no information how to carry these two approaches.
We intend to add this functionality by Karo Sedighiani in the development/release version of DAMASK 3.0 soon.