Hi For 2D (plane strain, plane stress and axisymmetric) and 3D the 1.0/3.0 should be used (not 1/dim). Because for example for a 2D plane stress problem, strain_33 is not zero or for a 2D plane strain problem, stress_33 is not zero. Check the book by Neto and own: computational methods for plasticity, pages 58-59
ftp://doc.nit.ac.ir/mec/h.afrasiab/Plasticity/Computational%20Methods%20for%20Plasticity%20Theory%20and%20Applications.pdf Deviatoric_strain = strain - (1/3) * trace(strain) * I and the fourth-order tensor defined as, I_dev = I_sys - (1/3) I * I Best H. B On Wednesday, December 7, 2016 at 5:19:45 AM UTC+3:30, benhour....@gmail.com wrote: > > Dear All, > I hope you have had a great time. I have a general question. I define > total strain and deviatoric part of the elastic strain tensor in two > different ways as below: > > 1- Total strain tensor: > const SymmetricTensor<2, dim> total_strain = 0.5*(Grad_u + > transpose(Grad_u)); (Tensor<2, dim> &Grad_u) > > const SymmetricTensor<2, dim> total_strain = symmetrize(Grad_u); > > 2-Deviatoric strain > dev_T_elastic = deviator(T_elastic); > > dev_T_elastic = T_elastic - (1/dim) * trace(T_elastic) * (Tensor<2, > dim>(StandardTensors<dim>::I))/3.0; > > It is interesting that I got two different results for each case. I would > be very kind of you if you let me know what is the difference between each > case of the two above section. > > Thanks, > Benhour > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
