Ehsan, In my code first I calculate displacements (uh) then in each cell at the > q_points I calculate S_xx, S_xy, S_yy stress components and project them to > the nodes and with a averaging method calculate stress nodal values. > > Now I want to calculate stress components in polar coordinates. > I would like to send Sigma_xx, Sigma_xy and Sigma_yy to DataPostprocessor > class and inside compute_derived_quantities_vector calculate S_rr. > If you already compute S_xx, S_xy and S_yy explicitly outside of DataPostprocessor, you can certainly also do that for S_rr. If you want to use DataPostprocessor for computing S_rr, you would create a FiniteElement with three components (S_xx, S_xy and S_yy) a corresponding DoFHandler and assign the values of S_xx, S_xy and S_yy to a finite element vector appropriately. This finite element vector could then be used in DataPostprocessor (using uh) to compute S_rr.
If you don't insist on projecting and averaging you stress components, all this can be done using DataPostprocessorn in your current setup. You would just hand your displacement vector to DataPostprocessor and compute S_xx, S_xy and S_yy from duh. Finally, use S_xx, S_xy, S_yy and evaluation_points to calculate S_rr. In this case, the resulting output is most likely discontinuous. Best, Daniel -- 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.