K, I'd recommend that you do this first for a "normal FE" example like systems_of_equations_ex4, and then apply what you learn there to the RB case.
David On 06/24/2012 07:35 PM, Derek Gaston wrote: > Lot's of options here... but what we generally do is compute the _average_ > stress and strain (pick a component) and store it per element using > CONSTANT, MONOMIAL's in an ExplicitSystem... that way we can view the > stress/strain in your visualization tool. > > This is pretty similar to what Abaqus and other solid mechanics codes do. > libMesh will even output a nodal interpolation of that CONSTANT, MONOMIAL > field by default if you are using Exodus... which again matches what Abaqus > typically does... > > Computing the average is trivially easy... just integrate whatever > component of stress/strain you are interested in (or compute Mises or > whatever) over the element (loop over qp's, multiply by JxW and add it up) > then just divide by elem->volume() to get the average on that element and > store the result into the ExplicitSystem solution vector at the > corresponding element DoF for your CONSTANT, MONOMIAL... > > Derek > > On Sun, Jun 24, 2012 at 1:19 PM, John Peterson <jwpeter...@gmail.com> wrote: > >> On Saturday, June 23, 2012, Kyunghoon Lee wrote: >> >>> Hi all, >>> >>> I wonder what is the best way of computing strain and stress values with >>> displacements obtained by solving linear elasticity problems. I can >> simply >>> follow displacement-strain and strain-stress relationships (using finite >>> difference to compute gradients), but I guess it would be more natural to >>> use basis function information. I'd appreciate it if someone can suggest >>> me some reference examples. >> >> What about using some kind of gradient recovery method like Zienkewicz-Zhu >> to postprocess the solution? >> >> Libmesh also has the patch recovery error estimator machinery that may be >> inspirational. >> >> >> -- >> John >> >> ------------------------------------------------------------------------------ >> Live Security Virtual Conference >> Exclusive live event will cover all the ways today's security and >> threat landscape has changed and how IT managers can respond. Discussions >> will include endpoint security, mobile security and the latest in malware >> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >> _______________________________________________ >> Libmesh-users mailing list >> Libmesh-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/libmesh-users >> > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Libmesh-users mailing list > Libmesh-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/libmesh-users ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
