Snippets would be great, thanks! Also, once it's in good shape I'll make a pull request for a new example based on this.
David On 05/29/2013 06:29 PM, Kirk, Benjamin (JSC-EG311) wrote: > We do this in a thermal analysis code. I can send you some snippets if you > like. > > I plan to add an example demonstrating this using nitsches method for > nonmatched boundaries, but I'd be happy to have you beat me! > > -Ben > > > > On May 29, 2013, at 3:45 PM, "David Knezevic" <[email protected]> > wrote: > >> In order to model a "film resistance" thermal interface condition, I'm >> using a mesh with a "crack", and I need to assemble an interface term on >> the crack. >> >> More precisely, I have two mesh subdomains, \Omega_1 and \Omega_2, with >> coincident boundaries, but which are not connected in the FE sense. Let >> \Gamma denote the coincident boundary. The term on \Gamma takes the form: >> >> \int_\Gamma (u_1 - u_2) (v_1 - v_2) ds, >> >> where u_1, u_2 (resp. v_1, v_2) are the trial (resp. test) functions on >> either side of \Gamma. >> >> This term looks much like an interface term in DG, and I've assembled it >> using an approach similar to miscellaneous_ex5 (note: I'm using C0 basis >> functions, but of course the solution is discontinuous across \Gamma). >> >> However, when I call solve, I get: >> >> [0]PETSC ERROR: --------------------- Error Message >> ------------------------------------ >> [0]PETSC ERROR: Argument out of range! >> [0]PETSC ERROR: New nonzero at (203,206) caused a malloc! >> >> This isn't surprising since the interface term introduces new non-zeros >> in the sparsity pattern. In order to make this work, it seems I just >> need to: >> - Augment the sparsity pattern >> - Augment the send_list (for it to work in parallel) >> >> I see that dof_map has functionality for doing this "augmentation", so >> I'm going to try those functions out. But also I was wondering if anyone >> has any example code that demonstrates this, or any >> comments/suggestions, in case there are any "gotchas" with this type of >> thing? >> >> Also, if there's interest, I'd be happy to use this model problem to >> make a new libMesh example, since it exercises some functionality that >> may be worthwhile having in the example suite. >> >> David >> >> >> ------------------------------------------------------------------------------ >> Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET >> Get 100% visibility into your production application - at no cost. >> Code-level diagnostics for performance bottlenecks with <2% overhead >> Download for free and get started troubleshooting in minutes. >> http://p.sf.net/sfu/appdyn_d2d_ap1 >> _______________________________________________ >> Libmesh-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/libmesh-users ------------------------------------------------------------------------------ Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET Get 100% visibility into your production application - at no cost. Code-level diagnostics for performance bottlenecks with <2% overhead Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap1 _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
