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
