Thanks. Could you answer the last question please? Basically I want to know if I still can use cg once I use mesh refinement? I did quick calculations with equation (7) and I see the matrix is not symmetric so I think I cannot use it. I would like to double check with you. Which preconditioner would you recommend for adaptive mesh refinement in elasticity?
Also, I had a question about the load balancing in the adaptive mesh refinement. Is this automatic? When is it done? The vectors associated with a system are balanced as well? What if we had created additional vectors that we initialize after each refinement with the function init (const NumericVector<T> other), i.e. http://libmesh.sourceforge.net/doxygen/classlibMesh_1_1PetscVector.php#a1a9ed9f54cab101da906d976e0b7bea1 Miguel On Thu, Sep 4, 2014 at 4:01 AM, Roy Stogner <[email protected]> wrote: > > > On Wed, 3 Sep 2014, Miguel Angel Salazar de Troya wrote: > > In this paper >> >> http://arxiv.org/pdf/1009.4975.pdf >> >> In page 9, at the bottom, they mention this: >> >> As indicated by the circled nodes in Figure 3(a), level-one mesh >> incompatibility results in hanging nodes. The libMesh package handles >> those >> hanging nodes by using the projection method to enforce constraints in the >> stiffness matrix >> > > This is correct > > > Since libMesh does not drop the constrained DOFs in the linear system, >> > > And this is correct > > > the projected system in (7) is singular when there is any hanging >> node. >> > > But this is only correct if they're computing (7) themselves rather > than letting libMesh handle it. Depending on the constraint options > you select we fill in those zero blocks with the constraint equations > themselves or with ones on the diagonal. > --- > Roy > -- *Miguel Angel Salazar de Troya* Graduate Research Assistant Department of Mechanical Science and Engineering University of Illinois at Urbana-Champaign (217) 550-2360 [email protected] ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
