Dear Ronan, You can use the level set strategy to describe S and define a finite element method which is discontinuous across this interface. But, there is in fact a little difficulty to compute the integral you need because on the surface itself, the value on the interface of the base function of the xfem (the mesh_fem_level_set object) is not guaranty. This is indeed a problem that we want to solve in a near future because we need to prescribe non elementary interface limit condition (such as contact condition or jump condition as you have).
If the interface is static and the mesh is conformal to this interface, there is a tool to partition a finite element method into two with regard to this interface. You can partition a fem into two or more parts with the method mf_u.set_dof_partition(cv, i) where cv is the element number and i is the zone number. Doing so, the dof between two zones will not be identified and you can represent a discontinuity between these two zones. In order to compute the integral you need, you have to define two mesh regions which will describe one side of the surface S and the other one respectively. Then you can integrate the terms you need with the usual strategy. Yves. Le mardi 15 mai 2007 09:16, vous avez écrit : > Dear getfem experts, > > I would like to solve a (relatively simple) problem with jump conditions > on an surface S. > > More precisely, if O denotes the domain, the variational form is the > following : > \int_O \sigma \grad u \grad v dx + \int_S \alpha [u][v] ds = <source terms> > where [u] is the jump of u over S. > > Is there some elegant solution to implement this? > If I have to use the level set strategy (NB: the surface is static and I > can easily include it in the mesh), how can I translate the \int_S > \alpha [u][v] ds integration? > > I will be glad to supply you further details. > Thank you in advance for your answer, > Best regards, > Ronan Perrussel ------------------------------------------------------------------------- Yves Renard ([EMAIL PROTECTED]) tel : (33) 04.72.43.80.11 Pole de Mathematiques, INSA de Lyon fax : (33) 04.72.43.85.29 Institut Camille Jordan - CNRS UMR 5208 20, rue Albert Einstein 69621 Villeurbanne Cedex, FRANCE http://math.univ-lyon1.fr/~renard ------------------------------------------------------------------------- _______________________________________________ Getfem-users mailing list [email protected] https://mail.gna.org/listinfo/getfem-users
