Hi Dafang, I've done this a lot for elasticity problems, and haven't had any problems with it.
If you can send through an example that illustrates what is happening (e.g. a modified version of systems_of_equations_ex6), I'd be happy to have a look. David On 03/04/2014 06:08 PM, Dafang Wang wrote: > Hi, > > The Libmesh Examples tell how to use the DirichletBoundary class to > constrain all the variables in a system, but I am not sure how to apply > zero Dirichlet BC to PART of the field variables in a system. I am > solving a simple 3D elastic problem and I want to fix a boundary in the > y direction while allowing it to move in the x-z plane. > > I did the following way but the results did not seem correct: > My system has 3 displacement variables: ux (id=0), uy (id=1), and uz > (id=2). > std::vector<int> variables(1); > variables[0] = uy; //the vector contains uy only > DirichletBoundary bc(boundary_ids, variables, &ZeroFunction); > > The result I got showed that ux and uz were somewhat fixed with respect > to one edge on the Dirichlet boundary side, which made no sense since ux > and uz are supposed to evenly spread. > > Any suggestions will be greatly appreciated. > > Cheers, > Dafang ------------------------------------------------------------------------------ Subversion Kills Productivity. Get off Subversion & Make the Move to Perforce. With Perforce, you get hassle-free workflows. Merge that actually works. Faster operations. Version large binaries. Built-in WAN optimization and the freedom to use Git, Perforce or both. Make the move to Perforce. http://pubads.g.doubleclick.net/gampad/clk?id=122218951&iu=/4140/ostg.clktrk _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
