Re: [Libmesh-users] hanging nodes and triangular elements

 Re: [Libmesh-users] hanging nodes and triangular elements From: Roy Stogner - 2005-02-15 16:36:42 ```On Tue, 15 Feb 2005, Michael Povolotskyi wrote: > We wonder if the adaptive mesh refinement (with hanging nodes) can be used > together with the triangular elements? If yes, do they need any special > treatment? As long as you're using the Lagrange (default) triangular elements, they shouldn't need any special treatment. Does your code work correctly with uniformly refined triangular elements? Perhaps there's something wrong with your coarse triangular mesh - it's easy to get a few nodes in the wrong order and create an oddly distorted element. --- Roy Stogner ```

 [Libmesh-users] hanging nodes and triangular elements From: Michael Povolotskyi - 2005-02-15 16:21:45 ```Hello everybody, We're going to solve a Poisson equation using the adaptive mesh refinement. We found some problems with triangular elements while the quadratic elements seem to work well. We wonder if the adaptive mesh refinement (with hanging nodes) can be used together with the triangular elements? If yes, do they need any special treatment? Thank you, Michael. ```
 Re: [Libmesh-users] hanging nodes and triangular elements From: Roy Stogner - 2005-02-15 16:36:42 ```On Tue, 15 Feb 2005, Michael Povolotskyi wrote: > We wonder if the adaptive mesh refinement (with hanging nodes) can be used > together with the triangular elements? If yes, do they need any special > treatment? As long as you're using the Lagrange (default) triangular elements, they shouldn't need any special treatment. Does your code work correctly with uniformly refined triangular elements? Perhaps there's something wrong with your coarse triangular mesh - it's easy to get a few nodes in the wrong order and create an oddly distorted element. --- Roy Stogner ```
 Re: [Libmesh-users] hanging nodes and triangular elements From: Michael Povolotskyi - 2005-02-15 18:07:26 ```Dear Roy, Thank you for the answer. Yes, the code works correctly with uniformly refined triangular elements. Could you, please, tell how can I check if the nodes are in a correct order? Thank you, Michael. Roy Stogner wrote: > On Tue, 15 Feb 2005, Michael Povolotskyi wrote: > >> We wonder if the adaptive mesh refinement (with hanging nodes) can be >> used together with the triangular elements? If yes, do they need any >> special treatment? > > > As long as you're using the Lagrange (default) triangular elements, > they shouldn't need any special treatment. > > Does your code work correctly with uniformly refined triangular > elements? Perhaps there's something wrong with your coarse triangular > mesh - it's easy to get a few nodes in the wrong order and create an > oddly distorted element. > --- > Roy Stogner > ```
 Re: [Libmesh-users] hanging nodes and triangular elements From: Roy Stogner - 2005-02-15 18:17:55 ```On Tue, 15 Feb 2005, Michael Povolotskyi wrote: > Yes, the code works correctly with uniformly refined triangular elements. > > Could you, please, tell how can I check if the nodes are in a correct order? If you're getting good results with uniform refinement, there's likely nothing wrong with your coarse mesh - the distorted triangle problem was just the only thing I'd ever seen that would give you problems with a triangular mesh but not a quadrilateral mesh. Could you specify exactly what problems you're getting with adaptive triangles that you aren't seeing with uniform triangles or adaptive quads? Is it a bad convergence rate, a crash, or something else? --- Roy Stogner ```