-
Filter by Topic
Most Popular
All Topics
- List all discussions
LinkedIn
Facebook
Twitter
Delicious
Digg
Stumbleupon
More services...One basic and fundamental question about boundary conditions
|
Thread index | Previous thread | Next thread | Start a new discussion |
RSS feed |
Turn on email notifications |
4 Replies
Last post: April 5, 2012 5:14pm UTC
February 10, 2012 10:40am UTC
One basic and fundamental question about boundary conditions
I feel confused about the introduction of Lagrange multipliers in generalized Neumann boundary condition. Why do we need to have extra dependent variables? I checked relevant items in documentation, and found the following description:
"When Dirichlet boundary conditions are introduced, the finite element algorithm makes a corresponding change to the Neumann boundary conditions so that the resulting model becomes solvable."
It sounds like there exists certain inconsistency within Neumann and Dirichlet BC's, making the equation system unsolvable.
If anyone knows about these details, could u please explain it? Thanks a lot! I really feel unsafe to run simulations with doubts in underlying systems.
Reply | Reply with Quote | Send private message | Report Abuse
February 11, 2012 9:42am UTC in response to Pu Zhang
Re: One basic and fundamental question about boundary conditions
Finally I got something in the documentation.
In the Modeling Guide, it is claimed the content on page 362 explains where the particular form of constraint force for ideal constraint comes from. However, the documentation is not aimed to beginners. I cannot understand it. Could anyone explain it in plain language or point out any reference?
Thanks a lot!
Reply | Reply with Quote | Send private message | Report Abuse
February 12, 2012 3:06pm UTC in response to Pu Zhang
Re: One basic and fundamental question about boundary conditions
Perhaps my questions is too simple for most people, especially advanced people here. But please anyone give me some hint, or reference. Thanks!
Reply | Reply with Quote | Send private message | Report Abuse
February 14, 2012 8:13pm UTC in response to Pu Zhang
Re: One basic and fundamental question about boundary conditions
After so long time searching, it's found the sections on weak form in Reference Guide of Version 4.0a are helpful for understanding my concerns.
Hope this information can help more people who have the same question in mind.
Reply | Reply with Quote | Send private message | Report Abuse
April 5, 2012 5:14pm UTC in response to Pu Zhang
Re: One basic and fundamental question about boundary conditions
hi, i work with 4.2 version and too have problems with the boundary conditions, you aren't alone, good luck!
Reply | Reply with Quote | Send private message | Report Abuse
Rules and guidelines
