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- Newsgroups: sci.engr.civil
- Path: sparky!uunet!munnari.oz.au!bunyip.cc.uq.oz.au!brolga!e2liuzhe
- From: e2liuzhe@brolga.cc.uq.oz.au (Zhen Liu)
- Subject: Re: Strcutural Engr.(?? Solve a negative-definite stiffness matrix ??)
- Message-ID: <C186J3.LG2@bunyip.cc.uq.oz.au>
- Sender: news@bunyip.cc.uq.oz.au (USENET News System)
- Organization: Prentice Centre, University of Queensland
- References: <20JAN199313220783@envmsa.eas.asu.edu>
- Date: Thu, 21 Jan 1993 22:30:39 GMT
- Lines: 26
-
- sychen@envmsa.eas.asu.edu (Chen, Shen Yeh) writes:
- you may use modified Root of Square method which need not square function
- but would overflow when there is zero on diagonal
-
- > I always use Cholesky Decompsition to reduce the size of stiffness [k].
- > However, now I have some situation that [K] is negative-definite but I
- > still have to solve the equation. I have not try Gauss method yet, however.
-
- > Does anyone kow :
- > 1) Is there any method I can use to reduce [K], and still solve the system
- > when [K] is negative-definite ?
- > 2) If such method exists, what's the criteria for positive- or negative-
- > definite?
- > 3) If no such method exits,( We can not take advantage of symetry to
- > reduce the size of [k], I mean.), does Gauss method work? What's
- > the criteria for question (2)?
-
- > NOTE : [ ] ====> matrix { } ====> column vector
-
- > It will be greatly appreciated if anyone can give me some idea. If you
- > do not want to type all that stuff to me, just tell me the theorem used.
- > Of course, it will be better if you can tell me reference books. Any
- > assistance will be greatly appreciated.
-
- > Thank you very very very much !!!!!!
-
-