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Subject: Re: One question about the superelement matrix, K and M
Author: Wangming Lu
Date: 1999-11-19 00:42:00

HI, Homayoon,

thanks a lot, yes , you already caught my question,and it helped me a lot.
thanks.
william, lu

>From: Homayoon Rezvani Naraghi
>Reply-To: xansys@o...
>To: xansys@o...
>Subject: Re: [xansys] One question about the superelement matrix, K and M
>Date: Thu, 18 Nov 1999 23:07:01 +0100

>Hello William,

>I'm not sure I understood your problem. If I understood well, the quad 42's
>are
>not part of the structure, but you used them only to easily mesh the model?

>If this is the case, of course they should be deleted before the
>substructure
>stiffness and mass matrices are generated. Substructures are nothing else
>than
>parts of a structure, the stiffness and mass matrices, etc. of which are
>pre
>calculated (instead of being calculated in the whole assembly). They should
>not
>contain any extra elements that are not a part of the global structure.

>Best regards,

>Homayoon

>Lu Wangming wrote:

> > From: "Lu Wangming"

> > Hi, dear all,

> > I have one question about the superelement (substructure) matrices, such
>as
> > the stiffness and mass matrices, K and M. while creating the 3d solid
>model,
> > i first create a rectagular and then use the element type quad 42 to
>mesh
> > this rectagular with the
> > selcted mesh option (density), and then
> > I switch the element type to brick solid 45 and
> > extrude the meshed area along z direction to get
> > the meshed 3d solid block (I also specified the mesh density along z
>before
> > the extrude operation), and so, i finished the preprosessing---
> > creating the 3d solid model.

> > the next step is to choose the substructur to do the analysis by taking
>all
> > DOF as master dofs (m, all, all), and write the mass and stiffness
>matrix,
> > load vector, ect. and i got the stiffness matrix and mass matrix. But i
>have
> > some question about the resultant K, and M for the strucutre. after I
>delete
> > the quad 42 elements before solution, i also run the substruture, the
> > resultant K and M are different with those i got without deleting the
>quad
> > 42. So, i do not know which way is correct , can you tell me if
>anybody
> > know this .

> > thanks so much.

> > regards,

> > william, Lu
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Posts possibly associated with message #6397AuthorDateScore
6394One question about the superelement matrix, K and MWangming Lu1999/11/18 
6396Re: One question about the superelement matrix, K and MHomayoon Rezvani Naraghi1999/11/18 
6397Re: One question about the superelement matrix, K and MWangming Lu1999/11/19