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Subject: Re: top down model associativity
Author: John Swanson
Date: 1999-01-14 16:02:00

When we introduced the term "Bottom-up" modeling, it was in the
context of
creating the solid model, before meshing the model. The "Bottom-up"
modeling
is the label for the procedure of creating key points, then lines, then
areas, and
finally volumes. This is in contrast to the boolean procedure which
starts with
volumes and modifies them by way of boolean operations.
Has anyone tried creating surface elements on a finite element mesh,
then
making the surface elements into areas, and finally creating a facetted
volume.
I suspect it would be a good way of getting rid of your excess computer
resources.
John

> -----Original Message-----
> From: Sanjeev Srivastav [SMTP:sanjeev@e...]
> Sent: Thursday, January 14, 1999 3:48 PM
> To: 'xansys@o...'
> Subject: [xansys] Re: top down model associativity

> From: Sanjeev Srivastav

> Don's message bring up an interesting point.

> Although ANSYS describes a "Bottom-up" modeling procedure, it really
> is a
> "Stay-at-the-bottom" procedure because you can't get the "upper level"
> entities (lines, surfaces, or volumes) if you create the mesh (nodes &
> elements) directly.

> The only "upper" entity for a directly-generated mesh would be a
> component,
> but that's not in the same category as the entities used in the
> Top-down
> approach.

> Right?

> Sanjeev

> -----Original Message-----
> From: John Swanson [mailto:John.Swanson@a...]
> Sent: Thursday, January 14, 1999 12:36 PM
> To: 'xansys@o...'
> Subject: [xansys] Re: top down model associativity

> From: John Swanson

> If you are looking at a higher level associativity for loadings,
> etc
> in an existing
> finite element model I suggest reviewing the Component Capability.
> With this capability you can create named groups of elements or
> nodes, and
> then can apply the boundary conditions to those named groups.
> The Components can be combined into Assemblies, and the Assemblies
> can also be used for boundary condition specification.

> For example,

> Select the nodes representing the BASE of the model

> CM,BASE,NODE

> Then D,BASE,UY,.05
> will impose a 0.05 displacement in the UY direction on all the
> nodes
> in the Component BASE.
> John

> > -----Original Message-----
> > From: Don L. Shaffer;(W)439-5308;101-1W08
> > [SMTP:shaffedl@o...]
> > Sent: Wednesday, January 13, 1999 4:14 PM
> > To: xansys@o...
> > Subject: [xansys] top down model associativity

> > From: "Don L. Shaffer;(W)439-5308;101-1W08"
> >

> > Hello,

> > Reading in the user manual the description says
> > the user may create the model from the bottom
> > up or from the top down. I want to create the
> > nodes and elements; then create the associativity
> > to created full volumes, areas, lines and keypoints.

Posts possibly associated with message #226AuthorDateScore
205top down model associativityDon Shaffer1999/01/13 
214Re: top down model associativityDan Bohlen1999/01/14 
216Re: top down model associativityDon Shaffer1999/01/14 
222Re: top down model associativityJohn Swanson1999/01/14 
224Re: top down model associativitySanjeev Srivastav1999/01/14 
225Re: top down model associativityDon Shaffer1999/01/14 
226Re: top down model associativityJohn Swanson1999/01/14 
228Re: top down model associativitySanjeev Srivastav1999/01/14 
229Re: top down model associativityRick Fischer1999/01/14