[GiDlist] Request for some data about Gauss point appr.

[Andrea Calaon]

Hello everyone,
I'm using Gauss point results in post-processing to visualize a stress tensor field which
is actually very smooth (in many cases C infinite). At present I don't calculate the field
values on the elements boundary. I use min and max as a means of evaluating the
quality of the solution obtained. When using "Contour Fill" (or the smoothed one), I get
legend values for the min and max which depend on the kind of local approximation
used by GiD on the element in case of Gauss Points.
Which is exactly the approximation GiD uses for displaying Gauss point results?

A second question is:
Would it be possible to give Gauss point coordinates laying on the element boundary or
very near it?

Thanks for any suggestion
Have a nice day,
Andrea

Andrea Calaon

Ashurst Lodge, Ashurst
Southampton, Hampshire
SO40 7AA, UK
Tel. office: +44 23 80 293 223
Fax office: +44 23 80 292 853
Mobile: +44 7766 488 225
E-mail: andrea at beasy.com

[Enrique Escolano]

The Gauss point values are extrapolated to the nodes, using the "standard"
Finite Element shape funcions.
This is a polynomial (or product of polynomials in each direction) of degree
n interpolates n+1 values, then using
this function are extrapolated the nodal element values.

The gauss point coordinates can be on the element boundary without problems.

The values extrapolated to nodes are not continuous between neighbourg
elements, for a smooth result must
be calculated an averaged single nodal value.

Regards
Enrique Escolano

----- Original Message -----
From: "Andrea Calaon" andrea at beasy.com
To: gidlist at gatxan.cimne.upc.es
Sent: Wednesday, April 14, 2004 11:39 AM
Subject: [GiDlist] Request for some data about Gauss point appr.


Hello everyone,
I'm using Gauss point results in post-processing to visualize a stress
tensor field which
is actually very smooth (in many cases C infinite). At present I don't
calculate the field
values on the elements boundary. I use min and max as a means of
evaluating the
quality of the solution obtained. When using "Contour Fill" (or the
smoothed one), I get
legend values for the min and max which depend on the kind of local
approximation
used by GiD on the element in case of Gauss Points.
Which is exactly the approximation GiD uses for displaying Gauss point
results?

A second question is:
Would it be possible to give Gauss point coordinates laying on the element
boundary or
very near it?

Thanks for any suggestion
Have a nice day,
Andrea

Andrea Calaon

Ashurst Lodge, Ashurst
Southampton, Hampshire
SO40 7AA, UK
Tel. office: +44 23 80 293 223
Fax office: +44 23 80 292 853
Mobile: +44 7766 488 225
E-mail: andrea at beasy.com

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