INPUT/OUTPUT FILES FOR nurbFEAP Ver 8.5

[Yaakov]

Dear FEAP TEAM,

I would ask, is it possible that we can get the INPUT/OUTPUT FILES FOR nurbFEAP Ver 8.5 ?

in our FEAPwiki Option: Isogeometric Analyses
http://feap.berkeley.edu/wiki/index.php/Examples

Warm regards,
Yaakov

[Prof. R.L. Taylor]

nurbfeap has been replaced by igafeap in ver8.5

Just what files did you want?

[FEAP_Admin]

The version 8.5 distribution has a set of examples in the igafeap/inputs folder.
There is a plan to add these to the wiki but progress has been slow.  Volunteers are welcome.

[Yaakov]

Dear Prof. Taylor and Administrator,

many thanks for your answer. I think, I should better change this question, namely,  how can we get the geometries for IGA?
As far as I only know Rhino (commercial software) and Nurbs toolbox for Matlab (totally free for everyone) which is not cad software, but it has some interesting geometries (it is preprogrammed if I'm not mistaken.).


Warm regards,
Yaakov

[Axuni]

Hi Yaakov,

I wonder if you get more information about alternatives of software for creating NURBS geometries.
Currently what I am using is Autocad (student version).
It is easy to create splines and obtain the information about the order, control points and coordinates. However, it is tricky to make everything automatic. So far I am getting the information I need for my geometries by clicking at every spline.
After having the general geometry, the remeshing tools from FEAP becomes very handy.
Regards,
Axuni

[Prof. S. Govindjee]

We have also used Rhino in the past, but as you note the process is hardly automatic; there are lots of small steps to the process.

[fethio]

Thanks Prof Govindjee. Is there a guide to constructing meshes in igafeap that includes the pre-processing (the CAD steps).
Best regards,

[Prof. S. Govindjee]

I found some (very old) notes on using Rhino to generate an analysis mesh; they are attached.  The notes mention a STP to igaFEAP conversion program.  Unfortunately, I have three copies of the program and can not tell which one is correct (the program was written by a student that has long since graduated).

[fethio]

Thank you very much.

[Prof. S. Govindjee]

STP to IGAfeap converter.

Here is a simple converter for extracting knot and control point information from a STP file and writing it out in IGAfeap format.  I probably only works on the most simple of cases, but it is something that you can play with if you are interested.  I've also attached a sample STP file to try it with.

[fethio]

There is enough for a wikipage here 

[resammc]

nurbfeap has been replaced by igafeap in ver8.5

Just what files did you want?

Dear Professor,

Could you please upload a very simple Hierarchical T-Spline mesh data input file? It would be very helpful in order to understand the code in umesh8.f .

Many thanks in advance.

[Yaakov]

Dear Prof. S. Govindjee,

Thanks  a lot for your research support in numerical mechanics community!

I will also post a small package which can get the FEAP Input File from Nurbs Toolbox (Octave/Matlab) in the next step.

Kind regards,
Yaakov

STP to IGAfeap converter.

Here is a simple converter for extracting knot and control point information from a STP file and writing it out in IGAfeap format.  I probably only works on the most simple of cases, but it is something that you can play with if you are interested.  I've also attached a sample STP file to try it with.

[Yaakov]

Dear Axuni,

Thanks very much for your sharing the  research experience about IGA:

I just attach a famous chart flow (jpg file & single patch) which is based on Hughes et al. book. (P.S.:  IGA fits well into the existing FE-codes and only a few changes of FE codes are necessary.)

Four different Parts (yellow color), Part 2 & Part 3 & Part 4 have been totally done by FEAP Team.

for Part 1 preprocessing (question in this post), I personally stilll always like to use open resource program , e.g. Gmsh (only for FEA), etc. P.S.: Rih Price seems not so cheap & fully commercial license.

My research topics don't focus on IGA, but in the part time, I always like to learn IGA from Articles/Lecture Notes by J. Kiendl, Ambati, Hughes , De Lorenzis, etc. since I find that High Order Elements can describe complex structure of objects in a beautiful way.

Also thanks for your help again.

Warm regards,
Yaakov

Hi Yaakov,

I wonder if you get more information about alternatives of software for creating NURBS geometries.
Currently what I am using is Autocad (student version).
It is easy to create splines and obtain the information about the order, control points and coordinates. However, it is tricky to make everything automatic. So far I am getting the information I need for my geometries by clicking at every spline.
After having the general geometry, the remeshing tools from FEAP becomes very handy.
Regards,
Axuni