[Gmsh] how to mesh rods

Christophe Geuzaine cgeuzaine at ulg.ac.be
Sun May 31 10:01:55 CEST 2009


jean pierre aubry wrote:
>  
> 
> hello
> 
> 
> i have to model a structure made of beams and sustaining rods or cables,
> 
> think of a suspension brigdge
> 
> rods have no flexural rigidity and must be modelled as a single element 
> along their length
> 
> otherwise the matrix will be singular
> 
> 
> here is a small example model, 4 nodes and 3 lines
> 
> 
> P1                                         P2
> 
> +--------------------L1--------------------+
> 
>                                             |
> 
>                                             |
> 
>                                             L3
> 
>                                             |
> 
>                                             ||
> 
> +--------------------L2--------------------+
> 
> P3                                         P4
> 
> 
> i want Line L1 and L2 to be meshed as beams with (ideally) equally 
> spaced nodes along them
> 
> but
> 
> i want Line L3 to be meshed as a ROD i e one single finite element along 
> its length -NO INTERMEDIATE NODES-
> 
> how to apply « Charcateristic Length » at the Points to do that
> 
> or any other clever way to it
> 


Hi Jean-Pierre - Use a structured mesh on the rods:

Transfinite Line{1,2} = 13; // 13 points on lines 1 and 2
Transfinite Line{3} = 2; // 2 points on line 3




> 
> I mean more clever than altering *.msh file by hand the saving it as 
> *.med or *.unv and repeating that process every time a change is made
> 
> 
> anybody has a good idea
> 
> 
> thanks
> 
> 
> jean pierre
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> gmsh mailing list
> gmsh at geuz.org
> http://www.geuz.org/mailman/listinfo/gmsh


-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science
http://www.montefiore.ulg.ac.be/~geuzaine