[Gmsh] How to generate 'plugin crack' for post processing

[Christophe Geuzaine]

Hi Xiaoxin,

Plugin(Crack) works on meshes: you thus need to have a mesh before you can run it. For example, add "Mesh 3;" before calling the plugin.

Christophe

> On 29 Sep 2016, at 17:44, Xiaoxin Lu <xiaoxin.lu at u-pem.fr> wrote:
> 
> Hello,
> 
> I am a PhD student using GMSH to generate crack faces. However, I could not find any example for this kind of post processing.
> My .geo file is attached below, I put 'plugin crack' command inside but it did not work, I was wondering how to generate a post process file for this command. 
> 
> Thank you for your help.
> 
> best regards,
> Xiaoxin
> //start of the file
> lc1 = 3;
> lc2 = 3;
> 
> // We proceed by defining some elementary entities describing a cube:
> 
> Point(1) = {0,0,0,lc1};
> Point(2) = {40,0,0,lc1};
> Point(3) = {40,40,0,lc1};
> Point(4) = {0,40,0,lc1};
> Point(5) = {0,0,40,lc1};
> Point(6) = {40,0,40,lc1};
> Point(7) = {40,40,40,lc1};
> Point(8) = {0,40,40,lc1};
> 
>   Line(30)={1,2};
>   Line(31)={2,3};
>   Line(32)={3,4};
>   Line(33)={4,1};
>   Line(34)={5,6};
>   Line(35)={6,7};
>   Line(36)={7,8};
>   Line(37)={8,5};
>   Line(38)={1,5};
>   Line(39)={2,6};
>   Line(40)={3,7};
>   Line(41)={4,8};
> Line Loop(42)={30,31,32,33};
> Plane Surface(14)={42};
> Line Loop(43)={-37,-36,-35,-34};
> Plane Surface(16)={43};
> Line Loop(44)={38,34,-39,-30};
> Plane Surface(18)={44};
> Line Loop(45)={-32,40,36,-41};
> Plane Surface(20)={45};
> Line Loop(46)={-33,41,37,-38};
> Plane Surface(22)={46};
> Line Loop(47)={39,35,-40,-31};
> Plane Surface(24)={47};
> vol1[]=Extrude{0,0,40}{Surface{14};};
> Delete {Volume{vol1[1]};}
> vol2[]=Extrude{0,40,0}{Surface{18};};
> Delete {Volume{vol2[1]};}
> vol3[]=Extrude{40,0,0}{Surface{22};};
> Delete {Volume{vol3[1]};}
> Physical Surface(1)={14};
> Physical Surface(2)={vol1[0]};
> Physical Surface(3)={18};
> Physical Surface(4)={vol2[0]};
> Physical Surface(5)={22};
> Physical Surface(6)={vol3[0]};
> Surface Loop(1)={14,vol2[0],vol3[0],18,22,vol1[0]};
> Volume(1)={1};
> Physical Volume(1)={1};
> 
>   //n=1; add a crack surface. 
>  Point(5000)={1.645000e+01,7.466800e+00,5.890600e+00,lc2};
>  Point(5001)={1.728000e+01,2.112300e+01,1.204100e+01,lc2};
>  Point(5002)={2.823700e+01,1.636900e+01,2.111600e+01,lc2};
>  Point(5003)={2.740700e+01,2.713500e+00,1.496600e+01,lc2};
>   Line(5004)={5000,5001};
>   Line(5005)={5001,5002};
>   Line(5006)={5002,5003};
>   Line(5007)={5003,5000};
> Line Loop(5008)={5004,5005,5006,5007};
> Plane Surface(5009)={5008};
> Physical Surface(11)={5009};
> Surface{5009}  In Volume{1};
> 
> Plugin(Crack).Dimension = 2 ;
> Plugin(Crack).PhysicalGroup = 11 ;
> Plugin(Crack).OpenBoundaryPhysicalGroup = 0 ;
> Plugin(Crack).Run ;
> //end of the file
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-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science 
http://www.montefiore.ulg.ac.be/~geuzaine

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