Create an edge from two vertex in a 3D model using PDE Toolbox

Hello,

I am very new to the PDE toolbox, I'm running into an issue and I can't find any solutions.

I want to study the modes and frequencies of a fixed beam.

I originaly fixed it on the face located on its side but now I want to create and fix my own specific faces.

%creation of the beam
gm = multicuboid(0.3,0.03,0.003);
model = createpde("structural","modal-solid");
model.Geometry = gm;
pdegplot(gm, "VertexLabels", "on","FaceAlpha",0.5)

%add a vertex on the edgeq of the beam
VertexID1 = addVertex(gm,"Coordinates",[-0.11  -0.015 0.003]);
VertexID2 = addVertex(gm,"Coordinates",[-0.11  0.015 0.003]);
pdegplot(gm, "VertexLabels", "on", "EdgeLabels","on")

What I have done for now is creation the beam and setting up two vertex points on the edges, I want now to define a new edge, the segment between these two new vertex so I can have a new face delimited by E8, E7, E5 and my new edge.

Thanks.

Answer 1

[Matteo]

Hi Antoine,

One possible solution is to get first the decomposed geometry matrix of two adjacent rectangles using decsg. Then, you can turn the decomposed geometry matrix into a 2D geometry using geometryFromEdges. Lastly, utilize extrude to create the 3D geometry, which includes the face with edges highlighted in red in your original post.

%Create the 3D geometry by extruding two adjacent rectangles
gd = [ 3 4 -.15 -.11 -.11 -.15 -.015 -.015 .015 .015 ;
       3 4 -.11  .15  .15 -.11 -.015 -.015 .015 .015 ]';
dl = decsg(gd);  
gm = geometryFromEdges(dl);
gm = extrude(gm,0.003);

%Create the model and add the geometry
model = createpde("structural","modal-solid");
model.Geometry = gm;
pdegplot(gm,"FaceLabels","on")

[Antoine]

Thanks a lot Matteo! It worked perfectly.