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Stop meshing since boundary mesh is overlapping

bhaveshshrimali
Topic Author
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Junior Member

4 years 1 month ago - 4 years 1 month ago #2448 by bhaveshshrimali

Stop meshing since boundary mesh is overlapping was created by bhaveshshrimali

Hi,
I am trying to mesh a unit cube containing several randomly distributed spherical inclusions. Since the cube is triply periodic (along `x`, `y` and `z`) I create matching spheres on the faces/edges to be able to generate a mesh with matching pairs of vertices.

I am currently running two cases:

1. Not including the spheres (basically meshing `cube - all_spheres` object). This runs fine and produces a matching mesh as desired.

2. Including the spheres. In this case I get the error, " Stop meshing since boundary mesh is overlapping ". I am assuming that it could arise from the spheres on two faces not being exactly mirrored. But then why would case 1. run perfectly fine? Any suggestions?

I am attaching the portion of the code that generates the mesh

Code:

def generateGmshMesh(xc, pc, rc):
    """
    docstring
    """    
    left = Plane(Pnt(0,0,0),Vec(-1,0,0))
    bottom = Plane(Pnt(0,0,0),Vec(0,-1,0))
    back = Plane(Pnt(0,0,0),Vec(0,0,-1))
    right = Plane(Pnt(1,0,0),Vec(1,0,0))
    top = Plane(Pnt(0,1,0),Vec(0,1,0))
    front = Plane(Pnt(0,0,1),Vec(0,0,1))

    cube = left * right * bottom * top * back * front
    all_spheres = [Sphere(Pnt(sph[0], sph[1], sph[2]), rc[i]) for i, sph in enumerate(xc)]
    all_particles = [Sphere(Pnt(sph[0], sph[1], sph[2]), rc[i]) for i, sph in enumerate(pc)]

    for i, sph in enumerate(all_spheres):
        if i==0:
            sphAll = all_spheres[i]
        else:
            sphAll += all_spheres[i]

    for i, sph in enumerate(all_particles):
        if i==0:
            partAll = all_particles[i]
        else:
            partAll += all_particles[i]
     
    # reduce(operator.mul, all_spheres)
    # partAll = reduce(operator.mul, all_particles, 1)

    matrix = cube - sphAll
    partsinCube = cube * partAll
    matrix.maxh(0.01)
    partsinCube.maxh(0.005)
    matrix.transp()
    partsinCube.col([1,0,0])

    matrix.mat("mat")
    partsinCube.mat("parts")
    geo = CSGeometry()
    geo.Add(matrix)
    geo.Add(partsinCube)
    geo.PeriodicSurfaces(left,right)
    geo.PeriodicSurfaces(bottom,top)
    geo.PeriodicSurfaces(back,front)
    geo.Draw()
    Redraw()
    msh = geo.GenerateMesh()
    msh.Export("trialMesh.msh", "Gmsh2 Format")
    msh.Export("trialMesh.inp", "Abaqus Format")

I tried playing with the `maxh` paramter but to no avail.

Last edit: 4 years 1 month ago by bhaveshshrimali.

christopher
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Administrator

4 years 1 month ago #2451 by christopher

Replied by christopher on topic Stop meshing since boundary mesh is overlapping

could you attach the calling code as well?
Best
Christopher

bhaveshshrimali
Topic Author
Offline
Junior Member

4 years 1 month ago - 4 years 1 month ago #2453 by bhaveshshrimali

Replied by bhaveshshrimali on topic Stop meshing since boundary mesh is overlapping

Hi Christopher,
Thanks for your reply. Here is the calling code:

Code:

rad = np.loadtxt("radii_10.txt")
sph = np.loadtxt("spheres_10.txt")
generateGmshMesh(sph, sph, rad) 

Note that if I do

Code:

rad = np.loadtxt("radii_10.txt")
sph = np.loadtxt("spheres_10.txt")
generateGmshMesh(sph,[], rad) 

and comment out the relevant lines in the function, it generates the mesh as desired. The microstructure looks something like this. The spheres are close but non-intersecting, and the unit cell (cube with spheres) is periodic by construction.

File Attachment:

File Name: spheres_10...3-02.txt
File Size:12 KB

File Attachment:

File Name: radii_10_2...3-02.txt
File Size:4 KB

Attachments:

Last edit: 4 years 1 month ago by bhaveshshrimali.

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