import sys
sys.path.append("/usr/local/lib/python3.8/site-packages/gmsh-4.8.3-Linux64-sdk/lib")
%load_ext autoreload
%autoreload 2

from pyvirtualdisplay import Display
display = Display(backend="xvfb", visible=False, size=(800, 600))
display.start()

import gmsh
import sys
import math

gmsh.initialize()

gmsh.model.add("HoledPlate2D")

# Geometrical parameters from examples from:
# Computational Methods For Plasticity: Theory and Application
# Souza Neto 2009
 
L = 18
H = 10
R = 5

p1 = gmsh.model.occ.addPoint(0, 0, 0, 0, 1)
p2 = gmsh.model.occ.addPoint(R, 0, 0, 0, 2)
p3 = gmsh.model.occ.addPoint(L, 0, 0, 0, 3)
p4 = gmsh.model.occ.addPoint(L, H, 0, 0, 4)
p5 = gmsh.model.occ.addPoint(0, H, 0, 0, 5)
p6 = gmsh.model.occ.addPoint(0, R, 0, 0, 6)

# Creating connection lines
l1 = gmsh.model.occ.addLine(2, 3, 7)
l2 = gmsh.model.occ.addLine(3, 4, 8)
l3 = gmsh.model.occ.addLine(4, 5, 9)
l4 = gmsh.model.occ.addLine(5, 6, 10)
l5 = gmsh.model.occ.addCircleArc(6, 1, 2, 11)
loop1 = gmsh.model.occ.addCurveLoop([l1,l2,l3,l4,l5], 12)
gmsh.model.occ.addPlaneSurface([12], 13)
# This command is mandatory and synchronize CAD with GMSH Model. The less you launch it, the better it is for performance purpose
gmsh.model.occ.synchronize()

BCs

gmsh.model.addPhysicalGroup(2, [13], 400)
gmsh.model.setPhysicalName(2, 400, 'BODY')
gmsh.model.addPhysicalGroup(1, [10], 300)
gmsh.model.setPhysicalName(1, 300, 'FIX_X1')
gmsh.model.addPhysicalGroup(1, [7], 301)
gmsh.model.setPhysicalName(1, 301, 'FIX_Y1')
gmsh.model.addPhysicalGroup(1, [8], 302)
gmsh.model.setPhysicalName(1, 302, 'FIX_X2')
#gmsh.model.setPhysicalName(1, 302, 'FORCE')
# gmsh.model.addPhysicalGroup(1, [7], 303)
# gmsh.model.setPhysicalName(1, 200, 'REACTION')

Meshing

# Mesh 
mesh_size=3 # change to improve the mesh of the plate
gmsh.model.mesh.setSize(
    gmsh.model.getEntitiesInBoundingBox(0, 0, 0, L, H, 0), mesh_size)
gmsh.model.mesh.setSize(
    gmsh.model.getEntitiesInBoundingBox(0, 0, 0, 2*R, H, 0), mesh_size/6)
gmsh.model.mesh.generate(2)

# Save mesh

gmsh.write("plate_with_hole.med")

# Launch the GUI (not mandatory at all)

#gmsh.fltk.run()

# Finalize GMSH = END OF CODE=

gmsh.finalize()

config_file='bc_displacement_control.cfg'
#config_file='bc_force_control.cfg'
out_file='plate_with_hole.h5m'
!read_med -med_file plate_with_hole.med -output_file {out_file} -meshsets_config {config_file} -log_sl inform

!mbconvert {out_file} plate_with_hole.vtk

import pyvista as pv
import matplotlib.pyplot as plt
from matplotlib.colors import ListedColormap
 
mesh = pv.read('plate_with_hole.vtk')
mesh = mesh.shrink(0.9)
mesh.plot(show_grid=True, cpos="xy", smooth_shading=True, notebook=True, jupyter_backend='ipygany')  