class BoxGrid(object):
def __init__(self, x0, x1, y0, y1, z0, z1, n, unstructured=False):
class Left(SubDomain):
def inside(self, x, on_boundary):
return near(x[0], x0)
class Right(SubDomain):
def inside(self, x, on_boundary):
return near(x[0], x1)
class Back(SubDomain):
def inside(self, x, on_boundary):
return near(x[1], y0)
class Front(SubDomain):
def inside(self, x, on_boundary):
return near(x[1], y1)
class Bottom(SubDomain):
def inside(self, x, on_boundary):
return near(x[2], z0)
class Top(SubDomain):
def inside(self, x, on_boundary):
return near(x[2], z1)
if unstructured:
self.geometry = Box(Point(x0, y0, z0), Point(x1, y1, z1))
self.mesh = generate_mesh(self.geometry, n)
else:
nx = int(round(n**(1./3.)*(x1 - x0)))
ny = int(round(n**(1./3.)*(y1 - y0)))
nz = int(round(n**(1./3.)*(z1 - z0)))
self.mesh = BoxMesh(Point(x0, y0, z0), Point(x1, y1, z1), nx, ny, nz)
self.domains = MeshFunction("size_t", self.mesh, self.mesh.topology().dim())
self.domains.set_all(0)
self.dx = Measure('dx', domain=self.mesh, subdomain_data=self.domains)
self.boundaries = MeshFunction("size_t", self.mesh, self.mesh.topology().dim()-1)
self.boundaries.set_all(0)
self.left = Left()
self.left.mark(self.boundaries, 1)
self.right = Right()
self.right.mark(self.boundaries, 2)
self.front = Front()
self.front.mark(self.boundaries, 3)
self.back = Back()
self.back.mark(self.boundaries, 4)
self.bottom = Bottom()
self.bottom.mark(self.boundaries, 5)
self.top = Top()
self.top.mark(self.boundaries, 6)
self.ds = Measure('ds', domain=self.mesh, subdomain_data=self.boundaries)
self.dS = Measure('dS', domain=self.mesh, subdomain_data=self.boundaries)
def create_mesh():
N = 20
x0, y0, z0 = -1.5, -1.5, -0.25
x1, y1, z1 = 1.5, 1.5, 0.25
# mesh = UnitCubeMesh.create(N, N, N//2, CellType.Type.hexahedron)
mesh = BoxMesh(Point(x0, y0, z0), Point(x1, y1, z1), N, N, N//2)
# mesh = UnitCubeMesh(N, N, N)
# mesh size is smaller near x=y=0
# mesh.coordinates()[:, :2] = mesh.coordinates()[:, :2]**2
# mesh size is smaller near z=0 and mapped to a [-1;0] domain along z
# mesh.coordinates()[:, 2] = -mesh.coordinates()[:, 2]**2
# left = CompiledSubDomain("near(x[0], side) && on_boundary", side = 0.0)
# right = CompiledSubDomain("near(x[0], side) && on_boundary", side = 1.0)
class Top(SubDomain):
def inside(self, x, on_boundary):
return near(x[2], z1) and on_boundary
class Bottom(SubDomain):
def inside(self, x, on_boundary):
return near(x[2], z0) and on_boundary
class Left(SubDomain):
def inside(self, x, on_boundary):
return near(x[0], x0) and on_boundary
class Right(SubDomain):
def inside(self, x, on_boundary):
return near(x[0], x1) and on_boundary
class Front(SubDomain):
def inside(self, x, on_boundary):
return near(x[1], y0) and on_boundary
class Back(SubDomain):
def inside(self, x, on_boundary):
return near(x[1], y1) and on_boundary
class Symmetry_x(SubDomain):
def inside(self, x, on_boundary):
return near(x[0], 0) and on_boundary
class Symmetry_y(SubDomain):
def inside(self, x, on_boundary):
return near(x[1], 0) and on_boundary
# exterior facets MeshFunction
boundaries = MeshFunction("size_t", mesh, mesh.topology().dim()-1)
boundaries.set_all(0)
Top().mark(boundaries, 1)
Bottom().mark(boundaries, 2)
Left().mark(boundaries, 3)
Right().mark(boundaries, 4)
Front().mark(boundaries, 5)
Back().mark(boundaries, 6)
# Symmetry_x().mark(boundaries, 2)
# Symmetry_y().mark(boundaries, 3)
subdomains = MeshFunction("size_t", mesh, mesh.topology().dim())
subdomains.set_all(0)
File("hyperelastic_cube.xml") << mesh
File("hyperelastic_cube_physical_region.xml") << subdomains
File("hyperelastic_cube_facet_region.xml") << boundaries
return (mesh, subdomains, boundaries)
