def bench_elasticity_edge(tetra: bool = True, r_lvl: int = 0, out_hdf5=None, xdmf: bool = False,
boomeramg: bool = False, kspview: bool = False, degree: int = 1, info: bool = False):
N = 3
for i in range(r_lvl):
N *= 2
ct = CellType.tetrahedron if tetra else CellType.hexahedron
mesh = create_unit_cube(MPI.COMM_WORLD, N, N, N, ct)
# Get number of unknowns on each edge
V = VectorFunctionSpace(mesh, ("Lagrange", int(degree)))
# Generate Dirichlet BC (Fixed)
u_bc = Function(V)
with u_bc.vector.localForm() as u_local:
u_local.set(0.0)
def boundaries(x):
return np.isclose(x[0], np.finfo(float).eps)
fdim = mesh.topology.dim - 1
facets = locate_entities_boundary(mesh, fdim, boundaries)
topological_dofs = locate_dofs_topological(V, fdim, facets)
bc = dirichletbc(u_bc, topological_dofs)
bcs = [bc]
def PeriodicBoundary(x):
return np.logical_and(np.isclose(x[0], 1), np.isclose(x[2], 0))
def periodic_relation(x):
out_x = np.zeros(x.shape)
out_x[0] = x[0]
out_x[1] = x[1]
out_x[2] = x[2] + 1
return out_x
with Timer("~Elasticity: Initialize MPC"):
edim = mesh.topology.dim - 2
edges = locate_entities_boundary(mesh, edim, PeriodicBoundary)
arg_sort = np.argsort(edges)
periodic_mt = meshtags(mesh, edim, edges[arg_sort], np.full(len(edges), 2, dtype=np.int32))
mpc = MultiPointConstraint(V)
mpc.create_periodic_constraint_topological(V, periodic_mt, 2, periodic_relation, bcs, scale=0.5)
mpc.finalize()
# Create traction meshtag
def traction_boundary(x):
return np.isclose(x[0], 1)
t_facets = locate_entities_boundary(mesh, fdim, traction_boundary)
facet_values = np.ones(len(t_facets), dtype=np.int32)
arg_sort = np.argsort(t_facets)
mt = meshtags(mesh, fdim, t_facets[arg_sort], facet_values)
# Elasticity parameters
E = PETSc.ScalarType(1.0e4)
nu = 0.1
mu = Constant(mesh, E / (2.0 * (1.0 + nu)))
lmbda = Constant(mesh, E * nu / ((1.0 + nu) * (1.0 - 2.0 * nu)))
g = Constant(mesh, PETSc.ScalarType((0, 0, -1e2)))
x = SpatialCoordinate(mesh)
f = Constant(mesh, PETSc.ScalarType(1e3)) * as_vector((0, -(x[2] - 0.5)**2, (x[1] - 0.5)**2))
# Stress computation
def epsilon(v):
return sym(grad(v))
def sigma(v):
return (2.0 * mu * epsilon(v) + lmbda * tr(epsilon(v)) * Identity(len(v)))
# Define variational problem
u = TrialFunction(V)
v = TestFunction(V)
a = inner(sigma(u), grad(v)) * dx
rhs = inner(g, v) * ds(domain=mesh, subdomain_data=mt, subdomain_id=1) + inner(f, v) * dx
# Setup MPC system
if info:
log_info(f"Run {r_lvl}: Assembling matrix and vector")
bilinear_form = form(a)
linear_form = form(rhs)
with Timer("~Elasticity: Assemble LHS and RHS"):
A = assemble_matrix(bilinear_form, mpc, bcs=bcs)
b = assemble_vector(linear_form, mpc)
# Create nullspace for elasticity problem and assign to matrix
null_space = rigid_motions_nullspace(mpc.function_space)
A.setNearNullSpace(null_space)
# Apply boundary conditions
apply_lifting(b, [bilinear_form], [bcs], mpc)
b.ghostUpdate(addv=PETSc.InsertMode.ADD_VALUES, mode=PETSc.ScatterMode.REVERSE)
set_bc(b, bcs)
opts = PETSc.Options()
if boomeramg:
opts["ksp_type"] = "cg"
opts["ksp_rtol"] = 1.0e-5
opts["pc_type"] = "hypre"
opts['pc_hypre_type'] = 'boomeramg'
opts["pc_hypre_boomeramg_max_iter"] = 1
opts["pc_hypre_boomeramg_cycle_type"] = "v"
# opts["pc_hypre_boomeramg_print_statistics"] = 1
else:
opts["ksp_rtol"] = 1.0e-8
opts["pc_type"] = "gamg"
opts["pc_gamg_type"] = "agg"
opts["pc_gamg_coarse_eq_limit"] = 1000
opts["pc_gamg_sym_graph"] = True
opts["mg_levels_ksp_type"] = "chebyshev"
opts["mg_levels_pc_type"] = "jacobi"
opts["mg_levels_esteig_ksp_type"] = "cg"
opts["matptap_via"] = "scalable"
opts["pc_gamg_square_graph"] = 2
opts["pc_gamg_threshold"] = 0.02
# opts["help"] = None # List all available options
# opts["ksp_view"] = None # List progress of solver
# Setup PETSc solver
solver = PETSc.KSP().create(MPI.COMM_WORLD)
solver.setFromOptions()
if info:
log_info(f"Run {r_lvl}: Solving")
with Timer("~Elasticity: Solve problem") as timer:
solver.setOperators(A)
uh = b.copy()
uh.set(0)
solver.solve(b, uh)
uh.ghostUpdate(addv=PETSc.InsertMode.INSERT, mode=PETSc.ScatterMode.FORWARD)
mpc.backsubstitution(uh)
solver_time = timer.elapsed()
if kspview:
solver.view()
mem = sum(MPI.COMM_WORLD.allgather(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss))
it = solver.getIterationNumber()
num_dofs = V.dofmap.index_map.size_global * V.dofmap.index_map_bs
if out_hdf5 is not None:
d_set = out_hdf5.get("its")
d_set[r_lvl] = it
d_set = out_hdf5.get("num_dofs")
d_set[r_lvl] = num_dofs
d_set = out_hdf5.get("num_slaves")
d_set[r_lvl, MPI.COMM_WORLD.rank] = mpc.num_local_slaves
d_set = out_hdf5.get("solve_time")
d_set[r_lvl, MPI.COMM_WORLD.rank] = solver_time[0]
if info:
log_info(f"Lvl: {r_lvl}, Its: {it}, max Mem: {mem}, dim(V): {num_dofs}")
if xdmf:
# Write solution to file
u_h = Function(mpc.function_space)
u_h.vector.setArray(uh.array)
u_h.name = "u_mpc"
fname = f"results/bench_elasticity_edge_{r_lvl}.xdmf"
with XDMFFile(MPI.COMM_WORLD, fname, "w") as outfile:
outfile.write_mesh(mesh)
outfile.write_function(u_h)
ct_parser.add_argument('--tet', dest='tetra', action='store_true', help="Tetrahedron elements")
ct_parser.add_argument('--hex', dest='tetra', action='store_false', help="Hexahedron elements")
solver_parser = parser.add_mutually_exclusive_group(required=False)
solver_parser.add_argument('--boomeramg', dest='boomeramg', default=True, action='store_true',
help="Use BoomerAMG preconditioner (Default)")
solver_parser.add_argument('--gamg', dest='boomeramg', action='store_false',
help="Use PETSc GAMG preconditioner")
args = parser.parse_args()
N = args.n_ref + 1
h5f = h5py.File('bench_edge_output.hdf5', 'w', driver='mpio', comm=MPI.COMM_WORLD)
h5f.create_dataset("its", (N,), dtype=np.int32)
h5f.create_dataset("num_dofs", (N,), dtype=np.int32)
h5f.create_dataset("num_slaves", (N, MPI.COMM_WORLD.size), dtype=np.int32)
sd = h5f.create_dataset("solve_time", (N, MPI.COMM_WORLD.size), dtype=np.float64)
solver = "BoomerAMG" if args.boomeramg else "GAMG"
ct = "Tet" if args.tetra else "Hex"
sd.attrs["solver"] = np.string_(solver)
sd.attrs["degree"] = np.string_(str(int(args.degree)))
sd.attrs["ct"] = np.string_(ct)
for i in range(N):
log_info(f"Run {i} in progress")
bench_elasticity_edge(tetra=args.tetra, r_lvl=i, out_hdf5=h5f, xdmf=args.xdmf,
boomeramg=args.boomeramg, kspview=args.kspview,
degree=args.degree, info=args.info)
if args.timings and i == N - 1:
list_timings(MPI.COMM_WORLD, [TimingType.wall])
h5f.close()
def demo_stacked_cubes(outfile: XDMFFile,
theta: float,
gmsh: bool = True,
quad: bool = False,
compare: bool = False,
res: float = 0.1):
log_info(
f"Run theta:{theta:.2f}, Quad: {quad}, Gmsh {gmsh}, Res {res:.2e}")
celltype = "quadrilateral" if quad else "triangle"
if gmsh:
mesh, mt = gmsh_2D_stacked(celltype, theta)
mesh.name = f"mesh_{celltype}_{theta:.2f}_gmsh"
else:
mesh_name = "mesh"
filename = f"meshes/mesh_{celltype}_{theta:.2f}.xdmf"
mesh_2D_dolfin(celltype, theta)
with XDMFFile(MPI.COMM_WORLD, filename, "r") as xdmf:
mesh = xdmf.read_mesh(name=mesh_name)
mesh.name = f"mesh_{celltype}_{theta:.2f}"
tdim = mesh.topology.dim
fdim = tdim - 1
mesh.topology.create_connectivity(tdim, tdim)
mesh.topology.create_connectivity(fdim, tdim)
mt = xdmf.read_meshtags(mesh, name="facet_tags")
# Helper until meshtags can be read in from xdmf
V = VectorFunctionSpace(mesh, ("Lagrange", 1))
r_matrix = rotation_matrix([0, 0, 1], theta)
g_vec = np.dot(r_matrix, [0, -1.25e2, 0])
g = Constant(mesh, PETSc.ScalarType(g_vec[:2]))
def bottom_corner(x):
return np.isclose(x, [[0], [0], [0]]).all(axis=0)
# Fix bottom corner
bc_value = np.array((0, ) * mesh.geometry.dim, dtype=PETSc.ScalarType)
bottom_dofs = locate_dofs_geometrical(V, bottom_corner)
bc_bottom = dirichletbc(bc_value, bottom_dofs, V)
bcs = [bc_bottom]
# Elasticity parameters
E = PETSc.ScalarType(1.0e3)
nu = 0
mu = Constant(mesh, E / (2.0 * (1.0 + nu)))
lmbda = Constant(mesh, E * nu / ((1.0 + nu) * (1.0 - 2.0 * nu)))
# Stress computation
def sigma(v):
return (2.0 * mu * sym(grad(v)) +
lmbda * tr(sym(grad(v))) * Identity(len(v)))
# Define variational problem
u = TrialFunction(V)
v = TestFunction(V)
a = inner(sigma(u), grad(v)) * dx
ds = Measure("ds", domain=mesh, subdomain_data=mt, subdomain_id=3)
rhs = inner(Constant(mesh, PETSc.ScalarType(
(0, 0))), v) * dx + inner(g, v) * ds
def left_corner(x):
return np.isclose(x.T, np.dot(r_matrix, [0, 2, 0])).all(axis=1)
# Create multi point constraint
mpc = MultiPointConstraint(V)
with Timer("~Contact: Create contact constraint"):
nh = create_normal_approximation(V, mt, 4)
mpc.create_contact_slip_condition(mt, 4, 9, nh)
with Timer("~Contact: Add non-slip condition at bottom interface"):
bottom_normal = facet_normal_approximation(V, mt, 5)
mpc.create_slip_constraint(V, (mt, 5), bottom_normal, bcs=bcs)
with Timer("~Contact: Add tangential constraint at one point"):
vertex = locate_entities_boundary(mesh, 0, left_corner)
tangent = facet_normal_approximation(V, mt, 3, tangent=True)
mtv = meshtags(mesh, 0, vertex, np.full(len(vertex), 6,
dtype=np.int32))
mpc.create_slip_constraint(V, (mtv, 6), tangent, bcs=bcs)
mpc.finalize()
rtol = 1e-9
petsc_options = {
"ksp_rtol": 1e-9,
"pc_type": "gamg",
"pc_gamg_type": "agg",
"pc_gamg_square_graph": 2,
"pc_gamg_threshold": 0.02,
"pc_gamg_coarse_eq_limit": 1000,
"pc_gamg_sym_graph": True,
"mg_levels_ksp_type": "chebyshev",
"mg_levels_pc_type": "jacobi",
"mg_levels_esteig_ksp_type": "cg"
# , "help": None, "ksp_view": None
}
# Solve Linear problem
problem = LinearProblem(a, rhs, mpc, bcs=bcs, petsc_options=petsc_options)
# Build near nullspace
null_space = rigid_motions_nullspace(mpc.function_space)
problem.A.setNearNullSpace(null_space)
u_h = problem.solve()
it = problem.solver.getIterationNumber()
if MPI.COMM_WORLD.rank == 0:
print("Number of iterations: {0:d}".format(it))
unorm = u_h.vector.norm()
if MPI.COMM_WORLD.rank == 0:
print(f"Norm of u: {unorm}")
# Write solution to file
ext = "_gmsh" if gmsh else ""
u_h.name = "u_mpc_{0:s}_{1:.2f}{2:s}".format(celltype, theta, ext)
outfile.write_mesh(mesh)
outfile.write_function(u_h, 0.0,
f"Xdmf/Domain/Grid[@Name='{mesh.name}'][1]")
# Solve the MPC problem using a global transformation matrix
# and numpy solvers to get reference values
if not compare:
return
log_info("Solving reference problem with global matrix (using numpy)")
with Timer("~MPC: Reference problem"):
# Generate reference matrices and unconstrained solution
A_org = assemble_matrix(form(a), bcs)
A_org.assemble()
L_org = assemble_vector(form(rhs))
apply_lifting(L_org, [form(a)], [bcs])
L_org.ghostUpdate(addv=PETSc.InsertMode.ADD_VALUES,
mode=PETSc.ScatterMode.REVERSE)
set_bc(L_org, bcs)
root = 0
with Timer("~MPC: Verification"):
compare_mpc_lhs(A_org, problem.A, mpc, root=root)
compare_mpc_rhs(L_org, problem.b, mpc, root=root)
# Gather LHS, RHS and solution on one process
A_csr = gather_PETScMatrix(A_org, root=root)
K = gather_transformation_matrix(mpc, root=root)
L_np = gather_PETScVector(L_org, root=root)
u_mpc = gather_PETScVector(u_h.vector, root=root)
if MPI.COMM_WORLD.rank == root:
KTAK = K.T * A_csr * K
reduced_L = K.T @ L_np
# Solve linear system
d = scipy.sparse.linalg.spsolve(KTAK, reduced_L)
# Back substitution to full solution vector
uh_numpy = K @ d
assert np.allclose(uh_numpy, u_mpc, rtol=rtol)
def demo_stacked_cubes(outfile: XDMFFile, theta: float, gmsh: bool = False, ct: CellType = CellType.tetrahedron,
compare: bool = True, res: float = 0.1, noslip: bool = False):
celltype = "hexahedron" if ct == CellType.hexahedron else "tetrahedron"
type_ext = "no_slip" if noslip else "slip"
mesh_ext = "_gmsh_" if gmsh else "_"
log_info(f"Run theta:{theta:.2f}, Cell: {celltype}, GMSH {gmsh}, Noslip: {noslip}")
# Read in mesh
if gmsh:
mesh, mt = gmsh_3D_stacked(celltype, theta, res)
tdim = mesh.topology.dim
fdim = tdim - 1
mesh.topology.create_connectivity(tdim, tdim)
mesh.topology.create_connectivity(fdim, tdim)
else:
mesh_3D_dolfin(theta, ct, celltype, res)
MPI.COMM_WORLD.barrier()
with XDMFFile(MPI.COMM_WORLD, f"meshes/mesh_{celltype}_{theta:.2f}.xdmf", "r") as xdmf:
mesh = xdmf.read_mesh(name="mesh")
tdim = mesh.topology.dim
fdim = tdim - 1
mesh.topology.create_connectivity(tdim, tdim)
mesh.topology.create_connectivity(fdim, tdim)
mt = xdmf.read_meshtags(mesh, "facet_tags")
mesh.name = f"mesh_{celltype}_{theta:.2f}{type_ext}{mesh_ext}"
# Create functionspaces
V = fem.VectorFunctionSpace(mesh, ("Lagrange", 1))
# Define boundary conditions
# Bottom boundary is fixed in all directions
bottom_dofs = fem.locate_dofs_topological(V, fdim, mt.find(5)) # type: ignore
u_bc = np.array((0, ) * mesh.geometry.dim, dtype=PETSc.ScalarType)
bc_bottom = fem.dirichletbc(u_bc, bottom_dofs, V)
g_vec = np.array([0, 0, -4.25e-1], dtype=PETSc.ScalarType)
if not noslip:
# Helper for orienting traction
r_matrix = rotation_matrix([1 / np.sqrt(2), 1 / np.sqrt(2), 0], -theta)
# Top boundary has a given deformation normal to the interface
g_vec = np.dot(r_matrix, g_vec)
top_dofs = fem.locate_dofs_topological(V, fdim, mt.find(3)) # type: ignore
bc_top = fem.dirichletbc(g_vec, top_dofs, V)
bcs = [bc_bottom, bc_top]
# Elasticity parameters
E = PETSc.ScalarType(1.0e3)
nu = 0
mu = fem.Constant(mesh, E / (2.0 * (1.0 + nu)))
lmbda = fem.Constant(mesh, E * nu / ((1.0 + nu) * (1.0 - 2.0 * nu)))
# Stress computation
def sigma(v):
return (2.0 * mu * sym(grad(v)) + lmbda * tr(sym(grad(v))) * Identity(len(v)))
# Define variational problem
u = TrialFunction(V)
v = TestFunction(V)
a = inner(sigma(u), grad(v)) * dx
# NOTE: Traction deactivated until we have a way of fixing nullspace
# g = fem.Constant(mesh, PETSc.ScalarType(g_vec))
# ds = Measure("ds", domain=mesh, subdomain_data=mt, subdomain_id=3)
rhs = inner(fem.Constant(mesh, PETSc.ScalarType((0, 0, 0))), v) * dx
# + inner(g, v) * ds
bilinear_form = fem.form(a)
linear_form = fem.form(rhs)
mpc = MultiPointConstraint(V)
if noslip:
with Timer("~~Contact: Create non-elastic constraint"):
mpc.create_contact_inelastic_condition(mt, 4, 9)
else:
with Timer("~Contact: Create contact constraint"):
nh = create_normal_approximation(V, mt, 4)
mpc.create_contact_slip_condition(mt, 4, 9, nh)
with Timer("~~Contact: Add data and finialize MPC"):
mpc.finalize()
# Create null-space
null_space = rigid_motions_nullspace(mpc.function_space)
num_dofs = V.dofmap.index_map.size_global * V.dofmap.index_map_bs
with Timer(f"~~Contact: Assemble matrix ({num_dofs})"):
A = assemble_matrix(bilinear_form, mpc, bcs=bcs)
with Timer(f"~~Contact: Assemble vector ({num_dofs})"):
b = assemble_vector(linear_form, mpc)
apply_lifting(b, [bilinear_form], [bcs], mpc)
b.ghostUpdate(addv=PETSc.InsertMode.ADD_VALUES, mode=PETSc.ScatterMode.REVERSE)
fem.petsc.set_bc(b, bcs)
# Solve Linear problem
opts = PETSc.Options()
opts["ksp_rtol"] = 1.0e-8
opts["pc_type"] = "gamg"
opts["pc_gamg_type"] = "agg"
opts["pc_gamg_coarse_eq_limit"] = 1000
opts["pc_gamg_sym_graph"] = True
opts["mg_levels_ksp_type"] = "chebyshev"
opts["mg_levels_pc_type"] = "jacobi"
opts["mg_levels_esteig_ksp_type"] = "cg"
opts["matptap_via"] = "scalable"
# opts["pc_gamg_square_graph"] = 2
# opts["pc_gamg_threshold"] = 1e-2
# opts["help"] = None # List all available options
# opts["ksp_view"] = None # List progress of solver
# Create functionspace and build near nullspace
A.setNearNullSpace(null_space)
solver = PETSc.KSP().create(mesh.comm)
solver.setOperators(A)
solver.setFromOptions()
u_h = fem.Function(mpc.function_space)
with Timer("~~Contact: Solve"):
solver.solve(b, u_h.vector)
u_h.x.scatter_forward()
with Timer("~~Contact: Backsubstitution"):
mpc.backsubstitution(u_h.vector)
it = solver.getIterationNumber()
unorm = u_h.vector.norm()
num_slaves = MPI.COMM_WORLD.allreduce(mpc.num_local_slaves, op=MPI.SUM)
if mesh.comm.rank == 0:
num_dofs = V.dofmap.index_map.size_global * V.dofmap.index_map_bs
print(f"Number of dofs: {num_dofs}")
print(f"Number of slaves: {num_slaves}")
print(f"Number of iterations: {it}")
print(f"Norm of u {unorm:.5e}")
# Write solution to file
u_h.name = f"u_{celltype}_{theta:.2f}{mesh_ext}{type_ext}".format(celltype, theta, type_ext, mesh_ext)
outfile.write_mesh(mesh)
outfile.write_function(u_h, 0.0, f"Xdmf/Domain/Grid[@Name='{mesh.name}'][1]")
# Solve the MPC problem using a global transformation matrix
# and numpy solvers to get reference values
if not compare:
return
log_info("Solving reference problem with global matrix (using scipy)")
with Timer("~~Contact: Reference problem"):
A_org = fem.petsc.assemble_matrix(bilinear_form, bcs)
A_org.assemble()
L_org = fem.petsc.assemble_vector(linear_form)
fem.petsc.apply_lifting(L_org, [bilinear_form], [bcs])
L_org.ghostUpdate(addv=PETSc.InsertMode.ADD_VALUES, mode=PETSc.ScatterMode.REVERSE)
fem.petsc.set_bc(L_org, bcs)
root = 0
with Timer("~~Contact: Compare LHS, RHS and solution"):
compare_mpc_lhs(A_org, A, mpc, root=root)
compare_mpc_rhs(L_org, b, mpc, root=root)
# Gather LHS, RHS and solution on one process
A_csr = gather_PETScMatrix(A_org, root=root)
K = gather_transformation_matrix(mpc, root=root)
L_np = gather_PETScVector(L_org, root=root)
u_mpc = gather_PETScVector(u_h.vector, root=root)
if MPI.COMM_WORLD.rank == root:
KTAK = K.T * A_csr * K
reduced_L = K.T @ L_np
# Solve linear system
d = scipy.sparse.linalg.spsolve(KTAK, reduced_L)
# Back substitution to full solution vector
uh_numpy = K @ d
assert np.allclose(uh_numpy, u_mpc)
list_timings(mesh.comm, [TimingType.wall])
hex = parser.add_mutually_exclusive_group(required=False)
hex.add_argument('--hex', dest='hex', action='store_true',
help="Use hexahedron mesh", default=False)
slip = parser.add_mutually_exclusive_group(required=False)
slip.add_argument('--no-slip', dest='noslip', action='store_true',
help="Use no-slip constraint", default=False)
gmsh = parser.add_mutually_exclusive_group(required=False)
gmsh.add_argument('--gmsh', dest='gmsh', action='store_true',
help="Gmsh mesh instead of built-in grid", default=False)
comp = parser.add_mutually_exclusive_group(required=False)
comp.add_argument('--compare', dest='compare', action='store_true',
help="Compare with global solution", default=False)
time = parser.add_mutually_exclusive_group(required=False)
time.add_argument('--timing', dest='timing', action='store_true',
help="List timings", default=False)
args = parser.parse_args()
outfile = XDMFFile(MPI.COMM_WORLD, "results/demo_contact_3D.xdmf", "w")
ct = CellType.hexahedron if args.hex else CellType.tetrahedron
demo_stacked_cubes(outfile, theta=args.theta, gmsh=args.gmsh, ct=ct,
compare=args.compare, res=args.res, noslip=args.noslip)
outfile.close()
log_info("Simulation finished")
if args.timing:
list_timings(MPI.COMM_WORLD, [TimingType.wall])
def demo_stacked_cubes(theta, ct, noslip, num_refinements, N0, timings=False):
celltype = "hexahedron" if ct == CellType.hexahedron else "tetrahedron"
type_ext = "no_slip" if noslip else "slip"
log_info(f"Run theta: {theta:.2f}, Cell: {celltype:s}, Noslip: {noslip:b}")
# Read in mesh
mesh_3D_dolfin(theta=theta,
ct=ct,
ext=celltype,
num_refinements=num_refinements,
N0=N0)
comm.barrier()
with XDMFFile(comm, f"meshes/mesh_{celltype}_{theta:.2f}.xdmf",
"r") as xdmf:
mesh = xdmf.read_mesh(name="mesh")
tdim = mesh.topology.dim
fdim = tdim - 1
mesh.topology.create_connectivity(tdim, tdim)
mesh.topology.create_connectivity(fdim, tdim)
mt = xdmf.read_meshtags(mesh, "facet_tags")
mesh.name = f"mesh_{celltype}_{theta:.2f}{type_ext:s}"
# Create functionspaces
V = VectorFunctionSpace(mesh, ("Lagrange", 1))
# Define boundary conditions
# Bottom boundary is fixed in all directions
u_bc = Function(V)
with u_bc.vector.localForm() as u_local:
u_local.set(0.0)
bottom_dofs = locate_dofs_topological(V, fdim, mt.find(5))
bc_bottom = dirichletbc(u_bc, bottom_dofs)
g_vec = [0, 0, -4.25e-1]
if not noslip:
# Helper for orienting traction
r_matrix = rotation_matrix([1 / np.sqrt(2), 1 / np.sqrt(2), 0], -theta)
# Top boundary has a given deformation normal to the interface
g_vec = np.dot(r_matrix, [0, 0, -4.25e-1])
def top_v(x):
values = np.empty((3, x.shape[1]))
values[0] = g_vec[0]
values[1] = g_vec[1]
values[2] = g_vec[2]
return values
u_top = Function(V)
u_top.interpolate(top_v)
u_top.vector.ghostUpdate(addv=PETSc.InsertMode.INSERT_VALUES,
mode=PETSc.ScatterMode.FORWARD)
top_dofs = locate_dofs_topological(V, fdim, mt.find(3))
bc_top = dirichletbc(u_top, top_dofs)
bcs = [bc_bottom, bc_top]
# Elasticity parameters
E = PETSc.ScalarType(1.0e3)
nu = 0
mu = Constant(mesh, E / (2.0 * (1.0 + nu)))
lmbda = Constant(mesh, E * nu / ((1.0 + nu) * (1.0 - 2.0 * nu)))
# Stress computation
def sigma(v):
return (2.0 * mu * sym(grad(v)) +
lmbda * tr(sym(grad(v))) * Identity(len(v)))
# Define variational problem
u = TrialFunction(V)
v = TestFunction(V)
a = inner(sigma(u), grad(v)) * dx
rhs = inner(Constant(mesh, PETSc.ScalarType((0, 0, 0))), v) * dx
log_info("Create constraints")
mpc = MultiPointConstraint(V)
num_dofs = V.dofmap.index_map.size_global * V.dofmap.index_map_bs
if noslip:
with Timer(f"{num_dofs}: Contact-constraint"):
mpc.create_contact_inelastic_condition(mt, 4, 9)
else:
with Timer(f"{num_dofs}: FacetNormal"):
nh = create_normal_approximation(V, mt, 4)
with Timer(f"{num_dofs}: Contact-constraint"):
mpc.create_contact_slip_condition(mt, 4, 9, nh)
with Timer(f"{num_dofs}: MPC-init"):
mpc.finalize()
null_space = rigid_motions_nullspace(mpc.function_space)
log_info(f"Num dofs: {num_dofs}")
log_info("Assemble matrix")
bilinear_form = form(a)
linear_form = form(rhs)
with Timer(f"{num_dofs}: Assemble-matrix (C++)"):
A = assemble_matrix(bilinear_form, mpc, bcs=bcs)
with Timer(f"{num_dofs}: Assemble-vector (C++)"):
b = assemble_vector(linear_form, mpc)
apply_lifting(b, [bilinear_form], [bcs], mpc)
b.ghostUpdate(addv=PETSc.InsertMode.ADD_VALUES,
mode=PETSc.ScatterMode.REVERSE)
set_bc(b, bcs)
list_timings(MPI.COMM_WORLD, [TimingType.wall])
# Solve Linear problem
opts = PETSc.Options()
# opts["ksp_rtol"] = 1.0e-8
opts["pc_type"] = "gamg"
# opts["pc_gamg_type"] = "agg"
# opts["pc_gamg_coarse_eq_limit"] = 1000
# opts["pc_gamg_sym_graph"] = True
# opts["mg_levels_ksp_type"] = "chebyshev"
# opts["mg_levels_pc_type"] = "jacobi"
# opts["mg_levels_esteig_ksp_type"] = "cg"
# opts["matptap_via"] = "scalable"
# opts["pc_gamg_square_graph"] = 2
# opts["pc_gamg_threshold"] = 1e-2
# opts["help"] = None # List all available options
if timings:
opts["ksp_view"] = None # List progress of solver
# Create functionspace and build near nullspace
A.setNearNullSpace(null_space)
solver = PETSc.KSP().create(comm)
solver.setOperators(A)
solver.setFromOptions()
uh = b.copy()
uh.set(0)
log_info("Solve")
with Timer(f"{num_dofs}: Solve"):
solver.solve(b, uh)
uh.ghostUpdate(addv=PETSc.InsertMode.INSERT,
mode=PETSc.ScatterMode.FORWARD)
log_info("Backsub")
with Timer(f"{num_dofs}: Backsubstitution"):
mpc.backsubstitution(uh)
it = solver.getIterationNumber()
# Write solution to file
u_h = Function(mpc.function_space)
u_h.vector.setArray(uh.array)
u_h.name = "u"
with XDMFFile(comm, f"results/bench_contact_{num_dofs}.xdmf",
"w") as outfile:
outfile.write_mesh(mesh)
outfile.write_function(u_h, 0.0,
f"Xdmf/Domain/Grid[@Name='{mesh.name}'][1]")
# Write performance data to file
if timings:
log_info("Timings")
num_slaves = MPI.COMM_WORLD.allreduce(mpc.num_local_slaves, op=MPI.SUM)
results_file = None
num_procs = comm.size
if comm.rank == 0:
results_file = open(f"results_bench_{num_dofs}.txt", "w")
print(f"#Procs: {num_procs}", file=results_file)
print(f"#Dofs: {num_dofs}", file=results_file)
print(f"#Slaves: {num_slaves}", file=results_file)
print(f"#Iterations: {it}", file=results_file)
operations = [
"Solve", "Assemble-matrix (C++)", "MPC-init", "Contact-constraint",
"FacetNormal", "Assemble-vector (C++)", "Backsubstitution"
]
if comm.rank == 0:
print("Operation #Calls Avg Min Max", file=results_file)
for op in operations:
op_timing = timing(f"{num_dofs}: {op}")
num_calls = op_timing[0]
wall_time = op_timing[1]
avg_time = comm.allreduce(wall_time, op=MPI.SUM) / comm.size
min_time = comm.allreduce(wall_time, op=MPI.MIN)
max_time = comm.allreduce(wall_time, op=MPI.MAX)
if comm.rank == 0:
print(op,
num_calls,
avg_time,
min_time,
max_time,
file=results_file)
list_timings(MPI.COMM_WORLD, [TimingType.wall])