def DefineTestStructure1D(self, s):
s.SetShowTime(False)
s.SetNumTimeDerivatives(2)
meshInfo = nuto.MeshGenerator.Grid(s, [L], [1])
s.InterpolationTypeAdd(meshInfo[1], "Displacements", "Equidistant2")
section = nuto.SectionTruss.Create(A)
lawId = s.ConstitutiveLawCreate("Linear_Elastic_Engineering_Stress")
s.ConstitutiveLawSetParameterDouble(lawId, "Youngs_Modulus", E)
s.ConstitutiveLawSetParameterDouble(lawId, "Density", rho)
s.ElementTotalConvertToInterpolationType()
s.ElementTotalSetSection(section)
s.ElementTotalSetConstitutiveLaw(lawId)
nodeLeft = s.NodeGetAtCoordinate(np.array([0.0]), 1.e-10)
s.Constraints().Add(nuto.eDof_DISPLACEMENTS, nuto.Value(nodeLeft))
nodeRight = s.NodeGetIdAtCoordinate(np.array([L]), 1.e-10)
nodeRightGroup = s.GroupCreate("nodes")
s.GroupAddNode(nodeRightGroup, nodeRight)
nodeRight = s.NodeGetNodePtr(nodeRight)
s.Constraints().Add(nuto.eDof_DISPLACEMENTS,
nuto.Value(nodeRight, lambda t: u * t))
return nodeRightGroup
def SetupBoundaryConditions(structure, BCType):
# fix left node at x = [0]
nodeLeft = structure.NodeGetAtCoordinate(np.array([0.]))
structure.Constraints().Add(nuto.eDof_DISPLACEMENTS, nuto.Value(nodeLeft))
# apply nonzero BC at x = length
nodeRight = structure.NodeGetAtCoordinate(np.array([Geometry.lx]))
nodeRightId = structure.NodeGetIdAtCoordinate(np.array([Geometry.lx]))
if BCType == "DisplacmentBC":
structure.Constraints().Add(
nuto.eDof_DISPLACEMENTS,
nuto.Value(nodeRight, BoundaryCondition.displacement))
if BCType == "ForceBC":
xDirection = np.array([1.0])
structure.LoadCreateNodeForce(nodeRightId, xDirection,
BoundaryCondition.force)
def define_bc_line_source(l_0, n):
"""Define the boundary conditions for a line source.
Wave coming from the line defined by point l_0 and normal vector n.
Assumes that l_0 is in the SOUTH_WEST of the domain and n pointing towards
it. So the bcs are applied to the SOUTH and the WEST boundary and NORTH and
EAST are in their shadow
"""
nodes_west = s.GroupGetNodesAtCoordinate(nuto.eDirection_X, 0)
nodes_south = s.GroupGetNodesAtCoordinate(nuto.eDirection_Y, 0)
id_west = s.GroupGetId(nodes_west)
id_south = s.GroupGetId(nodes_south)
id_union = s.GroupUnion(id_west, id_south)
for node_id in s.GroupGetMemberIds(id_union):
node = s.NodeGetNodePtr(node_id)
pos = node.Get(nuto.eDof_COORDINATES).flatten()
distance_to_source = line_distance(l_0, n, pos)
time_to_source = distance_to_source # assumes: wave speed = 1
s.Constraints().Add(
nuto.eDof_ELECTRICPOTENTIAL,
nuto.Value(
node, partial(smooth_dirac_constraint_function,
time_to_source)))
def setUp(self):
self.s = nuto.Structure(1)
self.s.SetNumTimeDerivatives(2)
self.s.SetShowTime(False)
self.s.SetVerboseLevel(7) # sounds about right
mesh_info = nuto.MeshGenerator_Grid(self.s, [2.], [25])
self.s.InterpolationTypeAdd(mesh_info[1], "ElectricPotential",
"Lobatto4")
self.s.ElementTotalConvertToInterpolationType()
law_id = self.s.ConstitutiveLawCreate("Linear_Dielectric")
dielectric_tensor = np.eye(3)
self.s.ConstitutiveLawSetParameterMatrixDouble(law_id,
"Dielectric_Tensor",
-dielectric_tensor)
self.s.ElementTotalSetConstitutiveLaw(law_id)
self.s.ElementTotalSetSection(nuto.SectionTruss_Create(12.))
self.s.AddVisualizationComponent(self.s.GroupGetElementsTotal(),
"ElectricPotential")
n = self.s.NodeGetAtCoordinate(0)
self.s.Constraints().Add(nuto.eDof_ELECTRICPOTENTIAL,
nuto.Value(n, self.load))
self.rk4 = nuto.RungeKutta4(self.s)
self.rk4.SetTimeStep(0.01)
self.rk4.SetShowTime(False)
def define_bc_point_source():
"""Define the boundary conditions for a line source.
This currently assumes that the point source only influences the WEST
border of the domain. EAST, NORTH and SOUTH are in the _shadow_ of WEST
"""
nodes_west = s.GroupGetNodesAtCoordinate(nuto.eDirection_X, 0)
source_position = np.array([-1.5, 1.5])
for node_id in nodes_west.GetMemberIds():
node = s.NodeGetNodePtr(node_id)
pos = node.Get(nuto.eDof_COORDINATES).flatten()
distance_to_source = np.linalg.norm(pos - source_position)
time_to_source = distance_to_source - 1.5 # assumens: wave speed = 1
s.Constraints().Add(
nuto.eDof_ELECTRICPOTENTIAL,
nuto.Value(
node, partial(smooth_dirac_constraint_function,
time_to_source)))