def _writeVtkFile(self):
"""
Function to write out vertex and cell info along with principal axes
computed as vectors.
"""
from enthought.tvtk.api import tvtk
# Set up mesh info for VTK file.
mesh = tvtk.UnstructuredGrid(points=self.vertArray)
mesh.set_cells(self.cellType, self.cells)
# Add scalar fields.
minEigenName = "min_eigenvalue"
intEigenName = "int_eigenvalue"
maxEigenName = "max_eigenvalue"
mesh.cell_data.scalars = self.minEigenValue
mesh.cell_data.scalars.name = minEigenName
s2 = mesh.cell_data.add_array(self.intEigenValue)
mesh.cell_data.get_array(s2).name = intEigenName
s3 = mesh.cell_data.add_array(self.maxEigenValue)
mesh.cell_data.get_array(s3).name = maxEigenName
mesh.update()
# Add vector fields and write VTK file
minAxisName = "min_principal_axis"
intAxisName = "int_principal_axis"
maxAxisName = "max_principal_axis"
mesh.cell_data.vectors = self.minPrincAxis
mesh.cell_data.vectors.name = minAxisName
v2 = mesh.cell_data.add_array(self.intPrincAxis)
mesh.cell_data.get_array(v2).name = intAxisName
v3 = mesh.cell_data.add_array(self.maxPrincAxis)
mesh.cell_data.get_array(v3).name = maxAxisName
mesh.update()
w = tvtk.UnstructuredGridWriter(file_name=self.vtkOutputFile,
input=mesh)
w.write()
return
def _CffPredefined(self, refStress, newStress, vtkOutputFile):
"""Function to compute CFF for predefined planes and output results to a file.
"""
from enthought.tvtk.api import tvtk
beta = math.atan(self.frictionCoeff) / 2.0
sinBeta = math.sin(beta)
cosBeta = math.cos(beta)
sin2Beta = math.sin(2.0 * beta)
cos2Beta = math.cos(2.0 * beta)
sinCosBeta = sinBeta * cosBeta
sinBetaSq = sinBeta * sinBeta
cosBetaSq = cosBeta * cosBeta
cff = numpy.empty((self.numStressPoints), dtype=numpy.float64)
failDir1 = numpy.empty((self.numStressPoints, self.spaceDim),
dtype=numpy.float64)
failDir2 = numpy.empty((self.numStressPoints, self.spaceDim),
dtype=numpy.float64)
effFrictionCoeff = self.frictionCoeff * (1.0 - self.skemptonCoeff)
presFac = -self.skemptonCoeff / 3.0
vec1 = numpy.array([cosBeta, 0.0, sinBeta], dtype=numpy.float64)
vec2 = numpy.array([cosBeta, 0.0, -sinBeta], dtype=numpy.float64)
# Loop over stress points, compute total stress and the associated
# principal stresses, as well as the stress difference, and then
# compute CFF.
for point in range(self.numStressPoints):
totStress = newStress[point, :]
deltaStress = newStress[point, :] - refStress[point, :]
(totPrincStress, totPrincAxes) = self._princStress(totStress)
# Rotate stress changes into principal axis coordinate system for
# total stress.
deltaStressMat = numpy.array(
[(deltaStress[0], deltaStress[3], deltaStress[5]),
(deltaStress[3], deltaStress[1], deltaStress[4]),
(deltaStress[5], deltaStress[4], deltaStress[2])],
dtype=numpy.float64)
prod1 = numpy.dot(totPrincAxes, deltaStressMat)
deltaStressRot = numpy.dot(prod1, totPrincAxes.transpose())
s33 = deltaStressRot[0, 0] * sinBetaSq - \
2.0 * deltaStressRot[0, 2] * sinCosBeta + \
deltaStressRot[2, 2] * cosBetaSq
s13 = 0.5 * (deltaStressRot[2, 2] - deltaStressRot[0, 0]) * sin2Beta + \
deltaStressRot[0, 2] * cos2Beta
deltaNormStress = deltaStress[0] + deltaStress[1] + deltaStress[2]
# Compute CFF depending on which model is used
if self.isotropicPoroelastic:
cff[point] = s13 + self.frictionCoeff * \
(s33 + presFac * deltaNormStress)
else:
cff[point] = s13 + effFrictionCoeff * s33
# Get failure planes by rotating vector in principal axis coordinate
# system into global coordinate system.
# NOTE: make sure I'm applying the rotation the right way.
failDir1[point, :] = numpy.dot(totPrincAxes.transpose(), vec1)
failDir2[point, :] = numpy.dot(totPrincAxes.transpose(), vec2)
# Set up mesh info for VTK file
mesh = tvtk.UnstructuredGrid(points=self.vertArray)
mesh.set_cells(self.cellType, self.cells)
# Add output fields and write VTK file
# For now, output cff as a scalar, failDir1 as a vector, and failDir2 as
# a general array.
cffName = "cff"
failDir1Name = "failure_plane_1"
failDir2Name = "failure_plane_2"
mesh.cell_data.scalars = cff
mesh.cell_data.scalars.name = cffName
mesh.cell_data.vectors = failDir1
mesh.cell_data.vectors.name = failDir1Name
mesh.cell_data.add_array(failDir2)
w = tvtk.UnstructuredGridWriter(file_name=vtkOutputFile, input=mesh)
w.write()
return