def DisplayCellQual(meshtype='tet'):
"""
Displays minimum scaled jacobian of a sample mesh
For an ANSYS analysis to run properly, the minimum scaled jacobian of each
cell must be greater than 0.
Parameters
----------
meshtype string, optional
Set to 'hex' to display cell quality of a hexahedral meshed beam.
"""
# load archive file and parse for subsequent FEM queries
if meshtype == 'hex':
archive = pyansys.ReadArchive(hexarchivefile)
else:
archive = pyansys.ReadArchive(tetarchivefile)
# create vtk object
grid = archive.ParseVTK()
# get cell quality
qual = pyansys.CellQuality(grid)
# plot cell quality
grid.Plot(scalars=qual, stitle='Cell Minimum Scaled\nJacobian', rng=[0, 1])
def SolveKM():
"""
Loads and solves a mass and stiffness matrix from an ansys full file
"""
try:
from scipy.sparse import linalg
from scipy import sparse
except ImportError:
print('scipy not installed, aborting')
return
# load the mass and stiffness matrices
full = pyansys.FullReader(pyansys.examples.fullfile)
dofref, k, m = full.LoadKM(sort=True)
# make symmetric
k += sparse.triu(k, 1).T
m += sparse.triu(m, 1).T
k += sparse.diags(np.random.random(k.shape[0]) / 1E20, shape=k.shape)
# Solve
w, v = linalg.eigsh(k, k=20, M=m, sigma=1000)
# System natural frequencies
f = (np.real(w))**0.5 / (2 * np.pi)
# %% Plot result
# Get the 4th mode shape
full_mode_shape = v[:, 3] # x, y, z displacement for each node
# reshape and compute the normalized displacement
disp = full_mode_shape.reshape((-1, 3))
n = (disp * disp).sum(1)**0.5
n /= n.max() # normalize
# load an archive file and create a vtk unstructured grid
archive = pyansys.ReadArchive(pyansys.examples.hexarchivefile)
grid = archive.ParseVTK()
# Fancy plot the displacement
plobj = vtkInterface.PlotClass()
# add two meshes to the plotting class
plobj.AddMesh(grid.Copy(), style='wireframe')
plobj.AddMesh(grid,
scalars=n,
stitle='Normalized\nDisplacement',
flipscalars=True)
# Update the coordinates by adding the mode shape to the grid
plobj.UpdateCoordinates(grid.GetNumpyPoints() + disp / 80, render=False)
plobj.AddText('Cantliver Beam 4th Mode Shape at {:.4f}'.format(f[3]),
fontsize=30)
plobj.Plot()
#==============================================================================
# Load a beam and write it
#==============================================================================
import pyansys
from pyansys import examples
# Sample *.cdb
filename = examples.hexarchivefile
# Read ansys archive file
archive = pyansys.ReadArchive(filename)
# Print raw data from cdb
for key in archive.raw:
print "%s : %s" % (key, archive.raw[key])
# Create a vtk unstructured grid from the raw data and plot it
archive.ParseFEM()
archive.uGrid.Plot()
# write this as a vtk xml file
archive.SaveAsVTK('hex.vtu')
# Load this from vtk
import vtkInterface
grid = vtkInterface.LoadGrid('hex.vtk')
grid.Plot()
#==============================================================================
# load beam results
#==============================================================================
def DisplayHexBeam():
""" Displays a hex beam mesh """
# Load an archive file
archive = pyansys.ReadArchive(hexarchivefile)
grid = archive.ParseVTK()
grid.Plot()
def SolveKM():
"""
Loads and solves a mass and stiffness matrix from an ansys full file
"""
import numpy as np
from scipy.sparse import linalg
import pyansys
# load the mass and stiffness matrices
full = pyansys.FullReader(pyansys.examples.fullfile)
dofref, k, m = full.LoadKM(utri=False)
# removing constrained nodes (this is not efficient)
free = np.logical_not(full.const).nonzero()[0]
k = k[free][:, free]
m = m[free][:, free]
# Solve
w, v = linalg.eigsh(k, k=20, M=m, sigma=10000)
# System natural frequencies
f = (np.real(w))**0.5 / (2 * np.pi)
#%% Plot result
import vtkInterface
# Get the 4th mode shape
mode_shape = v[:, 3] # x, y, z displacement for each node
# create the full mode shape including the constrained nodes
full_mode_shape = np.zeros(dofref.shape[0])
full_mode_shape[np.logical_not(full.const)] = mode_shape
# reshape and compute the normalized displacement
disp = full_mode_shape.reshape((-1, 3))
n = (disp * disp).sum(1)**0.5
n /= n.max() # normalize
# load an archive file and create a vtk unstructured grid
archive = pyansys.ReadArchive(pyansys.examples.hexarchivefile)
grid = archive.ParseVTK()
# plot the normalized displacement
# grid.Plot(scalars=n)
# Fancy plot the displacement
plobj = vtkInterface.PlotClass()
# add two meshes to the plotting class. Meshes are copied on load
plobj.AddMesh(grid, style='wireframe')
plobj.AddMesh(grid,
scalars=n,
stitle='Normalized\nDisplacement',
flipscalars=True)
# Update the coordinates by adding the mode shape to the grid
plobj.UpdateCoordinates(grid.GetNumpyPoints() + disp / 80, render=False)
plobj.AddText('Cantliver Beam 4th Mode Shape at {:.4f}'.format(f[3]),
fontsize=30)
plobj.Plot()
del plobj
def DisplayHexBeam():
""" Displays a hex beam mesh """
# Load an archive file
archive = pyansys.ReadArchive(hexarchivefile)
archive.ParseFEM()
archive.uGrid.Plot()