def LoadKM():
""" Loads m and k matrices from a full file """
# Create file reader object
fobj = pyansys.FullReader(fullfile)
dofref, k, m = fobj.LoadKM()
# print results
ndim = k.shape[0]
print('Loaded {:d} x {:d} mass and stiffness matrices'.format(ndim, ndim))
print('\t k has {:d} entries'.format(k.indices.size))
print('\t m has {:d} entries'.format(m.indices.size))
# compute natural frequencies if installed
try:
from scipy.sparse import linalg
from scipy import sparse
except ImportError:
return
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=10000)
# System natural frequencies
f = np.real(w)**0.5 / (2 * np.pi)
print('First four natural frequencies:')
for i in range(4):
print('{:.3f} Hz'.format(f[i]))
def LoadKM():
""" Loads m and k matrices from a full file """
import numpy as np
# Create file reader object
fobj = pyansys.FullReader(fullfile)
dofref, k, m = fobj.LoadKM(utri=False)
# print results
ndim = k.shape[0]
print('Loaded {:d} x {:d} mass and stiffness matrices'.format(ndim, ndim))
print('\t k has {:d} entries'.format(k.indices.size))
print('\t m has {:d} entries'.format(m.indices.size))
# compute natural frequencies if installed
try:
from scipy.sparse import linalg
except BaseException:
return
# removing constrained nodes (this is not efficient)
free = np.logical_not(fobj.const).nonzero()[0]
k = k[free][:, free]
m = m[free][:, free]
import numpy as np
# Solve
w, v = linalg.eigsh(k, k=20, M=m, sigma=10000)
# System natural frequencies
f = np.real(w)**0.5 / (2 * np.pi)
print('First four natural frequencies:')
for i in range(4):
print('{:.3f} Hz'.format(f[i]))
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.Archive(pyansys.examples.hexarchivefile)
grid = archive.parse_vtk()
# Fancy plot the displacement
plobj = vtki.Plotter()
# add two meshes to the plotting class
plobj.add_mesh(grid.copy(), style='wireframe')
plobj.add_mesh(grid,
scalars=n,
stitle='Normalized\nDisplacement',
flipscalars=True)
# Update the coordinates by adding the mode shape to the grid
plobj.update_coordinates(grid.GetNumpyPoints() + disp / 80, render=False)
plobj.add_text('Cantliver Beam 4th Mode Shape at {:.4f}'.format(f[3]),
fontsize=30)
plobj.plot()
def load_km():
""" Loads m and k matrices from a full file """
# Create file reader object
fobj = pyansys.FullReader(fullfile)
dofref, k, m = fobj.load_km()
# print results
ndim = k.shape[0]
print('Loaded {:d} x {:d} mass and stiffness matrices'.format(ndim, ndim))
print('\t k has {:d} entries'.format(k.indices.size))
print('\t m has {:d} entries'.format(m.indices.size))
# compute natural frequencies if installed
try:
from scipy.sparse import linalg
from scipy import sparse
except ImportError:
return
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=10000)
# System natural frequencies
f = np.real(w)**0.5 / (2 * np.pi)
print('First four natural frequencies:')
for i in range(4):
print('{:.3f} Hz'.format(f[i]))
# breakpoint()
known_result = np.array([
1283.20036921, 1283.20036921, 5781.97486169, 6919.39887714,
6919.39887714, 10172.61497694, 16497.85701889, 16497.85701889,
17343.9939669, 27457.18472747, 27457.18472747, 28908.52552073,
30326.16886062, 39175.76412419, 39175.76412419, 40503.70406456,
49819.91597612, 51043.03965541, 51043.03965541, 52193.86143879
])
assert np.allclose(f, known_result)
# Plot the displacement of Mode 0 in the x direction
result.PlotNodalResult(0, 'x', label='Displacement')
#==============================================================================
# Load KM
#==============================================================================
# Load the reader from pyansys
import pyansys
from pyansys import examples
filename = examples.fullfile
# Create result reader object and read in full file
fobj = pyansys.FullReader(filename)
fobj.LoadFullKM()
import numpy as np
from scipy.sparse import csc_matrix, linalg
ndim = fobj.nref.size
k = csc_matrix((fobj.kdata, (fobj.krows, fobj.kcols)), shape=(ndim, ndim))
m = csc_matrix((fobj.mdata, (fobj.mrows, fobj.mcols)), shape=(ndim, ndim))
# Solve
w, v = linalg.eigsh(k, k=20, M=m, sigma=10000)
# System natural frequencies
f = (np.real(w))**0.5 / (2 * np.pi)
print('First four natural frequencies')
for i in range(4):
def test_fullreader():
fobj = pyansys.FullReader(fullfile)
dofref, k, m = fobj.LoadKM()
assert dofref.size
assert k.size
assert m.size
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