DAMASK_EICMD/processing/post/h5_addStrainTensors.py

157 lines
5.3 KiB
Python
Raw Normal View History

#!/usr/bin/env python2.7
# -*- coding: UTF-8 no BOM -*-
import os
import sys
import damask
import numpy as np
from optparse import OptionParser
scriptName = os.path.splitext(os.path.basename(__file__))[0]
scriptID = ' '.join([scriptName, damask.version])
# ----- Helper functions ----- #
def operator(stretch, strain, eigenvalues):
# Albrecht Bertram: Elasticity and Plasticity of Large Deformations
# An Introduction (3rd Edition, 2012), p. 102
return {'V#ln': np.log(eigenvalues),
'U#ln': np.log(eigenvalues),
'V#Biot': (np.ones(3, 'd') - 1.0/eigenvalues),
'U#Biot': (eigenvalues - np.ones(3, 'd')),
'V#Green': (np.ones(3, 'd') - 1.0/eigenvalues/eigenvalues)*0.5,
'U#Green': (eigenvalues*eigenvalues - np.ones(3, 'd'))*0.5,
}[stretch+'#'+strain]
def calcEPS(defgrads, stretchType, strainType):
2016-10-25 00:46:29 +05:30
"""Calculate specific type of strain tensor"""
eps = np.zeros(defgrads.shape) # initialize container
# TODO:
# this loop can use some performance boost
# (multi-threading?)
2016-10-25 00:46:29 +05:30
for ri in range(defgrads.shape[0]):
2016-10-18 02:28:04 +05:30
f = defgrads[ri, :].reshape(3, 3)
U, S, Vh = np.linalg.svd(f)
R = np.dot(U, Vh) # rotation of polar decomposition
if stretchType == 'U':
stretch = np.dot(np.linalg.inv(R), f) # F = RU
elif stretchType == 'V':
stretch = np.dot(f, np.linalg.inv(R)) # F = VR
# kill nasty noisy data
stretch = np.where(abs(stretch) < 1e-12, 0, stretch)
(D, V) = np.linalg.eig(stretch)
# flip principal component with negative Eigen values
neg = np.where(D < 0.0)
D[neg] *= -1.
V[:, neg] *= -1.
# check each vector for orthogonality
# --> brutal force enforcing orthogonal base
# and re-normalize
for i, eigval in enumerate(D):
if np.dot(V[:, i], V[:, (i+1) % 3]) != 0.0:
V[:, (i+1) % 3] = np.cross(V[:, (i+2) % 3], V[:, i])
V[:, (i+1) % 3] /= np.sqrt(np.dot(V[:, (i+1) % 3],
V[:, (i+1) % 3].conj()))
# calculate requested version of strain tensor
d = operator(stretchType, strainType, D)
eps[ri] = (np.dot(V, np.dot(np.diag(d), V.T)).real).reshape(9)
return eps
# --------------------------------------------------------------------
# MAIN
# --------------------------------------------------------------------
desp = "Add column(s) containing given strains based on given stretches"
parser = OptionParser(option_class=damask.extendableOption,
usage='%prog options [file[s]]',
description=desp,
version=scriptID)
msg = 'material strains based on right Cauchy-Green deformation, i.e., C and U'
parser.add_option('-u', '--right',
dest='right',
action='store_true',
help=msg)
msg = 'spatial strains based on left Cauchy--Green deformation, i.e., B and V'
parser.add_option('-v', '--left',
dest='left',
action='store_true',
help=msg)
parser.add_option('-0', '--logarithmic',
dest='logarithmic',
action='store_true',
help='calculate logarithmic strain tensor')
parser.add_option('-1', '--biot',
dest='biot',
action='store_true',
help='calculate biot strain tensor')
parser.add_option('-2', '--green',
dest='green',
action='store_true',
help='calculate green strain tensor')
2016-10-18 02:28:04 +05:30
# NOTE:
# It might be easier to just calculate one type of deformation gradient
# at a time.
msg = 'heading(s) of columns containing deformation tensor values'
parser.add_option('-f', '--defgrad',
dest='defgrad',
action='extend',
metavar='<string LIST>',
help=msg)
parser.set_defaults(right=False, left=False,
logarithmic=False, biot=False, green=False,
2016-10-18 02:28:04 +05:30
defgrad='f')
(options, filenames) = parser.parse_args()
stretches = []
strains = []
if options.right:
stretches.append('U')
if options.left:
stretches.append('V')
if options.logarithmic:
strains.append('ln')
if options.biot:
strains.append('Biot')
if options.green:
strains.append('Green')
if options.defgrad is None:
parser.error('no data column specified.')
# ----- Loop over input files ----- #
for name in filenames:
try:
h5f = damask.H5Table(name, new_file=False)
except:
continue
damask.util.report(scriptName, name)
# extract defgrads from HDF5 storage
2016-10-18 02:28:04 +05:30
F = h5f.get_data(options.defgrad)
# allow calculate multiple types of strain within the
# same cmd call
for stretchType in stretches:
for strainType in strains:
# calculate strain tensor for this type
eps = calcEPS(F, stretchType, strainType)
# compose labels/headers for this strain tensor
labelsStrain = strainType + stretchType
# prepare log info
cmd_log = scriptID + '\t' + ' '.join(sys.argv[1:])
# write data to HDF5 file
h5f.add_data(labelsStrain, eps, cmd_log=cmd_log)