import sfepy.base.testing as tst
[docs]def test_elastic_constants():
import numpy as nm
from sfepy.mechanics.matcoefs import ElasticConstants
ok = True
names = ['bulk', 'lam', 'mu', 'young', 'poisson', 'p_wave']
ec = ElasticConstants(lam=1.0, mu=1.5)
vals = ec.get(names)
tst.report('using values:', vals)
for i1 in range(len(names)):
for i2 in range(i1+1, len(names)):
kwargs = {names[i1] : vals[i1], names[i2] : vals[i2]}
try:
ec.init(**kwargs)
except:
_ok = False
else:
_ok = True
ec_vals = ec.get(names)
_ok = _ok and nm.allclose(ec_vals, vals)
tst.report(names[i1], names[i2], '->', _ok)
if not _ok:
tst.report('correct:', vals)
tst.report(' got:', ec_vals)
ok = ok and _ok
assert ok
[docs]def test_conversion_functions():
import numpy as nm
import sfepy.mechanics.matcoefs as mc
ok = True
lam = 1.0
mu = 1.5
ec = mc.ElasticConstants(lam=lam, mu=mu)
young, poisson, bulk = ec.get(['young', 'poisson', 'bulk'])
lam = nm.array([lam] * 3)
mu = nm.array([mu] * 3)
young = nm.array([young] * 3)
poisson = nm.array([poisson] * 3)
_lam, _mu = mc.lame_from_youngpoisson(young, poisson)
_ok = (nm.allclose(lam, _lam, rtol=0.0, atol=1e-14) and
nm.allclose(mu, _mu, rtol=0.0, atol=1e-14))
tst.report('lame_from_youngpoisson():', _ok)
if not _ok:
tst.report('correct:', lam, mu)
tst.report(' got:', _lam, _mu)
ok = ok and _ok
_bulk = mc.bulk_from_youngpoisson(young, poisson)
_ok = nm.allclose(bulk, _bulk, rtol=0.0, atol=1e-14)
tst.report('bulk_from_youngpoisson():', _ok)
if not _ok:
tst.report('correct:', bulk)
tst.report(' got:', _bulk)
ok = ok and _ok
_bulk = mc.bulk_from_lame(lam, mu)
_ok = nm.allclose(bulk, _bulk, rtol=0.0, atol=1e-14)
tst.report('bulk_from_lame():', _ok)
if not _ok:
tst.report('correct:', bulk)
tst.report(' got:', _bulk)
ok = ok and _ok
assert ok
[docs]def test_stiffness_tensors():
import numpy as nm
from sfepy.base.base import assert_
import sfepy.mechanics.matcoefs as mc
ok = True
lam = 1.0
mu = 4.0
lam = nm.array([lam] * 3)
mu = nm.array([mu] * 3)
d = nm.array([[ 9., 1., 1., 0., 0., 0.],
[ 1., 9., 1., 0., 0., 0.],
[ 1., 1., 9., 0., 0., 0.],
[ 0., 0., 0., 4., 0., 0.],
[ 0., 0., 0., 0., 4., 0.],
[ 0., 0., 0., 0., 0., 4.]])
_ds = mc.stiffness_from_lame(3, lam, mu)
assert_(_ds.shape == (3, 6, 6))
_ok = True
for _d in _ds:
__ok = nm.allclose(_d, d, rtol=0.0, atol=1e-14)
_ok = _ok and __ok
tst.report('stiffness_from_lame():', _ok)
ok = ok and _ok
_lam, _mu = mc.lame_from_stiffness(d)
_ok = (_lam == 1) and (_mu == 4)
tst.report('lame_from_stiffness():', _ok)
ok = ok and _ok
young = 1.0
poisson = 0.25
d = mc.stiffness_from_youngpoisson(3, young, poisson, plane='strain')
_young, _poisson = mc.youngpoisson_from_stiffness(d, plane='strain')
_ok = nm.allclose([young, poisson], [_young, _poisson],
rtol=0.0, atol=1e-14)
tst.report('youngpoisson_from_stiffness(plane="strain"):', _ok)
ok = ok and _ok
d = mc.stiffness_from_youngpoisson(2, young, poisson, plane='stress')
_young, _poisson = mc.youngpoisson_from_stiffness(d, plane='stress')
_ok = nm.allclose([young, poisson], [_young, _poisson],
rtol=0.0, atol=1e-14)
tst.report('youngpoisson_from_stiffness(plane="stress"):', _ok)
ok = ok and _ok
d = 4.0 / 3.0 * nm.array([[ 4., -2., -2., 0., 0., 0.],
[-2., 4., -2., 0., 0., 0.],
[-2., -2., 4., 0., 0., 0.],
[ 0., 0., 0., 3., 0., 0.],
[ 0., 0., 0., 0., 3., 0.],
[ 0., 0., 0., 0., 0., 3.]])
_ds = mc.stiffness_from_lame_mixed(3, lam, mu)
assert_(_ds.shape == (3, 6, 6))
_ok = True
for _d in _ds:
__ok = nm.allclose(_d, d, rtol=0.0, atol=1e-14)
_ok = _ok and __ok
tst.report('stiffness_from_lame_mixed():', _ok)
ok = ok and _ok
blam = - mu * 2.0 / 3.0
_ds = mc.stiffness_from_lame(3, blam, mu)
assert_(_ds.shape == (3, 6, 6))
_ok = True
for _d in _ds:
__ok = nm.allclose(_d, d, rtol=0.0, atol=1e-14)
_ok = _ok and __ok
tst.report('stiffness_from_lame() with modified lambda:', _ok)
ok = ok and _ok
assert ok
[docs]def test_wave_speeds():
import numpy as nm
import sfepy.mechanics.matcoefs as mc
E = 1e10
nu = 0.3
rho = 1100
vp, vs = mc.wave_speeds_from_youngpoisson(E, nu, rho)
E2, nu2 = mc.youngpoisson_from_wave_speeds(vp, vs, rho)
tst.report(E, nu, ' == ', E2, nu2)
assert nm.allclose(E, E2, rtol=1e-14, atol=0.0)
assert nm.allclose(nu, nu2, rtol=1e-14, atol=0.0)