def test_st_bearing_elements_odd_length():
tim0 = ShaftElement(
L=0.25,
idl=0,
odl=0.05,
material=steel,
)
tim1 = ShaftElement(
L=0.25,
idl=0,
odl=0.05,
material=steel,
)
shaft_elm = [tim0, tim1]
disk0 = DiskElement(n=1, m=20, Id=1, Ip=1)
brg0 = ST_BearingElement(
n=0,
kxx=[1e6, 2e6],
cxx=[1e3, 2e3],
is_random=["kxx", "cxx"],
)
brg1 = ST_BearingElement(
n=2,
kxx=[1e6, 2e6, 3e6],
cxx=[1e3, 2e3, 3e3],
is_random=["kxx", "cxx"],
)
with pytest.raises(ValueError) as ex:
ST_Rotor(shaft_elm, [disk0], [brg0, brg1])
assert "not all random bearing elements lists have same length." in str(
ex.value)
def rotor1():
# rotor with 6 shaft elements, 2 disks and 2 random bearings
i_d = 0
o_d = 0.05
n = 6
L = [0.25 for _ in range(n)]
shaft_elem = [ShaftElement(l, i_d, o_d, material=steel) for l in L]
disk0 = DiskElement.from_geometry(n=2,
material=steel,
width=0.07,
i_d=0.05,
o_d=0.28)
disk1 = DiskElement.from_geometry(n=4,
material=steel,
width=0.07,
i_d=0.05,
o_d=0.28)
kxx = [1e6, 2e6]
cxx = [1e3, 2e3]
bearing0 = ST_BearingElement(n=0,
kxx=kxx,
cxx=cxx,
is_random=["kxx", "cxx"])
bearing1 = ST_BearingElement(n=6,
kxx=kxx,
cxx=cxx,
is_random=["kxx", "cxx"])
return ST_Rotor(shaft_elem, [disk0, disk1], [bearing0, bearing1])
def test_elements_odd_length():
tim0 = ST_ShaftElement(
L=[1, 1.1],
idl=0,
odl=[0.1, 0.2],
material=steel,
is_random=["L", "odl"],
)
shaft_elm = [tim0, tim0]
disk0 = ST_DiskElement(n=0, m=[20, 30, 40], Id=1, Ip=1, is_random=["m"])
disk1 = ST_DiskElement(n=2, m=[20, 30, 40], Id=1, Ip=1, is_random=["m"])
disks = [disk0, disk1]
brg0 = ST_BearingElement(
n=0,
kxx=[1e6, 2e6],
cxx=[1e3, 2e3],
is_random=["kxx", "cxx"],
)
brg1 = ST_BearingElement(
n=2,
kxx=[1e6, 2e6],
cxx=[1e3, 2e3],
is_random=["kxx", "cxx"],
)
bearings = [brg0, brg1]
with pytest.raises(ValueError) as ex:
ST_Rotor(shaft_elm, disks, bearings)
assert "not all the random elements lists have the same length." in str(
ex.value)
def st_rotor_example():
"""Return an instance of random rotors.
The purpose of this is to make available a simple model
so that doctest can be written using this.
Returns
-------
An instance of random rotors.
Examples
--------
>>> import ross.stochastic as srs
>>> rotors = srs.st_rotor_example()
>>> len(list(iter(rotors)))
10
"""
import ross as rs
from ross.materials import steel
i_d = 0
o_d = 0.05
n = 6
L = [0.25 for _ in range(n)]
shaft_elem = [rs.ShaftElement(l, i_d, o_d, material=steel) for l in L]
disk0 = rs.DiskElement.from_geometry(n=2,
material=steel,
width=0.07,
i_d=0.05,
o_d=0.28)
disk1 = rs.DiskElement.from_geometry(n=4,
material=steel,
width=0.07,
i_d=0.05,
o_d=0.28)
s = 10
kxx = np.random.uniform(1e6, 2e6, s)
cxx = np.random.uniform(1e3, 2e3, s)
bearing0 = ST_BearingElement(n=0,
kxx=kxx,
cxx=cxx,
is_random=["kxx", "cxx"])
bearing1 = ST_BearingElement(n=6,
kxx=kxx,
cxx=cxx,
is_random=["kxx", "cxx"])
return ST_Rotor(shaft_elem, [disk0, disk1], [bearing0, bearing1])
def rand_bearing_varying_coefs():
kxx = [[1e6, 1.1e6], [2e6, 2.1e6]]
kxy = [[1.5e6, 1.6e6], [2.5e6, 2.6e6]]
kyx = [[1.5e6, 1.6e6], [2.5e6, 2.6e6]]
kyy = [[3e6, 3.1e6], [4e6, 4.1e6]]
cxx = [[1e3, 1.1e3], [2e3, 2.1e3]]
cxy = [[1.5e3, 1.6e3], [2.5e3, 2.6e3]]
cyx = [[1.5e3, 1.6e3], [2.5e3, 2.6e3]]
cyy = [[3e3, 3.1e3], [4e3, 4.1e3]]
frequency = np.array([500, 800])
elm = ST_BearingElement(
n=1,
kxx=kxx,
kxy=kxy,
kyx=kyx,
kyy=kyy,
cxx=cxx,
cxy=cxy,
cyx=cyx,
cyy=cyy,
frequency=frequency,
is_random=["kxx", "kxy", "kyx", "kyy", "cxx", "cxy", "cyx", "cyy"],
)
return elm
def test_st_bearing_error_messages(rand_bearing_constant_coefs):
kxx = [1e6, 2e6]
cxx = [1e3, 2e3]
freq = [500, 1000]
with pytest.raises(ValueError) as ex:
ST_BearingElement(n=1,
kxx=kxx,
cxx=cxx,
frequency=freq,
is_random=["kxx", "cxx", "frequency"])
assert "frequency can not be a random variable" in str(ex.value)
with pytest.raises(ValueError) as ex:
rand_bearing_constant_coefs.plot_random_var(["kxy"])
assert (
"Random variable not in var_list. Select variables from ['kxx', 'cxx', 'kyy', 'cyy']"
in str(ex.value))
with pytest.raises(KeyError) as ex:
rand_bearing_constant_coefs["odd"] = [1, 2]
assert "Object does not have parameter: odd." in str(ex.value)
with pytest.raises(KeyError) as ex:
rand_bearing_constant_coefs["odd"]
assert "Object does not have parameter: odd." in str(ex.value)
def rand_bearing_constant_coefs():
kxx = [1e6, 2e6]
cxx = [1e3, 2e3]
elm = ST_BearingElement(n=1, kxx=kxx, cxx=cxx, is_random=["kxx", "cxx"])
return elm
