ross.Rotor.run_unbalance_response

Rotor.run_unbalance_response(node, unbalance_magnitude, unbalance_phase, frequency=None, modes=None)

Unbalanced response for a mdof system.

This method returns the unbalanced response for a mdof system given magnitide and phase of the unbalance, the node where it’s applied and a frequency range.

Available plotting methods:

.plot() .plot_magnitude() .plot_phase() .plot_polar_bode() .plot_deflected_shape() .plot_bending_moment() .plot_deflected_shape_3d() .plot_deflected_shape_2d()

Parameters:

nodelist, int

Node where the unbalance is applied.

unbalance_magnitudelist, float, pint.Quantity

Unbalance magnitude (kg.m).

unbalance_phaselist, float, pint.Quantity

Unbalance phase (rad).

frequencylist, pint.Quantity

List with the desired range of frequencies (rad/s). Default is 0 to 1.5 x highest damped natural frequency.

modeslist, optional

Modes that will be used to calculate the frequency response (all modes will be used if a list is not given).

Returns:

resultsross.ForcedResponseResults

For more information on attributes and methods available see: ross.ForcedResponseResults

Examples

>>> import ross as rs
>>> rotor = rs.rotor_example()
>>> speed = np.linspace(0, 1000, 101)
>>> response = rotor.run_unbalance_response(node=3,
...                                         unbalance_magnitude=10.0,
...                                         unbalance_phase=0.0,
...                                         frequency=speed)

Return the response amplitude >>> abs(response.forced_resp) # doctest: +ELLIPSIS array([[0.00000000e+00, 5.06073311e-04, 2.10044826e-03, …

Return the response phase >>> np.angle(response.forced_resp) # doctest: +ELLIPSIS array([[ 0. , 0. , 0. , …

plot unbalance response: >>> probe_node = 3 >>> probe_angle = np.pi / 2 >>> probe_tag = “my_probe” # optional >>> fig = response.plot(probe=[rs.Probe(probe_node, probe_angle, tag=probe_tag)])

plot response for major or minor axis: >>> probe_node = 3 >>> probe_angle = “major” # for major axis >>> # probe_angle = “minor” # for minor axis >>> probe_tag = “my_probe” # optional >>> fig = response.plot(probe=[rs.Probe(probe_node, probe_angle, tag=probe_tag)])

To plot velocity and acceleration responses, you must change amplitude_units from “[length]” units to “[length]/[time]” or “[length]/[time] ** 2” respectively Plotting velocity response >>> fig = response.plot( … probe=[rs.Probe(probe_node, probe_angle)], … amplitude_units=”m/s” … )

Plotting acceleration response >>> fig = response.plot( … probe=[rs.Probe(probe_node, probe_angle)], … amplitude_units=”m/s**2” … )

Plotting deflected shape configuration Speed value must be in speed_range. >>> value = 600 >>> fig = response.plot_deflected_shape(speed=value)