ross.MisalignmentRigid

ross.MisalignmentRigid#

class ross.MisalignmentRigid(rotor, n, mis_distance, input_torque=0, load_torque=0)#

Model misalignment on a given rigid coupling element of a rotor system.

Calculates the dynamic reaction force of hexangular rigid coupling induced by rotor parallel misalignment based on [Al-Hussain and Redmond, 2002].

Parameters:
nfloat

Number of shaft element where the misalignment is ocurring.

mis_distancefloat, pint.Quantity

Parallel misalignment distance between driving rotor and driven rotor.

input_torquefloat, pint.Quantity

Driving torque. Default is 0.

load_torquefloat, pint.Quantity

Driven torque. Default is 0.

Attributes:
shaft_elemross.ShaftElement

A 6 degrees of freedom shaft element object where misalignment is ocurring.

kl1float

Stiffness of the x-direction degree of freedom at the left node of the shaft element.

kl2float

Stiffness of the x-direction degree of freedom at the right node of the shaft element.

kt1float

Stiffness of the torsional degree of freedom at the left node of the shaft element.

kt2float

Stiffness of the torsional degree of freedom at the right node of the shaft element.

phifloat

Coupling angular position.

forcesnp.ndarray

Force matrix due to misalignment. Each row corresponds to a dof and each column to a time.

Returns:
A MisalignmentRigid object.

References

[AHR02]

KM Al-Hussain and I Redmond. Dynamic response of two rotors connected by rigid mechanical coupling with parallel misalignment. Journal of Sound and vibration, 249(3):483–498, 2002. doi:https://doi.org/10.1006/jsvi.2001.3866.

Examples

>>> rotor = rs.rotor_example_with_damping()
>>> fault = MisalignmentRigid(rotor, n=0, mis_distance=2e-4, input_torque=0, load_torque=0)
>>> fault.shaft_elem
ShaftElement(L=0.025, idl=0.0, idr=0.0, odl=0.019,  odr=0.019, material='Steel', n=0)

Methods

__init__(rotor, n, mis_distance, input_torque=0, load_torque=0)#
compute_reaction_force(y, ap)#

Calculate reaction forces of parallel misalignment.

Parameters:
ynp.ndarray

Displacement response of the element.

apfloat

Angular position of the element.

Returns:
Fnp.ndarray

Force matrix of the element due to misalignment.

run(node, unb_magnitude, unb_phase, speed, t, **kwargs)#

Run analysis for the system with rubbing given an unbalance force.

System time response is simulated.

Parameters:
nodelist, int

Node where the unbalance is applied.

unb_magnitudelist, float

Unbalance magnitude (kg.m).

unb_phaselist, float

Unbalance phase (rad).

speedfloat or array_like, pint.Quantity

Rotor speed.

tarray

Time array.

**kwargsoptional

Additional keyword arguments can be passed to define the parameters of the Newmark method if it is used (e.g. gamma, beta, tol, …). See ross.utils.newmark for more details. Other keyword arguments can also be passed to be used in numerical integration (e.g. num_modes). See Rotor.integrate_system for more details.

Returns:
resultsross.TimeResponseResults

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

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