ross.MisalignmentFlex

ross.MisalignmentFlex#

class ross.MisalignmentFlex(rotor, n, mis_type, mis_distance_x, mis_distance_y, mis_angle, radial_stiffness, bending_stiffness, input_torque=0, load_torque=0)#

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

Calculates the dynamic reaction force of hexangular flexible coupling induced by rotor misalignment of some kind based on [Xia et al., 2019].

Parameters:

rotorross.Rotor: Rotor object.
nfloat: Number of shaft element where the misalignment is ocurring.
mis_type: string: Name of the chosen misalignment type. The available types are: “parallel”, “angular” and “combined”.
mis_distance_xfloat, pint.Quantity: Parallel misalignment distance between driving rotor and driven rotor along X direction.
mis_distance_yfloat, pint.Quantity: Parallel misalignment distance between driving rotor and driven rotor along Y direction.
mis_anglefloat, pint.Quantity: Angular misalignment angle.
radial_stiffnessfloat, pint.Quantity: Radial stiffness of flexible coupling.
bending_stiffnessfloat, pint.Quantity: Bending stiffness of flexible coupling. Provide if mis_type is “angular” or “combined”.
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.
forcesnp.ndarray: Force matrix due to misalignment. Each row corresponds to a dof and each column to a time.

Returns:

A MisalignmentFlex 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.

[Cun25]

Bárbara N. T. Cunha. Método do Balanceamento Harmônico aplicado na solução das equações do movimento de máquinas rotativas com efeitos dinâmicos não-lineares. PhD Thesis, Universidade Federal de Uberlândia, Uberlândia, MG, 2025.

[dS26]

Murillo Álvaro Borges de Sousa. Implementation of a dynamic backlash model in gears for rotational dynamics analysis. Master's thesis, Federal University of Uberlândia, Uberlândia, MG, 2026. URL: https://repositorio.ufu.br/handle/123456789/49301.

[DSRG20]

Mohamed Desouki, Sadok Sassi, Jamil Renno, and Samer Gowid. Dynamic response of a rotating assembly under the coupled effects of misalignment and imbalance. Shock and Vibration, 2020:1–26, 10 2020. doi:10.1155/2020/8819676.

[Fri10]

Michael I Friswell. Dynamics of rotating machines. Cambridge University Press, 2010.

[Gas93]

R Gasch. A survey of the dynamic behaviour of a simple rotating shaft with a transverse crack. Journal of sound and vibration, 160(2):313–332, 1993.

[GG88]

Giancarlo Genta and Antonio Gugliotta. A conical element for finite element rotor dynamics. Journal of Sound and Vibration, 120:175–182, 01 1988. doi:10.1016/0022-460X(88)90342-2.

[KDA+13]

Jason Kaplan, sa Dousti, Paul Allaire, Bradley Nichols, Timothy Dimond, and Alexandrina Untaroiu. Rotor dynamic modeling of gears and geared systems. Proceedings of the ASME Turbo Expo, 7:, 06 2013. doi:10.1115/GT2013-94654.

[MSPW14]

Hui Ma, Rongze Song, Xu Pang, and Bangchun Wen. Time-varying mesh stiffness calculation of cracked spur gears. Engineering Failure Analysis, 44:179–194, 2014. doi:10.1016/j.engfailanal.2014.05.006.

[MD84]

IW Mayes and WGR Davies. Analysis of the response of a multi-rotor-bearing system containing a transverse crack in a rotor. Journal of Vibration, Acoustics, Stress, and Reliability in Design, 106(1):139–145, 1984.

[Nic99]

R Nicoletti. Efeitos térmicos em mancais segmentados híbridos—teoria e experimento. Thermal Effects in Hybrid Tilting-Pad Bearings—Theory and Experiment), M. Sc. dissertation, Universidade Estadual de Campinas, Campinas, http://libdigi. unicamp. br/document, 1999.

[RSC98]

JS Rao, TN Shiau, and JR Chang. Theoretical analysis of lateral response due to torsional excitation of geared rotors. Mechanism and Machine Theory, 33(6):761–783, 1998. doi:https://doi.org/10.1016/S0094-114X(97)00056-6.

[RK80]

K. E. Rouch and J. S. Kao. Dynamic reduction in rotor dynamics by the finite element method. Journal of Mechanical Design, 102(2):360–368, 1980. doi:10.1115/1.3254752.

[XPY+19]

Yuanfeng Xia, Jian Pang, Liang Yang, Qin Zhao, and Xianwu Yang. Study on vibration response and orbits of misaligned rigid rotors connected by hexangular flexible coupling. Applied Acoustics, 155:286–296, 2019. doi:https://doi.org/10.1016/j.apacoust.2019.05.022.

[YIK02]

T Yamamoto, Y Ishida, and RG Kirk. Linear and nonlinear rotordynamics: a modern treatment with applications. Applied Mechanics Reviews, 55(3):B45–B46, 06 2002. doi:https://doi.org/10.1115/1.1470671.

[YWWD16]

Yi Yang, Jiaying Wang, Xurong Wang, and Yiping Dai. A general method to predict unbalance responses of geared rotor systems. Journal of Sound and Vibration, 381:246–263, 2016. doi:https://doi.org/10.1016/j.jsv.2016.06.031.

[YHXS19]

Yong Yi, Kang Huang, Yangshou Xiong, and Meng Sang. Nonlinear dynamic modelling and analysis for a spur gear system with time-varying pressure angle and gear backlash. Mechanical Systems and Signal Processing, 132:18–34, 10 2019. doi:10.1016/j.ymssp.2019.06.013.

Filter:: docname in docnames

Examples

>>> rotor = rs.rotor_example_with_damping()
>>> fault = MisalignmentFlex(
...     rotor,
...     n=0,
...     mis_type="combined",
...     mis_distance_x=2e-4,
...     mis_distance_y=2e-4,
...     mis_angle=5 * np.pi / 180,
...     radial_stiffness=40e3,
...     bending_stiffness=38e3,
...     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_type, mis_distance_x, mis_distance_y, mis_angle, radial_stiffness, bending_stiffness, input_torque=0, load_torque=0)#

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

Run analysis for the system with misalignment 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: The Newmark method can be chosen by setting method=’newmark’. 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

ross.MisalignmentFlex

Contents

ross.MisalignmentFlex#