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On post-resonance backward whirl in an overhung rotor with snubbing contact / Mohammad A. AL-Shudeifat; Michael Friswell; Oleg Shiryayev; C. Nataraj

Nonlinear Dynamics, Volume: 101, Issue: 2, Pages: 741 - 754

Swansea University Author: Michael, Friswell

  • Accepted Manuscript under embargo until: 30th July 2021

Abstract

Rotordynamic systems are central to many aerospace and heavy-duty industrial applications. The vibrational response of such systems is usually associated with forward whirl (FW) and backward whirl (BW) precessions. It is well known in the literature that the BW precession generally precedes the pass...

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Published in: Nonlinear Dynamics
ISSN: 0924-090X 1573-269X
Published: Springer Science and Business Media LLC 2020
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URI: https://cronfa.swan.ac.uk/Record/cronfa54762
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spelling 2020-09-01T11:23:48.0905708 v2 54762 2020-07-16 On post-resonance backward whirl in an overhung rotor with snubbing contact 5894777b8f9c6e64bde3568d68078d40 Michael Friswell Michael Friswell true false 2020-07-16 EEN Rotordynamic systems are central to many aerospace and heavy-duty industrial applications. The vibrational response of such systems is usually associated with forward whirl (FW) and backward whirl (BW) precessions. It is well known in the literature that the BW precession generally precedes the passage through the critical FW resonance precession. Therefore, it can be named as a pre-resonance BW frequency (Pr-BW). However, another kind of BW has been recently observed to be immediately excited after the passage through the critical FW resonance frequency in cracked rotors with anisotropic supports during run-up and coast-down operations. Consequently, this kind of BW can be named as a post-resonance backward whirl (Po-BW) precession. The Pr-BW and Po-BW phenomena are investigated here with an overhung rotor system that exhibits snubbing contact and stiffness anisotropy in the supports. Incorporating the snubbing moment couple into the equations of motion of the considered overhung rotor model yields a piecewise and strongly nonlinear system. Full-spectrum analysis is employed to capture the BW zones of rotational speeds in the whirl response. Wavelet transform spectrum analysis is also employed to determine the frequency content in the Pr-BW and the Po-BW zones. Three cases are considered in this numerical study to explore the effect of the support stiffness isotropy and anisotropy with active and inactive snubbing contact on the Po-BW excitation. For all cases, the Po-BW zones of rotational speeds are found. Moreover, the broadness and recurrence of the Po-BW zones of rotational speeds are more prominent for the cases of active snubbing contact. Even though the Pr-BW and Po-BW zones are excited at different shaft rotational speeds, they are found to possess nearly similar BW frequencies which are less than the FW resonance frequency of the considered system. Journal Article Nonlinear Dynamics 101 2 741 754 Springer Science and Business Media LLC 0924-090X 1573-269X Backward whirl; Overhung rotor; Post-resonance backward whirl; Full-spectrum analysis; Rotor system 1 7 2020 2020-07-01 10.1007/s11071-020-05784-3 COLLEGE NANME Engineering COLLEGE CODE EEN Swansea University 2020-09-01T11:23:48.0905708 2020-07-16T12:33:07.3153621 Mohammad A. AL-Shudeifat 1 Michael Friswell 2 Oleg Shiryayev 3 C. Nataraj 4 Under embargo Under embargo 2020-07-16T15:47:05.0897450 Output 2668440 application/pdf Accepted Manuscript true 2021-07-30T00:00:00.0000000 true English
title On post-resonance backward whirl in an overhung rotor with snubbing contact
spellingShingle On post-resonance backward whirl in an overhung rotor with snubbing contact
Michael, Friswell
title_short On post-resonance backward whirl in an overhung rotor with snubbing contact
title_full On post-resonance backward whirl in an overhung rotor with snubbing contact
title_fullStr On post-resonance backward whirl in an overhung rotor with snubbing contact
title_full_unstemmed On post-resonance backward whirl in an overhung rotor with snubbing contact
title_sort On post-resonance backward whirl in an overhung rotor with snubbing contact
author_id_str_mv 5894777b8f9c6e64bde3568d68078d40
author_id_fullname_str_mv 5894777b8f9c6e64bde3568d68078d40_***_Michael, Friswell
author Michael, Friswell
author2 Mohammad A. AL-Shudeifat
Michael Friswell
Oleg Shiryayev
C. Nataraj
format Journal article
container_title Nonlinear Dynamics
container_volume 101
container_issue 2
container_start_page 741
publishDate 2020
institution Swansea University
issn 0924-090X
1573-269X
doi_str_mv 10.1007/s11071-020-05784-3
publisher Springer Science and Business Media LLC
document_store_str 0
active_str 0
description Rotordynamic systems are central to many aerospace and heavy-duty industrial applications. The vibrational response of such systems is usually associated with forward whirl (FW) and backward whirl (BW) precessions. It is well known in the literature that the BW precession generally precedes the passage through the critical FW resonance precession. Therefore, it can be named as a pre-resonance BW frequency (Pr-BW). However, another kind of BW has been recently observed to be immediately excited after the passage through the critical FW resonance frequency in cracked rotors with anisotropic supports during run-up and coast-down operations. Consequently, this kind of BW can be named as a post-resonance backward whirl (Po-BW) precession. The Pr-BW and Po-BW phenomena are investigated here with an overhung rotor system that exhibits snubbing contact and stiffness anisotropy in the supports. Incorporating the snubbing moment couple into the equations of motion of the considered overhung rotor model yields a piecewise and strongly nonlinear system. Full-spectrum analysis is employed to capture the BW zones of rotational speeds in the whirl response. Wavelet transform spectrum analysis is also employed to determine the frequency content in the Pr-BW and the Po-BW zones. Three cases are considered in this numerical study to explore the effect of the support stiffness isotropy and anisotropy with active and inactive snubbing contact on the Po-BW excitation. For all cases, the Po-BW zones of rotational speeds are found. Moreover, the broadness and recurrence of the Po-BW zones of rotational speeds are more prominent for the cases of active snubbing contact. Even though the Pr-BW and Po-BW zones are excited at different shaft rotational speeds, they are found to possess nearly similar BW frequencies which are less than the FW resonance frequency of the considered system.
published_date 2020-07-01T04:20:04Z
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score 10.788133