Crack Detection and Dynamic Analysis of a Cracked Rotor with Soft Bearings Using Different Methods of Solution
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Outros Autores: | |
Tipo de documento: | Artigo de conferência |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1007/978-3-319-99268-6_1 http://hdl.handle.net/11449/221145 |
Resumo: | The ratio of bearing stiffness to the shaft stiffness has a significant impact on the lower frequencies, mode shapes and, consequently, the whirl orbits. Most works studying crack detection methods in rotating systems use bearings relatively stiff, where the shaft bending is very pronounced. This paper analyzes how the nonlinear effect of the crack in the whirl orbits and the diagnostic forces technique for detecting cracks behave for soft bearings. The results show that the extra loops, very well known in the literature, are not present for the soft bearings. On the other hand, diagnostic peaks were successful in both cases. The efficiency of these methods depends on the mathematical model of the cracked rotor. This work considers the breathing mechanism in formulating the time-varying finite element stiffness matrix of the cracked element, requiring the solution of a set of equations at each time-step. With this concern, two approaches for the solution of the dynamic response are compared: direct time integration method using Newmark’s method and solution of discrete-time state equations. The Newmark’s method requires small time-step for the accuracy of the response, however, the processing time is much smaller when compared to solution of discrete-time state equations. |
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Repositório Institucional da UNESP |
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Crack Detection and Dynamic Analysis of a Cracked Rotor with Soft Bearings Using Different Methods of SolutionCrack identificationDiscrete-time state equationMultiple scales methodNewmark methodRotating machinesThe ratio of bearing stiffness to the shaft stiffness has a significant impact on the lower frequencies, mode shapes and, consequently, the whirl orbits. Most works studying crack detection methods in rotating systems use bearings relatively stiff, where the shaft bending is very pronounced. This paper analyzes how the nonlinear effect of the crack in the whirl orbits and the diagnostic forces technique for detecting cracks behave for soft bearings. The results show that the extra loops, very well known in the literature, are not present for the soft bearings. On the other hand, diagnostic peaks were successful in both cases. The efficiency of these methods depends on the mathematical model of the cracked rotor. This work considers the breathing mechanism in formulating the time-varying finite element stiffness matrix of the cracked element, requiring the solution of a set of equations at each time-step. With this concern, two approaches for the solution of the dynamic response are compared: direct time integration method using Newmark’s method and solution of discrete-time state equations. The Newmark’s method requires small time-step for the accuracy of the response, however, the processing time is much smaller when compared to solution of discrete-time state equations.Universidade Estadual PaulistaUniversidade Estadual PaulistaUniversidade Estadual Paulista (UNESP)de Oliveira, Lucas Rangel [UNESP]de Melo, Gilberto Pechoto [UNESP]2022-04-28T19:11:01Z2022-04-28T19:11:01Z2019-01-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/conferenceObject3-17http://dx.doi.org/10.1007/978-3-319-99268-6_1Mechanisms and Machine Science, v. 61, p. 3-17.2211-09922211-0984http://hdl.handle.net/11449/22114510.1007/978-3-319-99268-6_12-s2.0-85051806567Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengMechanisms and Machine Scienceinfo:eu-repo/semantics/openAccess2022-04-28T19:11:01Zoai:repositorio.unesp.br:11449/221145Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462022-04-28T19:11:01Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Crack Detection and Dynamic Analysis of a Cracked Rotor with Soft Bearings Using Different Methods of Solution |
title |
Crack Detection and Dynamic Analysis of a Cracked Rotor with Soft Bearings Using Different Methods of Solution |
spellingShingle |
Crack Detection and Dynamic Analysis of a Cracked Rotor with Soft Bearings Using Different Methods of Solution de Oliveira, Lucas Rangel [UNESP] Crack identification Discrete-time state equation Multiple scales method Newmark method Rotating machines |
title_short |
Crack Detection and Dynamic Analysis of a Cracked Rotor with Soft Bearings Using Different Methods of Solution |
title_full |
Crack Detection and Dynamic Analysis of a Cracked Rotor with Soft Bearings Using Different Methods of Solution |
title_fullStr |
Crack Detection and Dynamic Analysis of a Cracked Rotor with Soft Bearings Using Different Methods of Solution |
title_full_unstemmed |
Crack Detection and Dynamic Analysis of a Cracked Rotor with Soft Bearings Using Different Methods of Solution |
title_sort |
Crack Detection and Dynamic Analysis of a Cracked Rotor with Soft Bearings Using Different Methods of Solution |
author |
de Oliveira, Lucas Rangel [UNESP] |
author_facet |
de Oliveira, Lucas Rangel [UNESP] de Melo, Gilberto Pechoto [UNESP] |
author_role |
author |
author2 |
de Melo, Gilberto Pechoto [UNESP] |
author2_role |
author |
dc.contributor.none.fl_str_mv |
Universidade Estadual Paulista (UNESP) |
dc.contributor.author.fl_str_mv |
de Oliveira, Lucas Rangel [UNESP] de Melo, Gilberto Pechoto [UNESP] |
dc.subject.por.fl_str_mv |
Crack identification Discrete-time state equation Multiple scales method Newmark method Rotating machines |
topic |
Crack identification Discrete-time state equation Multiple scales method Newmark method Rotating machines |
description |
The ratio of bearing stiffness to the shaft stiffness has a significant impact on the lower frequencies, mode shapes and, consequently, the whirl orbits. Most works studying crack detection methods in rotating systems use bearings relatively stiff, where the shaft bending is very pronounced. This paper analyzes how the nonlinear effect of the crack in the whirl orbits and the diagnostic forces technique for detecting cracks behave for soft bearings. The results show that the extra loops, very well known in the literature, are not present for the soft bearings. On the other hand, diagnostic peaks were successful in both cases. The efficiency of these methods depends on the mathematical model of the cracked rotor. This work considers the breathing mechanism in formulating the time-varying finite element stiffness matrix of the cracked element, requiring the solution of a set of equations at each time-step. With this concern, two approaches for the solution of the dynamic response are compared: direct time integration method using Newmark’s method and solution of discrete-time state equations. The Newmark’s method requires small time-step for the accuracy of the response, however, the processing time is much smaller when compared to solution of discrete-time state equations. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-01-01 2022-04-28T19:11:01Z 2022-04-28T19:11:01Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/conferenceObject |
format |
conferenceObject |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1007/978-3-319-99268-6_1 Mechanisms and Machine Science, v. 61, p. 3-17. 2211-0992 2211-0984 http://hdl.handle.net/11449/221145 10.1007/978-3-319-99268-6_1 2-s2.0-85051806567 |
url |
http://dx.doi.org/10.1007/978-3-319-99268-6_1 http://hdl.handle.net/11449/221145 |
identifier_str_mv |
Mechanisms and Machine Science, v. 61, p. 3-17. 2211-0992 2211-0984 10.1007/978-3-319-99268-6_1 2-s2.0-85051806567 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Mechanisms and Machine Science |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
3-17 |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1797789676604489728 |