具有完整約束的復(fù)雜轉(zhuǎn)子—軸承耦合系統(tǒng)非線性動(dòng)力學(xué)研究.pdf

1、論文題目：具有完整約束的復(fù)雜轉(zhuǎn)子—軸承耦合系統(tǒng)非線性動(dòng)力學(xué)研究專業(yè)：固體力學(xué)碩士生：李自剛（簽名）指導(dǎo)教師：李明（簽名）摘要在不對(duì)中故障轉(zhuǎn)子—軸承系統(tǒng)的動(dòng)力學(xué)分析中，往往忽略了轉(zhuǎn)子間存在的運(yùn)動(dòng)約束或耦合關(guān)系，而這些約束在某些情況下有可能極大地改變系統(tǒng)的動(dòng)力學(xué)特性。因此深入研究具有不對(duì)中約束的復(fù)雜轉(zhuǎn)子—軸承耦合系統(tǒng)的非線性動(dòng)力學(xué)行為對(duì)系統(tǒng)的動(dòng)力學(xué)設(shè)計(jì)和故障診斷具有重要的理論及工程意義。本文以轉(zhuǎn)子間具有廣義位移約束關(guān)系的不對(duì)中轉(zhuǎn)子系統(tǒng)為研究

2、對(duì)象，基于轉(zhuǎn)子動(dòng)力學(xué)、非線性動(dòng)力學(xué)和流體動(dòng)壓潤(rùn)滑理論，建立了具有完整約束的多轉(zhuǎn)子耦合系統(tǒng)的動(dòng)力學(xué)模型。采用數(shù)值分析以及試驗(yàn)方法，重點(diǎn)研究了在非線性軸承力作用下轉(zhuǎn)子間具有定常和非定常完整約束的不對(duì)中轉(zhuǎn)子—軸承耦合系統(tǒng)的非線性動(dòng)力學(xué)行為。探討了具有平行不對(duì)中及交角不對(duì)中約束的轉(zhuǎn)子系統(tǒng)非線性故障振動(dòng)機(jī)理和特征。主要研究?jī)?nèi)容和成果如下：1.以國(guó)產(chǎn)某發(fā)電機(jī)轉(zhuǎn)子為研究對(duì)象，建立了具有平行不對(duì)中和質(zhì)量不平衡故障的非對(duì)稱柔性轉(zhuǎn)子系統(tǒng)力學(xué)模型，利用多種分

3、析方法研究了系統(tǒng)的非線性動(dòng)力學(xué)行為，并討論了轉(zhuǎn)子參數(shù)對(duì)系統(tǒng)動(dòng)力學(xué)特性的影響。結(jié)果顯示：在較低轉(zhuǎn)速和微小不對(duì)中量時(shí)，系統(tǒng)的穩(wěn)態(tài)響應(yīng)主要呈現(xiàn)出與轉(zhuǎn)速同步的周期運(yùn)動(dòng)特性，隨著轉(zhuǎn)速的提高，頻域內(nèi)諧波分量增多，振幅也隨之增大。另外，轉(zhuǎn)子間不對(duì)中量、轉(zhuǎn)軸剛度不對(duì)稱度以及質(zhì)量偏心等參數(shù)的改變使得系統(tǒng)的運(yùn)動(dòng)更加復(fù)雜，出現(xiàn)分叉、跳躍以及混沌等非線性動(dòng)力學(xué)現(xiàn)象。2.研究了一個(gè)具有交角不對(duì)中約束的轉(zhuǎn)子—軸承系統(tǒng)動(dòng)力學(xué)行為。建立了具有非定常完整約束的柔性多轉(zhuǎn)子

4、系統(tǒng)動(dòng)力學(xué)模型，分析了系統(tǒng)的非線性振動(dòng)特征和參數(shù)變化對(duì)系統(tǒng)動(dòng)力學(xué)行為的影響。數(shù)值結(jié)果表明：在較低轉(zhuǎn)速時(shí)，交角不對(duì)中量對(duì)系統(tǒng)的運(yùn)動(dòng)影響較小。隨著轉(zhuǎn)速的增加，其軸心軌跡出現(xiàn)明顯的“8”字形，特征頻率為工頻的兩倍。在較高轉(zhuǎn)速時(shí)，出現(xiàn)倍周期分叉、混沌運(yùn)動(dòng)等復(fù)雜動(dòng)力學(xué)現(xiàn)象。另外，轉(zhuǎn)子間的交角不對(duì)中量，轉(zhuǎn)軸剛度、質(zhì)量偏心等參數(shù)對(duì)系統(tǒng)的非線性動(dòng)力學(xué)行為也具有重要影響。3.建立了在油膜軸承支承下多轉(zhuǎn)子—軸承系統(tǒng)試驗(yàn)平臺(tái)，對(duì)不對(duì)中轉(zhuǎn)子的動(dòng)力學(xué)特性進(jìn)行了試

5、驗(yàn)研究。重點(diǎn)探討了平行不對(duì)中和交角不對(duì)中轉(zhuǎn)子—軸承系統(tǒng)的動(dòng)態(tài)響應(yīng)，例如，頻域特征、軸心軌跡等。試驗(yàn)結(jié)果顯示：具有不對(duì)中故障的轉(zhuǎn)子系統(tǒng)穩(wěn)態(tài)響應(yīng)中除了存在工頻和倍頻分量之外，還存在一些組合頻率成分，其中工頻和2倍頻成分Subject:NonlinearDynamicsofComplexRotbearingSystemSubjecttoaHolonomicConstraintofRotMisalignmentSpecialty:SolidMe

6、chanicsName:LiZigang(Signature)Instruct:LiMing(Signature)ABSTRACTTraditionallythemotionconstrainscouplingrelationshipsbetweentworotswereneglectedintheanalysisofrotbearingsystemwithamisalignedfault.Howevertheyplayasignifi

7、cantroleindynamicacteristicsofrotsysteminsomecases.Accdinglythestudyonnonlineardynamicsofthecomplexrotbearingcouplingsystemsubjecttoamisalignmentconstraintisofgreatsignificancefthedynamicdesignfaultdiagnosisofcomplexrotb

8、earingsystem.Basedonrotdynamicsnonlineardynamicshydrodynamiclubricationsoonthedynamicmodelofthemultirotcouplingsystemsubjecttoaholonomicconstraintisestablishedwhichdescribestherelationshipofthegeneralizeddisplacementsbet

9、weentwomisalignedrots.Nonlineardynamicbehavioursofrotbearingsystemundertheactionofnonlinearoilfilmfcesweremainlyinvestigatedbyusingboththenumericalapproachexperimentmethodrespectivelyinwhichthescleronomousrhenomousholono

10、micconstraintsfmisalignmentfaultswereembedded.Thevibrationmechanismsacteristicsofrotsystemwithparallelangularmisalignmentswerepaidmeattentioninthisthesis.Themaincontentscontributionsaresummarizedasfollows:Themechanicalmo

11、delofrotbearingsystemwasdevelopedafterconsideringtheeffectsoftheunsymmetricalflexibleshaftswiththefaultsoftheparallelmisalignmentmassunbalancefapracticalgeneratset.Indertostudythedynamicbehavisofthesystemanumericalmethod

12、wasintroducedtheparametriceffectsondynamicacteristicswerealsodiscussed.Theresultsindicatethatthesteadystateresponsesinlateraldirectionaresynchronouswithrotatingspeedfthecaseoftinymisalignmentatlowspeed.Asincreasingthespe

13、edsomeharmoniccomponentsoccursthevibrationamplitudesincrease.Furthermesomeparameterssuchastheparallelmisalignmentasymmetryofrotstiffnessmassunbalanceexertasignificantinfluenceondynamicsofrotsystemwhichcancauseaseriesofco