機車振動論文：機車車輛多點激勵模態(tài)試驗系統(tǒng)研究

機車振動論文：機車車輛多點激勵模態(tài)試驗系統(tǒng)研究【中文摘要】隨著機車車輛運營速度的提高,車輛振動強度也隨之增強,影響了結(jié)構(gòu)的疲勞壽命。研究結(jié)構(gòu)振動特性,可以優(yōu)化車輛結(jié)構(gòu),抑制過大振動,改善車輛性能,具有重要意義。而模態(tài)試驗是獲得結(jié)構(gòu)振動特性的主要手段之一,其中多點協(xié)調(diào)激勵模態(tài)試驗能夠在提高模態(tài)純度的同時準確識別鐵道車輛模態(tài)參數(shù)。本文以車輛為研究對象,研制了多點協(xié)調(diào)激勵系統(tǒng),并進行結(jié)構(gòu)動態(tài)特性參數(shù)測試。第二章闡述了多點協(xié)調(diào)激勵模態(tài)試驗技術原理；探討了多點協(xié)調(diào)激勵在二系懸掛車輛上進行模態(tài)試驗的適用性,同時建立具有二系懸掛車輛的純模態(tài)判據(jù)和模態(tài)純度指示函數(shù)；應用多點協(xié)調(diào)激勵模態(tài)技術,對某二系懸掛車輛進行了仿真。第三章以二系懸掛模型車為對象,以多點協(xié)調(diào)激勵理論為基礎,Labview為編寫平臺,研制了多輸入多輸出純模態(tài)試驗系統(tǒng)。系統(tǒng)采用網(wǎng)格法對調(diào)力區(qū)間進行了優(yōu)化設計；利用模態(tài)純度指標為目標函數(shù)實現(xiàn)了系統(tǒng)的反饋控制。最后,應用研制的模態(tài)試驗系統(tǒng)對二系懸掛模型車進行了多點協(xié)調(diào)激勵模態(tài)試驗,得到了模型車各階固有頻率及振型。對比使用Ploymax參數(shù)識別方法獲得的該模型車的固有頻率和振型,表明在誤差范圍內(nèi)兩次試驗的結(jié)果是一致的,而多點協(xié)調(diào)激勵法獲得的各階模態(tài)純度更高?！居⑽恼縒iththeincreasingvelocityoflocomotivetrain,thetrainvibrationalsohasincreased,thusthestructurefatiguelifeisinfluenced.Itismeaningfultostudythevibrationcharacteristicsofstructure,throughwhichwecanoptimizethestructureofvehicles,restraintheoverlargevibrationandimprovetheperformanceofvehicles.Modaltestisoneofthemajormeanstoobtainstructuralvibrationcharacteristics.Multi-pointcoordinatedexcitationmodaltestcanaccuratelyidentifythemodalparametersofrailwayvehiclesandimprovethemodalpurityatthesametime.Takingthevehicleastheobjectofstudy,thispaperdevelopedamulti-pointcoordinatedexcitationsystem,andmadethestructuraldynamiccharacteristicsparametertesting.Chaptertwointroducedtheprincipleofthemulti-pointcoordinatedexcitationmodaltesttechnology,theapplicabilityofmulti-pointcoordinatedexcitationmodaltestonsecondarysuspensionvehicles,andestablishedthepuremodalcriterionandmodalpurityindicatingfunctionsofsecondarysuspensionvehiclesatthesametime,thenconductedthesimulationonsecondarysuspensionvehiclebyapplyingthemulti-pointcoordinatedexcitationmodaltechnique.Inchapterthree,takingthesecondarysuspensionmodelcarastheobject,takingthemulti-pointcoordinatedexcitationtheoryasthebasisandtheLabviewasthecompilingplatform,amulti-inputandmulti-outputpuremodaltestsystemwasdeveloped.Thesystem

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4.1.4試驗的原理

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4.1.5多點協(xié)調(diào)激勵模態(tài)試驗的流程

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4.1.6模型車試驗準備

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4.2模型車2點協(xié)調(diào)激勵模態(tài)試驗

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4.2.1掃頻過程

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4.2.2調(diào)力調(diào)頻過程

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4.3與LMS多點激振數(shù)學分離法結(jié)果比較

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4.4對比與分析

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第5章結(jié)論及展望