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  本文關(guān)鍵詞：輪式裝載機液壓缸載荷譜編制方法與時域信號重構(gòu)　出處：《吉林大學(xué)》2011年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 輪式裝載機 液壓缸 載荷譜 極值理論 馬爾可夫鏈 疲勞壽命

【摘要】：液壓缸是輪式裝載機液壓傳動系統(tǒng)的重要動力執(zhí)行部件,裝載機作業(yè)過程中的惡劣地面環(huán)境和復(fù)雜多變的鏟掘載荷經(jīng)常導(dǎo)致液壓缸發(fā)生疲勞失效。載荷譜可以反映液壓缸實際載荷情況,是液壓缸疲勞分析的基礎(chǔ)。本文結(jié)合國家自然科學(xué)基金資助項目(編號:50805065),根據(jù)輪式裝載機的作業(yè)特點,研究了輪式裝載機液壓缸載荷的測試方案和數(shù)據(jù)預(yù)處理方法,提出了基于分段處理的液壓缸載荷譜編制方法和基于馬爾可夫理論的時域載荷重構(gòu)方法;然后,應(yīng)用所編制的載荷譜進行了缸筒的疲勞壽命預(yù)測。本文的研究工作可以為液壓缸載荷譜的編制和時域信號的重構(gòu)提供理論基礎(chǔ)。論文主要內(nèi)容和結(jié)論如下: 1、分析了液壓缸的疲勞失效機理,描述了載荷譜的研究現(xiàn)狀,進一步明確了編制液壓缸載荷譜和進行時域信號重構(gòu)的意義。 2、確定了測試方案并對樣本載荷進行了預(yù)處理。從路面條件、司機的操作行為、裝載機行進路線和物料的準(zhǔn)備等方面對液壓缸載荷的測試方案進行了規(guī)范。采用低通巴特沃斯的濾波方法對測試信號進行了濾波,并由幅值門限法進行了剔除奇異值。結(jié)合液壓缸的工作特點,對測試載荷進行了分段處理,然后對每段載荷進行了統(tǒng)計分析和平穩(wěn)性檢驗。 3、基于POT(峰值門限穿越法)外推方法,編制了液壓缸全壽命載荷譜。根據(jù)POT理論,建立了廣義帕累托分布(GDP)數(shù)學(xué)模型,并估計出分布參數(shù)。由雨流計數(shù)法統(tǒng)計出載荷的均值、幅值以及相應(yīng)的頻次。最后,由非參數(shù)外推將統(tǒng)計到的載荷頻次外推到全壽命,完成了液壓缸載荷譜的編制。 4、基于馬爾可夫鏈理論,重構(gòu)了液壓缸時域載荷�；�于馬爾可夫鏈?蒙特卡羅方法對液壓缸各作業(yè)段時域載荷和整體時域載荷進行了重構(gòu),模擬出實際工況中的載荷信號,實現(xiàn)了由測試載荷到模擬載荷的重現(xiàn)。 5、以動臂缸為例,進行了液壓缸的有限元分析和疲勞壽命預(yù)測方法研究。首先,采用有限元軟件分析了動臂缸筒體的強度和剛度。然后,基于實測的載荷數(shù)據(jù)和疲勞累積理論,計算了每一載荷幅值水平對液壓缸產(chǎn)生的疲勞損傷。在有限元分析結(jié)果的基礎(chǔ)上,利用本文編制的載荷譜預(yù)測出了動臂缸的疲勞壽命。
[Abstract]:The hydraulic cylinder is the important power executing part of the hydraulic transmission system of wheel loader . The severe ground environment and the complicated multi - variable shovel load in loader operation often result in the fatigue failure of the hydraulic cylinder . The load spectrum can reflect the actual load of the hydraulic cylinder and the method of time domain load reconstruction based on Markov theory . The research work of this paper can provide the theoretical basis for the compilation of hydraulic cylinder load spectrum and the reconstruction of time domain signal . The main contents and conclusions are as follows : 1 . The fatigue failure mechanism of the hydraulic cylinder is analyzed , the research status of the load spectrum is described , and the significance of the hydraulic cylinder load spectrum and the time domain signal reconstruction is further clarified . 2 . The test plan is determined and the sample load is pre - treated . The test scheme of hydraulic cylinder load is regulated in terms of pavement condition , driver ' s operating behavior , loading route of loader and preparation of material . The test signal is filtered by low - pass filter method . Combined with the working characteristics of hydraulic cylinder , the test load is subjected to segmentation treatment , and then the statistical analysis and stationarity test are carried out for each load . 3 . Based on POT ( peak threshold crossing method ) extrapolation method , the full life load spectrum of hydraulic cylinder is compiled . According to POT theory , the mathematical model of generalized Pareto distribution ( GDP ) is established , and the distribution parameters are estimated . The mean value , amplitude and frequency of the load are calculated by the rain flow counting method . Finally , the calculated load frequency is extrapolated to full life from non - parametric extrapolation , and the load spectrum of hydraulic cylinder is compiled . 4 . Based on Markov chain theory , the time domain load of hydraulic cylinder is reconstructed . Based on Markov chain ? Monte Carlo method , the time domain load and the whole time domain load of hydraulic cylinder are reconstructed , the load signal in the actual working condition is simulated , and the recurrence of the test load to the simulated load is realized . 5 . Taking the boom cylinder as an example , the finite element analysis and fatigue life prediction method of the hydraulic cylinder are studied . Firstly , the strength and rigidity of the boom cylinder are analyzed by finite element software . Based on the measured load data and the fatigue accumulation theory , the fatigue damage caused by the hydraulic cylinder is calculated . On the basis of the results of the finite element analysis , the fatigue life of the boom cylinder is predicted by the load spectrum .

【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2011
【分類號】：TH243

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前3條

1 王振雨;載荷譜編制中極值載荷確定方法及應(yīng)用[D];吉林大學(xué);2012年

2 張建華;風(fēng)力機葉片疲勞壽命估算方法研究[D];吉林大學(xué);2013年

3 劉偉;2B_0軸式33噸大軸重機車軸箱定位方式的研究[D];西南交通大學(xué);2013年

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本文編號：1373278