發(fā)布時(shí)間：2018-03-10 06:02

  本文選題：裝載機(jī)動(dòng)臂　切入點(diǎn)：載荷譜　出處：《集美大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著裝載機(jī)朝著大型化、重型化和高速化發(fā)展，，對裝載機(jī)的安全性、可靠性等工作性能提出了更高的要求，裝載機(jī)車架和執(zhí)行結(jié)構(gòu)的主要破壞形式是交變載荷作用下長期積累而導(dǎo)致的疲勞失效。本課題建立在與企業(yè)聯(lián)合研究開發(fā)的裝載機(jī)疲勞試驗(yàn)臺架的基礎(chǔ)上，通過裝載機(jī)整車疲勞試驗(yàn)，研究裝載機(jī)臺架疲勞試驗(yàn)與實(shí)際工況下動(dòng)臂疲勞失效的等效機(jī)理。通過等幅加載疲勞試驗(yàn)推斷動(dòng)臂在現(xiàn)實(shí)作業(yè)中的疲勞壽命及失效形式、失效位置，以便于進(jìn)行產(chǎn)品的開發(fā)、質(zhì)量控制等。并為其它型號裝載機(jī)在該試驗(yàn)臺架上的應(yīng)用以及裝載機(jī)的加速壽命試驗(yàn)仿真研究奠定基礎(chǔ)。 本論文主要研究內(nèi)容包括： （1）裝載機(jī)鏟斗實(shí)際受力計(jì)算及實(shí)驗(yàn)室工況加載譜的編制。根據(jù)實(shí)驗(yàn)室加載情況對被試裝載機(jī)鏟斗受到的動(dòng)載荷進(jìn)行計(jì)算；采用庫倫土壓力理論分析計(jì)算裝載機(jī)從鏟斗插入料堆至卸載物料、鏟斗降回原處整個(gè)過程鏟斗受到的鏟裝阻力計(jì)算。根據(jù)實(shí)驗(yàn)室的加載情況滿足正負(fù)峰對稱分布以及無中間過渡峰的要求，以及理論計(jì)算加載得到的載荷循環(huán)較平滑、峰值變化頻率較平緩的特點(diǎn)，分別采用全峰值計(jì)數(shù)法和振程計(jì)數(shù)法對所計(jì)算獲得的樣本進(jìn)行計(jì)數(shù)并編制成載荷譜。 （2）基于材料S-N曲線，對裝載機(jī)動(dòng)臂的S-N曲線進(jìn)行修正，并進(jìn)行裝載機(jī)動(dòng)臂疲勞壽命預(yù)測。本文運(yùn)用建模軟件PRO/E建立裝載機(jī)的實(shí)體模型，并導(dǎo)入前處理軟件Hypermesh中進(jìn)行網(wǎng)格劃分、添加實(shí)驗(yàn)室工況和理論計(jì)算下載荷和約束狀態(tài)，導(dǎo)入Ansys中計(jì)算處理以獲得裝載機(jī)動(dòng)臂在實(shí)驗(yàn)室工況和理論計(jì)算下應(yīng)力分布情況。并計(jì)算獲得動(dòng)臂在特定載荷環(huán)境下的應(yīng)力集中系數(shù)，基于材料的S-N曲線，結(jié)合對動(dòng)臂S-N曲線影響因素進(jìn)行分析計(jì)算修正得到相應(yīng)動(dòng)臂的S-N曲線。通過獲得的動(dòng)臂S-N曲線，并結(jié)合線性累積疲勞損傷理論對載荷循環(huán)進(jìn)行統(tǒng)計(jì)，預(yù)測其疲勞壽命。 （3）裝載機(jī)動(dòng)臂臺架疲勞試驗(yàn)與理論計(jì)算疲勞失效的等效機(jī)理研究。運(yùn)用灰色關(guān)聯(lián)度理論對裝載機(jī)動(dòng)臂實(shí)驗(yàn)室工況與理論計(jì)算下疲勞預(yù)測曲線二者的相關(guān)性進(jìn)行分析，得到兩者關(guān)聯(lián)度系數(shù)為0.9012的結(jié)果；通過加速因子對實(shí)驗(yàn)室工況與理論計(jì)算下的疲勞壽命預(yù)測折算分析兩者關(guān)聯(lián)度密切性；建立基于灰色關(guān)聯(lián)度的等幅譜預(yù)測模型，分析實(shí)驗(yàn)室等幅譜預(yù)測模型與實(shí)際疲勞預(yù)測曲線的吻合度，并可以通過建立多個(gè)預(yù)測模型或者建立殘差模型提高模型的預(yù)測精度。
[Abstract]:With the development of loaders towards large scale, heavy duty and high speed, higher requirements are put forward for the safety and reliability of loaders. The main failure form of loader frame and executive structure is fatigue failure caused by long-term accumulation under alternating load. In this paper, the equivalent mechanism of the fatigue failure of the loader bench fatigue test and the moving arm fatigue under the actual working condition is studied through the fatigue test of the loader, and the fatigue life, failure form and failure position of the arm are inferred through the fatigue test of equal amplitude loading. It is convenient for product development, quality control and so on. It also lays a foundation for the application of other types of loaders on the test stand and the simulation study on the accelerated life test of loaders. The main contents of this thesis are as follows:. 1) calculation of the actual force of the loader bucket and compilation of the loading spectrum of the laboratory conditions. The dynamic load of the hopper of the loader is calculated according to the loading condition in the laboratory; The Coulomb earth pressure theory is used to analyze and calculate the loading machine from the bucket insert material pile to the unloading material. According to the loading conditions of laboratory, the symmetrical distribution of positive and negative peaks and the requirement of no intermediate transition peak are satisfied, and the load cycle obtained by theoretical calculation is smoother. The peak frequency is relatively gentle. The full peak counting method and the vibration range counting method are used to count the calculated samples and the load spectrum is compiled. Based on the material S-N curve, the S-N curve of the loader arm is modified and the fatigue life of the loader arm is predicted. In this paper, the solid model of the loader is established by using the modeling software PRO/E, and the mesh is divided into the pre-processing software Hypermesh. Add laboratory conditions and theoretical calculations to download load and constraint states, In order to obtain the stress distribution of the loader arm under the laboratory condition and the theoretical calculation, the stress concentration factor of the arm under specific load environment is calculated, based on the S-N curve of the material. The S-N curve of the corresponding arm is obtained by the analysis and correction of the influence factors of S-N curve of the arm. The fatigue life of the arm is predicted by the S-N curve of the arm and the statistics of the load cycle combined with the linear cumulative fatigue damage theory. 3) the equivalent mechanism of fatigue test and theoretical calculation fatigue failure of loader arm is studied. The correlation between the fatigue prediction curve and the laboratory condition of loader arm is analyzed by using the grey correlation degree theory. The correlation coefficient is 0.9012; the fatigue life prediction under the laboratory condition and the theoretical calculation is converted by the acceleration factor; the correlation degree between the two is analyzed; and the equal amplitude spectrum prediction model based on the grey correlation degree is established. The prediction accuracy of the model can be improved by establishing multiple prediction models or residual models.
【學(xué)位授予單位】：集美大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U653.92

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 劉兵;何國球;蔣小松;朱e

本文編號：1592052