本文關(guān)鍵詞：基于仿真加速試驗(yàn)和數(shù)理統(tǒng)計(jì)的活塞可靠性研究　出處：《山東大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 活塞 CFD 有限元分析 疲勞壽命 加速試驗(yàn)

【摘要】：隨著對(duì)產(chǎn)品性能要求的提高和國(guó)家低碳經(jīng)濟(jì)發(fā)展的需要,內(nèi)燃機(jī)作為當(dāng)今社會(huì)的主要?jiǎng)恿ρb置之一,其功率密度有著顯著提高,這就帶來(lái)了高熱負(fù)荷和高爆發(fā)壓力的挑戰(zhàn)。而活塞作為內(nèi)燃機(jī)的核心部分之一,頂面直接承受燃燒室內(nèi)高溫高壓工質(zhì)影響,其可靠性備受相關(guān)人員的關(guān)注。本文針對(duì)該領(lǐng)域尚未解決的問(wèn)題,利用三維仿真對(duì)缸內(nèi)燃燒進(jìn)行分析,運(yùn)用有限元得到活塞應(yīng)力分布,并結(jié)合加速試驗(yàn)理論通過(guò)不同加速工況的仿真結(jié)果估算活塞額定工況的壽命,對(duì)活塞的可靠性進(jìn)行評(píng)估。具體的,首先針對(duì)國(guó)內(nèi)主要利用經(jīng)驗(yàn)公式獲取活塞頂面邊界條件的現(xiàn)狀,本文運(yùn)用三維CFD軟件對(duì)一個(gè)周期內(nèi)燃燒室中的情況進(jìn)行仿真,不僅能夠?qū)Ω變?nèi)流動(dòng)、傳熱、燃燒狀況進(jìn)行評(píng)估,還能從中獲得活塞頂面溫度與換熱系數(shù)分布規(guī)律,且相較于經(jīng)驗(yàn)公式法,更能充分地體現(xiàn)空間特性。之后利用一維仿真的結(jié)果進(jìn)行標(biāo)定,以保證仿真模型基本準(zhǔn)確的前提下,將仿真結(jié)果作為活塞頂面的邊界條件。其次,利用三維仿真獲得的頂面邊界條件,結(jié)合試驗(yàn)數(shù)據(jù)、經(jīng)驗(yàn)設(shè)置以及其他仿真結(jié)果,對(duì)活塞溫度場(chǎng)和應(yīng)力場(chǎng)的計(jì)算進(jìn)行相關(guān)設(shè)置,從而在Abaqus軟件中獲得活塞溫度場(chǎng),以及活塞在熱負(fù)荷、機(jī)械負(fù)荷和熱機(jī)耦合負(fù)荷影響下的應(yīng)力與應(yīng)變分布規(guī)律。仿真結(jié)果顯示,由于缸內(nèi)湍流和進(jìn)氣冷卻等原因,排氣側(cè)溫度普遍高于進(jìn)氣側(cè),從而熱應(yīng)力較大,且在第二環(huán)內(nèi)緣面上達(dá)到最大值。機(jī)械應(yīng)力則由于存在與活塞銷的接觸,從而在活塞銷座內(nèi)側(cè)上部出現(xiàn)了最大值。對(duì)于熱機(jī)耦合狀態(tài)下,活塞最大應(yīng)力值出現(xiàn)在第二環(huán)內(nèi)緣面,這是兩種負(fù)荷產(chǎn)生的應(yīng)力疊加的結(jié)果�；钊N座處由于剛銷柔座的材料設(shè)定,兩種應(yīng)力有所抵消,從而應(yīng)力相對(duì)變小。最后,利用仿真獲得的結(jié)果計(jì)算出活塞的疲勞壽命,結(jié)合加速試驗(yàn)相關(guān)理論,選取合適的加速模型,通過(guò)不同加速工況的仿真疲勞壽命在Matlab中進(jìn)行擬合。通過(guò)對(duì)比仿真值與擬合值可以看出擬合效果良好,從而通過(guò)擬合曲線估算活塞在額定工況下的疲勞壽命。與仿真值進(jìn)行比較,在熱負(fù)荷、機(jī)械負(fù)荷和耦合負(fù)荷下,相對(duì)誤差分別為4.11%,2.66%,7.91%,均相對(duì)較小,基本符合工程使用的要求,從而證明阿倫尼斯模型、逆冪律模型和廣義艾林模型分別作為這三種負(fù)荷下加速模型的可行性。之后還討論了當(dāng)有實(shí)際故障數(shù)據(jù)時(shí),需先分析其分布模型,從而獲得對(duì)應(yīng)的特征壽命,接著便可根據(jù)情況利用合適加速模型估計(jì)額定工況的壽命。綜上,本文提出的利用三維CFD獲取活塞頂面邊界條件,結(jié)合加速試驗(yàn)理論預(yù)測(cè)活塞疲勞壽命的方式有著較高的準(zhǔn)確度,可以在工程上運(yùn)用于活塞可靠性的評(píng)估。
[Abstract]:With the improvement of product performance requirements and the development of national low carbon economy, the power density of internal combustion engine as a major power device in today's society has been significantly improved, which brings the challenge of high heat load and high explosive pressure. As one of the core parts of the internal combustion engine, the piston is directly affected by the high temperature and high pressure working quality in the combustion chamber. The reliability of the piston has attracted much attention from the relevant personnel. According to the field of unsolved problems of cylinder combustion were analyzed by using the finite element simulation, get the stress distribution, combined with the accelerated test theory through the simulation results of different acceleration estimation of piston rated life, to assess the reliability of the piston. Specifically, first at home mainly by empirical formula to get the status quo of the piston top surface boundary conditions, this paper uses 3D CFD software to simulate the combustion chamber in a cycle, not only can the in cylinder flow, heat transfer, combustion condition assessment, but also get the piston top surface temperature and heat transfer coefficient distribution from, and compared with the empirical formula, can fully reflect the spatial characteristics. Then the results of one dimensional simulation are calibrated to ensure the accuracy of the simulation model, and the simulation results are used as the boundary conditions of the piston top surface. Secondly, the top surface of the boundary conditions obtained by 3D simulation, combined with the test data and the experience of setting up and other simulation results of the temperature field and stress field calculation related settings, so as to obtain the temperature field in Abaqus software, and the piston in the thermal load, mechanical load and thermal mechanical coupling loads under the influence of the the stress and strain distribution. The simulation results show that the in cylinder turbulence and inlet air cooling and other reasons, the exhaust side temperature is generally higher than the intake side, thus the thermal stress is larger, and the maximum in the second ring inner surface. Mechanical stress is due to the existence of contact with the piston pin, and the maximum value appears in the upper part of the piston pin seat. For the thermo mechanical coupling condition, the maximum stress in the piston of the second inner face, this is the two kind of load stress produced by superposition of the results. Because of the material setting of the rigid pin flexible seat, the two kinds of stress are offset, and the stress is relatively small. Finally, the fatigue life of the piston is calculated by the results obtained by simulation. Combined with the accelerated test theory, a suitable acceleration model is selected, and the simulation fatigue life of different acceleration conditions is fitted in Matlab. By comparing the simulation value and the fitting value, it can be seen that the fitting effect is good, thus the fatigue life of the piston is estimated under the rated condition through the fitting curve. Compared with the simulation results, the thermal load, mechanical load and coupled load, the relative errors were 4.11%, 2.66%, 7.91%, are relatively small, basically meet the engineering requirements, thus proving Allen nice model, inverse power law model and generalized Eyring model respectively as the feasibility of these three kinds of acceleration model under load. After that, it is discussed that when the actual fault data is available, the distribution model should be analyzed first, so that the corresponding characteristic life can be obtained. Then the suitable acceleration model can be used to estimate the service life of the rated condition according to the situation. In conclusion, the three-dimensional boundary condition of piston top surface obtained by 3D CFD and the accelerated test theory are of high accuracy for predicting piston fatigue life. It can be applied to piston reliability evaluation in engineering.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TK401;O21

【相似文獻(xiàn)】

相關(guān)期刊論文 前7條

1 雷曉蔚,焦善慶;削弱活塞熱負(fù)荷的實(shí)驗(yàn)研究[J];西南師范大學(xué)學(xué)報(bào)(自然科學(xué)版);2001年06期

2 譚建松;龐銘;解志民;虞鋼;胡定云;;活塞激光熱負(fù)荷數(shù)值模擬[J];中國(guó)激光;2010年04期

3 鄭永剛;有限元法分析活塞溫度場(chǎng)[J];山東內(nèi)燃機(jī);1995年04期

4 李平;李德智;;農(nóng)機(jī)零部件字碼的識(shí)別[J];科技致富向?qū)?1999年03期

5 李寧;;材料非線性對(duì)活塞熱負(fù)荷的影響分析[J];科技情報(bào)開(kāi)發(fā)與經(jīng)濟(jì);2010年02期

6 白冰;;農(nóng)機(jī)零部件上字碼的識(shí)別[J];科技致富向?qū)?1999年12期

7 宋宏偉;虞鋼;王立新;周良;張金城;;激光誘發(fā)活塞的熱負(fù)荷[J];中國(guó)激光;2006年05期

相關(guān)會(huì)議論文 前1條

1 張東輝;;Authorware活塞運(yùn)動(dòng)范例的改進(jìn)[A];中國(guó)教育技術(shù)協(xié)會(huì)2004年年會(huì)論文集[C];2004年

相關(guān)重要報(bào)紙文章 前1條

1 若訥;怎樣判斷并排除活塞常見(jiàn)故障[N];中國(guó)水運(yùn)報(bào);2008年

相關(guān)博士學(xué)位論文 前2條

1 袁晨恒;自由活塞柴油直線發(fā)電機(jī)系統(tǒng)設(shè)計(jì)與運(yùn)行特性研究[D];北京理工大學(xué);2015年

2 楊洪秀;活塞缸套系統(tǒng)仿生非光滑界面摩擦與潤(rùn)滑機(jī)理的研究[D];吉林大學(xué);2008年

相關(guān)碩士學(xué)位論文 前10條

1 陳永哲;基于數(shù)據(jù)分析的發(fā)動(dòng)機(jī)活塞可靠性研究[D];山東大學(xué);2015年

2 劉泉;活塞設(shè)計(jì)參數(shù)與熱損傷關(guān)聯(lián)分析[D];山東大學(xué);2015年

3 胡成永;熱機(jī)載荷對(duì)活塞應(yīng)力與變形影響規(guī)律研究[D];北京理工大學(xué);2015年

4 潘志剛;某船用低速柴油機(jī)活塞性能研究[D];江蘇科技大學(xué);2015年

5 郭亮;基于正交分析的活塞結(jié)構(gòu)參數(shù)熱敏感性研究[D];中北大學(xué);2016年

6 付志申;活塞熱負(fù)荷模擬試驗(yàn)機(jī)方案設(shè)計(jì)及冷卻系統(tǒng)優(yōu)化[D];中北大學(xué);2016年

7 劉一鳴;鈦合金活塞耐磨性設(shè)計(jì)及鑄造缺陷影響研究[D];北京理工大學(xué);2016年

8 趙冠華;復(fù)合隔熱活塞氣隙隔熱機(jī)理研究及整體結(jié)構(gòu)設(shè)計(jì)[D];北京理工大學(xué);2016年

9 林梅君;增壓柴油機(jī)活塞熱力性能有限元仿真分析[D];湖南大學(xué);2016年

10 魏特特;基于ControlBase的小型煤油活塞發(fā)動(dòng)機(jī)控制策略研究[D];南京航空航天大學(xué);2016年

，

本文編號(hào)：1343378