【摘要】：近年來,節(jié)能減排日益成為人們關(guān)注的焦點,而汽車輕量化作為節(jié)能減排的有效途徑之一,也受到人們的重視。為降低發(fā)動機(jī)質(zhì)量,達(dá)到節(jié)能減排的目的,發(fā)動機(jī)中越來越多的金屬零件被工程塑料制件所取代,而機(jī)油冷卻器蓋也是其中的一個。但塑料機(jī)油冷卻器蓋距離振動激勵源較近且屬于薄壁件,容易產(chǎn)生較大的輻射噪聲;同時采用工程塑料材質(zhì),剛度小強(qiáng)度低,容易產(chǎn)生裂紋等強(qiáng)度問題。所以本文以塑料機(jī)油冷卻器蓋為研究對象,對其進(jìn)行振動噪聲和結(jié)構(gòu)強(qiáng)度仿真計算并以低噪聲和高強(qiáng)度為目標(biāo)對其進(jìn)行結(jié)構(gòu)優(yōu)化。主要研究內(nèi)容如下:建立塑料機(jī)油冷卻器蓋結(jié)構(gòu)有限元模型并通過模態(tài)試驗對該模型的正確性進(jìn)行了驗證;建立機(jī)油冷卻器蓋內(nèi)腔流體模型并與機(jī)油冷卻器蓋一起構(gòu)成流固耦合模型,對其進(jìn)行耦合模態(tài)分析與對比,結(jié)果表明機(jī)油冷卻器蓋內(nèi)腔冷卻液的存在對其頻率和振型都有著較大的影響,在后續(xù)的仿真計算及優(yōu)化過程中應(yīng)當(dāng)考慮流體與固體的耦合作用。選定典某型工況,測取螺栓點處的加速度信號,采用模態(tài)疊加法對塑料機(jī)油冷卻器蓋進(jìn)行頻響分析,得到罩蓋速度響應(yīng)并對其振動特性進(jìn)行分析;基于上述計算結(jié)果進(jìn)行虛擬聲功率級預(yù)測,提取其中的關(guān)鍵頻率作為優(yōu)化目標(biāo);同時,計算了機(jī)油冷卻器蓋內(nèi)腔流體壓力,將其映射到機(jī)油冷卻器蓋上進(jìn)行應(yīng)力應(yīng)變計算分析;最后計算了等壓下的應(yīng)變能并將其作為優(yōu)化目標(biāo)。在塑料機(jī)油冷卻器蓋底面增加一層設(shè)計空間,采用加權(quán)指數(shù)法將各優(yōu)化目標(biāo)歸一化為一個總目標(biāo),同時施加約束條件,對塑料機(jī)油冷卻器蓋進(jìn)行多目標(biāo)拓?fù)鋬?yōu)化。在塑料機(jī)油冷卻器底面布置加強(qiáng)筋并定義加強(qiáng)筋參數(shù)變量,根據(jù)最優(yōu)拉丁超立方進(jìn)行樣本點設(shè)計,得到加強(qiáng)筋試驗設(shè)計矩陣;根據(jù)試驗設(shè)計矩陣建立流固耦合模型并計算得到各優(yōu)化目標(biāo)的取值;將加強(qiáng)筋各參數(shù)變量作為輸入,各優(yōu)化目標(biāo)計算結(jié)果作為輸出,采用響應(yīng)面模型(RSM)建立輸入與輸出的近似模型并對該近似模型的正確性進(jìn)行驗證;以低噪聲、高強(qiáng)度和加強(qiáng)筋體積小為優(yōu)化目標(biāo),采用第二代非劣排序遺傳算法(NSGA-II)對加強(qiáng)筋參數(shù)進(jìn)行優(yōu)化。優(yōu)化后塑料機(jī)油冷卻器蓋振動噪聲都有所下降且整體結(jié)構(gòu)強(qiáng)度增加,為塑料機(jī)油冷卻器蓋的設(shè)計提供指導(dǎo)。
[Abstract]:In recent years, energy saving and emission reduction have increasingly become the focus of attention, and as one of the effective ways of energy saving and emission reduction, automobile lightweight has also been paid attention to. In order to reduce the engine quality and achieve the purpose of energy saving and emission reduction, more and more metal parts are replaced by engineering plastic parts in the engine, and the oil cooler cover is one of them. But the plastic oil cooler cover is close to the vibration excitation source and belongs to the thin-walled parts, which is easy to produce large radiation noise. At the same time, using engineering plastic material, the stiffness is low and the strength is low, and cracks are easy to occur. So this paper takes the plastic oil cooler cover as the research object, carries on the vibration noise and the structural strength simulation calculation to it, and takes the low noise and the high strength as the target to carry on the structure optimization. The main research contents are as follows: the finite element model of plastic oil cooler cover structure is established and the correctness of the model is verified by modal test. The fluid model of the inner cavity of the oil cooler cap is established and the fluid-solid coupling model is constructed together with the oil cooler cover. The coupling modal analysis and comparison are carried out. The results show that the existence of coolant in the inner cavity of the oil cooler has a great influence on its frequency and mode shape. The coupling effect between fluid and solid should be considered in the subsequent simulation and optimization. The acceleration signal at the bolt point is measured under a typical working condition, and the frequency response of the plastic oil cooler cover is analyzed by modal superposition method, and the velocity response of the cover is obtained and its vibration characteristics are analyzed. Based on the above calculation results, the virtual acoustic power level is predicted and the key frequency is extracted as the optimization objective. At the same time, the pressure of fluid in the inner cavity of the oil cooler cap is calculated and mapped to the oil cooler cover for the stress and strain calculation and analysis. Finally, the strain energy under isobaric pressure is calculated and used as the optimization objective. A layer of design space is added to the bottom surface of the plastic oil cooler cover. Each optimization objective is normalized to a general objective by using the weighted exponent method. At the same time, the multi-objective topology optimization of the plastic oil cooler cover is carried out by applying the constraint condition. The reinforcement bars are arranged on the bottom surface of the plastic oil cooler and the parameter variables of the reinforcement bars are defined. According to the optimal Latin hypercube sample point design matrix is obtained. Based on the experimental design matrix, the fluid-solid coupling model is established and the values of each optimization target are calculated. The parameter variables of reinforcement bar are taken as input and the calculation results of each optimization objective are taken as output. The approximate model of input and output is established by using response surface model (RSM) and the correctness of the approximate model is verified. The second generation noninferior sorting genetic algorithm (NSGA-II) is used to optimize the reinforcement parameters with the aim of low noise, high strength and small reinforcement volume. After optimization, the vibration and noise of the plastic oil cooler cover are decreased and the overall structural strength is increased, which provides guidance for the design of the plastic oil cooler cover.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：U464.13

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 唐作興,蔣冬明;發(fā)動機(jī)機(jī)油冷卻器的設(shè)計原理及應(yīng)用[J];內(nèi)燃機(jī);1999年01期

2 秦萌,陳江平,陳芝久;車用發(fā)動機(jī)機(jī)油冷卻器流動的數(shù)值模擬研究[J];車用發(fā)動機(jī);2004年03期

3 馬海健;;內(nèi)置螺旋片管式機(jī)油冷卻器的設(shè)計[J];農(nóng)機(jī)化研究;2006年09期

4 李頂根;杜一;黃榮華;;發(fā)動機(jī)機(jī)油冷卻器性能試驗系統(tǒng)的研制[J];中國測試;2009年03期

5 童寶宏;桂長林;;發(fā)動機(jī)機(jī)油冷卻器流量特性的試驗與仿真[J];車用發(fā)動機(jī);2009年03期

6 周輝志;;6DY柴油機(jī)機(jī)油冷卻器的試驗研究與設(shè)計優(yōu)化[J];現(xiàn)代車用動力;2012年03期

7 管宇;趙晴;;條形機(jī)油冷卻器缺陷的有限元分析[J];機(jī)械制造與自動化;2013年05期

8 祥根;王伯順;趙以生;;無銀焊接板翅武機(jī)油冷卻器[J];汽車技術(shù);1989年06期

9 玄哲浩,高青,崔淑琴;依維柯汽車機(jī)油冷卻器傳熱及流阻性能的試驗研究[J];汽車技術(shù);1994年07期

10 王忠合;工程機(jī)械新型機(jī)油冷卻器[J];工程機(jī)械;1997年01期

相關(guān)會議論文 前1條

1 陸紅兵;;機(jī)油冷卻器試驗方法研究[A];四川省汽車工程學(xué)會二屆二次學(xué)術(shù)年會論文集[C];1996年

相關(guān)重要報紙文章 前2條

1 王功勝;奧迪轎車油水混合[N];中國汽車報;2002年

2 寧波;聯(lián)合收割機(jī)封存保養(yǎng)有技巧[N];運城日報;2005年

相關(guān)碩士學(xué)位論文 前10條

1 劉世海;X6105BC-15型船用高速柴油機(jī)機(jī)油冷卻器的改進(jìn)設(shè)計[D];江西農(nóng)業(yè)大學(xué);2016年

2 郭遷;低噪聲、高強(qiáng)度塑料機(jī)油冷卻器蓋結(jié)構(gòu)優(yōu)化設(shè)計研究[D];天津大學(xué);2016年

3 唐佳;機(jī)油冷卻器氣密性檢測流程優(yōu)化及實現(xiàn)技術(shù)研究[D];上海交通大學(xué);2009年

4 江雪峰;內(nèi)燃機(jī)機(jī)油冷卻器傳熱性能試驗系統(tǒng)的研制[D];浙江大學(xué);2003年

5 謝勇志;高速汽油機(jī)機(jī)油冷卻器的性能優(yōu)化研究[D];湖南大學(xué);2014年

6 王學(xué)豐;車輛機(jī)油冷卻器綜合測試系統(tǒng)的研究和實現(xiàn)[D];浙江大學(xué);2007年

7 翁玲靈;一種機(jī)油冷卻器自動組片控制系統(tǒng)研制[D];揚州大學(xué);2014年

8 管宇;機(jī)油冷卻器焊接缺陷的有限元分析及實驗研究[D];揚州大學(xué);2013年

9 夏云晴;條形機(jī)油冷卻器自動組片系統(tǒng)研究與開發(fā)[D];揚州大學(xué);2009年

10 周燕峰;車用機(jī)油冷卻器靜壓爆破試驗系統(tǒng)的研究與開發(fā)[D];浙江大學(xué);2006年

，

本文編號：2428260