低噪声、高强度塑料机油冷却器盖结构优化设计研究
发布时间：2019-02-22 13:07
【摘要】：近年来,节能减排日益成为人们关注的焦点,而汽车轻量化作为节能减排的有效途径之一,也受到人们的重视。为降低发动机质量,达到节能减排的目的,发动机中越来越多的金属零件被工程塑料制件所取代,而机油冷却器盖也是其中的一个。但塑料机油冷却器盖距离振动激励源较近且属于薄壁件,容易产生较大的辐射噪声;同时采用工程塑料材质,刚度小强度低,容易产生裂纹等强度问题。所以本文以塑料机油冷却器盖为研究对象,对其进行振动噪声和结构强度仿真计算并以低噪声和高强度为目标对其进行结构优化。主要研究内容如下:建立塑料机油冷却器盖结构有限元模型并通过模态试验对该模型的正确性进行了验证;建立机油冷却器盖内腔流体模型并与机油冷却器盖一起构成流固耦合模型,对其进行耦合模态分析与对比,结果表明机油冷却器盖内腔冷却液的存在对其频率和振型都有着较大的影响,在后续的仿真计算及优化过程中应当考虑流体与固体的耦合作用。选定典某型工况,测取螺栓点处的加速度信号,采用模态叠加法对塑料机油冷却器盖进行频响分析,得到罩盖速度响应并对其振动特性进行分析;基于上述计算结果进行虚拟声功率级预测,提取其中的关键频率作为优化目标;同时,计算了机油冷却器盖内腔流体压力,将其映射到机油冷却器盖上进行应力应变计算分析;最后计算了等压下的应变能并将其作为优化目标。在塑料机油冷却器盖底面增加一层设计空间,采用加权指数法将各优化目标归一化为一个总目标,同时施加约束条件,对塑料机油冷却器盖进行多目标拓扑优化。在塑料机油冷却器底面布置加强筋并定义加强筋参数变量,根据最优拉丁超立方进行样本点设计,得到加强筋试验设计矩阵;根据试验设计矩阵建立流固耦合模型并计算得到各优化目标的取值;将加强筋各参数变量作为输入,各优化目标计算结果作为输出,采用响应面模型(RSM)建立输入与输出的近似模型并对该近似模型的正确性进行验证;以低噪声、高强度和加强筋体积小为优化目标,采用第二代非劣排序遗传算法(NSGA-II)对加强筋参数进行优化。优化后塑料机油冷却器盖振动噪声都有所下降且整体结构强度增加,为塑料机油冷却器盖的设计提供指导。
[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.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U464.13
本文编号：2428260
[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.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U464.13
【相似文献】
相关期刊论文 前10条
1 唐作兴,蒋冬明;发动机机油冷却器的设计原理及应用[J];内燃机;1999年01期
2 秦萌,陈江平,陈芝久;车用发动机机油冷却器流动的数值模拟研究[J];车用发动机;2004年03期
3 马海健;;内置螺旋片管式机油冷却器的设计[J];农机化研究;2006年09期
4 李顶根;杜一;黄荣华;;发动机机油冷却器性能试验系统的研制[J];中国测试;2009年03期
5 童宝宏;桂长林;;发动机机油冷却器流量特性的试验与仿真[J];车用发动机;2009年03期
6 周辉志;;6DY柴油机机油冷却器的试验研究与设计优化[J];现代车用动力;2012年03期
7 管宇;赵晴;;条形机油冷却器缺陷的有限元分析[J];机械制造与自动化;2013年05期
8 祥根;王伯顺;赵以生;;无银焊接板翅武机油冷却器[J];汽车技术;1989年06期
9 玄哲浩,高青,崔淑琴;依维柯汽车机油冷却器传热及流阻性能的试验研究[J];汽车技术;1994年07期
10 王忠合;工程机械新型机油冷却器[J];工程机械;1997年01期
相关会议论文 前1条
1 陆红兵;;机油冷却器试验方法研究[A];四川省汽车工程学会二届二次学术年会论文集[C];1996年
相关重要报纸文章 前2条
1 王功胜;奥迪轿车油水混合[N];中国汽车报;2002年
2 宁波;联合收割机封存保养有技巧[N];运城日报;2005年
相关硕士学位论文 前10条
1 刘世海;X6105BC-15型船用高速柴油机机油冷却器的改进设计[D];江西农业大学;2016年
2 郭迁;低噪声、高强度塑料机油冷却器盖结构优化设计研究[D];天津大学;2016年
3 唐佳;机油冷却器气密性检测流程优化及实现技术研究[D];上海交通大学;2009年
4 江雪峰;内燃机机油冷却器传热性能试验系统的研制[D];浙江大学;2003年
5 谢勇志;高速汽油机机油冷却器的性能优化研究[D];湖南大学;2014年
6 王学丰;车辆机油冷却器综合测试系统的研究和实现[D];浙江大学;2007年
7 翁玲灵;一种机油冷却器自动组片控制系统研制[D];扬州大学;2014年
8 管宇;机油冷却器焊接缺陷的有限元分析及实验研究[D];扬州大学;2013年
9 夏云晴;条形机油冷却器自动组片系统研究与开发[D];扬州大学;2009年
10 周燕峰;车用机油冷却器静压爆破试验系统的研究与开发[D];浙江大学;2006年
，本文编号：2428260
本文链接：https://www.wllwen.com/kejilunwen/qiche/2428260.html
