小型柴油机轴系模态分析及仿真计算研究
|
摘要
曲轴是柴油机中的重要组成部分,其振动是引发内燃机振动的重要因素,它的性能直接影响着柴油机的可靠性和寿命。近年来,随着各种新技术的应用,对内燃机的可靠性和动力性要求越来越高,已有的曲轴轴系振动分析方法越来越难以完全满足内燃机设计的要求。因此,对曲轴轴系振动问题的更精确、更全面的研究显得非常重要。
本文以某一小型柴油机曲轴系为研究对象,模态分析理论为基础,分别对曲轴系在自由状态和约束状态下的多种情况进行试验模态分析。结合试验模态分析的结果,探讨曲轴系各种动态特性仿真建模方法的优缺点。并在发动机运转状态下,对联轴器的扭转刚度、负载的转动惯量和活塞连杆与曲柄销等接触处的润滑情况等因素对曲轴系扭转振动的影响进行了研究。
本论文的主要工作如下：
首先,对某一小型柴油机的曲轴轴系在自由状态和约束状态下的多种情形进行模态敲击试验,并对其进行模态参数识别。将自由状态和约束状态下各种情形的模态试验结果进行对比分析。通过对比分析得出飞轮对曲轴的模态影响较大；主轴承及其润滑油膜的约束支撑刚度对曲轴的弯曲和纵向振动影响较大,对曲轴的扭转振动影响较小。因此可通过对自由状态下带飞轮、皮带轮及活塞连杆曲轴的模态试验来获得运转状态下曲轴的扭转振动模态特性。
其次,以柴油机曲轴系实物为原型,在三维建模软件Pro／Engineer中建立曲轴系的三维实体模型；同时,将曲轴系实体模型导入有限元软件ANSYS中建立其自由状态和约束状态下的多种动态特性仿真计算有限元模型,并对其进行计算模态分析。通过与模态试验结果的对比分析,探讨自由状态和约束状态下各种动态特性仿真建模方法的准确性、优缺点及适用情况。
最后,在发动机运转状态下,对联轴器扭转刚度、负载转动惯量及活塞连杆与曲柄销接触处的润滑情况等因素对曲轴系扭转振动的影响进行了研究,得出了轴系扭转振动频率随联轴器扭转刚度、负载转动惯量及润滑变化的规律。
As an important part of diesel engine, the vibration of crankshaft is an important factor causing engine vibration, the performance of which directly affects the engine reliability and life. In recent years, with the application of new technologies on engine, the requirements for engine's reliability and power performance have become higher and higher. The existing analysis method of engine vibration is difficult to satisfy the requirements of engine design. Therefore, it is very important to study the vibration of crankshafts more accurately and comprehensively.
It focuses on the crankshafts of a small diesel engine, and then tests the model of crankshafts in free state and constrained state based on modal analysis theory.Combining with the results of experimental modal analysis, disscusses the advantages and disadvantages of dynamic characteristics simulation modelling methods for crankshafts. Then in engine's operating condition, studies the influence of coupling's torsional stiffness, load's moment of inertia and lubrication conditions on crankshafts torsional vibration.
The main contents are as follows:
Firstly, it focuses on the crankshafts of a small diesel engine and tests the crankshafts model in free state and constrained state, and the modal parameters of crankshaft in different states are obtained. Then compares and analyzes the modal test results of free state and constrained state. From the contrastive analysis we know that the flywheel has great effect on crankshafts modal characteristics, moreover, the crankshaft's bending and longitudinal vibration is affected by the restraining and supporting stiffness of main bearing, which has little effect on the crankshafts torsional vibration.Therefore,we can get the torsional vibration mode characteristics.of opreating crankshafts from modal tests on the crankshafts with flywheel, pulley, piston and connecting rod in the free state.
Secondly, take diesel engine crankshafts as physical prototypes, create a series of three-dimensional solid model of crankshafts using the three-dimensional modeling software of Pro/Engineer. At the same time, take the solid model of crankshafts into the finite element software of ANSYS to build the dynamic characteristics simulation models in free state and constrained state and calculate the crankshafts modals. From the contrastive analysis with modal test results, disscusses the dynamic characteristics simulation modelling methods of crankshafts which is more excellent and applicable.
Finally, in engine's operating condition, study the influence of coupling's torsional stiffness, load's moment of inertia and lubrication conditions on crankshafts torsional vibration. From the studies, we can obtained the variation of torsional vibration frequencies changed with coupling's torsional stiffness, load's moment of inertia and lubrication conditions.
本文以某一小型柴油机曲轴系为研究对象,模态分析理论为基础,分别对曲轴系在自由状态和约束状态下的多种情况进行试验模态分析。结合试验模态分析的结果,探讨曲轴系各种动态特性仿真建模方法的优缺点。并在发动机运转状态下,对联轴器的扭转刚度、负载的转动惯量和活塞连杆与曲柄销等接触处的润滑情况等因素对曲轴系扭转振动的影响进行了研究。
本论文的主要工作如下：
首先,对某一小型柴油机的曲轴轴系在自由状态和约束状态下的多种情形进行模态敲击试验,并对其进行模态参数识别。将自由状态和约束状态下各种情形的模态试验结果进行对比分析。通过对比分析得出飞轮对曲轴的模态影响较大；主轴承及其润滑油膜的约束支撑刚度对曲轴的弯曲和纵向振动影响较大,对曲轴的扭转振动影响较小。因此可通过对自由状态下带飞轮、皮带轮及活塞连杆曲轴的模态试验来获得运转状态下曲轴的扭转振动模态特性。
其次,以柴油机曲轴系实物为原型,在三维建模软件Pro／Engineer中建立曲轴系的三维实体模型；同时,将曲轴系实体模型导入有限元软件ANSYS中建立其自由状态和约束状态下的多种动态特性仿真计算有限元模型,并对其进行计算模态分析。通过与模态试验结果的对比分析,探讨自由状态和约束状态下各种动态特性仿真建模方法的准确性、优缺点及适用情况。
最后,在发动机运转状态下,对联轴器扭转刚度、负载转动惯量及活塞连杆与曲柄销接触处的润滑情况等因素对曲轴系扭转振动的影响进行了研究,得出了轴系扭转振动频率随联轴器扭转刚度、负载转动惯量及润滑变化的规律。
As an important part of diesel engine, the vibration of crankshaft is an important factor causing engine vibration, the performance of which directly affects the engine reliability and life. In recent years, with the application of new technologies on engine, the requirements for engine's reliability and power performance have become higher and higher. The existing analysis method of engine vibration is difficult to satisfy the requirements of engine design. Therefore, it is very important to study the vibration of crankshafts more accurately and comprehensively.
It focuses on the crankshafts of a small diesel engine, and then tests the model of crankshafts in free state and constrained state based on modal analysis theory.Combining with the results of experimental modal analysis, disscusses the advantages and disadvantages of dynamic characteristics simulation modelling methods for crankshafts. Then in engine's operating condition, studies the influence of coupling's torsional stiffness, load's moment of inertia and lubrication conditions on crankshafts torsional vibration.
The main contents are as follows:
Firstly, it focuses on the crankshafts of a small diesel engine and tests the crankshafts model in free state and constrained state, and the modal parameters of crankshaft in different states are obtained. Then compares and analyzes the modal test results of free state and constrained state. From the contrastive analysis we know that the flywheel has great effect on crankshafts modal characteristics, moreover, the crankshaft's bending and longitudinal vibration is affected by the restraining and supporting stiffness of main bearing, which has little effect on the crankshafts torsional vibration.Therefore,we can get the torsional vibration mode characteristics.of opreating crankshafts from modal tests on the crankshafts with flywheel, pulley, piston and connecting rod in the free state.
Secondly, take diesel engine crankshafts as physical prototypes, create a series of three-dimensional solid model of crankshafts using the three-dimensional modeling software of Pro/Engineer. At the same time, take the solid model of crankshafts into the finite element software of ANSYS to build the dynamic characteristics simulation models in free state and constrained state and calculate the crankshafts modals. From the contrastive analysis with modal test results, disscusses the dynamic characteristics simulation modelling methods of crankshafts which is more excellent and applicable.
Finally, in engine's operating condition, study the influence of coupling's torsional stiffness, load's moment of inertia and lubrication conditions on crankshafts torsional vibration. From the studies, we can obtained the variation of torsional vibration frequencies changed with coupling's torsional stiffness, load's moment of inertia and lubrication conditions.
引文
[1]贾锡印.船舶内燃机结构[M].哈尔滨工程大学出版社,1995：2-6
[2]吴炎庭,袁卫平.内燃机噪声振动与控制[M].北京：机械工业出版社,2005：239-240
[3]张德文.从约束试验数据提取自由结构模态参数[J].强度与环境,2005,32(1)：10-15
[4]王全英.曲轴弯曲带来的后果[J].山东农机化,1996,(07)
[5]李海涛.曲轴弯曲带来的恶果[J].山东农机化,2001,(02)
[6]吕兴才,舒歌群,沈红斌.汽车发动机曲轴纵向振动的研究[J].汽车工程,2001,23(5)：332-336
[7]梁兴雨,舒歌群,张宝欢,王养军,陈达亮.基于瑞利法的内燃机曲轴纵向振动研究[J].中国机械工程,2008,1 9(6)：648-652
[8]张洪田,张志华,刘志刚,张天元等.船舶推进轴系纵扭耦合振动研究[J].中国造船,1995(2)：68-76
[9]王长荣,谭达明.内燃机动力学[M].北京：中国铁道出社.1990
[10]李震,桂长林,孙军.内燃机曲轴轴系振动分析研究的现状、讨论与展望.内燃机学报,2002,20(5)：469-474
[11]顾培英,邓昌,吴福生.结构模态分析及其损伤诊断[M].南京：东南大学出版社,2008：3-4
[12]张令弥.动态测试技术的发展系列讲座.振动与冲击,1998,17(3)：83-85
[13]管迪华.模态分析技术[M].北京：清华大学出版社,1996：45-46
[14]Ward Heylen,Stefan Lammens,Paul Sas.Modal Analysis Theory and Testing[M]. Levven:Katholieke Universiteit Levven-Department werktvi gkunde,1997.
[15]林循鸿.振动模态参数识别及其应用[M].南京：东南大学出版社,1994.
[16]王彤,张令弥.运行模态分析的频域空间域分解法及其应用[J].航空学报.2006,1：62-66
[17]P. Mohanty, D. J. Rixen. Modified SSTD method to account for harmonic excitations during operational modal analysis[J].Mechanism and Machine Theory.2004, 39(12):1247-1255.
[18]Bor-Tsuen Wang, Deng-Kai Cheng. Modal analysis of mdof system by using free vibration response data only [J] Journal of Sound and Vibration,2008,311:737-755.
[19]杨华.模态参数识别的研究现状及发展[J].机械,2006,33(10A)：1-3
[20]方远翔,陈安宁,董卫平.振动模态分析技术[M].北京：国防工业出版社,1993
[21]Ibrahim.S.R, Mikulcik.E.C. A Method for the direct identification of vibration parameters from the free response[J].The Shock and Vibration Bulletin,1977,47(4):183-189.
[22]Ibrahim. S.R. Random Decrement Technique for Modal Identification of Structures[J].AIAAJ. of Spacecraft and Rockets,1977,14(11),697-70
[23]Juang, J.N. and Pappa,R.S.,An Eigensystem Realization Algorithm for Modal Parameter Identification and Model Reduction, J.Guidance[J],1985,8(5):620-627.
[24]黄积喜.发动机扭振模态试验及响应分析[J],汽车工程,1982,4：7-21
[25]王国治.柴油机轴系扭振研究中的模态分析方法[J],内燃机学报,1986,4(3)：249-259
[26]张准,彭玉莺.内燃机曲轴一飞轮系统扭振的复模态分析[J],江苏工学院学报,1 986,7(2)：45-59
[27]阳松林,刘裕昭.曲轴模态分析的有限元方法[J],二汽科技,1991,5：19-24
[28]申屠森,章文辉,盛建军,缪岳川,吕国培。TC387型柴油机曲轴飞轮系统扭转应力动态试验与计算[J],内燃机学报,1993,11(3)：243-248
[29]邹春平.凸轮发动机轴系扭振模态综合分析[J],中国造船,1996,4：74-82
[30]邹春平.凸轮发动机轴系横向振动模态综合技术[J],华东船舶工业学院学报,1998,12(1)：41-50
[31]樊文欣,李霆.柴油机模态试验与分析[J].车用发动机,1997,1：51-54
[32]韩松涛,郝志勇.6102B型柴油机曲轴三维有限元模态分析与试验研究[J],农业机械学报,2001,32(4)：74-77
[33]郝志勇,韩松涛.主轴承刚度对曲轴振动特性影响的研究[J],车辆与动力技术,2001,2：31-35
[34]雷宣扬,宋希庚,徐继承.内燃机曲轴的三维振动特性模拟—飞轮细分.振动、测试与诊断,2003,23(2)：105-109
[35]雷宣扬,宋希庚,薛冬新.含裂纹曲轴的振动特性分析[J],农业机械学报,2003,34(6)：179-181
[36]刘永红,任工昌,王步康.曲轴轴系的动特性分析[J].内燃机学报,2003,21(5)：351-355
[37]刘永红,任工昌,王步康.发电机活塞—曲轴的周期动特性分析[J].武汉理工大学学报：交通科学与工程版,2003,27(5)：585-588
[38]陈敏雄,陈端石.柴油机各缸负荷不均衡对轴系扭转振动特性影响的研究[J].噪声与振动控制,2003(2)：3-10
[39]刘永红,任工昌,王步康.润滑性能对活塞-轴系的影响[J].润滑与密封,2004(4)：16-18
[40]华春蓉,闫兵,董大伟,许明恒.识别运行状态下内燃机曲轴角振动模态参数的新方法[J],内燃机工程,2010,31(1)：92-96
[41]曹树谦,张文德,萧龙翔著.振动结构模态分析[M].天津：天津大学出版社,2001.3
[42]李德葆,陆秋海著.实验模态分析及其应用[M].北京：科学出版社,2001
[43]张洪信,吴俊飞,沈孝芹.有限元基础理论与ANSYS应用[M].北京：机械工业出版社,2006：1-3
[44]陈国荣.有限单元法原理及应用[M].北京：科学出版社,2009：1-3
[45]王助成,邵敏.有限单元法基本原理和数值方法[M].北京：清华大学出版社,1997：443-481
[46]应隆安,陈传淼.有限元理论与方法[M].北京：科学出版社,2009：688-700
[47]Ahmad A.Smaili,Mahaveer P. Khetawat. Dynamic modeling of automotive engine erankshafts[J].Mechanism and Machine Theory.1994,29(7):995-1006
[48]Okamura H,Shinno A,Sogabe K. Dynamic stiffness matrix method for three-dimensional analysis of crankshaft vibrations. (1st report. The background and applications to a planar structure crankshaft system).Nippon Kikai Gakkai Ronbunshu,C Hen/Transactions of the Japan Society of MechanicalEngineers,1989 55(516):1965-1972
[49]Kimura J, Shiono K,Okamura H. Experiments and Analysis of Crankshaft Three-Dimensional Vibrations and Bending Stressesina V-Type Ten Cylinder Engine:Influence of Crankshaft Gyroscopic Motions.SAE Paper 971995,1997:999～1007
[50]Morita T,Okamura H. Simple modeling and analysis for crankshaft three-dimensional vibrations, Part 2:application to an operating engine crankshaft. ASME Journal of Vibration and Acoustics.1995,117:80～87
[51]雷宣扬,宋希庚,徐继承.内燃机曲轴的三维振动特性模拟—飞轮细分[J].振动、测试与诊断,2003,23(2)：105—109
[52]博弈创作室.ANSYS9.0经典产品基础教程与实例详解[M].中国水利水电出版社,2006：420—-435
[53]杨镭.汽车发动机曲轴扭转振动分析及控制[D].重庆大学,2005
[54]Hideo Okamura, Tetsuji Morita. Influence of Crankshaft-Pulley Dimensions on Crankshaft Vibrations and Engine-Structure Noise and Vibration [R]. SAE 931303,1993.
[55]张直明.滑动轴承的流体动力润滑理论[M].北京：高等教育出版社,1986.
[56]R.AUB J,KLDY P. Analytical investigation of crankshaft dynamics as a virtual engine module[N].SAE paper,1999-01-17 507.
[2]吴炎庭,袁卫平.内燃机噪声振动与控制[M].北京：机械工业出版社,2005：239-240
[3]张德文.从约束试验数据提取自由结构模态参数[J].强度与环境,2005,32(1)：10-15
[4]王全英.曲轴弯曲带来的后果[J].山东农机化,1996,(07)
[5]李海涛.曲轴弯曲带来的恶果[J].山东农机化,2001,(02)
[6]吕兴才,舒歌群,沈红斌.汽车发动机曲轴纵向振动的研究[J].汽车工程,2001,23(5)：332-336
[7]梁兴雨,舒歌群,张宝欢,王养军,陈达亮.基于瑞利法的内燃机曲轴纵向振动研究[J].中国机械工程,2008,1 9(6)：648-652
[8]张洪田,张志华,刘志刚,张天元等.船舶推进轴系纵扭耦合振动研究[J].中国造船,1995(2)：68-76
[9]王长荣,谭达明.内燃机动力学[M].北京：中国铁道出社.1990
[10]李震,桂长林,孙军.内燃机曲轴轴系振动分析研究的现状、讨论与展望.内燃机学报,2002,20(5)：469-474
[11]顾培英,邓昌,吴福生.结构模态分析及其损伤诊断[M].南京：东南大学出版社,2008：3-4
[12]张令弥.动态测试技术的发展系列讲座.振动与冲击,1998,17(3)：83-85
[13]管迪华.模态分析技术[M].北京：清华大学出版社,1996：45-46
[14]Ward Heylen,Stefan Lammens,Paul Sas.Modal Analysis Theory and Testing[M]. Levven:Katholieke Universiteit Levven-Department werktvi gkunde,1997.
[15]林循鸿.振动模态参数识别及其应用[M].南京：东南大学出版社,1994.
[16]王彤,张令弥.运行模态分析的频域空间域分解法及其应用[J].航空学报.2006,1：62-66
[17]P. Mohanty, D. J. Rixen. Modified SSTD method to account for harmonic excitations during operational modal analysis[J].Mechanism and Machine Theory.2004, 39(12):1247-1255.
[18]Bor-Tsuen Wang, Deng-Kai Cheng. Modal analysis of mdof system by using free vibration response data only [J] Journal of Sound and Vibration,2008,311:737-755.
[19]杨华.模态参数识别的研究现状及发展[J].机械,2006,33(10A)：1-3
[20]方远翔,陈安宁,董卫平.振动模态分析技术[M].北京：国防工业出版社,1993
[21]Ibrahim.S.R, Mikulcik.E.C. A Method for the direct identification of vibration parameters from the free response[J].The Shock and Vibration Bulletin,1977,47(4):183-189.
[22]Ibrahim. S.R. Random Decrement Technique for Modal Identification of Structures[J].AIAAJ. of Spacecraft and Rockets,1977,14(11),697-70
[23]Juang, J.N. and Pappa,R.S.,An Eigensystem Realization Algorithm for Modal Parameter Identification and Model Reduction, J.Guidance[J],1985,8(5):620-627.
[24]黄积喜.发动机扭振模态试验及响应分析[J],汽车工程,1982,4：7-21
[25]王国治.柴油机轴系扭振研究中的模态分析方法[J],内燃机学报,1986,4(3)：249-259
[26]张准,彭玉莺.内燃机曲轴一飞轮系统扭振的复模态分析[J],江苏工学院学报,1 986,7(2)：45-59
[27]阳松林,刘裕昭.曲轴模态分析的有限元方法[J],二汽科技,1991,5：19-24
[28]申屠森,章文辉,盛建军,缪岳川,吕国培。TC387型柴油机曲轴飞轮系统扭转应力动态试验与计算[J],内燃机学报,1993,11(3)：243-248
[29]邹春平.凸轮发动机轴系扭振模态综合分析[J],中国造船,1996,4：74-82
[30]邹春平.凸轮发动机轴系横向振动模态综合技术[J],华东船舶工业学院学报,1998,12(1)：41-50
[31]樊文欣,李霆.柴油机模态试验与分析[J].车用发动机,1997,1：51-54
[32]韩松涛,郝志勇.6102B型柴油机曲轴三维有限元模态分析与试验研究[J],农业机械学报,2001,32(4)：74-77
[33]郝志勇,韩松涛.主轴承刚度对曲轴振动特性影响的研究[J],车辆与动力技术,2001,2：31-35
[34]雷宣扬,宋希庚,徐继承.内燃机曲轴的三维振动特性模拟—飞轮细分.振动、测试与诊断,2003,23(2)：105-109
[35]雷宣扬,宋希庚,薛冬新.含裂纹曲轴的振动特性分析[J],农业机械学报,2003,34(6)：179-181
[36]刘永红,任工昌,王步康.曲轴轴系的动特性分析[J].内燃机学报,2003,21(5)：351-355
[37]刘永红,任工昌,王步康.发电机活塞—曲轴的周期动特性分析[J].武汉理工大学学报：交通科学与工程版,2003,27(5)：585-588
[38]陈敏雄,陈端石.柴油机各缸负荷不均衡对轴系扭转振动特性影响的研究[J].噪声与振动控制,2003(2)：3-10
[39]刘永红,任工昌,王步康.润滑性能对活塞-轴系的影响[J].润滑与密封,2004(4)：16-18
[40]华春蓉,闫兵,董大伟,许明恒.识别运行状态下内燃机曲轴角振动模态参数的新方法[J],内燃机工程,2010,31(1)：92-96
[41]曹树谦,张文德,萧龙翔著.振动结构模态分析[M].天津：天津大学出版社,2001.3
[42]李德葆,陆秋海著.实验模态分析及其应用[M].北京：科学出版社,2001
[43]张洪信,吴俊飞,沈孝芹.有限元基础理论与ANSYS应用[M].北京：机械工业出版社,2006：1-3
[44]陈国荣.有限单元法原理及应用[M].北京：科学出版社,2009：1-3
[45]王助成,邵敏.有限单元法基本原理和数值方法[M].北京：清华大学出版社,1997：443-481
[46]应隆安,陈传淼.有限元理论与方法[M].北京：科学出版社,2009：688-700
[47]Ahmad A.Smaili,Mahaveer P. Khetawat. Dynamic modeling of automotive engine erankshafts[J].Mechanism and Machine Theory.1994,29(7):995-1006
[48]Okamura H,Shinno A,Sogabe K. Dynamic stiffness matrix method for three-dimensional analysis of crankshaft vibrations. (1st report. The background and applications to a planar structure crankshaft system).Nippon Kikai Gakkai Ronbunshu,C Hen/Transactions of the Japan Society of MechanicalEngineers,1989 55(516):1965-1972
[49]Kimura J, Shiono K,Okamura H. Experiments and Analysis of Crankshaft Three-Dimensional Vibrations and Bending Stressesina V-Type Ten Cylinder Engine:Influence of Crankshaft Gyroscopic Motions.SAE Paper 971995,1997:999～1007
[50]Morita T,Okamura H. Simple modeling and analysis for crankshaft three-dimensional vibrations, Part 2:application to an operating engine crankshaft. ASME Journal of Vibration and Acoustics.1995,117:80～87
[51]雷宣扬,宋希庚,徐继承.内燃机曲轴的三维振动特性模拟—飞轮细分[J].振动、测试与诊断,2003,23(2)：105—109
[52]博弈创作室.ANSYS9.0经典产品基础教程与实例详解[M].中国水利水电出版社,2006：420—-435
[53]杨镭.汽车发动机曲轴扭转振动分析及控制[D].重庆大学,2005
[54]Hideo Okamura, Tetsuji Morita. Influence of Crankshaft-Pulley Dimensions on Crankshaft Vibrations and Engine-Structure Noise and Vibration [R]. SAE 931303,1993.
[55]张直明.滑动轴承的流体动力润滑理论[M].北京：高等教育出版社,1986.
[56]R.AUB J,KLDY P. Analytical investigation of crankshaft dynamics as a virtual engine module[N].SAE paper,1999-01-17 507.