车架试验模态分析及其结构动力修改研究
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摘要
汽车行驶时,作用在汽车各部件上的载荷都是动载荷。车架作为汽车结构的主要部分,承受着来自路面和其上各种部件的复杂动载。若这些动载荷的频率与车架的某阶固有频率接近时,车架将产生强烈的振动,这种共振现象不仅会影响汽车的舒适性,还会引起结构很高的动应力,造成较早的疲劳破坏或产生不允许的变形。为使车架在使用中避免共振、确保安全可靠,需要深入了解其动态特性,必要时进行合理的动力修改。模态分析技术是研究构件动态特性的一种行之有效的试验方法,通过试验模态分析技术可以较为准确地得到结构的固有频率和模态振型等模态参数。
本文以某车架为研究对象,在综合考虑悬挂条件、激励方式及位置对试验结果影响的基础上,对其进行试验模态分析,得到车架前五阶模态参数;之后,利用路面谱采集试验得到的路面激励信号作为输入,对车架进行动力响应模拟,以得到车架在典型路面上的响应特性;最后,在研究质量和刚度的改变对车架动态特性影响的基础上,探索一种提高车架固有频率的结构动力修改方法,为车架的结构优化提供理论依据。
All the loads that act on the automobile's parts belong to dynamic loads when the vehicle runs on the road. As one part of the automobile structure, the frame withstands the complex dynamic loads coming from the road surface and the other parts that fixed on it. If the frequency of these dynamic load close with some the natural frequency of the frame, the frame will be caused the intense vibration which will not only affect automobile's comfortableness, but also cause the very high dynamic-load stress, and make the early fatigue failure or the un-allowed distortion happened .In order to prevent the frame' resonating and make sure the safety and the reliableness in the use, its dynamic characteristic need to be studied deeply and the dynamic modification should be carried on if necessary . The modal analysis is an effective method which studies the dynamic characteristic of the component and structure. The modal parameters such as natural frequency and vibration mode, can be obtain through the modal test exactly.
One type automobile frame is regarded as the studied object in this paper. Based on the overall evaluation of the influence on the result by the hanging condition, the excitation method and the point arrangement, the first five modal parameters are obtained through the modal test firstly. Then the simulation force response analysis of the frame is carried on under the typical road surface condition. The simulation force signal is obtained through the road testing for some typical road surface. Finally, a structural dynamic modification method which is going to raise the natural frequency of the frame is explored based on the studying of the dynamic characteristic which influenced by the change of its mass and rigidity. It provided one helpful method for frame structure optimization.
本文以某车架为研究对象,在综合考虑悬挂条件、激励方式及位置对试验结果影响的基础上,对其进行试验模态分析,得到车架前五阶模态参数;之后,利用路面谱采集试验得到的路面激励信号作为输入,对车架进行动力响应模拟,以得到车架在典型路面上的响应特性;最后,在研究质量和刚度的改变对车架动态特性影响的基础上,探索一种提高车架固有频率的结构动力修改方法,为车架的结构优化提供理论依据。
All the loads that act on the automobile's parts belong to dynamic loads when the vehicle runs on the road. As one part of the automobile structure, the frame withstands the complex dynamic loads coming from the road surface and the other parts that fixed on it. If the frequency of these dynamic load close with some the natural frequency of the frame, the frame will be caused the intense vibration which will not only affect automobile's comfortableness, but also cause the very high dynamic-load stress, and make the early fatigue failure or the un-allowed distortion happened .In order to prevent the frame' resonating and make sure the safety and the reliableness in the use, its dynamic characteristic need to be studied deeply and the dynamic modification should be carried on if necessary . The modal analysis is an effective method which studies the dynamic characteristic of the component and structure. The modal parameters such as natural frequency and vibration mode, can be obtain through the modal test exactly.
One type automobile frame is regarded as the studied object in this paper. Based on the overall evaluation of the influence on the result by the hanging condition, the excitation method and the point arrangement, the first five modal parameters are obtained through the modal test firstly. Then the simulation force response analysis of the frame is carried on under the typical road surface condition. The simulation force signal is obtained through the road testing for some typical road surface. Finally, a structural dynamic modification method which is going to raise the natural frequency of the frame is explored based on the studying of the dynamic characteristic which influenced by the change of its mass and rigidity. It provided one helpful method for frame structure optimization.
引文
[1]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
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[3]杨华.模态参数识别的研究现状及发展[J].机械,2006,33(10A):1-3
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[5]Ibrahim.S.R.Random Decrement Technique for Modal Identification of Structures[J].AIAA J.of Spacecraft and Rockets,1977,14(11),697-700
[6]林循泓.振动模态参数识别及其应用[M].南京:东南大学出版社,1990
[7]李德葆,陆秋海.实验模态分析及其应用[M].北京:科学出版社,2001
[8]王柏生.结构损伤检测与识别技术[M].杭州:浙江大学出版社,2000.
[9]白化同,郭继忠译.模态分析理论与实验[M].北京理工大学出版社,2001:86-88
[10]Rodden W.P.A Method for Deriving Structural Influence Coefficients from Ground VibrationTest[J].AIAAJ,1967,Vol.5:991-1000
[11]McGrew J.Orthogonlization of Measured Modes and Calculation of Influence Coefficients[J].AIAAJ,1967,Vol.5:774-776
[12]陈德成等.动力修改的理论与方法[M].北大力学系,1987
[13]Fu-Shang Wei.Stiffness Matrix Correction from Incomplete Test Data[J].AIAA J,1980,V18:1274-1275
[14]彭晓洪等.用模态参数识别结果对实际结构有限元动力模型的修正[J].振动与冲击
[15]Zhang D.W.A new Method for Updating the Dynamic Mathematical Medal of a Structure[J].Quasi-complete Modified,1987
[16]王朝永,张令弥.利用试验模态参数修正有限元模型的再正交拉格朗日乘子法[J].振动工程学报,1989
[17]卜建清,满洪高.基于动力响应的结构动力修改方法[J].工程力学,1999,3(03A):812-817
[18]顾亮,胡琪琪.结构动力修改的拟力修改法[J].北京理工大学学报,1997,17(5A):533-538
[19]张华俊,张学荣.轿车车身结构动力修改技术应用[J].机械设计与制造,2003:91-93
[20]徐征峰,陈洪斌,苏树锋等.光电跟踪系统的结构动力修改及优化分析[J].机械制造,2007,4(9A):29-31
[21]康剑飞.车桥动态特性的试验模态分析及数值模拟分析方法研究[D].西安:长安大学,2006
[22]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
[23]左鹤声,彭玉莺等.振动试验模态分析[M],北京:中国铁道出版社,1994
[24]Y.Narkis.Identification of Crack Location in Vibrating Simply Supported beams[M].Journal of Sound and Vibration,1987
[25]Fang T,Zhang T S.Stationary Response of Combined linear Dynamic System to White Noise Excitation[J].Proc.ICMD ShenngYang,1987
[26]Huang L.Analysis of Dynamic Stress Responses in Structure Vibration[R].The 16~(th)Biennial ASME Conference on Mechanical Vibration and Noise.Sacramento Califomia,1997
[27]傅志方.振动模态分析与参数识别[M].北京:机械工业出版社,1990
[28]王济,胡晓.MATLAB在振动信号处理中的应用[M].北京:中国水利水电出版社,知识产权出版社,2006
[29]余志华.汽车理论[M].第三版.北京:机械工业出版社,2000
[30]MODENT USERS GUIDE,www.icats.co.uk,2008
[31]王柏村,曹文昌.应用有限元素分析与实验模态分析之结构模型验证[R].第十届CSSV学术研讨会,2002
[32]李德葆,陆秋海著,工程振动试验分析[M].北京:清华大学出版社,2004.9
[33]刘习军.贾启芬工程振动与测试技术[M].北京:高等教育出版社,2004:477-479
[34]刘梦丛.基于AR模型的现代谱技术及其在路谱分析中的应用[D].沈阳:东北大学,2005
[35]韩晓峰,董斌,陈剑.汽车电器可靠性试验台的路谱信号采集及其再现[J]噪声与振动控制,2008,28(5A):109-112
[36]Wei F.S.Stiffness Matrix Correction From Incomplete Test Data[J].AIAA J.1980,18(10)
[37]段志平,张亚.结构阻尼识别的方法及比较[J].福州大学学报,2005,33(supp.):208-212
[38]Karem A,Gurley K.Damping in structures:its evaluation and treatment of uncertainty[J].Journal of Wind Engineering and Industrial Aerodynamics,1996(59):131-157
[2]管迪华.模态分析技术[M].北京:清华大学出版社,1996
[3]杨华.模态参数识别的研究现状及发展[J].机械,2006,33(10A):1-3
[4]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.
[5]Ibrahim.S.R.Random Decrement Technique for Modal Identification of Structures[J].AIAA J.of Spacecraft and Rockets,1977,14(11),697-700
[6]林循泓.振动模态参数识别及其应用[M].南京:东南大学出版社,1990
[7]李德葆,陆秋海.实验模态分析及其应用[M].北京:科学出版社,2001
[8]王柏生.结构损伤检测与识别技术[M].杭州:浙江大学出版社,2000.
[9]白化同,郭继忠译.模态分析理论与实验[M].北京理工大学出版社,2001:86-88
[10]Rodden W.P.A Method for Deriving Structural Influence Coefficients from Ground VibrationTest[J].AIAAJ,1967,Vol.5:991-1000
[11]McGrew J.Orthogonlization of Measured Modes and Calculation of Influence Coefficients[J].AIAAJ,1967,Vol.5:774-776
[12]陈德成等.动力修改的理论与方法[M].北大力学系,1987
[13]Fu-Shang Wei.Stiffness Matrix Correction from Incomplete Test Data[J].AIAA J,1980,V18:1274-1275
[14]彭晓洪等.用模态参数识别结果对实际结构有限元动力模型的修正[J].振动与冲击
[15]Zhang D.W.A new Method for Updating the Dynamic Mathematical Medal of a Structure[J].Quasi-complete Modified,1987
[16]王朝永,张令弥.利用试验模态参数修正有限元模型的再正交拉格朗日乘子法[J].振动工程学报,1989
[17]卜建清,满洪高.基于动力响应的结构动力修改方法[J].工程力学,1999,3(03A):812-817
[18]顾亮,胡琪琪.结构动力修改的拟力修改法[J].北京理工大学学报,1997,17(5A):533-538
[19]张华俊,张学荣.轿车车身结构动力修改技术应用[J].机械设计与制造,2003:91-93
[20]徐征峰,陈洪斌,苏树锋等.光电跟踪系统的结构动力修改及优化分析[J].机械制造,2007,4(9A):29-31
[21]康剑飞.车桥动态特性的试验模态分析及数值模拟分析方法研究[D].西安:长安大学,2006
[22]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
[23]左鹤声,彭玉莺等.振动试验模态分析[M],北京:中国铁道出版社,1994
[24]Y.Narkis.Identification of Crack Location in Vibrating Simply Supported beams[M].Journal of Sound and Vibration,1987
[25]Fang T,Zhang T S.Stationary Response of Combined linear Dynamic System to White Noise Excitation[J].Proc.ICMD ShenngYang,1987
[26]Huang L.Analysis of Dynamic Stress Responses in Structure Vibration[R].The 16~(th)Biennial ASME Conference on Mechanical Vibration and Noise.Sacramento Califomia,1997
[27]傅志方.振动模态分析与参数识别[M].北京:机械工业出版社,1990
[28]王济,胡晓.MATLAB在振动信号处理中的应用[M].北京:中国水利水电出版社,知识产权出版社,2006
[29]余志华.汽车理论[M].第三版.北京:机械工业出版社,2000
[30]MODENT USERS GUIDE,www.icats.co.uk,2008
[31]王柏村,曹文昌.应用有限元素分析与实验模态分析之结构模型验证[R].第十届CSSV学术研讨会,2002
[32]李德葆,陆秋海著,工程振动试验分析[M].北京:清华大学出版社,2004.9
[33]刘习军.贾启芬工程振动与测试技术[M].北京:高等教育出版社,2004:477-479
[34]刘梦丛.基于AR模型的现代谱技术及其在路谱分析中的应用[D].沈阳:东北大学,2005
[35]韩晓峰,董斌,陈剑.汽车电器可靠性试验台的路谱信号采集及其再现[J]噪声与振动控制,2008,28(5A):109-112
[36]Wei F.S.Stiffness Matrix Correction From Incomplete Test Data[J].AIAA J.1980,18(10)
[37]段志平,张亚.结构阻尼识别的方法及比较[J].福州大学学报,2005,33(supp.):208-212
[38]Karem A,Gurley K.Damping in structures:its evaluation and treatment of uncertainty[J].Journal of Wind Engineering and Industrial Aerodynamics,1996(59):131-157