【作者】 龙岩；

【导师】 史文库；

【作者基本信息】 吉林大学 ， 车辆工程， 2010， 博士

【摘要】 本文应用传递路径分析方法对车内振动进行研究。通过介绍传递路径分析方法基本原理,推导复杂系统间的传递函数和无偏估计方法的数学表达式,在理论上提高传递路径计算精度。在消声室转鼓上进行整车匀加速工况振动测试,以发动机到驾驶员座椅导轨、方向盘处、仪表板处和变速操纵杆处的振动传递为例,建立车内振动传递路径分析模型。对各个能量传递路径的传递函数进行分析并计算振动贡献量。根据车内振动传递模型,提出基于传递路径分析方法的悬置系统优化方法及评价方法;本文还提出基于整车试验模态分析方法的动力总成参数识别方法,在整车实际工况下对动力总成的刚体模态和惯量参数进行识别,为动力总成悬置系统优化设计提供准确参数;分别应用能量解耦优化方法与传递路径优化方法对样车动力总成悬置系统进行优化设计,并在悬置刚度、能量解耦、振动传递率以及车内振动控制四个方面进行对比。最后应用传递路径优化的结果制作悬置样件,实测悬置元件性能,并将悬置特性带入到整车传递路径分析模型中进行车内振动预测,改进结果证明本文提出的方法可以更有效控制车内振动;本文从建模分析到试验,全面系统地形成了基于传递路径分析方法的整车车内振动分析与动力总成悬置系统开发的方法和技术流程,为动力总成悬置系统优化设计及解决整车NVH问题提供了一个新思路。更多还原

【Abstract】 With the rapid development of industrialization, the vibration and noise have been one of the pollute sources, and influence the people’s life、work and study, even the health and psychology, leading to many psychogenic and physiological diseases. During the one hundred years of automotive naissance, the science and technology has been rapid developed, and many newest research production have been applied on the vehicle, the total number of vehicle in the world is increasing, so the pollute problem caused by vehicle is universal and serious. At the same time, with the improvement of people’s living standard, they do not settle for the walking instrument only, especially they also need vehicles have better ride and traveling comfort of vehicle, so the NVH of vehicle (Noise、Vibration and Harshness) have been paid attention more and more in the world. The noises of vehicle include two parts, one is the interior noise, and the other is the exterior noise, and the developed nations have established many statutes and measurement methods based on the characteristic of country, even these rules prohibit selling the vehicle which does not meet the criterion of the vibration and noise rules. These methods make the interior and exterior noise become lower and lower, and the statutes have become rigid more and more. At the same time, these methods also accelerate the development of NVH technology and measurement technology.In china, the research of NVH is only carried out in recent years, and Chinese government has established correlative statutes, but they are not rigorous as the developed country. In these years, the total number of vehicle in China is increasing rapidly, and Chinese government has to amend the correlative statutes and keep the same step with the development of world, so all of these needs the auto manufacturer and research institute try their best to achieve farther detailed understanding of the compartment vibration generation mechanisms and the measurement methods, only by this way, it can confirm the indigenous automotive production can have a room in the international competition, and improve the technology level of independent research and development of Chinese vehicle.There are many elements can lead to NVH problems and generation mechanism is very complicated, the interior and exterior noise is caused by vibration of vehicle, and the powertrain is the main source of vibration and noise, so the control of vibration and noise of powertrain is the main aspect of improving the NVH and traveling comfort. In a national project of Jilin University (863 Program), the goal of this work was to achieve farther detailed understanding of the compartment vibration generation mechanisms. Through the test, an innovative optimum method of identification parameters of powertrain rigid body based on operation modal method was improved, and the vehicle vibration and analysis model was built based on transfer path analysis of vibration energy. By the method of test and simulation, the main vibration source can be found, and an innovative optimum method of engine mounting system based on transfer path analysis was introduced. Then the method was applied to optimize engine mounting system, and the optimum results were contrasted with the traditional energy decoupling method, finally, the effectiveness of the proposed method was validated through optimum of engine mounting system of the car.The control of the interior noise is a complicated system project. The background knowledge of transfer path analysis and the transfer function relation of complicated subsystem were introduced, and then the mathematical equations of improved transfer path analysis method were introduced, the Accuracy of transfer function was improved in theory, so the test period of traditional transfer path analysis can be shorted. With the method, under laboratory conditions, the vehicle was located and accelerated slowly, the acceleration data (engine mounts/chair rail/steering wheel/board/gearshift) were obtained, and the vehicle vibration transfer path analysis model was built and amended by these data, . Then the transfer function model of engine mount was built too. These data were put into the vehicle vibration model and predicted the interior vibration, by the contrast of predict results and test results, the effectiveness of the proposed approach was validated.By analysis the vibration generation mechanisms of interior vibration, the vehicle interior vibration model of transfer path analysis was built. The structure of each vibration transfer path and the calculational method of transfer function were analyzed, the each essentials and step in the process of building the vehicle model were analyzed in detail. After the analysis of the vibration source of interior aim point and transfer function of each vibration transfer path, the main vibration transfer paths of interior aim point were picked out.By the vehicle model based on the test data, an innovative optimum method of engine mounting system, which based on transfer path analysis, was introduced. Then the optimum of transfer functions of engine mounting system can be carried out based on this method, and the optimization results of stiffness were obtained, at the same time, an innovative criterion of engine mounting system also was improved under real vehicle operation conditions. So it is not necessary to use the general criterion of engine mount system (20dB) to evaluate the mount system.An innovative optimum method of identification parameters of powertrain rigid body based on operation modal method was improved. With the method, under real vehicle operation condition, the modal parameters and inertia parameters of the powertrain were identified, and these parameters are more accurate and can be used to optimize the engine mounting system. At the same time, these parameters also can be used to evaluate the rigid body modal design of powertrain. The original stiffness of engine mounts was tested and the stiffness can be the preliminary data in optimum of engine mounting system.The mount system of the car was decoupled and optimized. The results of energy decoupling method were contrasted with the results of transfer path analysis method in following aspects, such as stiffness, energy decoupling, vibration transfer rate, interior vibration and so on. The contrast results show the transfer path analysis method is better in vibration transfer rate and interior vibration, but is worse in energy decoupling. So the effectiveness of the transfer path analysis method was validated in theory. Finally, the samples of the mount were made by the results of transfer path analysis method, and assembled them on the car. By the real car testing, the results show that the interior vibration can be controlled effectively, and the effectiveness of the proposed approach was validated.In the paper, the vibration energy transfer characteristic relations of vehicle different subsystems were built by vehicle test data and the main vibration sources and transfer paths of interior vibration were picked out by the model, the engine mounting system was optimized by an innovative transfer path analysis optimum method, then an innovative criterion of engine mounting system also was improved under real vehicle operation conditions for different kind of vehicle.更多还原