【作者】 孙玉华；

【导师】 董大伟；

【作者基本信息】 西南交通大学 ， 车辆工程， 2013， 博士

【摘要】 高速铁路因其运输量大、速度快、便捷舒适等诸多优点而成为现在最重要的交通运输方式之一,世界各国都在大力发展高速铁路,高速铁路的发展是现代铁路运输的必然选择。随着列车运营速度的不断提高,由此带来的振动和噪声问题也随之增加,而振动问题是影响乘坐舒适性的最重要因素。随着人们环境意识的增强和对乘坐舒适性要求的不断提高,振动控制问题不断引起设计人员的关注。在激励源一定的情况下,如何有效降低车体的振动,使乘坐舒适性满足预定的要求是设计人员面临的主要任务之一。目前,世界高速铁路客运广泛采用电力动车运输,但在铁路电气化水平不高的亚非国家比如孟加拉,为了提高铁路运输能力,其铁路客运采用内燃动车运输。先进的内燃动车主要采用动力包结构,柴油发电机组通过一级隔振器与公共构架相连接,各个附属设备集成弹性、刚性安装于公共构架上,公共构架通过二级隔振器与车体相连接,弹性悬挂于车体下方,共同组成了多子系统双层隔振的动力包结构。现在国内外已经掌握了动力包和车体设计的关键技术,但对于内燃机车动力设备的隔振设计,国内多次出现动力设备振动过大问题,通过更换机型或多次实验的办法解决了该问题,但其隔振机理不明确,并没有真正掌握隔振设计的关键技术。因此,极有必要对国内某内燃动车上首次采用双层隔振系统的动力包结构的隔振机理、隔振设计进行全面深入的研究。在系统研究双层隔振系统隔振设计国内外发展现状的基础上,针对出口孟加拉内燃动车首次采用的动力包双层隔振系统的设计及其与弹性车体之间的振动耦合问题,采用理论推导、动力学方法、有限元方法及实验验证相结合的手段,研究动力包多子系统双层隔振系统隔振器刚度的优化设计问题、动力包多子系统双层隔振系统模态匹配问题以及动力包双层隔振系统与弹性车体之间的振动耦合问题。抽象动力包为多子系统双层隔振系统,推导了多子系统双层隔振系统振幅频率响应公式,研究了子系统质量对双层隔振系统振幅的影响规律,构建了双层隔振系统振幅频率响应曲面,为隔振设计优化区域的选择提供了依据。根据隔振理论和解耦原则以及本文所提出的隔振优化设计方法,对国内某内燃动车首次采用的动力包多子系统双层隔振系统的隔振器刚度进行了设计。利用设计的隔振器刚度参数和动力包的结构参数,建立了动力包多子系统双层隔振系统的有限元模型和动力包机组、构架双层隔振系统的有限元模型,并分别进行了模态计算。模态计算结果表明：机组倾倒力矩方向的模态频率基本一致,验证了理论推导的正确性。在系统研究弹性中心偏移对隔振系统解耦度影响并提出具有指导实际工程隔振设计建议的基础上,针对动力包双层隔振系统解耦优化问题,根据双层隔振系统隔振理论和解耦原则,利用本文所提出的隔振优化设计思路,采用枚举法确定一级、二级隔振器的刚度的所有可能组合,以不同的优化目标进行编程,比较动力包隔振设计的刚度和优化刚度的综合隔振效果,并最终确定了动力包双层隔振系统的最优刚度方案。利用隔振器的最终刚度方案建立了动力包多子系统双层隔振系统的有限元模型,施加柴油机的激振力,对系统进行强迫振动计算。通过与动力学方法计算的支反力总和进行对比分析,验证了本文所提出的双层隔振优化设计思路的正确性。利用最终刚度方案,对动力包进行模态和谐响应计算,分析模态匹配是否合理。结果表明：动力包模态匹配合理,系统不会出现危险共振。对动力包进行了地面台架实验,根据测试的实验数据,从柴油发电机组的振动烈度,一级、二级各个隔振器加速度传递率以及各个隔振器动态减振力的有效值随转速变化曲线对系统的隔振效果进行系统深入的研究。结果表明,采用本文提出的优化设计思路所设计的隔振器隔振效果良好,从实验角度验证了提出的考虑多优化目标双层隔振优化设计思路的正确性。建立白车体和包含动力包的整车整备状态的有限元模型,并且进行了模态计算,掌握车体的固有振动特性,车体垂弯模态频率大于10Hz,满足了车体垂弯振动的要求。在此基础上对整车进行了平稳性实验测试,评价整车的平稳性指标；并且进行了动力包装车和地面台架实验两种情况下机组振动烈度和隔振器传递率的对比分析。结果表明：整车的平稳性指标等级为优级,动力包与车体之间没有存在振动耦合；装车后的机组的振动烈度和隔振器的传递率总体上优于地面台架实验的测试结果,从而进一步说明动力包多子系统双层隔振系统设计合理,本文所提出的考虑多优化目标双层隔振系统隔振设计思路正确。通过对动力包的隔振设计,已经成功投入运营的内燃动车的横向和垂向平稳性指标分别为1.765和1.615,均小于2.5,属于优级；动力包中柴油机的振动烈度等级为A级和B级,动力包多子系统双层隔振设计合理,完全满足实际工程的需要,最终验证了本文所提出的考虑多优化目标双层隔振优化设计思路的正确性。更多还原

【Abstract】 High-speed railway has become one of the most important transportation modes for many advantages such as large freight volume, fast speed, convenience and comfort. Countries all over the world are trying to develop their own high-speed railway, which is an inevitable choice of modern railway transportation. With the increasing running speed of the train, the vibration and noise issues are becoming more and more prominent, thus affecting the riding comfort of passengers. The vibration control problem has been more and more concerned by designers with people’s strengthening environmental awareness and requirements for riding comfort. Under a certain excitation source, how to effectively reduce car body vibration in order to meet the predetermined comfort requirements is one of the major tasks for designers.At present, the world has seen a widespread adoption of electric motor cars in high-speed railway passenger transport, however in some Asian and African countries such as Bangladesh, where its railway electrification level is rather basic, diesel motor cars are used in railway passenger transport to improve rail transport capacity. An advanced diesel motor car uses mainly a powerpack structure, in which the diesel generator set is connected to the public framework through a first stage isolator, while various ancillary equipment assemblies are installed on the public framework flexibly or rigidly, the public framework is then connected to the car body through a second stage isolator, and suspended elastically at the bottom of the car body, together constituting the powerpack structure of a two-stage vibration isolation system with multiple subsystems. At home and abroad, researchers have mastered the key technologies of powerpack and car body design, but concerning the vibration isolation design of diesel locomotive power equipments, several excessive vibration issues of power equipment have already occurred domestically, although these problems were resolved by replacing models or conducting experiments, their vibration isolation mechanism stayed unclear, and the key technologies of vibration isolation design were not really mastered.On the basis of studying on vibration isolation design of two-stage vibration isolation system at home and abroad systematically, aiming at designing the two-stage vibration isolation system of powerpack, which is used on the diesel locomotive exported to Bangladesh, and solving the coupled vibration problem between power assembly and flexible car body, a combination of theoretical derivation, dynamic and finite element method, and experimental verification were applied to study the issues of vibration isolator’s stiffness optimization and mode matching of powerpack with multiple subsystems in two-stage vibration isolation system, as well as coupled vibration problem between powerpack and car body.Powerpack was abstracted as a two-stage vibration isolation system with multiple subsystems, and its amplitude frequency response formula was derived. The influence of subsystem mass to the two-stage vibration isolation system amplitude was studied, the system amplitude frequency response surface was calculated, which provides the basis for the selection of the optimization region in vibration isolation design.According to the vibration isolation theory, decoupling principle and the vibration isolation optimum design method proposed in this paper, the vibration isolator’s stiffness of two-stage vibration isolation system with multi subsystems was defined. The finite element models of powerpack with multiple subsystems, the powerpack unit and the frame were established by using parameters of vibration isolator stiffness and powerpack structure, and mode calculations were carried out respectively. The results show that:mode frequency on the unit’s overturning moment direction remains essentially consistent, thus the correctness of theoretical derivation is verified.The suggestions that could guide vibration isolation design were proposed after systematically research on the effect of elastic center migration to decoupling degree of vibration isolation system, On this basis, in order to solve two-stage vibration isolation decoupling optimization problems on powerpack, according to the vibration isolation theory, decoupling principle and the vibration isolation optimum design method proposed above, an enumeration method was used to determine all possible stiffness schemes of the first and secondary vibration isolators, the program was compiled with different optimization goals, and the isolation effects of the optimized stiffness of powerpack vibration isolation design were compared, and the stiffness scheme of powerpack two-stage vibration isolation system is obtained finally.The finite element model of powerpack two-stage vibration isolation system with multiple subsystems was established by using the final stiffness scheme. Forced vibration calculation was carried out by applying diesel exciting force to the finite element model. The correctness of the optimum design thought of two-stage vibration isolation system was verified through the comparison between vibration intensity calculated by dynamic method and the sum of support reaction. Modal and harmonic response calculations were carried out by applying the final stiffness scheme, the appropriateness of mode matching was analyzed. The results show that:mode matching of powerpack is reasonable, there is no dangerous system resonance. Powerpack’s ground platform experiment was carried out. The isolation effect of powerpack was studied in depth from the unit’s vibration intensity, displacement and acceleration transmissibility of each first and secondary vibration isolator to its harmonic analysis. The results show that:the vibration isolator designed by the optimum design thought proposed has good isolation effects, and the correctness of the optimum design ideas of two-stage vibration isolation optimization considering multiple optimization objectives is verified from the experimental aspect.The finite element models of car body and the whole vehicle containing powerpack were established, their modal calculation were carried out respectively, and the natural vibration characteristics of car body were mastered. Its vertical bending natural frequency is bigger than lOHz, which meets the car body vertical bending vibration requirement. On this basis, the riding comfort experiment of the whole vehicle was carried out to evaluate its riding comfort index. Furthermore, the unit’s vibration intensity and isolator’s transmissibility were compared by experiments under the conditions of powerpack being assembled on the vehicle and on the ground platform. The results show that:the riding comfort index of the whole vehicle is in superior grade, there is no coupled vibration between powerpack and car body; the unit’s vibration intensity and isolator’s transmissibility of powerpack assembled on the car are superior to powerpack on the ground platform, which further explains the reasonable design of powerpack’s two-stage vibration isolation and the correctness of optimum design ideas of two-stage vibration isolation optimization considering multiple optimization objectives.After the vibration isolation design of powerpack, the horizontal and vertical riding comfort index of the diesel motor car which has been successfully put into operation are1.765and1.615respectively, both factors are less than2.5, thus in superior grade; the vibration intensity levels of diesel engine in the powerpack are class A and class B, thus the design of two-stage isolation system with multiple subsystems of powerpack is reasonable, and fully meets the actual needs of the project. The correctness of the proposed design ideas of two-stage vibration isolation optimization considering multiple optimization objectives is finally verified.更多还原