Theoretical research and experimental validation of elastic dynamic load spectra on bogie frame of high-speed train

When a train runs at high speeds, the external exciting frequencies approach the natural frequencies of bogie critical components, thereby inducing strong elastic vibrations. The present international reliability test evaluation standard and design criteria of bogie frames are all based on the quasi-static deformation hypothesis. Structural fatigue damage generated by structural elastic vibrations has not yet been included. In this paper, theoretical research and experimental validation are done on elastic dynamic load spectra on bogie frame of high-speed train. The construction of the load series that correspond to elastic dynamic deformation modes is studied. The simplified form of the load series is obtained. A theory of simplified dynamic load–time histories is then deduced. Measured data from the Beijing–Shanghai Dedicated Passenger Line are introduced to derive the simplified dynamic load–time histories. The simplified dynamic discrete load spectra of bogie frame are established. Based on the damage consistency criterion and a genetic algorithm, damage consistency calibration of the simplified dynamic load spectra is finally performed. The computed result proves that the simplified load series is reasonable. The calibrated damage that corresponds to the elastic dynamic discrete load spectra can cover the actual damage at the operating conditions. The calibrated damage satisfies the safety requirement of damage consistency criterion for bogie frame. This research is helpful for investigating the standardized load spectra of bogie frame of high-speed train.     

动车组转向架构架加工工艺分析

介绍了动车组转向架构架加工的工艺设计过程,通过对动车组构架加工过程各环节的分析,达到了优化工艺流程的目的,为行业内同类产品的工艺流程设计提供了参考。     

Modi cation of Roll Flattening Analytical Model Based on the Plane Assumption

Roll flattening is an important component in the roll stack elastic deformation,which has important influence on controlling of the strip crown and flatness. Foppl formula and semi?infinite body model are the most popular analyti?cal models in the roll flattening calculation. However,the roll flattening calculated by traditional flattening models has a great deviation from actual situation,especially near the barrel edges. Therefore,in order to improve the accuracy of roll flattening,a new model is proposed based on the elastic half plane theory. The calculation formulas of roll flatten?ing are deduced respectively under the assumptions of plane strain and plane stress. Then,the two assumptions are combined through the method of introducing an transition coe cient,and the distribution rules of roll flattening for di erent rolling force,flattening width,roll length and roll diameter are analyzed by using the FEM analysis software Marc. Regarding the ratio of the length to roll end and the roll diameter as variable to fit the transition coe cient,the new model of roll flattening is established based on the elastic half plane theory. Finally,the transition coe cient is fitted to establish the model. Compared with the traditional models,the new model can e ectively improve the cal?culation deviation in the roll end,which has important significance for accurate simulation of plate shape,especially for the distribution of rolling force between rolls.     

动车转向架构架强度分析

以CRH3动车转向架为研究对象,针对动车转向架构架的结构特点和受力特性,建立CRH3动车转向架构架的实体模型,根据TB/T 2368-2005《动力转向架构架强度试验方法》规范确定了构架的载荷工况,并将实体模型导入有限元分析软件ANSYS中对构架进行强度分析。分析结果表明：构架各部位的最大应力值均小于材料的许用应力,构架满足静强度和疲劳强度设计要求。     

动车组转向架制动吊座表面损伤故障分析与改进

分析动车组转向架构架组成制动吊座表面损伤产生的原因，并从改进检修工艺及提高工艺管理方面制定措施，有效地减少了构架组成制动吊座表面损伤现象。     

新型160 km／h城际动车组制动性能的计算分析

根据新型160 km/h城际动车组制动系统的设计要求,运用有限元法对动车组在紧急制动工况下和模拟线路运营工况下制动盘的热容量进行计算分析,以及对初速度为160 km/h最大载重工况下的紧急制动距离进行计算。计算结果表明,新型160 km/h城际车制动性能满足动车组的正常运营要求。     

基于UIC标准的转向架构架强度评估

介绍了某型动车转向架焊接构架的结构特征,建立了其有限元模型;根据国际铁路联盟标准UIC615-4详细计算了构架强度分析所需的载荷条件,其中包含超常载荷、运营载荷、及附加载荷;对得到的载荷进行了组合,确定了强度分析的载荷工况,载荷工况又分为静强度评价载荷工况和疲劳强度评价载荷工况;对构架静强度进行了计算与评定,并用Goodman疲劳强度极限图对构架疲劳强度进行了评定。结果表明该转向架焊接构架能够满足标准规定的静强度及疲劳强度的要求。     

高速动车转向架构架静强度试验和仿真研究

高速动车组转向架构架是保证高速列车安全运行的重要部件。针对某高速动车组转向架构架,通过采用科学合理的静强度试验方法和设备,对构架的静强度进行评估,同时与理论计算结果相互验证其准确性,以检验构架是否满足强度要求,为列车的安全运行提供保证。     

Manufacturing and testing of a GFRP composite bogie frame with straight side beam members

To replace a traditional steel bogie with a composite one, this study designed and manufactured a composite bogie frame made of glass fiber-reinforced plastics to be applied to the bogie of an urban subway train. To evaluate its structural behavior, the composite bogie frame was tested under critical load conditions encompassing vertical loads and a twisting load. The test revealed that the maximum strain measured under the vertical load corresponded to 16.3% of the failure strain of the GEP224 glass fabric/epoxy sample. According to a durability evaluation using Goodman diagrams, both the measured and the calculated stress data were within the endurance limit. Therefore, the composite bogie frame satisfied the structural safety requirements. The evaluation of the contribution of each load case clearly showed that the vertical and braking loads were the most critical load cases. Adding the braking load cases led to movement of the critical point from the inner joint to the outer joint due to the increased torsion.     

阶梯式半挂车车架疲劳寿命预测

根据某阶梯式半挂车车架的结构特点,建立了其有限元模型,通过分析得到车架静态应力分布;基于半挂车多体动力学模型,以H级路面的路面载荷作为边界条件进行动力学分析得到车架载荷谱。以上述分析数据为依据,综合考虑影响半挂车车架疲劳特性的主要因素,采用多轴临界面法Brown-Miller疲劳损伤平均应力修正模型预测了半挂车车架的多轴疲劳寿命,得到其疲劳薄弱部分,为结构和工艺优化提供参考。     

Methodology to Evaluate Fatigue Damage of High-Speed Train Welded Bogie Frames Based on On-Track Dynamic Stress Test Data

The current method of estimating the fatigue life of railway structures is to calculating the equivalent stress amplitude based on the measured stress data. However, the random of the measured data is not considered. In this paper, a new method was established to compute the equivalent stress amplitude to evaluate the fatigue damage based on the measurable randomness, since the equivalent stress is the key parameter for assessment of structure fatigue life and load derivation. The equivalent stress amplitude of a high-speed train welded bogie frame was found to obey normal distribution under uniform operation route that verified by on-track dynamic stress data, and the proposed model is,in e ect, an improved version of the mathematical model used to calculate the equivalent stress amplitude. The data of a long-term, on-track dynamic stress test program was analyzed to find that the normal distribution parameters of equivalent stress amplitude values di er across di erent operation route. Thus, the fatigue damage of the high-speed train welded bogie frame can be evaluated by the proposed method if the running schedule of the train is known a priori. The results also showed that the equivalent stress amplitude of the region connected to the power system is more random than in other regions of the bogie frame.     

Optimization of high speed EMU suspension parameters for vibration reduction

Various designs of high speed EMU (electric multiple units) operating at maximum speed of 400 km/h or above are under active development in many countries. Driving at such extreme high speed, the EMUs that are equipped with multiple power units and non articulated bogies normally experience severe level of vibration. Noting one of the primary design issues of the vertical EMU vibration, the present work tries an optimization of vehicle suspension system using ten degree of freedom analytical EMU model. The objective function for the work is consisted of the rail power spectral density (PSD), transfer function of car body, and frequency dependent weighting function which may represent human riding comfort. The transfer function is formulated using an autocorrelation of the model in frequency domain. For the enhanced reliability of the optimization work, both the US FRA (Federal Railway Administration) rail PSD and the actual rail PSD acquired from Kyeong-bu high speed rail in Korea on which the particular EMU will be driven are used. The well proven BFGS (Broyden-Fletcher-Goldfarb-Shanno) method is adopted for the optimization. The optimized design is verified using a commercial dynamic system simulation code at various operating conditions.     

跨座式单轨车辆转向架构架模态分析

以跨座式单轨车辆转向架构架为研究对象,建立了构架的几何模型和有限元模型。介绍了构架结构模型的建模技巧、建模过程、建模单元特性以及有限元模型的创建技巧。根据模态分析的理论基础对构架的有限元模型进行了自由模态分析,通过计算得出了构架前16阶模态的固有振动频率和振型模态,确定了构架结构的动态特性,指出构架中振动的薄弱环节。为构架动态特性的改进设计和有效地避免共振现象的发生提供了参考,对进一步构架的动力学分析也有重要的意义。     

高速列车头型气动外形关键结构参数优化设计*

降低列车运行阻力和气动噪声是提升高速列车速度能力和环境适应性的有效手段。针对气动阻力、气动噪声这两项优化目标,利用Isight软件建立了集参数化驱动建模、计算网格划分、气动计算、优化分析等步骤的高速列车新头型气动性能自动优化设计流程,运用基于多目标遗传算法NSGA-II的优化设计方法,对鼻尖高度、排障器前端伸缩量、转向架区域挡板倾角等关键设计变量进行了优化设计以及与气动阻力和气动噪声的相关性分析,在此基础上提出了综合性能较佳的新头型气动外形。通过计算结果可知,① 鼻尖高度对整车阻力和头车表面最大声功率均为正相关关系;② 转向架区域隔墙倾角对整车阻力和头车表面最大声功率影响的相关性最大;③ 通过优化转向架区域隔墙倾角可有效降低该处气动噪声的表面声功率。     

考虑齿轮传动影响的高速动车组电机吊架载荷及动应力研究

针对CRH3型高速动车组电机吊架焊接结构,结合有限元法和刚柔耦合多体动力学法建立考虑齿轮传动系统的啮合振动的高速列车动车整车动力学模型,仿真计算得到电机吊架在列车加速和匀速运行工况下的动载荷;利用准静态应力法计算两种工况下电机吊架上危险节点的动应力,通过对比吊架上危险节点动应力的模拟计算结果和线路实测结果研究齿轮传动系统的啮合振动对车辆运行中电机吊架所受载荷及其上危险位置动应力的影响。结果表明:在齿轮传动系统啮合振动的影响下,电机吊架的动载荷及其结构危险节点的动应力显著增大,垂向振动加剧,而且动应力仿真结果与线路实测结果更接近。因此,在对高速列车结构件进行动应力仿真时,为了更准确地仿真结构振动对动应力仿真结果的影响,应该在结构件弹性化的基础上,同时考虑齿轮传动系统啮合振动的影响。     

地铁车辆转向架构架有限元强度计算与分析

介绍了某改进型转向架构架的结构特征,建立了其有限元模型,根据标准UIC515-4/UIC615-4,计算了构架强度分析的主要载荷,并考虑了辅助载荷对疲劳强度的影响,确定了强度分析的工况,对静强度进行了计算与评定,用Goodman疲劳强度极限图对疲劳强度进行了评定,结果表明,该构架能够满足静强度及疲劳强度的要求.     

面向制造全过程的转向架装配制造仿真

为了解决转向架装配制造中的问题,考虑转向架装配制造全过程,利用Delmia各仿真模块及PPR,构建了涵盖虚拟装配线建模、装配工艺规划、装配工艺过程仿真、装配线物流仿真的转向架装配数字化仿真平台,阐述了转向架装配制造数字化仿真平台的框架组成、实施流程、仿真与分析方法,利用仿真平台可以对转向架装配制造全过程进行仿真,实现对转向架装配制造全过程的预规划、验证与优化,能够缩短制造周期,降低制造成本。     

大型城市公交车车身结构有限元分析

通过对半承载式大客车车身骨架的有限元分析计算,得到四种典型工况下的强度、刚度特性.并通过静态应力与形变测量实验,获得车身骨架的应力和形变的实际状况,验证有限元模型的准确性,为寻求切实可行的车身骨架结构优化途径提供依据.     

基于Optistruct的地铁构架有限元强度分析及优化

建立地铁构架的有限元模型,根据UIC515-4、UIC615 4和EN13749标准对构架进行静强度和疲劳强度评定.结果表明,构架符合静强度和疲劳强度要求.此外还使用Optistruct软件对构架板材厚度进行尺寸优化,优化结果符合构架静强度和疲劳强度评定要求,优化结果可行.优化结果相比初始设计,减重达到12.3％.     

基于有限元法的摇枕疲劳强度分析

以货车转K6型转向架摇枕为研究对象,建立了摇枕的三维几何模型,采用HyperMesh软件对摇枕进行了网格划分,利用ANSYS有限元分析软件,分别计算了典型载荷工况下的摇枕应力分布,从而确定了摇枕的疲劳薄弱部位并进行了局部优化,根据AAR标准,评价了摇枕的疲劳强度,对摇枕进行了寿命计算分析。