【作者】 王建斌；

【导师】 邬平波；

【作者基本信息】 西南交通大学 ， 载运工具运用工程， 2010， 博士

【摘要】 动车组高速运行引起的复杂高频振动恶化了转向架构架受力状态,构架强度设计在高速动车组研究中显得尤为重要。基于焊接结构疲劳设计方法,本文提出了在现行焊接构架制造工艺及材料性能条件下,以有限的线路试验数据作为支撑,利用数值仿真作为服役载荷获取的主要手段,强化台架强度试验验证,作为构架强度设计的基本框架。本文构建了部分焊接接头基础性能数据库,在各类强度评定方法的分析以及有限元计算与台架试验比较的基础上,得出名义应力法和结构应力法能满足构架强度设计的需要的结论。确定精细网格有限元模型可获得足够精度的应力数据,较高应力区的计算误差可控制在10%以内。为全面获取构架动态服役的载荷条件,本文开发了车辆系统动力学仿真软件。该软件的理论基础为多体动力学理论,根据小弹性变形假定对车体、构架进行模态柔性处理。程序使用面向对象C++语言编写,在MFC架构下实现动力学方程自动生成及求解。本文进行了箱梁型和管梁型两类构架在各种运行工况下的刚-柔耦合动力学仿真,对比分析两类构架的动应力水平及疲劳损伤分布状况,研究表明对于构架主体结构其扭转刚度和垂向弯曲刚度是动应力幅值和均值的直接相关指标。由两类构架谐响应分析及扭转频率与侧梁各部位疲劳损伤的相关性分析结果,确定了构架结构的刚度指标与强度指标的关联性,为构架强度设计提供了指导建议。本文在国外主要强度标准及主要厂商试验验证程序的基础上,研究了某型动车构架在各类验证程序下的评定结果的差异。在分析结果的基础上,总结出合理保守且代价较小的静载试验方案。本文还就动态加载的试验载荷谱开展研究。在损伤等同原则下,将经试验数据修正的短程仿真数据拓展生成与设计寿命目标一致的台架试验谱。由于车辆动力学性能随服役时间增长呈现下降的趋势,本文提出了利用特征指标和性能劣化函数计算全寿命周期内等效服役特征的方法。本文还采用刚-柔耦合动力学模型构建了虚拟试验加载系统以验证各影响因素对加载效果的影响。更多还原

【Abstract】 As the running velocity grade increased, high frequency vibrations deteriorate the service conditions of the bogie frames. Fatigue strength design and reliability are essential issues of the research of the high speed electric multi-units (EMU) trains. Based on the welded structures fatigue design methods, the thesis introduced a complete frame of design process composed of construction of the fatigue database of the welded joints, loads obtained by numerical simulations that validated by line tests and enhanced test behch verifications.Partial fatigue database of welding joints were constructed in the thesis. Based on the anslysis of main welding design codes and comparision between FEM calculations and bench tests, norminal stress and structural stress design methods are feasible for frame design. Nominal stress FEM evaluation model with extra dense finite elements grids could meet the precision requirements. Relative errors could be limited below 10% compared with tests in critical areas.According to the requirements of strength evaluation and fatigue damage computation, vehicle dynamics simulation program were developed. The software is based on the multibody dynamics theory and implemented with object oriented C++ language. The bogie frame and carbody can be made flexible with small elastic deformation assumption. Open source routine OpenSceneGraph was used to implement 3D graphic interface as the rendering engine. The workflow was implemented by the MFC single document view architecture that can manage vehicle components, assemble and solve system equations.Comparation analyses between box-type and pipe-type boige frames by rigid flexible dynamics simulations and fatigue damage computations were taken. Vertical bending stiffness and torsion stiffness are closely interrelated with the mean value and amplitue of the dynamic stresses. According to the FEM harmonic analyses and fatigue damage computations of the variational tortional stiffness frame, the stiffness and strength design parameters have the identical optimization targets.The differences of the evaluation results about a pipe-type motor bogie frame under four test programs were studied in the thesis. Based on the analyses, optimized static test program was summarized with the costs and safety margin respected.Dynamic tests were studied in the thesis. The tests spectrum is generated by short term simulation data that corrected by tests data and extrapolated by usage factor based on damage equivalent principle. Serve charecateric index and deterioration function were introduced for facts that vehicle dynamic performances decrease during operation cycles. Virtual test bench model was developed to research design factors of physical test bench that can influence the channels synchronization and loading effects.更多还原