基于损伤一致性的动车组转向架载荷实验谱研究

动车组转向架构架载荷状况复杂, 实际运用条件下包含多个基本载荷系, 因此转向架构架局部位置的总损伤是若干载荷系在该位置相应损伤的累积; 转向架构架实验谱是考核动车组构架寿命的关键手段, 在没有实测载荷的条件下如何编制实验谱是本文的研究目标.本文首先对转向架构架承载系统的线性假设、稳定假设及典型假设进行了确认研究; 然后根据长期实测线路仅有的动应力数据, 将转向架构架典型应力分区域编制应力谱; 其次根据构架受力特点对构架建立载荷系, 在试验台中标定各个载荷系下的载荷应力传递关系, 并将区域典型测点的最大标定系数作为该区域的载荷应力传递系数; 然后基于损伤一致性原则建立优化函数, 并将获得的载荷应力传递系数矩阵代入优化函数, 得到一种适用于由线路实测动应力大数据推导出实验载荷谱的方法. 试验结果证明该方法具有较高的精度, 对构架关键部位的考核实现了典型区域全覆盖; 在中国线路运用工况下, 相比国际通用规范, 该方法对所有典型区域做到损伤再现, 所编制实验谱对转向架构架的考核更具有适用性. 

RESEARCH ON LOAD TEST SPECTRUM OF EMU CAR BOGIES BASED ON DAMAGE CONSISTENCY 1)

The load situation of the EMU car bogie frame is complex, and it contains multiple basic load systems under actual operating conditions. Therefore, the damage of the local position of the bogie frame is the accumulation of the corresponding damage of several load systems at that location; the experimental spectrum of the bogie frame is to assess the life of the EMU frame. The bogie frame test spectrum is the key means to assess the life of EMU frame, and how to prepare the test spectrum without measured load is the research goal. In this paper, firstly, the linear assumption, the stability assumption and the typical assumption are researched and confirmed; Then, based on the only dynamic stress data of the long-term measured line, the typical stress of the bogie frame is compiled into a stress spectrum; the load system of the frame is established according to the stress characteristics, and the load stress transfer relationship under each load system is calibrated in the test bench; the maximum calibration coefficient of typical measuring points in the region is taken as the load stress transfer coefficient of the region; then, based on the damage consistency principle, the optimization function is established, and the load stress transfer coefficient matrix obtained is substituted into the optimization function, and a method for deriving the experimental load spectrum from the measured dynamic stress data of transmission lines is established. The test results prove that the method has high accuracy, and the assessment of key parts of the structure has achieved full coverage of typical areas; under the operating conditions of the Chinese line, compared with the international general specifications, this method can achieve damage reproduction in all typical areas. Compiling experimental spectrum is more applicable to the assessment of bogie frame.