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...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.展开更多
For complex engineering systems, such as trains, planes, and offshore oil platforms, load spectra are cornerstone of their safety designs and fault diagnoses. We demonstrate in this study that well-orchestrated machin...For complex engineering systems, such as trains, planes, and offshore oil platforms, load spectra are cornerstone of their safety designs and fault diagnoses. We demonstrate in this study that well-orchestrated machine learning modeling, in combination with limited experimental data, can effectively reproduce the high-fidelity, history-dependent load spectra in critical sites of complex engineering systems, such as high-speed trains. To meet the need for in-service monitoring, we propose a segmentation and randomization strategy for long-duration historical data processing to improve the accuracy of our data-driven model for longterm load-time history prediction. Results showed the existence of an optimal length of subsequence, which is associated with the characteristic dissipation time of the dynamic system. Moreover, the data-driven model exhibits an excellent generalization capability to accurately predict the load spectra for different levels of passenger-dedicated lines. In brief, we pave the way, from data preprocessing, hyperparameter selection, to learning strategy, on how to capture the nonlinear responses of such a dynamic system, which may then provide a unifying framework that could enable the synergy of computation and in-field experiments to save orders of magnitude of expenses for the load spectrum monitoring of complex engineering structures in service and prevent catastrophic fatigue and fracture in those solids.展开更多
为了实现典型工况载荷谱的编制,研究铁道工况识别软件的开发方法。分析原始数据的存储格式并将相关代码写入软件,实现由软件读取原始数据。研究各典型工况下信号波形的特征,提取出各典型工况的特征波形并由此建立各工况识别的核心算法。...为了实现典型工况载荷谱的编制,研究铁道工况识别软件的开发方法。分析原始数据的存储格式并将相关代码写入软件,实现由软件读取原始数据。研究各典型工况下信号波形的特征,提取出各典型工况的特征波形并由此建立各工况识别的核心算法。将VB.net与Javascript语言结合,编写软件核心代码。将谷歌卫星地图及Open Street Map模拟地图引入软件中,分析实测经纬度坐标和地图墨卡托坐标系之间的转换方法。进行实测数据典型工况识别,软件处理结果表明该软件能成功识别各工况数据,各工况线路识别结果与卫星图所示实际运行工况线路吻合,最后将所有识别的工况结果列表并分析了实测线路总体工况特征。展开更多
基金Supported by National Natural Science Foundation of China(Grant No.U1134201)
文摘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.
基金supported by the Basic Science Center of the National Natural Science Foundation of China for “Multiscale Problems in Nonlinear Mechanics”(Grant No. 11988102)the National Key Research and Development Program of China (Grant Nos. 2017YFB0202800 and2016YFB1200602)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB22020200)the Science Challenge Project (Grant No. TZ2018002)。
文摘For complex engineering systems, such as trains, planes, and offshore oil platforms, load spectra are cornerstone of their safety designs and fault diagnoses. We demonstrate in this study that well-orchestrated machine learning modeling, in combination with limited experimental data, can effectively reproduce the high-fidelity, history-dependent load spectra in critical sites of complex engineering systems, such as high-speed trains. To meet the need for in-service monitoring, we propose a segmentation and randomization strategy for long-duration historical data processing to improve the accuracy of our data-driven model for longterm load-time history prediction. Results showed the existence of an optimal length of subsequence, which is associated with the characteristic dissipation time of the dynamic system. Moreover, the data-driven model exhibits an excellent generalization capability to accurately predict the load spectra for different levels of passenger-dedicated lines. In brief, we pave the way, from data preprocessing, hyperparameter selection, to learning strategy, on how to capture the nonlinear responses of such a dynamic system, which may then provide a unifying framework that could enable the synergy of computation and in-field experiments to save orders of magnitude of expenses for the load spectrum monitoring of complex engineering structures in service and prevent catastrophic fatigue and fracture in those solids.
文摘为了实现典型工况载荷谱的编制,研究铁道工况识别软件的开发方法。分析原始数据的存储格式并将相关代码写入软件,实现由软件读取原始数据。研究各典型工况下信号波形的特征,提取出各典型工况的特征波形并由此建立各工况识别的核心算法。将VB.net与Javascript语言结合,编写软件核心代码。将谷歌卫星地图及Open Street Map模拟地图引入软件中,分析实测经纬度坐标和地图墨卡托坐标系之间的转换方法。进行实测数据典型工况识别,软件处理结果表明该软件能成功识别各工况数据,各工况线路识别结果与卫星图所示实际运行工况线路吻合,最后将所有识别的工况结果列表并分析了实测线路总体工况特征。
