中文摘要：

介绍了全世界高速铁路发展现状和中国高速铁路网的发展规划。列举了高速铁路在过去运营过程中出现的几次重大脱轨事故和引起脱轨事故的原因。详细讨论了关系到高速列车安全问题研究的一些关键科学问题，这些问题主要包含高速列车在高速运行条件下车辆／线路耦合动态行为分析建模和数值方法，以及在复杂状态下安全评估和分析方法。这里所指的复杂状态是指列车在高速运行状态下，车辆和轨道系统某些部件发生故障和失效、或遭到强横风和旋风的袭击、或地震发生的情况。阐述了现有车辆轨道耦合动力学模型存在的问题，如果使用它们能够有效准确地对高速列车／线路耦合动态行为和在复杂环境下高速运动时进行可靠地安全评估和分析，需要对这些模型在空间耦合范围、频率影响范围的建模进行扩大，结构重要连接件的线性建模考虑由非线性建模代替，从正常工作状态到非正常状态进行建模改进。并提出高速列车安全问题的主要研究内容。

英文摘要：

The paper introduces the development of high speed railways in the world and the detailed plans of high speed railway development in China in the near future. A few serious derailment accidents of high speed trains in the world are listed and the corresponding causes are briefly described. The paper emphasizes a few key scientific problems in theoretical evaluation for high speed train safety operation, which arise from the theoretical modeling and the corresponding numerical performance for such a large-scaled system under high speed operation and abnormality. The abnormality indicates the failure of some key components in the trains or the tracks, or the trains passing through strong cross-wind and cyclone, and earthquake occurring when the trains running. The advantages and disadvantages are discussed of the existing theoretical models and their numerical methods for railway vehicles coupled with tracks. These models need to be further improved to be suitable for the evaluation of the dynamic behavior and safety operation of high speed trains running in the abnormal situations. The improvement of the models includes the spatial modeling extension of the coupled structures and the analyzed frequency range, replacing the linear models by the nonlinear models for the key links between the components, such as suspension systems of the vehicles, the fastening systems of the tracks, etc., introducing failure models for some parts, and boundary modeling for cross-winds, tornados and earthquakes. The study on the running safety of high speed trains in operation is indicated.