铁道车辆碰撞过程中的纵向失稳机制及其抑制方法研究

It is frequent for railway vehicle collisions, especially when the secondary accident of train instability including climbing, buckling, deflection and hunch-up etc occurred after the collision, resulting in incalculable secondary damage. So far, not only is there a lack of systematic research for railway vehicles behavior evolution, instability mechanism and secondary derivative mechanisms after the collision, both domestic and international, but also there hasn’t formed a complete key technology of instability suppression. This project will carry out researches on the longitudinal instability mechanism and its suppression method of railway vehicle by the methods combining accident investigation, theoretical analysis, experiment and numerical simulation. Specific research contents include: (1) Construct the dynamic model of rigid - flexible coupling collision of railway vehicle, and delve into the dynamic response characteristics of vehicle structure under collision condition around the interfacial failure and instability way of multiple modes of multi-body coupling of train. (2) Research the dynamic evolution trend of the contact interface on the vehicle and the evolution law of the post-collision behavior, and clarify the induced mechanism of the accident including climbing, buckling, deflection and hunch-up etc. Meanwhile, reveal the reasons of vehicle instability. (3) Take active intervention to the response modes and longitudinal instability trend of the railway vehicle after collision, and develop the anti-destabilization connection structures which combine key technologies of buffer gear, anti-climbing , anti-deviation and anti-buckling in one. The research results provide the theoretical basis and technical support for the key technology of crashworthy design for train and passive safety protection.

铁道车辆碰撞事故频发，特别是碰撞后一旦发生爬车、措曲、偏转、拱起等列车失稳的继发事故，造成无法估量的二次伤害；国内外目前对铁道车辆碰撞后行为演化及失稳机理、碰撞后次生灾害衍生机制缺乏系统研究，更没有形成完备的失稳抑制关键技术。本项目采用事故调研、理论分析、实验和数值模拟相结合的方法开展列车纵向失稳机制及抑制方法研究，具体研究内容为：（1）围绕列车多体耦合互撞中多种模式的界面失效和失稳方式，构建铁道车辆刚柔耦合碰撞动力学模型，深入研究碰撞条件下车体结构动力学响应特性；（2）研究车辆间接触界面动态演变趋势及碰撞后行为演化规律，阐明爬车、措曲、偏转、拱起等现象的产生机理，揭示车辆失稳诱因；（3）对铁道车辆碰撞后的响应模式和纵向失稳趋势进行主动干预，开发出融合车端钩缓装置、防爬、防偏、防措曲等关键技术于一体的防失稳连接结构。研究成果为耐撞列车功能设计及被动安全保护关键技术提供理论基础和技术支撑。

碰撞过程中铁道车辆纵向失稳机理尚未形成清晰和全面的认识，缺乏完备的铁道车辆纵向失稳抑制关键技术。本项目围绕碰撞过程中列车纵向失稳机制及抑制方法开展研究，为我国铁道车辆撞后失稳抑制关键技术研究及耐撞列车的功能设计提供理论基础和技术支撑。具体研究结果和结论如下：（1）提出整列车碰撞模型简化方法，使仿真模拟更具针对性、计算速度更快，而且能够节省大量的存储空间；（2）设计了一种结构简单，安装方便，既能在纵向冲击方向实现很好的导向以发生有序可控的塑性变形、又能提高整个装置的垂向和横向承载能力的轨道车辆用导向式防爬吸能装置，可保证结构具有良好的防失稳能力；（3）构造了城规车辆前端复合式吸能结构的耐撞性响应模型和优化代理模型，解决了复合结构材料间相互影响、数学模型复杂等问题，具有优良的适用性与寻优性能；（4）综合工程力学、车辆结构理论、列车碰撞动力学理论和数值仿真技术，建立了详细的车辆和整个列车的碰撞动力学模型，揭示出了车辆间碰撞纵向失稳机理及后行为演化规律；（5）为寻求更加符合铁道车辆碰撞要求的车端吸能装置，从吸能机理、仿生设计、复合吸能等方面开发了多种新式防爬吸能结构，并通过实验和仿真证明其具有变形可控、作用力平稳、比吸能大等优点，可广泛应用于铁道车辆的防爬型能量耗散结构中；（6）针对金属薄壁结构和Nomex蜂窝的耦合机制及其应用展开研究，探索了Nomex蜂窝叠加结构中各层蜂窝间及蜂窝与金属面板的耦合力学行为，探讨了内嵌薄壁管的Nomex蜂窝结构中材料间耦合耗能机制，揭示了Nomex蜂窝填充金属薄壁元件所组成吸能结构的力学行为及耗能机制，开发出适用于更高速度标准的轨道车辆防爬吸能结构。依托本项目发表高水平SCI学术论文26篇；申请发明专利17项，授权发明专利13项，完成学术专著1项；获得湖南省技术发明一等奖1项；湖南省科学技术进步奖一等奖1项；培养研究生8名，其中已毕业博士研究生1名，已毕业硕士研究生7名。