长大线路服役状态演化模型及关键参数估计算法研究

发布时间：2018-10-05 16:03

【摘要】：高速铁路是一个复杂的大系统,列车与线路基础设施的服役性能随着长期运营不断发生动态变化。由于列车运行速度大幅提高,轮轨之间动力作用加大,造成对基础设施动态作用加强。我国高铁大规模成网运行,线路跨越多个气候带,服役性能的演变更加复杂。线路基础设施服役性能下降导致潜在病害更具突发性和严重性,极大的影响着线路的运行安全。掌握基础设施状态参数的形成和分布规律,准确感知关键路段部件状态参数的变化趋势,建立和完善科学的线路健康服役状态保障体系,对于保证高速铁路安全平稳运行具有重要意义。以反映线路安全的关键参数轨道应力为切入点,围绕长大线路服役状态演化过程,考虑温度因素的缓变作用和车辆冲击的瞬态作用,论文开展了无缝线路多尺度动静态建模以及相关参数智能估计算法研究。实现了对复杂路段钢轨应力演化过程模拟,分析了钢轨应力对车轨动态响应的影响,为钢轨应力的检测与评估提供了理论依据。首先提出了计算大型结构平均性能参数的渐进均匀化方法,建立了昼夜及季节温度变化作用下的长大线路多尺度静态模型。根据线路中不同区段的结构特点,采用不同的仿真尺度,分析了各区段线路状态参数的演变规律。对线路重点区域,采用细尺度建立了保留关键细节的精细化模型。对线路中具有结构周期性特点的路段,提取其典型结构的平均性能,建立了宏观尺度模型。将不同尺度局部模型按边界行为一致的原则,组成多尺度整体线路模型,模拟了由局部结构变化引起的线路应力重分布的过程。为提高钢轨在多重载荷下的变形计算精度,在多尺度模型中采用了改进的长钢轨单元,考虑了单元截面转动对纵横向位移场的非线性影响。同时,为实现循环载荷下的轨道累积变形的计算,模型中采用了能够反映滑动工况的非线性连接单元和接触单元模拟轨道各层次之间的约束关系。通过与京杭运河特大桥和京沪高铁新汴河大桥过渡段的现场测量数据进行对比分析,验证了该建模方法的有效性和准确性。其次,建立了钢轨纵向应力作用下的车辆-轨道耦合动态模型,分析了钢轨纵向应力与车轨动态响应的影响。提出了考虑纵向应力的钢轨振动微分方程。通过对轨道模型分段解析再组合求解,率先推导了板式轨道固有振动特性关于钢轨纵向应力的精确解析形式,研究了不同钢轨纵向应力下轨道固有振动特性的变化。在翟孙车轨耦合动力学模型的基础上,引入修正的轨道振型与频率,从而计算出随钢轨纵向应力变化的车轨动态响应。通过仿真试验分析了不同车速和不平顺条件对车轨动态响应中钢轨应力特征的影响,为开展基于车轨动态响应的应力估计算法的研究提供理论基础。最终,在掌握长大线路钢轨应力分布规律的基础上,根据轮轨动态响应与钢轨纵向应力之间的显著相关性,针对线路中状态敏感区域开展了基于轮轨振动响应的钢轨应力智能估计算法研究。提出了基于支持向量机的应力快速分类模型,通过测量轮轨动态响应,实现了车载条件下的钢轨应力快速分类。同时,针对强轨道不平顺的干扰,提出了基于遗传算法的应力参数估计模型。将应力求解转化成模型参数估计问题,利用应力分布的连续性,提高了估计算法的计算效率和准确性。通过仿真试验分析了这两种方法的识别精度和适用条件。研究成果有助于构建我国高速铁路线路服役状态综合监测系统,为科学指导养护维修提供了理论上和方法上的支持。
[Abstract]:High-speed railway is a complex large system, and service performance of train and line infrastructure changes dynamically with long-term operation. As the speed of train operation is greatly improved, the dynamic effect between wheel and rail is increased, resulting in the strengthening of the dynamic role of the infrastructure. China's high-speed railway is running on a large scale, and the line crosses multiple climatic zones, and the service performance is more complex. The decline of service performance of the line infrastructure leads to more bursty and serious potential disease, which greatly affects the operation safety of the line. Grasp the formation and distribution laws of the state parameters of the infrastructure, accurately sense the change trend of the state parameters of the critical section components, establish and perfect the scientific line health service status guarantee system, and have important significance for ensuring the safe and stable operation of the high-speed railway. In order to reflect the critical parameter orbital stress of line safety, this paper presents a study on multi-scale dynamic static modeling of seamless line and related parameter intelligent estimation algorithm, considering the evolution of service state of growth line, considering the slow change of temperature factor and transient effect of vehicle impact. The influence of rail stress on dynamic response of rail is analyzed, and the theory basis is provided for the detection and evaluation of rail stress. First, a gradual homogenization method for calculating the average performance parameters of large structures is put forward, and a multi-scale static model of growth line under the action of diurnal temperature and seasonal temperature is established. According to the structure characteristics of different sections in the circuit, different simulation scales are used to analyze the evolution rules of state parameters in each section. The refined model of retaining critical detail is established by using fine scale in line focus area. In this paper, the average performance of the typical structure is extracted and the macroscopic scale model is established. A multi-scale global line model is formed by the principle of consistent boundary behavior of local models with different scales, and the process of redistribution of line stress caused by local structural changes is simulated. In order to improve the calculation accuracy of the rail under multiple loads, an improved long rail unit is used in the multi-scale model, which takes into account the nonlinear effect of the unit cross-section rotation on the longitudinal and transverse displacement fields. At the same time, in order to calculate the accumulative deformation of the track under cyclic load, the constraint relation between the nonlinear connection unit and the contact unit of the sliding working condition can be reflected in the model. The validity and accuracy of the modeling method are verified by comparing the field measurement data of the transition section of the Beijing-Hangzhou Canal Bridge and the Xinqiao River Bridge of the Beijing-Hangzhou High-speed Railway. Secondly, the dynamic model of vehicle-rail coupling under longitudinal stress of rail is established, and the influence of longitudinal stress on rail and dynamic response of rail is analyzed. The differential equation of rail vibration considering longitudinal stress is presented. In this paper, the exact analytical form of the inherent vibration characteristics of the plate-type track on the longitudinal stress of the rail is derived by analyzing and re-combining the segment analysis of the track model, and the change of the inherent vibration characteristics of the rail under different longitudinal stress of the rail is studied. A modified track mode and frequency are introduced to calculate the dynamic response of the rail with the longitudinal stress of the rail. The influence of different vehicle speed and uneven condition on the rail stress in dynamic response of vehicle rail is analyzed by simulation test, and the theoretical foundation is provided for carrying out the research on the stress estimation algorithm based on the dynamic response of the rail. Finally, the rail stress intelligent estimation algorithm based on wheel-rail vibration response was carried out on the basis of mastering the stress distribution law of the track rail, and based on the significant correlation between wheel-rail dynamic response and longitudinal stress of rail. A rapid classification model of stress based on support vector machine is put forward, and the rail stress fast classification under vehicle-mounted condition is realized by measuring wheel-rail dynamic response. At the same time, the stress parameter estimation model based on genetic algorithm is proposed for the interference of strong orbit irregularity. The stress solution is transformed into the model parameter estimation problem, the continuity of stress distribution is utilized, and the calculation efficiency and accuracy of the estimation algorithm are improved. The recognition precision and applicable condition of these two methods are analyzed by simulation test. The research results help to construct a comprehensive monitoring system for service status of high-speed railway lines in our country, and provide theoretical and methodological support for scientific guidance and maintenance maintenance.
【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U216

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