多动力源作用下高速列车-轨道-桥梁系统随机振动分析与行车安全准则

The high speed railways in China are mostly distributed in the potential earthquake areas, and the bridge account for a significant proportion which makes the train nearly runs on it for the whole journey. The complex conditions of the natural environment like potential earthquakes have brought great challenges for engineers to ensure the running safety of high-speed trains on bridge. Deeply understanding the random dynamic characteristics of train-track-bridge system caused by wind and earthquake will greatly help improve the running safety of high-speed train. Based on the (generalized) probability density evolution theory, this project intends to carry out the random vibration analysis of high-speed train-track-bridge system caused by wind or earthquake, as well as the randomness of track irregularity, track-bridge structural parameters and so on. The development of random parameter point set definition with multidimensional probability distribution is included, as well as the generation of random excitations by the power spectral based on the random harmonic functions. The random model of high-speed train-track-bridge system, which involving the 3D random wheel/rail interaction, is established to support the newly developed analytical method of high-speed train-track-bridge system under the excitation of earthquake and wind load. The software of train-track-bridge system on the high speed railway is developed for the random dynamic simulation and parameter analysis. At last, based on the probability guarantee rate and the first pass reliability theory, the running safety criterion of high-speed train runs on the bridges under the action of earthquake and wind load is proposed. The theories developed in this project will provide stronger support for the dynamic analysis of train-track-bridge system in high speed railway, as well as the theoretical basis and technical support for the railway security operations and maintenance.

我国“八纵八横”高速铁路主通道大多处于地震区，且桥梁比例极大，复杂自然环境条件和潜在不可抗地震灾害为桥上行车安全带来了巨大的挑战，深刻揭示地震、风等多动力源作用下桥上行车系统的随机振动特征有助于确保高速列车行车安全。本项目基于（广义）概率密度演化理论，拟开展地震、风等多动力源作用下高速列车-轨道-桥梁系统随机振动研究，同时兼顾轨道不平顺、轨道-桥梁结构参数等随机性，发展多维多分布随机参数点集的选点规则和基于随机谐和函数的随机激励功率谱表达，建立高速列车-轨道-桥梁系统随机振动模型，提出多动力源作用下基于三维随机轮轨接触关系的高速列车-轨道-桥梁系统随机振动分析方法，研发车桥随机振动分析软件，在仿真模拟与参数分析的基础上，提出多动力源作用下基于概率保证率和首次超越破坏可靠度的高速列车-轨道-桥梁系统桥上行车安全准则，为高速铁路动力学分析、安全运营及养护维修提供更坚实的理论基础与技术支持。

我国高速铁路主通道大多处于地震区，且桥梁比例极大，复杂自然环境条件和潜在不可抗地震灾害为桥上行车安全带来了巨大的挑战。本项目以高速铁路铁路典型轨道-桥梁结构体系为研究对象，开展了“多动力源作用下高速列车-轨道-桥梁系统随机振动分析与行车安全准则”。经过3年研究攻关，项目组取得了以下研究成果：.（1）基于传统数论网格法和等概率变换原理，发展了一类能兼顾多维多分布随机参数离散代表性点集的选点规则—“多分布选点法”及其初始概率分配规则，提高系统随机振动分析精度与计算效率；.（2）引入功率谱表达的第二类随机谐和函数，建立了地震、横风及轨道不平顺的随机激励功率谱表达的随机函数模型，构造得到可精确反映输入激励随机过程的平稳/非平稳代表性时程样本集合；.（3）基于标准踏面的三维随机轮轨模型，发展了快速瞬时轮轨动态接触点定位方法和轮轨随机接触点的概率密度演化分布方法，建立了基于随机轮轨磨耗型面、具有广泛适用性的随机轮轨关系模型；.（4）建立了多动力源作用下基于三维随机轮轨关系的高速列车-轨道-桥梁系统随机振动分析模型，并同时研发了随机振动分析软件；.（5）开展了大量的随机激励作用下高速列车-轨道-桥梁系统随机振动特性规律与参数分析，输出了随机响应极值状态的概率密度演化分布；.（6）基于概率保证率的思想和首次超越动力可靠度，开展了多动力源作用下高速列车-轨道-桥梁系统桥上行车安全评估。.本项目研究已在国内外高水平期刊和国际学术会议上发表学术论文8篇，其中SCI检索论文收录6篇，申请和获得授权发明专利2项，软件著作权1项，国际/国内学术会议上做特邀报告1场，分组大会报告3场，国际/国内学术会议参会10余人次，培养研究生3名。项目相关研究成果作为重要理论和技术支撑，获得2019年湖南省科学技术进步一等奖1项（毛建锋，排名3/12）。.项目研究成果可为高速铁路动力学分析、安全运营及养护维修提供更坚实的理论基础与技术支持。