考虑轨道不平顺全概率分布的车桥随机分析方法

轨道不平顺是车桥耦合系统最主要的激励之一，其高维的随机性导致车桥耦合确定性计算模型不能精确反映实际系统动力响应的离散性。为了完整地反映实际线路中的轨道不平顺信息，文章建立一种适用于车桥耦合随机系统分析的轨道不平顺随机场模型，模型在包含了轨道谱概率、幅值、波长、相位等信息的基础之上，尽可能地减少了参数数量，通过与实测数据对比，该模型的有效性得以验证。此外，将该轨道不平顺随机场模型作为三维车 线 桥耦合时变计算模型的激励源，引入概率密度演化方法，对该耦合系统动力指标的统计特性及动力可靠度进行分析。结果表明，该轨道不平顺随机分析模型产生的空间序列较好地表征了平稳随机过程的谱表达；概率密度演化方法相对于蒙特卡洛方法有着更高的计算效率；不同的动力指标有着不同的均值、均方差、可靠度特征。

A stochastic analysis method of train bridge interactions considering#br# full probability distribution of track irregularities

Track irregularities might be the most important excitation source in train bridge interactionsThe high dimensional randomness of track irregularities might lead to the fact that the discrete nature of actual dynamic response cannot be revealed by applying the deterministic modelIn order to comprehensively reflect the track irregularity information in a railway line, a novel random field model of track irregularities for train bridge coupled system is presented, and the ergodic properties of probabilities, amplitudes, wavelengths and phases are fully characterizedMoreover, the number of stochastic variables has been reduced as much as possibleBy comparing to the measured data, the effectiveness of the model is verifiedAs an extended application, on the basis of the random field model for track irregularities, a stochastic analysis is performed for a train track bridge coupling by combing probability density evolution methodThe results indicate that the spatial series generated by the random field model for track irregularities is valid to represent the track spectra; probability density evolution method has a higher computational efficiency than the Monte Carlo method; different dynamic indices hold different mean, standard deviation and reliability characteristics