车轮踏面磨耗及轨道不平顺联合作用下的车辆-轨道系统随机分析模型

Stochastic Analysis Model for Vehicle-track Coupled Systems under Joint Random Irregularities of Wheel Treads and Track Irregularities

车轮磨耗和轨道不平顺具有随机特征。基于车轮圆周磨耗的概率特征及高斯分布假设,将车轮型面离散化,形成车轮型面磨耗量的概率反演方法;同时,基于轨道不平顺概率模型,实现轨道不平顺在不同幅-频状态下的遍历随机模拟。结合车辆-轨道耦合动力学理论和概率方法,建立考虑车轮踏面磨耗-轨道随机不平顺耦合作用的车辆-轨道随机分析模型,并用一类概率密度演化方程解决模型的概率密度传递问题。此模型能较好分析车辆-轨道系统在不同车轮型面磨损及线路随机不平顺联合作用下的动力响应分析及可靠度计算问题。

The formation and development of the wheel tread wear and track irregularities are random in nature.Based on the probabilistic feature of wheel wear and Gaussian distribution hypothesis,the wheel profiles can be discretized,to establish a probability inversion mechanism for wheel profile points.Meanwhile,a track irregularity probabilistic model was introduced to achieve the ergodic simulation of track random irregularities under different amplitude and frequency states.By combining the vehicle-track coupled dynamics and probability theory,a vehicle-track stochastic dynamic model in which the wheel profile wear and track random irregularities are jointly used as the excitations was developed.Meanwhile,the issues on probabilistic transmission between exciting loadings and system responses were solved by a class of general probability density evolution equation(PDEM).This model can be used to predict the dynamic responses and assess the dynamical reliability for vehicle-track systems.