车辆-轨道系统动力极值预测及可靠度计算OA北大核心CSTPCDEI

To analyze vehicle running safety and quantify system reliability from the viewpoint of the dynamic extreme prediction and reliability calculations for vehicle-track systems,based on vehicle-track coupled dynamics and probability theory,a method for predicting dynamic extreme responses and evaluating system reliability was proposed.First,a track irregularity probabilistic model was introduced to determine the random sequences of irregular samples with different excitation energies,in which the cumulative probability spectrum was treated as an indicator.Based on the discrete Parseval theorem,the relationship between time-domain track irregularities and their power spectral densities(PSDs)was established.By combining the track irregularity probabilistic model and vehicle-track coupled dynamics model,the dynamic extremes and reliability information of the vehicle-track system were extracted from the stochastic analysis.Subsequently,by using vehicle-track coupled dynamics analysis and a two-dimensional interpolation operator,the dynamic response extremum was predicted based on the energy relationship of the PSD curves.Additionally,based on the probabilistic equivalence between the excitation input and response output,the reliability formula of dynamic extreme responses was derived.The numerical results of lateral wheel-rail forces and vertical rail displacements obtained from the measured track irregularities and vehicle acceleration,subjected to the combination of four types of irregularities at different cumulative probabilities,were used as samples and compared to the predictions.The distribution of the predicted values is consistent with that of the measured values at high accuracy.Due to the randomness of track irregularities,the dynamic responses of the vehicle-track system exhibit discrete and variance characteristics,but the method of extremum prediction through the amplitude-frequency and energy characteristics of track irregularities is proven to be feasible.