轨道不平顺数值模拟方法

为了提高将轨道功率谱密度函数(PSD)通过数值模拟方法转换为时域样本的可靠度,分析了国内外常用的轨道不平顺数值模拟方法的模拟原理和步骤,采用计算机仿真程序模拟出各种方法生成的时域样本,并以此作为车辆垂向动力学模型的输入激励,通过数值仿真得出系统的时间-响应历程。各种模拟方法模拟结果比较表明采用各种方法模拟出的轨道不平顺时域样本是正确的,用三角级数法和逆Fourier变换法模拟出的时域样本的离散度较小,而用白噪声滤波法和二次滤波法模拟的时域样本离散度较大,因此后两种方法模拟出的轨道不平顺时域样本不宜作为研究系统时域响应时的轨道激励。

Numerical Simulation Methods of Railway Track Irregularities

In order to improve the reliability that the power spectrum densities of railway track were transformed into time domain samples by numerical simulation methods,the principles and steps of the methods were analyzed,some simulation samples in time domain were achieved by simulating programs respectively,the samples were taken as the inputting disturbances of a vehicle vertical dynamics model,the time response courses of vehicle system were obtained by numerical simulation.The comparison of simulation results show that each simulated sample in time domain is true,the samples simulated by trigonometric series and IFFT method have little discretenesses,but the samples simulated by white noise filter and secondary filter method have greater discretenesses and are not feasible to act as the track disturbances of studying non-linear system time response.1 tab,3 figs,10 refs.