Random Oscillations of Rail Vehicles with Nonlinear Spring Suspension Characteristics

There is considered about the problem of nonsteady random processes as related to rail vehicle oscillations under action of multidimentional random forcing process in the form of vertical and horizontal irregularities of the left and right rail lines. In terms of vehicle movement speed variations it is necessary to change the number and consist of summands in the analytical expression describing pulse-response characteristic of the shaping filter involved in the random process generation of the in-track equivalent geometric irregularity. There are obtained 3-D implementations of such random oscillation processes for the discussed rail vehicle model. Also it is shown that individual implementations of such processes are much different from each other which is evidence of unsteadiness of these oscillation processes. There are obtained 2-D distribution densities of random processes’ instantaneous values of the vehicle body, bogie and wheelset swaying oscillations, which can be smoothed out by the 2-D Gaussian law. Correlation functions and Fourier densities of these oscillations proved to be 3-D ones. At that Fourier density functions’ surface turns to be a nonnegative one with a number of maximums, which highest y-coordinates are located in the principal diagonal plane. There is justified the emergence of principal and side spectral density maximums and it is indicated that the frequencies corresponding to side maximums are in the ratios 2: 1 and 3: 1 with the respective diagonal maximum frequency. This is evidence of the presence of ultraharmonic constituents, characteristic to nonlinear systems, within the respective oscillation processes’ implementations. There is calculated distribution of the processes absolute maximums and are found average values of distributions, characterizing ability rating values.

random processes of the rail lines’ geometric irregularities, vehicle movement speed effect on the irregularities’ random processes, 2-D probability density, correlation function, spectral density, absolute maximums distribution of the vehicle oscillations’ nonsteady random processes

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