Abstract
The paper gives the methodology of differential equations solution for description of bouncing, galloping and side swaying oscillations of railcar with asymmetrically located cargoes of different masses which were carried out on computer. Continuous vertical irregularities in the rail track and level difference (track skewness) of two rail tracks in the vertical transverse plane were taken as disturbances, spectral density of which is shown, respectively. To obtain the spectral densities depending on the speed, the abscissa of the spectral densities plots were multiplied by the speed, and the ordinates were divided by the speed at which the oscillations of the loaded car were investigated at that moment. As a result, spectral densities of unevenness of rail thread and misalignment of two rail threads in vertical transverse plane at speeds of 50; 80; 100 and 120 km/h of four-axle car with tare weight 21 t with bogies type CNIIKhZ were obtained.