부산대학교 도서관

To study the dynamic response of railway ballast excited by forces from the moving train at different speeds, a finite element model of track is developed. The rail is represented by a Timoshenko beam on discrete pad-sleeper-ballast supports. The ballast is considered as a three-dimensional finite element model. Wheel/rail irregularities and moving loads are taken into account. The displacement, acceleration and dynamic stress at different parts of the ballast are calculated. Vibration propagation is also presented. The responses of ballast, for constant loads and travelling at constant speeds over track with and without irregularity, are studied. It is shown that, at high speeds, stone may be projected out of the ballast bed.