Identification of Rail-Surface Irregularity for Railway Track Vibration Analysis

When a rail-surface profile is taken into account as an excitation, in a numerical track vibration analysis, it is necessary to decide the irregularity which reflects the whole source of noise. In this study, identification of the rail-surface irregularity which reproduces observed acceleration is attempted. The identification method is constructed based on equations describing the relation between the observed acceleration and the rail-surface irregularity. Since the identification of the rail-surface profile is so called ill-posed problem, in order to augment the stability of solution the Tikhonov's method is employed. The identification is achieved using accelerations observed at the rail, sleeper, and substratum. The developed method is applied to a numerical model and to observed data. Through numerical experiments validity of the proposed method is investigated.