Improvement of the Method for Determining Relative Rail Wear

Abstract

Purpose. To evaluate the existing method of determining the relative wear of the rail in modern operating conditions of the railway track and to improve it. Methodology. An analysis of the existing method of determining the relative wear of rails was carried out to achieve the goal. 30 pieces of cross-sections of worn rails were processed. They were compared with the profile of the new rail. The actual wear area is determined digitally. Due to the measured values of vertical and lateral wear, calculations, corresponding analysis and research were carried out. Findings. The existing method of calculating the rail wear area is not relevant for modern rails and operating conditions. The inaccuracy is 60 %. A detailed analysis made it possible to establish a new mathematical dependence of the rail wear area on vertical and lateral wear. The condition of the wheels of the rolling stock is taken into account. Inaccuracy decreased to 3 %. Originality. On the basis of the conducted research, the concept of «pseudo lateral wear» was introduced for the first time. This is the vertical wear of the working face of the rail, measured as the lateral wear of the rail. Vertical wear of the rail is caused by the action of a vertical force. The mathematical dependence is given. This made it possible to clarify the value of parameter e for practical calculations and its physical meaning (e=50 mm2 with vertical wear greater than 1.5 mm, and e=20 mm2 with vertical wear equal to or less than 1.5 mm). Practical value. It is established that the relative wear of the rail is the sum of 94 % vertical wear and 30 % lateral wear for modern conditions. The physical essence of the specified percentages is the ratio of the average width and height of the vertical and lateral wear to the width of the rail head in the calculated plane. The physical meaning of relative wear is an estimate of the mass of worn metal. For every 1 mm of relative wear of the P65 rail, according to the refined methodology, there is 0.50 kg of worn metal per 1 m of the rail length.