Determining the force of interaction in a wheel - rail system based on measuring stresses in rails neck

Abstract

When implementing new or modernized rolling the train in most cases is in the range of 0.9-0.95 and varies de-stock, one of the main problems is the provision of both traffic pending on the position in the track of a group of wheelsets. The safety, and the strength of the carriage and the ways that are de-correlation level of the frame force measured in the carriage and termined by forces in the wheel - rail system. It is almost impossible the sum of lateral forces by its average values is 0.98. A practical to directly measure the forces of interaction between the crew and method for determining the forces of interaction with respect to the track. Their determination can be carried out by measuring the stresses in the neck of a rail was proposed by Schlumpf. It involves stresses in rails, the interdependencies of which with forces are of determining the difference of the moments in the two cross sections a probabilistic nature. Correlation of the strength and stresses for of the rail neck with the angular moment of resistance to bending being equal. In this case, when the scale factors are equal to the difference of the moments, the lateral force is determined. The calculations were made by subtracting electrical signals (four strain gauges were included in the shoulders of the Wheatstone bridge), and a separate bridge was used to determine the vertical load. Errors in determining the lateral force are due to inaccurate location of the sensor sticking, the difference in the dimensions of the rail neck and the displacement of the point of application of the vertical load on the rail head. However, since the maximum forces are realized when the wheel climbs on the rail, this displacement varies insignificantly. Therefore, the results obtained can be used in conducting certification tests. The method of digital processing of data on stresses at three points of the rail neck requires for its implementation more strain gages, but the accuracy of its results is much higher, since it depends only on the errors of preliminary calibration of the cross sections. The error in calculating the forces does not exceed 4%, which shows the expediency of using the three-point method in determining the interaction forces to establish the conditions of circulation.

Influence of change in frictional condition of track rail surfaces on interaction forces in the “wheel/rail” contact

“…The Russian scientists (Railway Research Institute) actively collect the statistical data and analyse the train movement in the curved tracks. They develop and implement the methods to determine the dynamic lateral forces in the random and curved tracks [3,4,5]. The foreign scientists (USA) point out the necessity of quantitative assessment of the "wheel/rail" operation, especially in the curved tracks.…”