Wayside identification method for railway wheel rail force and vertical load position

To solve the problems of complex manufacturing processes, high manufacturing costs, and inability to measure wheel rail contact positions in existing wheel rail force identification methods, a new wayside identification method was proposed. This method aimed to measure the magnitude of lateral and vertical wheel rail contact forces, as well as the position of vertical load. Based on the decoupling of multiple loads in wheel rail contact, a theoretical relationship model was established, linking the magnitudes of lateral and vertical wheel-rail contact forces and the position of the vertical contact force to the vertical strain summation and strain subtraction on both sides of the rail web. Subsequently, a reverse calculation model for identifying the magnitude and position of wheel rail force was obtained based on the calculation of strain on both sides of the rail web. An orthogonal strain gauge bridge, designed to act on both sides of the rail web, was implemented to identify the strain responses corresponding to wheel-rail contact loads at the rail web position. The designed bridge performs arithmetic operations on strains from both sides of the web while simultaneously considering temperature self-compensation. Relationship coefficients between multiple loads and strains on both sides of the web were obtained through loading calibration experiments. Randomly loading tests were conducted to validate the accuracy of identifying the magnitudes of lateral and vertical wheel-rail contact forces, as well as the positions of vertical contact forces. The accuracy of identifying the magnitude of wheel rail contact forces using the new measurement method and the national standard method was compared and analyzed in vehicle tests. The research results can indicate that the proposed wheel-rail contact force identification method achieves an error within 6.2% for force magnitude and 7.6% for the position of the vertical load, thereby realizing accurate identification of wheel-rail contact force magnitudes and vertical load eccentric positions using the wayside identification method. The research results can provide scientific data support for further ensuring the precise assessment of the reliable serviceability of rails. © 2024, Central South University Press. All rights reserved.