Measurement method and experimental verification of the wheel-rail contact stress distribution

This study presents a comprehensive approach for measuring wheel-rail contact stress and its distribution. To address the limitations of existing measurement methods, the research integrates direct and indirect measurement techniques. A novel thin-film pressure sensor with an inclined test area arrangement is designed for the direct stress measurement under low-load conditions. By introducing a correction function from direct measurement results under low loads, an indirect measurement is developed, thereby resolving the error issues inherent in the traditional indirect methods when measuring edge stress states. The accuracy of edge contact stress measurement has been significantly enhanced. A single-wheel contact test apparatus was developed to validate the effectiveness and applicability of the proposed method under varying loads and wheel diameters, with comparative verification conducted through finite element simulations. The results demonstrate that the proposed method can effectively measure both the edge stress in the wheel-rail contact and the stress distribution across the entire contact area, providing a reliable theoretical foundation for the structural design of wheels and rails.