Experimental investigation of wheel-rail lateral forces and dynamic running behavior in sharp curves of heavy-haul railway systems

For the heavy-haul railway curve section with a 500 m radius, dynamic whole-vehicle passing tests were conducted by setting three different curve superelevation values of 60 mm, 90 mm, and 120 mm, achieving comprehensive dynamic testing of all parameters in wheel-rail interaction. Strain gauges were attached to the rails to measure the wheel-rail lateral forces when the train passed at different speeds, and the variation patterns of lateral forces on the guiding and trailing axles under different superelevation conditions were analyzed. A real-time angle-of-attack (AoA) measurement method based on synchronous wheel-rail force sampling was proposed, overcoming the limitations of traditional techniques in dynamically capturing wheelset attitudes, which can be used to analyze the operational characteristics of guiding and trailing axles under varying superelevation conditions. Results demonstrate that unbalanced superelevation (-5 to −25 mm) effectively reduces rail wear and enhances curve negotiation for 25 t axle-load trains. Increased deficient superelevation decreases the steering axle’s AoA but increases the trailing axle’s AoA. Lateral forces exhibit distinct patterns: for steering axles, inner rail inward forces decrease, while outer rail outward forces increase and inward forces diminish; trailing axles experience amplified lateral forces on both rails in opposing directions. These findings reveal superelevation’s dual role in governing lateral force distribution and wheelset alignment. The proposed AoA measurement technique provides critical insights into dynamic wheelset behavior during sharp curve transitions. The study establishes an optimal superelevation range to balance lateral force mitigation and operational stability, offering actionable guidelines for track maintenance and superelevation design in heavy-haul corridors. This work advances the understanding of vehicle-track interaction mechanics in tight curves, with direct implications for extending rail service life and improving safety in challenging geometric conditions.