Characterization and assessment of rolling stock structural durability under elevated operating temperatures

This study examines the effect of elevated operating temperatures on the structural durability of locomotive frame assemblies. Material specimens taken from long-serving locomotive frames were tested under controlled heating up to 100 °C to evaluate thermal-mechanical responses using calibrated strain gauges and temperature sensors at critical load-bearing zones. The statistical analysis of the results (mean values, standard deviations, confidence intervals) confirmed data reliability. Elevated temperatures were found to reduce the yield strength, elastic modulus, and fatigue endurance limit of structural steels, resulting in an estimated 15-17 % decrease in service life compared with normal conditions. The novelty of this research lies in incorporating thermal degradation into the durability model of locomotive structures, providing a more realistic basis for strength assessment and design optimisation of rolling stock operating under high-temperature environments.