Thermal buckling monitoring in continuous welded rails by means of temperature and strain measurements

This paper presents a method for the monitoring of the safety of rails against thermal buckling caused by temperature changes. The monitoring strategy is based on the measurement of couples of strains and temperatures by optic fibers. Measured strains and temperatures are observed and examined in order to elaborate an interpretative model to estimate neutral temperature and force eccentricity. The interpretative model is applied to real data showing the evolution of neutral temperature and rail eccentricity in a timespan of a couple of months. The values determined, at least as regards their variation, may provide an indication of the need for intervention when high values of eccentricity and excessive lowering of neutral temperature are observed.