A method of estimating railway axle stress spectra

All British railway axles require regular non-destructive testing to ensure that no dangerous cracks are present. The required periodicity for such testing can be calculated using probabilistic fracture mechanics, which outputs the probability of service failure as a function of inspection interval. A major input to this process is the stress histogram experienced by the axle. Such histograms have been measured for a typical British railway vehicle over two years, and the findings have been used to develop a methodology to predict axle stresses that can in principle be applied to any vehicle and route.