Influence of Threshold Values on Residual Fatigue Lifetime of Railway Axles under Variable Amplitude Loading

Abstract

The paper deals with an estimation of residual fatigue lifetime of railway axles under real loading spectrum. The residual fatigue lifetime is given by magnitude of fatigue crack propagation rate. This rate depends predominantly on load, geometry and material of the axle. Standard steel EA4T for manufacturing of railway axles is considered in this paper. The scatter of data in v-K curve could be caused by inaccuracy of experimental measurement or by local change of material properties. The paper shows important differences between obtained residual fatigue lifetime estimations considering scatter in measured material data, especially near the threshold region.The paper deals with an estimation of residual fatigue lifetime of railway axles under real loading spectrum. The residual fatigue lifetime is given by magnitude of fatigue crack propagation rate. This rate depends predominantly on load, geometry and material of the axle. Standard steel EA4T for manufacturing of railway axles is considered in this paper. The scatter of data in v-K curve could be caused by inaccuracy of experimental measurement or by local change of material properties. The paper shows important differences between obtained residual fatigue lifetime estimations considering scatter in measured material data, especially near the threshold region.