Influence of axle-wheel interface on ultrasonic testing of fatigue cracks in wheelset

► Influence of axle-wheel interface on ultrasonic testing of railway axle is described. ► Interfacial stiffnesses are identified experimentally for spring interface model. ► Reflection coefficient for shear-wave oblique incidence is calculated. ► Parametric study is performed to relate these stiffnesses to reflection coefficient. ► This coefficient is compared to echo-height decrease by fitted wheel in experiment.