Ultrasonic Set-Up to Characterize Stress States in Rims of Railroad Wheels

Abstract

The stress state in the wheels of railroad freight cars is strongly influenced by the brakings. By pressing brake-shoes, the rolling surface of the wheels are getting hot and the subsequent cooling causes the development of tensile stresses in the circumferential direction. Small cracks in the rolling surface, which are not harmful otherwise may grow under the influence of the tensile stress and may even cause the failure of a wheel. In order to assure the reliability of the wheels and the safety of the traffic, the stress states of railroad wheels need to be inspected periodically. Because of the large number of endangered wheels, the inspection should not only be nondestructive but also fast and easy to apply in daily routines.