Experimental Evaluation of Crack Evolution in Rails Using a Phased Array

Abstract

Crack growth in rail heads can lead to rail breaks that cause delays in train operation and, in rare cases, train derailments. As a result, it is important to develop models that are able to accurately predict crack growth rates in order to avoid such events. Accordingly, it is necessary to develop complex rail testing protocols that are capable of validating such models, thereby increasing the safety, reliability, and efficiency of railway operations.

One approach to rail testing involves the non-destructive evaluation (NDE) of internal rail cracks using phased array ultrasonic testing (PAUT). This paper focuses on our efforts to utilize PAUT methodology to nondestructively measure internal crack geometry during long term multiaxial cyclic loading of rails with growing internal cracks.

Our efforts have in some cases resulted in anomalous measurements of crack geometry, thereby impacting the accuracy of the results of these complex experiments. In this paper we present an overview of our experimental results to date as well as our efforts to improve this critical testing methodology for assessing crack growth rates in rails subject to cyclic loading.