A Markov Chain Model for Fatigue Crack Growth, Inspection and Repair: The Relationship Between Probability of Detection, Reliability and the Number of Repairs in Fleets of Railroad Tank Cars

A Markov chain model to simulate the process of fatigue crack growth, non-destructive inspection and repair in a fleet of railroad tank cars is developed and presented. Crack growth is modeled to reproduce crack shapes that were observed during destructive tear-down tests at the end of life for several tank cars. The Markov chain model is further extended to include non-destructive inspections using POD curves that were established during baseline tests of several methods used in the railroad tank car industry. Next, the model is used to predict the effect of various non-destructive inspection techniques on fatigue-related reliability of the fleet, as well as the number of repairs that are required as a result of the inspections.Copyright © 2005 by ASME