Fracture mechanics analysis of a rail-end bolt hole crack

Abstract Analytic and experimental investigations were conducted to establish the cause of a peculiar ridge feature observed on the fracture surface of a railroad rail-end bolt hole fatigue crack. Calculations are performed which indicate that the ridges were caused by the change in stress caused by the thermal expansion of the rails during each day of fatigue. The ridge features were closely reproduced by a novel laboratory experiment on a four-hole compact tension specimen.