Fatigue Crack Growth Properties of Rail Steels

摘要

Fatigue crack propagation properties of rail steels were determined experimentally. The investigation covered 66 rail steels. The effects of the following parameters were studied: stress ratio (ratio of minimum to maximum stress in a cycle), frequency, temperature and orientation. The results were presented on the basis of the stress intensity factor. The threshold value of the stress intensity was determined. An equation correlating the crack growth rate and the stress intensity factor was established. A limited number of mixed mode crack growth tests were conducted. Also the behavior of surface flaws was studied. The results serve as a data base for a failure model presented in DOT-TSC-FRA-80-30/FRA/ORD-81/31.