TTCI investigated two methods of determining rail structural integrity:
Crack growth test results and FM analysis using the FM approach suggests a large variability in MGT to fracture, endorsing railroad service experience. This approach is not recommended.
The SoM approach suggests railhead wear limits similar to those generally adopted by railroads; depending on material endurance limit and independent of head side wear. This method is being pursued with fatigue tests of a spectrum of rail materials, as well as possible service stress measurements.