Technical Reports

Sleeve Expansion of Bolt Holes in Railroad Rail Volume Ill - Field Experiment ResuIts

  • 01
  • Feb
  • 1980
AUTHOR: Federal Railroad Administration
KEYWORDS: Cold expansion; Crack; Fatigue; Mandrel; Rail bolt hole; Sleeve; Flashwelds; Vacuum; Crack growth rate
ABSTRACT: The bolt-hole cold-expansion process has been demonstrated by laboratory tests to significantly affect the initiation and propagation of fatigue cracks from rail bolt holes such that a reduction of the incidence of rail-bolt-hole failure in cold-expanded rail would be expected. A field-verification experiment was implemented in 1977 and reported in Volume I of this report. This volume contains the results of the field experiment, an examination of the effect of fatigue ratio (R) on the observed laboratory fatigue-life improvement of cold-expanded bolt holes, an investigation of crack growth of rails in a vacuum environment, and a comparison of the fatigue performance of cold-expanded bolt holes with rail flashwelds.