| Popis: |
The paper provides a systematic analysis of the origin, spread, and causes of shaft failure in the four-axle electric locomotive series 441. Based on this analysis, recommendations for preventive diagnostic maintenance are provided to timely identify the condition and avoid shaft failure, which is a vital component of the locomotive. Failure to maintain it in a timely manner can lead to catastrophic human, ecological, and material consequences. The paper also presents and explains the fracture surfaces of the locomotive’s hollow drive shaft, following a railway incident that caused the derailment of the rail vehicle, resulting in significant material damage. The presented fracture analysis is based on research into the mechanisms of failure, which by their appearance and action cause the formation of an initial crack. The dominant factor in the formation of the initial crack is material fatigue, and the potential presence of inclusions or local initial notches in the material structure formed during the shaft manufacturing process. Research has shown that the measured residual internal stresses after the shaft failure reached up to 470 MPa, significantly exceeding the allowable 300 MPa. |
