Weld Fatigue Damage Assessment of Rail Track Maintenance Equipment:
Regulatory Compliance and Practical Insights 05-17-02-0010
This also appears in
SAE International Journal of Materials and Manufacturing-V133-5EJ
The use of appropriate loads and regulations is of great importance in weld
fatigue assessment of rail on-track maintenance equipment and similar vehicles
for optimized design. The regulations and available loads, however, are often
generalized for several categories, which proves to be overly conservative for
some specific categories of machines. EN (European Norm) and AAR (Association of
American Railroads) regulations play a pivotal role in determining the
applicable loads and acceptance criteria within this study. The availability of
track-induced fatigue load data for the cumulative damage approach in track
maintenance machines is often limited. Consequently, the FEA-based validation of
rail track maintenance equipment often resorts to the infinite life approach
rather than cumulative damage approach for track-induced travel loads, resulting
in overly conservative designs. The work presented in this article evaluates and
compares the weld fatigue damage of track maintenance equipment for EN loads
using infinite life approach and AAR loads using cumulative damage approach and
highlights the need of having distinct category for track maintenance machines
in regulations based on its usage and application to have close representative
loads for the endurance limit approach or suitable loads for the cumulative
damage approach. Additionally, the study utilizes the BS7608 regulation to
determine weld class and predict weld fatigue damage. Both nominal and hot-spot
stress approaches are employed to thoroughly investigate and calculate fatigue
damage, providing a comprehensive analysis of weld fatigue in rail maintenance
equipment.