Neutron residual stress measurements on rail sections for different production conditions

Details

• Creators:
  Gordon, J E ; Luzin, Vladimir ; Gnaupel-Herold, Thomas ; Prask, Henry J.
• Corporate Creators:
  National Institute of Standards and Technology (U.S.) ; John A. Volpe National Transportation Systems Center (U.S.) ; University of Maryland (College Park, Md.)
• Subject/TRT Terms:
  Defects Failure Measurement Prevention Rail (Railroads) Railroad Safety Rails Residual Stress Strain Measurement
• Publication/ Report Number:
  IMECE2004-61754
• Resource Type:
  Proceedings
• Geographical Coverage:
  United States
• Corporate Publisher:
  American Society of Mechanical Engineers
• Abstract:
  Rail sectioning with subsequent neutron diffraction experiments has been used to assess residual stresses in the rails. In this study we present the results of neutron stress
  
  measurements performed at the NIST Center for Neutron Research (NCNR) on rail sections from rails that were produced under various conditions. Specifically, these are aircooled,
  
  air-cooled and roller-straightened, head-hardened and head-hardened and roller-straightened. More significantly, a head-hardened and roller-straightened rail was also studied
  
  after service to elucidate evolution of the service-induced residual stresses. In the latter case both a transverse-cut slice and the central region of a 0.53 m long piece were studied.
  
  Measurements on this piece are the first in which triaxial stresses have been determined for an intact rail. Neutron strain measurements with 3x3x3 mm3 spatial resolution were successfully employed for transversally cut slices to verify the difference in the stress state depending on the production process. Although examination of slices allows determination of only two-dimensional stresses in the plane of the slice, additional measurements on obliquely-cut slices, which were also carried out, and utilization of FEM gives the possibility of reconstructing the full triaxial stress distribution. Together, these approaches provide a better understanding of rail fabrication and the possibility of improving the durability and safety of rails in the future.
  
  
• Format:
  PDF
• Collection(s):
  Volpe Center
• Main Document Checksum:
  urn:sha-512:109a14f8b293317b4912db7874ab7bf20d7bdbd098a8799e8c87c4309bb889ed5c413ad62c74a996c2db93085f0be27aed6bae9307769211d01ed2d870bc0887
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/9110/dot_9110_DS1.pdf
• File Type:
  [PDF - 314.39 KB ]