Railroad Tie Responses to Directly Applied Rail Seat Loading in Ballasted Tracks : A Computational Study.

Details

• Creators:
  Yu, Hailing ; Jeong, David Y.
• Corporate Creators:
  John A. Volpe National Transportation Systems Center (U.S.)
• Subject/TRT Terms:
  • Finite element method
  • Structural analysis
  • Elasticity (Mechanics)
  • Mathematical prediction
  • Railroad ties
  • Concrete ties
  • Prestressed concrete ties
  • Wood ties
  • Railroad safety
  • Finite element method
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• Publication/ Report Number:
  JRC2012-74149
• Resource Type:
  Proceedings
• Geographical Coverage:
  United States
• Corporate Publisher:
  American Society of Mechanical Engineers
• Abstract:
  This paper describes work in-progress that applies the ; finite element (FE) method in predicting the responses of ; individual railroad crossties to rail seat pressure loading in a ; ballasted track. Both wood and prestressed concrete crossties ; are examined. The concrete tie is modeled as a heterogeneous ; medium with prestressing wires or strands embedded in a ; concrete matrix. The constitutive relations employed in the ; models are: elasticity followed by damaged plasticity for the ; concrete material, linear elastic bond-slip relations with ; potential initiation and evolution of damage to the bond for the ; steel-concrete interfaces, orthotropic elasticity followed by ; failure dictated by orthotropic stress criteria for the wood ties, ; extended Drucker-Prager plasticity for the granular and ; frictional ballast material, and elastic half space for the ; subgrade. The corresponding material parameters are obtained ; from the open literature. ; Under a simplified pressure load uniformly distributed ; over the rail seat area, the FE method predicts tensile cracking ; at the tie base below the rail seats of a concrete tie and ; compressive failure in the rail seats of a wood tie. The rail seat ; force-displacement relations are obtained from the simulations. ; The resultant rail seat forces at which tie failures occur are ; compared for concrete and wood ties. ; The FE method appears to be a promising tool for ; studying the railroad tie behavior under rail seat loading ; conditions in a ballasted track. Experimental data will be ; sought to calibrate the material parameters and verify the ; modeling approach. Additional track components, particularly ; rails, rail pads and fasteners, will be incorporated in future ; modeling efforts. This detailed modeling approach may help to ; shed light on the rail seat deterioration failure mechanisms ; observed in some concrete ties.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/9604/dot_9604_DS1.pdf
• File Type:
  [PDF - 892.10 KB]
• Collection(s):
  Volpe Center
• Main Document Checksum:
  urn:sha-512:1dcbc48b9063bacde74cb0bd50c0f8d2ab878d7c74d7741cb5614b9b66f18e769e44b9ed501a47e3e8b1182087e541546561f752ebde1425ddd4850d77f67f2e