Crossings – Deformation, Damage and Optimization

Julian Wiedorn

Research output: ThesisDoctoral Thesis

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Abstract

In this thesis an explicit finite element model for the impact of a wheel on a nose of a railway crossing is introduced. The crucial parameters that describe the dynamic response (contact forces and pressures) of the impact of the wheel on the crossing nose are used to develop a simplified model. This includes (a) geometrical parameters described by the geometry of the crossing and wheel, such as impact angles (movement of the wheel due to the wing rail and crossing nose) and rail radii but also (b) dynamical parameters, such as the velocity of the wheel. First the influence of those parameters is evaluated performing a parametric study. The simplified model and its results provide a fast way to calculate the dynamic forces and stresses for geometry evaluation and optimization. Including plastic material behavior the deformation of three crossing nose materials (manganese steel, chromium-bainitic steel and tool steel) is predicted. By applying a damage parameter the deformed crossings are then compared and the influence of different axle loads, velocities and wheel types is evaluated. Furthermore, the positive effect of changing the geometry of higher strength steel crossings is discussed. To investigate the severe deformation of manganese steel crossings, explosion-depth hardened manganese crossings are modelled using measured geometries and hardness measurements of crossings in track. Additionally, the observed ability of manganese steel crossings to withstand unfavorable load situations is calculated.
Translated title of the contributionHerzstücke von Weichen - Verformung, Schädigung und Optimierung
Original languageEnglish
QualificationDr.mont.
Awarding Institution
  • Montanuniversität
Supervisors/Advisors
  • Pippan, Reinhard, Assessor B (internal)
  • Antretter, Thomas, Assessor A (internal)
Publication statusPublished - 2020

Bibliographical note

no embargo

Keywords

  • crossing nose
  • railway
  • crossing
  • contact mechanics
  • damage
  • deformation
  • optimization
  • numeric methods
  • finite elements
  • finite element method
  • cyclic load
  • plasticity
  • plastic deformation
  • cyclic deformation

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