Sökning: "railway and track irregularities"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden railway and track irregularities.

1. 1. Mechanical track deterioration due to lateral geometry irregularities

   Författare :Kalle Karttunen; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rolling contact fatigue; track maintenance; track irregularities; wear; multibody dynamics simulations; Railway track geometry;

   Sammanfattning : This thesis deals with how a degraded track geometry influences further degradation of the geometry and the formation of rolling contact fatigue (RCF) and wear of rails. The overall objective is optimisation of railway maintenance. For this, further understanding and quantification of the deterioration of track components are needed. LÄS MER

3. 2. Simulation of track settlement in railway turnouts-An iterative approach

   Författare :Xin Li; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; track settlement; Railway switch and crossing; cyclic loading; visco-plasticity; vehicle‒track interaction; 3D finite element analysis; granular material; ballast;

   Sammanfattning : In this thesis, a methodology for simulation of track settlement in railway turnouts (switches andcrossings, S&C) is presented. The methodology predicts the accumulated settlement for a given setof traffic loads using an iterative and cross-disciplinary procedure. LÄS MER

4. 3. Data-driven models for railway track geometry maintenance

   Författare :Hamid Khajehei; Alireza Ahmadi; John Andrews; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Data-driven models; degradation; maintenance; tamping; track geometry; planning and scheduling; railway infrastructure; Drift och underhållsteknik; Operation and Maintenance;

   Sammanfattning : Railways are currently experiencing higher demands on safety, infrastructure performance, network capacity and service quality, etc. As a result, a high level of track availability, service quality and infrastructure robustness against unexpected events is required, at reduced cost, to meet the demands. LÄS MER

5. 4. Wheel–Rail Impact Loads and Track Settlement in Railway Crossings

   Författare :Xin Li; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vehicle--track dynamics; wheel--rail contact; track settlement; material modelling of ballast; Switches and crossings; turnout; cyclic loading; Green s functions;

   Sammanfattning : Turnouts (Switches & Crossings, S&C) are critical components of a railway track requiring regular maintenance and generating high life cycle costs. A main driver for the high maintenance costs is the need to repair and replace switch rails and crossings as these components are subjected to a severe load environment. LÄS MER

7. 5. Influence of rail, wheel and track geometries on wheel and rail degradation

   Författare :Kalle Karttunen; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; track geometry; rolling contact; rail; railway; Rolling contact fatigue; maintenance; wear; wheel;

   Sammanfattning : For more efficient railway maintenance there is a need to increase the understanding of the influence of operational conditions on wheel and rail degradation. To this end, the chosen primary investigation strategy is to employ dynamic multibody simulations, where operational conditions are altered, to estimate the influence on material deterioration. LÄS MER