Sökning: "Rail surface irregularities"

Hittade 5 avhandlingar innehållade orden Rail surface irregularities.

1. 1. Surface defects in rails - Potential influence of operational parameters on squat initiation

   Författare :Robin Andersson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; RCF; squats; dynamic vehicle–track interaction; rail corrugation; Rail surface irregularities;

   Sammanfattning : Despite significant efforts throughout the last decades, the mechanisms behind the formation of squats — a form of rolling contact fatigue (RCF) damage in rails — are not fully understood. Proposed causes of initiation involve, but are not limited to, small initial rail surface irregularities which yield high contact stresses, rail corrugation and varying friction conditions. LÄS MER

3. 2. Squat defects and rolling contact fatigue clusters - Numerical investigations of rail and wheel deterioration mechanisms

   Författare :Robin Andersson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rail surface irregularities; rolling contact fatigue clusters; dynamic vehicle–track interaction; rolling contact fatigue; studs; squats; fracture mechanics;

   Sammanfattning : Squat defects, a type of localised rolling contact fatigue damage appearing on rail surfaces with rail break as an ultimate consequence, have concerned infrastructure managers for the last couple of decades. In recent years similar types of defects—so-called studs—that are visually resembling squats, have started to appear. LÄS MER

4. 3. 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

5. 4. Structural Behaviour of Concrete Railway Sleepers

   Författare :Rikard Gustavson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; concrete; finite element analysis; three-wire strand; sleeper; bond; strand; pull-through tests; steel encased; push-in tests; bond mechanism; numerical bond model; dynamic loads;

   Sammanfattning : The railway concrete sleeper is an important part of the railway track structure. The sleeper member requires substantial engineering skills during the design and manufacturing process in order to fulfil the requirements set by modern train traffic. LÄS MER

7. 5. An Investigation of the Iron-Ore Wheel Damages using Vehicle Dynamics Simulation

   Författare :Saeed Hossein Nia; Sebastian Stichel; Matti Rantatalo; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; three-piece bogie; wear; RCF; prediction; traction; braking; heavy haul; simulation; Vehicle and Maritime Engineering; Farkostteknik;

   Sammanfattning : Maintenance cost is one of the important issues in railway heavy haul operations. For the iron-ore company LKAB, these costs are mainly associated with the reprofiling and changing of the wheels of the locomotives and wagons. The main reason for the wheel damages is usually surface initiated rolling contact fatigue (RCF) on the wheels. LÄS MER