Sökning: "rolling contact fatigue clusters"

Hittade 4 avhandlingar innehållade orden rolling contact fatigue clusters.

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

    Författare :Robin Andersson; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 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

  2. 2. Modelling of cyclic and viscous behaviour of thermomechanically loaded pearlitic steels; Application to tread braked railway wheels

    Författare :Ali Esmaeili; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; Railway wheels; plasticity; phase transformations; finite element analyses; viscoplasticity; rolling contact fatigue; pearlitic steel; tread braking; ratchetting; full-scale brake rig testing;

    Sammanfattning : In service, railway wheel and rail materials are subjected to high stresses and, in some cases, elevated temperatures. The high stresses are caused by the rolling contact between wheel and rail. Furthermore, heat generated from tread braking and/or sliding between wheel and rail gives additional stress due to constrained thermal expansion. LÄS MER

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

    Författare :Robin Andersson; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; 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

  4. 4. Damage and thermally induced defects in railway materials

    Författare :Casey Jessop; Chalmers University of Technology; []

    Sammanfattning : A major concern for the railway industry today is the problem of rolling contact fatigue (RCF) damage in wheels and rails as a result of increased traffic, accelerations, and loading conditions. The wheel/rail contact condition that occurs in railway applications is complex, and it is essential to understand the associated damage from combined mechanical and thermal loadings in order to predict component life and develop appropriate maintenance systems. LÄS MER