Sökning: "RCF"

Visar resultat 6 - 10 av 37 avhandlingar innehållade ordet RCF.

  1. 6. Microstructural Decay in High-Strength Bearing Steels under Rolling Contact Fatigue

    Författare :Tania Loaiza; Peter Hedström; Mårten Olsson; Steve Ooi; Prasath Babu; Harry Bhadeshia; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microstructural decay; microscopy; rolling contact fatigue; Hybrid 60 steel; Bearing steel; 52100; dislocations; ferrite microbands; Mikrostrukturell nedbrytning; mikroskopi; rullande kontaktfatigue; Hybrid 60-stål; dislokationer; Materials Science and Engineering; Teknisk materialvetenskap;

    Sammanfattning : The work presented in this thesis aims to enhance our understanding of material decay in high-strength steels used for bearing applications. The primary objective is to investigate the microstructural changes in two high-strength steels: 52100 steels, a popular bearing steel, and Hybrid 60, a relatively new bearing steel designed for long fatigue life and use at elevated temperatures. LÄS MER

  3. 7. 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

  4. 8. On fatigue crack growth modelling of surface initiated rolling contact fatigue using the asperity point load mechanism

    Författare :Dave Hannes; Bo Alfredsson; Sylvie Pommier; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Load transfer in applications or between machine components is generally achieved through contact. In case of recurrent high contact loads in combination with a rolling motion, i.e. with a relatively small amount of slip, the contact surface may eventually suffer from rolling contact fatigue (RCF). LÄS MER

  5. 9. Thermal impact on rolling contact fatigue of railway wheels

    Författare :Sara Caprioli; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Railway wheels; Thermomechanical finite element analysis; Frictional rolling contact; Thermal fracture; Tread braking; Rolling contact fatigue;

    Sammanfattning : Rolling contact fatigue (RCF) is a very common and costly damage mechanism for rails and wheels. This thesis investigates the influence of combined thermal and mechanical loading on RCF of railway wheels on the basis of numerical predictions. LÄS MER

  7. 10. 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