Sökning: "wheel flat"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden wheel flat.

  1. 1. Out-of-Round Railway Wheels - Causes and Consequences An Investigation Including Field Tests, Out-of-Roundness Measurements and Numerical Simulations

    Författare :Anders Johansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polygonalization; wheel flat; full-scale measurements; wear modelling; impact load detector; railway wheel out-of-roundness; wheel removal criterion; dynamic train-track interaction; corrugation;

    Sammanfattning : Causes and consequences of out-of-round railway wheels are investigated through literature studies, full-scale field experiments, out-of-roundness measurements, and numerical simulations. Both defects around the complete wheel circumference (e.g. polygonal wheels with wavelengths up to one wheel circumference) and local defects (e. LÄS MER

  3. 2. Railway Wheel Flats. Martensite Formation, Residual Stresses, and Crack Propagation

    Författare :Johan Jergeus; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sliding contact; metallographic investigation; crack propagation; thermal shock; constitutive modelling; phase transformations; railway wheel flats; full-scale field experiments; transformation plasticity; tread damage; residual stresses; spalling; martensite formation;

    Sammanfattning : A railway wheel flat is a flat spot on the rolling surface of a wheel caused by its unintentional sliding on the rail. The reason for the sliding may be poorly adjusted, frozen or defect brakes, or too high braking forces in relation to the available wheel/rail adhesion. LÄS MER

  4. 3. Development of Multi-grit cBN Grinding Wheel for Crankshaft Grinding

    Författare :Nastja Macerol; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; crankshaft; grinding; wear; grit concentration; grit toughness; grinding wheels; grit size; automotive; grit shape; cubic Boron Nitride;

    Sammanfattning : A crankpin, part of a crankshaft, has a complex profile that is difficult to grind. The process often causes challenges such as excessive heat on the crankpin sidewall and wheel wear on the radius, causing reduced dressing interval. Different solutions were proposed to overcome these challenges, mainly focusing on the process, i.e. LÄS MER

  5. 4. Analysis of rail breaks and insulated joint deterioration

    Författare :Johan Sandström; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rail breaks; Heavy Haul; Insulated joints; Wheel flats; Railway mechanics; Material fatigue;

    Sammanfattning : The thesis deals with fatigue related issues in the field of railway mechanics. In particular rail breaks and deterioration of insulating joints are investigated. The study is largely motivated by plans to increase allowed axle loads in Sweden. LÄS MER

  7. 5. Thermo-Mechanical-Metallurgical Modelling of Pearlitic Steels and Railhead Repair Welding

    Författare :Björn Andersson; 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; Pearlitic steels; Railhead repair; Welding simulations; Phase transformations; Cyclic plasticity; Finite element analysis; Homogenisation;

    Sammanfattning : The efficiency of rail transport is attributed to low rolling resistance, which comes at the cost of high contact pressures between rail and wheel. Consequently, both the rail and wheel can be susceptible to fatigue crack initiation and propagation due to the resulting high stresses and large number of load cycles in service. LÄS MER