Sökning: "railway mechanics"

Visar resultat 31 - 35 av 67 avhandlingar innehållade orden railway mechanics.

  1. 31. Multiobjective Optimisation and Active Control of Bogie Suspension

    Författare :Milad Mousavi Bideleh Seyed; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; global sensitivity analysis; Bogie; active control.; robustness analysis; suspension system; multiobjective optimisation;

    Sammanfattning : Railways provide fast, safe, clean, and cheap transportation service. The cost efficiency inrailway operations can be scrutinized from different perspectives. LÄS MER

  3. 32. Modeling of phase transformations and cyclic plasticity in pearlitic steels

    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; Phase transformations; TRIP; Pearlitic steel; FEM; Cyclic plasticity; Homogenization;

    Sammanfattning : The low rolling resistance in railway transportation is a key factor for its high efficiency, but it comes at the price of very high contact pressure between the rail and wheel. Due to the high stresses and the large number of load cycles during railway operation, both the rail and the wheel can be susceptible to fatigue crack initiation and propagation. LÄS MER

  4. 33. Modeling and experimental characterization of large biaxial strains and induced anisotropy in pearlitic rail steel

    Författare :Knut Andreas Meyer; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pearlitic steel; yield criteria; distortional hardening; axial-torsion; kinematic hardening; biaxial loading; hyperelasto-plasticity;

    Sammanfattning : Large shear strains accumulate in the near-surface region under the running band of railway rails. In this region, rolling contact fatigue cracks often initiate, causing major problems for the railway industry. LÄS MER

  5. 34. 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

  7. 35. On the modeling of large ratcheting strains and anisotropy in pearlitic steel

    Författare :Göran Johansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Large strains; Plasticity; Anisotropy; Ratcheting; Kinematic hardening;

    Sammanfattning : Thermodynamically consistent constitutive material models for describing the large strain response of polycrystalline metals are proposed. Emphasis is put on the multiaxial ratcheting under cyclic loading and the evolution of anisotropy in pearlitic steel. LÄS MER