Sökning: "railway rails"

Visar resultat 36 - 40 av 52 avhandlingar innehållade orden railway rails.

  1. 36. Rolling Contact Fatigue of Railway Wheels Towards Tread Life Prediction through Numerical Modelling Considering Material Imperfections, Probabilistic Loading and Operational Data

    Författare :Anders Ekberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Higher train speeds and increased axle loads have led to larger forces acting on the railway wheels. Also, efforts are presently being made to straighten existing tracks, to design new tracks with larger curve radii and to optimize bogie designs. LÄS MER

  3. 37. Train---Track Interaction. Coupling of Moving and Stationary Dynamic Systems: Theoretical and Experimental Analysis of Railway Structures Considering Wheel and Track Imperfections

    Författare :Jens Nielsen; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : A general and well-structured method is advanced for analysis of the vertical dynamic interaction between a train and its track. The trains studied are modelled as linear or non-linear discrete mass-spring-damper systems. LÄS MER

  4. 38. Optimization of track geometry maintenance : a study of track geometry degradation to specify optimal inspection intervals

    Författare :Iman Arasteh khouy; Per-Olof Larsson-Kråik; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Drift och underhållsteknik; Operation and Maintenance;

    Sammanfattning : Railway infrastructure is a complex system which comprises different subsystems. Long useful life span is one of the important aspects of this prime mode of transport. The useful life length of its assets is highly dependent on the maintenance and renewal strategy used during its life cycle. LÄS MER

  5. 39. Modeling and experimental characterization of pearlitic rail steels subjected to large biaxial strains

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

    Sammanfattning : Large shear strains develop in the near-surface region under the running band of railway rails. Rolling Contact Fatigue (RCF) cracks often initiate in this region, causing major problems for the railway industry. However, characterization of the constitutive and fatigue behavior of this region is difficult due to the large gradient of properties. LÄS MER

  7. 40. 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