Sökning: "railway rails"

Visar resultat 26 - 30 av 52 avhandlingar innehållade orden railway rails.

1. 26. Wheel–Rail Impact Loads and Track Settlement in Railway Crossings

   Författare :Xin Li; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vehicle--track dynamics; wheel--rail contact; track settlement; material modelling of ballast; Switches and crossings; turnout; cyclic loading; Green s functions;

   Sammanfattning : Turnouts (Switches & Crossings, S&C) are critical components of a railway track requiring regular maintenance and generating high life cycle costs. A main driver for the high maintenance costs is the need to repair and replace switch rails and crossings as these components are subjected to a severe load environment. LÄS MER

3. 27. Influence of railway wheel tread damage and track properties on wheelset durability – Field tests and numerical simulations

   Författare :Michele Maglio; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dynamic wheel–rail interaction; axle stresses; railway wheel tread damage; wheelset durability; instrumented wheelset; rail vehicle maintenance; wheel–rail impact loads;

   Sammanfattning : Wheel tread damage leading to high magnitudes of vertical wheel–rail contact forces is a major cause of train delays in the Swedish railway network, particularly during the coldest months of the year. According to regulations, vehicles generating wheel–rail impact loads exceeding the limit values must be taken out of service for wheel maintenance. LÄS MER

4. 28. 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

5. 29. Modelling Stiffness and Damping by Use of Fractional Calculus with Application to Railpads

   Författare :Åsa Fenander; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; stiffness; initial conditions; modal synthesis; time integration; measurements; fractional calculus; railway tracks; fractional integrals; damping; railpads; structural dynamics; fractional derivatives; mathematical models;

   Sammanfattning : When studying the dynamic behaviour of a structure, e g a railway track, it is important for the analyst to model both stiffness and damping accurately. Mathematical models including fractional derivatives have been found to work well for many materials. Such models are linear and causal. LÄS MER

7. 30. On the Modelling of Train Induced Ground Vibrations with Analytical Methods

   Författare :Anders Karlström; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ground vibrations; train; wave propagation; dynamic flexibility; trench; railway track; vibration isolation; wave barrier; soil-structure interaction;

   Sammanfattning : A novel analytical approach to model train induced ground vibrations is proposed. Integral transform solutions are combined with series solutions to obtain fast numericalalgorithms, where a particular designed boundary condition for finite regions is seen to enable the solution procedure. LÄS MER