Search for dissertations about: "rail or plane"

Showing result 1 - 5 of 6 swedish dissertations containing the words rail or plane.

2. 1. On Active Secondary Suspension in Rail Vehicles to Improve Ride Comfort

   Author : Anneli Orvnäs; Sebastian Stichel; Rickard Persson; Roger Goodall; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rail vehicle; active secondary suspension; ride comfort; sky-hook damping; H∞ control; multi-body simulations; on-track tests; Järnvägsgruppen - Gröna tåget; Järnvägsgruppen - Gröna tåget; Järnvägsgruppen - Fordonsteknik; Järnvägsgruppen - Fordonsteknik;

   Abstract : One way to make rail vehicles a competitive means of transportation is to increase running speed. However, higher speeds usually generate increased forces and accelerations on the vehicle, which have a negative effect on ride comfort. With conventional passive suspension, it may be difficult to maintain acceptable passenger comfort. READ MORE

4. 2. Shear cracks in concrete structures subjected to in-plane stresses

   Author : Richard Malm; Håkan Sundquist; Kent Gylltoft; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Shear; plane state stress; crack width; FE analysis; design standards; serviceability state; Civil engineering and architecture; Samhällsbyggnadsteknik och arkitektur;

   Abstract : After only two years of service, extensive cracking was found in the webs of two light-rail commuter line bridges in Stockholm, the Gröndal and Alvik bridges. Due to this incident it was found necessary to study the means available for analysing shear cracking in concrete structures subjected to in-plane stresses. READ MORE

5. 3. Railway tread braking temperatures - Numerical simulation and experimental studies

   Author : Shahab Teimourimanesh; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; railway tread braking; finite element analysis; railway wheels; rail chill; hot spots; frictional heating; heat partitioning; metro; field experiment; rig experiment;

   Abstract : Tread (block) braking is still one of the most common braking systems on railway vehicles. The action is carried out by pressing brake blocks against the tread of a wheel, which is also in rolling contact with the rail. READ MORE

6. 4. Rolling Contact Fatigue of Railway Rails with Emphasis on Crack Initiation

   Author : Jonas Ringsberg; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; variable amplitude; crack closure; rolling contact fatigue; crack propagation; railway rails; damage accumulation; critical plane approach; crack initiation; plasticity; multiaxial fatigue;

   Abstract : Increased traffic density and the heavier axle loads of modern trains have led to severe problems with rolling contact fatigue (RCF) which cause initiation of surface cracks in railheads. In this thesis, a specific type of surface crack, the head check, is studied numerically with emphasis on fatigue crack initiation. READ MORE

7. 5. Elastic-Plastic Fracture Mechanics and RCF in Rails

   Author : Johan Tillberg; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; RCF; elastic-plastic fracture mechanics; Material-forces; Multiple crack interaction;

   Abstract : This thesis concerns issues regarding the modeling and numerical simulation of singularcracks and their propagation in the context of Rolling Contact Fatigue (RCF) in rails.Typically, such cracks are associated with squats and head-checks in the rail head. READ MORE