Sökning: "high-speed rail"

Visar resultat 1 - 5 av 30 avhandlingar innehållade orden high-speed rail.

  1. 1. Simplified dynamic analysis of railway bridges under high-speed trains

    Författare :Christoffer Johansson; Costin Pacoste; Raid Karoumi; Jose M Goicolea; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic; Railway bridge; High-speed train; Moving load; Multi-span beam; Probabilistic;

    Sammanfattning : The world-wide development of new high-speed rail lines has led to more stringent design requirements for railway bridges. This is mainly due to the fact that a train at high speeds can cause resonance in the bridge superstructure. LÄS MER

  3. 2. Discrete element technique for modeling high-speed railway tracks

    Författare :Alireza Ahmadi; Stefan Larsson; Carl Wersäll; Liang Cui; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polygonal particles; Direct shear test; Particle scaling; Bal- lasted track; DEM; Polygonala partiklar; direkt skjuvförsök; partikelskalning; ballastspår; DEM; Soil and Rock Mechanics; Jord- och bergmekanik;

    Sammanfattning : The Discrete element method (DEM) is a methodology to investigatethe interactions among granular materials. It analyzes the behavior of par-ticulate environments by solving force-displacement equations that adhereto Newton’s second law of motion. LÄS MER

  4. 3. Lateral Stability of High-Speed Trains at Unsteady Crosswind

    Författare :Dirk Thomas; Mats Berg; Sebastian Stichel; Carsten Bussmann; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vehicle engineering; Farkostteknik;

    Sammanfattning : Crosswind stability of rail vehicles has been a research area for several decades,mainly motivated by vehicle overturning accidents and higher speeds, but in recenttimes also by issues of lower energy consumption and track maintenance costsdemanding lower vehicle weights. During everyday operation, rail vehicles are subjectedto large lateral influences from track irregularities, track curves and crosswind,leading to large suspension deflections and increased crosswind sensitivity. LÄS MER

  5. 4. Justifying mega-projects : An analysis of the Swedish high-speed rail project

    Författare :Erik Ronnle; Företagsekonomiska institutionen; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; transport policy; decision making; cost-benefit analysis; narrative; mega-projects;

    Sammanfattning : Mega-projects are a growing phenomenon worldwide. More and more projects are started and they grow ever bigger in size. At the same time, there is overwhelming evidence that mega-projects tend to run late, overrun in terms of costs and fail to deliver the expected benefits. LÄS MER

  7. 5. Wheels, Rails and Insulated Joints - Damage and Failure Probability at High Speed and Axle Load

    Författare :Johan Sandström; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rail breaks; probability; railway mechanics; contact mechanics; insulated joints; defects; fatigue;

    Sammanfattning : The thesis deals with some fatigue related problems in railway mechanics related to increased axle loads and speeds. The focus is on defects and discontinuities in the wheel--rail system that affect the risk of fatigue and fracture of railway components such as wheels, rails and insulated joints. LÄS MER