Sökning: "rail corrugation"

Visar resultat 6 - 10 av 11 avhandlingar innehållade orden rail corrugation.

1. 6. Out-of-Round Railway Wheels - Causes and Consequences An Investigation Including Field Tests, Out-of-Roundness Measurements and Numerical Simulations

   Författare :Anders Johansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polygonalization; wheel flat; full-scale measurements; wear modelling; impact load detector; railway wheel out-of-roundness; wheel removal criterion; dynamic train-track interaction; corrugation;

   Sammanfattning : Causes and consequences of out-of-round railway wheels are investigated through literature studies, full-scale field experiments, out-of-roundness measurements, and numerical simulations. Both defects around the complete wheel circumference (e.g. polygonal wheels with wavelengths up to one wheel circumference) and local defects (e. LÄS MER

3. 7. Effects of top-of-rail friction modifiers on the friction, wear and cracks of railway rails

   Författare :Saad Ahmed Khan; Jan Lundberg; Rolf Dollevoet; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Drift och underhållsteknik; Operation and Maintenance;

   Sammanfattning : The railway is an economical and environmentally friendly mode of transport for long distances and heavy loads. The demands on the operators are increasing with increased competition in the market, and therefore they are currently demanding more track capacity. In the short term, the existing network is expected to deliver the increased capacity. LÄS MER

4. 8. Dynamic Train/Track Interaction: Simulation of Railhead Corrugation Growth under a Moving Bogie Using Mathematical Models Combined with Full-Scale Measurements

   Författare :Annika Igeland; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; railhead corrugation growth; railway and track irregularities; railway dynamics and measurements; train track interaction; complex-valued modal analysis;

   Sammanfattning : Heavier trains and higher speeds have increased the need for high-quality tracks and vehicles in order to fulfill safety and environmental requests. The phenomena involved in dynamic train/track interaction lead to noise radiation, induce ground-borne vibrations and degrade the track structure and the railcar wheels. LÄS MER

5. 9. 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

7. 10. Development of new techniques for the numerical modelling of railway track dynamics. Application to rolling noise assessment

   Författare :Blas Blanco; Leif Kari; Ernesto García-Vadillo; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Track modelling; Timoshenko element; local deformation; distributed supports; moving Green s functions; rolling noise;

   Sammanfattning : The numerical modelling is widely employed for the prediction of the railway track dynamic behaviour, which is of utmost importance for the characterisation of the undesired medium-high frequency phenomena, such as corrugation, wheel-out-of-roundness and noise emission. This study is devoted to the improvement of railway track numerical modelling, the efficient resolution of the problem in the time domain and the assessment of rolling noise for different approaches of the track modelling. LÄS MER