Sökning: "Random railway"
Visar resultat 1 - 5 av 11 avhandlingar innehållade orden Random railway.
1. Random railways and cycles in random regular graphs
Sammanfattning : In a cubic multigraph certain restrictions on the paths are made to define what is called a railway. Due to these restrictions a special kind of connectivity is defined. As the number of vertices tends to infinity, the asymptotic probability of obtaining an, in this sense, connected random cubic multigraph is shown to be 1/3. LÄS MER
2. Improving the Dynamic Design Philosophy of High-Speed Railway Bridges Using Reliability-Based Methods
Sammanfattning : Modern railway infrastructures, especially bridges, are exposed to significant vibrations with potential safety implications. In this context, previous studies have shown the inconsistency and inadequacy of some conventional design methods necessitaing them to be improved. The assessment of safety inherently deals with uncertainties. LÄS MER
3. On cyclic accumulation models for degradation of railway foundations
Sammanfattning : The degradation of railway foundations due to the repeated loading of traffic induces maintenance and safety obligations for the track operator. One major contributor to track degradation is the accelerated settlement rates in soft soils below the track that lead to alignment issues, especially at stiffness transitions. LÄS MER
4. Wheels, Rails and Insulated Joints - Damage and Failure Probability at High Speed and Axle Load
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
5. Dynamic Train/Track Interaction: Simulation of Railhead Corrugation Growth under a Moving Bogie Using Mathematical Models Combined with Full-Scale Measurements
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