Sökning: "stochastic track properties"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden stochastic track properties.

1. 1. Dynamic Train-Track Interaction: Linear and Non-Linear Track Models with Property Scatter

   Författare :Johan Oscarsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; stochastic track properties; non-linear track properties; dynamic train-track interaction; Latin Hypercube; perturbation technique; full-scale and laboratory measurements;

   Sammanfattning : A numerical method was developed to investigate the vertical dynamic behaviour of a railway track subjected to the loading of a moving train. The numerical simulations are carried out in the time-domain with what is known as a moving mass model. LÄS MER

3. 2. Structural Reliability and Identification with Stochastic Simulation - Application to Railway Mechanics

   Författare :Sadegh Rahrovani; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; model reduction; time-integration; finite element model; sleeper-ballast load characterization; stochastic simulation; Bayesian system identification;

   Sammanfattning : System identification of structures based on measured response data can play a key role in improving reliability based structural designs. However, the experimental limitations of in situ tests and uncertainties of required model complexity together with the inverse nature of system identification give rise to a number of challenging issues. LÄS MER

4. 3. Micro/nanometric Scale Study of Energy Deposition and its Impact on the Biological Response for Ionizing Radiation : Brachytherapy radionuclides, proton and carbon ion beams

   Författare :Fernanda Villegas Navarro; Anders Ahnesjö; Carmen Villagrasa; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Ionizing radiation; Monte Carlo track structure code; Microdosimetric spread; Energy deposition clustering; RBE; Medicinsk radiofysik; Medical Radiophysics;

   Sammanfattning : Research in radiotherapy for cancer treatment focuses on finding methods that can improve the compromise between tumour cell inactivation versus damage to the surrounding healthy tissue. As new radiation modalities such as proton therapy become accessible for everyday clinical practice, a better understanding of the variation in biological response of the tumour and healthy tissues would improve treatment planning to achieve optimal outcome. LÄS MER

5. 4. Evaluation, Generation, and Transformation of Driving Cycles

   Författare :Peter Nyberg; Lars Nielsen; Erik Frisk; Richard Stobart; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Driving cycles are important components for evaluation and design of vehicles. They determine the focus of vehicle manufacturers, and indirectly they affect the environmental impact of vehicles since the vehicle control system is usually tuned to one or several driving cycles. 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