Sökning: "railway safety"

Visar resultat 6 - 10 av 91 avhandlingar innehållade orden railway safety.

  1. 6. Railway Infrastructure Robustness : Attributes, evaluation, assurance and improvement

    Författare :Per Norrbin; Ragnar Hedström; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Drift och underhållsteknik; Operation and Maintenance Engineering;

    Sammanfattning : According to the European program Horizon 2020, multifaceted challenges in transportinfrastructure include 1) making infrastructure more resilient to keep pace with the increasing mobility needs; 2) reducing the impact of infrastructure on the environment;and 3) dealing with declining resources to maintain and upgrade transport infrastructure. New design and maintenance approaches must be developed to handle these issues, ascurrent methods are inadequate. LÄS MER

  3. 7. Electromagnetic noise generated in the electrified railway propulsion system

    Författare :Kelin Jia; Rajeev Thottappillil; Hans Bängtsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electromagnetic compatibility; railway; propulsion system; shielded cable; transmission line; Electrical engineering; Elektroteknik; Telecommunication; Telekommunikation; SRA - Transport; SRA - Transport;

    Sammanfattning : The electromagnetic compatibility (EMC) problem in the railway propulsion system is a significant safety issue of high concern. The problems can be caused by any part of the propulsion system as well as any combination of the sub systems. Simulation is a fast economical way to understand the system and to predict the EMC performance. LÄS MER

  4. 8. Utmattningsanalys av järnvägsbroar : En fallstudie av stålbroarna mellan Stockholm Central och Söder Mälarstrand, baserat på teoretiska analyser och töjningsmätningar

    Författare :Andreas Andersson; Håkan Sundquist; Kjell Eriksson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fatigue; Palmgren-Miners cumulative damage theory; Rainflow-analysis; railway bridges; finite element methods; Utmattning; Palmgren-Miners delskadehypotes; Rainflow-analys; järnvägsbroar; finita element metoder; Civil engineering and architecture; Samhällsbyggnadsteknik och arkitektur;

    Sammanfattning : Föreliggande avhandling omfattar en fallstudie av utmattningsrisken för järnvägsbroarna mellan Stockholm Central och Söder Mälarstrand. Ett stort antal utmattningssprickor i broarna över Söderström och Söder Mälarstrand har sedan länge varit kända. LÄS MER

  5. 9. High Frequency Model of Electrified Railway Propulsion System for EMC Analysis

    Författare :Kelin Jia; Rajeev Thottappillil; Hans Bängtsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electromagnetic compatibility; railway; propulsion system; multitransmission line; ac motor modeling; vector fitting; fast transient;

    Sammanfattning : A model of the electrified railway propulsion system working in a wide frequency range is studied in this thesis. The high frequency modeling is the first stage to study and predict the Electromagnetic compatibility (EMC) problems in the electrified railway propulsion system, which are safety and reliability issues of high concern. LÄS MER

  7. 10. Improving the Dynamic Design Philosophy of High-Speed Railway Bridges Using Reliability-Based Methods

    Författare :Reza Allahvirdizadeh; Raid Karoumi; Andreas Andersson; Christoph Adam; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High-speed railway bridges; Bridge dynamics; Running safety; Passenger comfort; Structural reliability; Surrogate models; Active learning; Reliability-based design optimization; Partial safety calibration; Epistemic uncertainties; Höghastighetsjärnvägsbroar; Brodynamik; Trafiksäkerhet; Passagerarkomfort; Konstruktioners tillförlitlighet; Surrogatmodeller; Aktivt lärande; Tillförlitlighetsbaserad optimering; Kalibrering av partialkoefficienter; Epistemiska osäkerheter; Bro- och stålbyggnad; Structural Engineering and Bridges;

    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