Avancerad sökning

Visar resultat 1 - 5 av 134 avhandlingar som matchar ovanstående sökkriterier.

1. 1. 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

3. 2. Reliability-Based Assessment and Optimization of High-Speed Railway Bridges

   Författare :Reza Allahvirdizadeh; Raid Karoumi; Andréas Andersson; Daniel Straub; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High-speed railway bridges; Bridge dynamics; Running safety; Passenger comfort; Structural reliability; Meta-models; Surrogate models; Adaptive sampling; Reliability-based design optimization; Höghastighetsjärnvägsbroar; Brodynamik; Trafiksäkerhet; Passagerarkomfort; Konstruktioners tillförlitlighet; Metamodeller; Surrogatmodeller; Adaptiv sampling; Tillförlitlighetsbaserad designoptimering; Structural Engineering and Bridges; Bro- och stålbyggnad;

   Sammanfattning : Increasing the operational speed of trains has attracted a lot of interest in the last decades and has brought new challenges, especially in terms of infrastructure design methodology, as it may induce excessive vibrations. Such demands can damage bridges, which in turn increases maintenance costs, endangers the safety of passing trains and disrupts passenger comfort. LÄS MER

4. 3. An Ontology-Based Platform for Information Integration : Supporting Sustainable Smart Transportation Infrastructure

   Författare :Wiebke Belitz-Hellwich; Nicole Kringos; Annika Gram; Romain Balieu; Vangelis Angelakis; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Ontology; Semantic Web; Interoperability; Information Integration; Logistics; Simulation; Smart Port; ontologi; semantisk webb; interoperabilitet; informationsintegration; logistik; simulering; smart hamn.; Bro- och stålbyggnad; Structural Engineering and Bridges;

   Sammanfattning : Transportation and transportation infrastructure are major contributors to global emissions. Even though most of these emissions can be attributed to fuel consumption of vehicles, some of it is due to pavement construction and maintenance. LÄS MER

5. 4. Dynamic properties of two pedestrian timber bridges : Experimental and numerical analysis at several stages of construction

   Författare :Jens Bergenudd; Jean-Marc Battini; Roberto Crocetti; Patricia Hamm; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic analysis; Modal analysis; Pedestrian bridge; Timber; Railings; Asphalt; Slip modulus; Finite element modelling; Dynamisk analys; Modal analys; Gång- och cykelbro; Trä; Räcken; Asfalt; Förskjutningsmodul; Finita element modellering.; Bro- och stålbyggnad; Structural Engineering and Bridges;

   Sammanfattning : Pedestrian bridges can beneficially be made from timber in order for our society to reach a sustainable future. This positive development is partly made possible due to advances in engineered wood products (e.g. glued laminated timber) and the possibilities for pre-fabrication of structural parts. LÄS MER

7. 5. Human-structure interaction effect on the dynamic response of footbridges : An analytical and experimental study

   Författare :Daniel Colmenares; Raid Karoumi; Andreas Andersson; Federica Tubino; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; footbridges; dynamics; human induced loads; human structure interaction.; Bro- och stålbyggnad; Structural Engineering and Bridges;

   Sammanfattning : Lightweight, slender and lightly damped footbridges are often susceptible to HumanInduced Loads (HILs) when pedestrian step frequencies coincide with the naturalfrequencies of the structure. For vertical vibrations, this can compromise the serviceabilitylimit state of the system. LÄS MER