Browsing NTNU Open by Author "Frøseth, Gunnstein Thomas"
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Aktiv Demping av Bromodeller
Harper, Daniel; Muren, Lars Maukon (Master thesis, 2019)Ved gjennomføring av forsøk med brumodeller i NTNUs vindtunnel, kan uønskede høyfrekvente vibrasjoner forekomme i modellene på grunn av vind og andre dynamiske krefter. I denne oppgaven diskuteres bruken av aktuatorer, ... -
Aktiv Demping av Bromodeller
Harper, Daniel; Muren, Lars Maukon (Master thesis, 2019)Ved gjennomføring av forsøk med brumodeller i NTNUs vindtunnel, kan uønskede høyfrekvente vibrasjoner forekomme i modellene på grunn av vind og andre dynamiske krefter. I denne oppgaven diskuteres bruken av aktuatorer, ... -
Assessment of pantograph-catenary interaction in a railway overlap section via a novel optical-based method
Jiang, Tengjiao; Frøseth, Gunnstein Thomas; Nåvik, Petter Juell; Rønnquist, Anders (Peer reviewed; Journal article, 2022)Smooth pantograph-catenary contact is essential for regular train operation. However, catenary section overlaps are locations where peak contact forces occur, which significantly affects current collection quality. This ... -
Comparison of methods for automatic modal analysis
Guddal,Olav (Master thesis, 2022)Denne masteroppgåva samanliknar to algoritmar føreslege av Reynders (2012) og Yang (2019) for automatisk modal analyse. Algoritmane er implementert ved bruk av objektorientert programmering i Python. Samanlikninga er ... -
Damage Detection Applied to a Full-Scale Steel Bridge Using Temporal Momens
Svendsen, Bjørn Thomas; Frøseth, Gunnstein Thomas; Rønnquist, Anders (Peer reviewed; Journal article, 2020)The most common damages in existing highway and railway steel bridges are related to fatigue and are, as reported in the literature, found in the structural system of the bridge deck. This paper proposes a methodology for ... -
Damage Identification of Structures with Accelerometers Under Idealized Conditions
Fjelldal, Jens Roar; Kjøle, Agnethe Maria (Master thesis, 2020)Dagens vei og jernbanenett består av et stort antall bruer som enten nærmer seg eller har overskredet levetiden som ble lagt til grunn for dimensjonering av disse konstruksjonene. Det er ikke økonomisk å erstatte disse ... -
Damage Identification of Structures with Accelerometers Under Idealized Conditions
Fjelldal, Jens Roar; Kjøle, Agnethe Maria (Master thesis, 2020)Dagens vei og jernbanenett består av et stort antall bruer som enten nærmer seg eller har overskredet levetiden som ble lagt til grunn for dimensjonering av disse konstruksjonene. Det er ikke økonomisk å erstatte disse ... -
A data-based structural health monitoring approach for damage detection in steel bridges using experimental data
Svendsen, Bjørn Thomas; Frøseth, Gunnstein Thomas; Øiseth, Ole Andre; Rønnquist, Anders (Journal article; Peer reviewed, 2022)There is a need for reliable structural health monitoring (SHM) systems that can detect local and global structural damage in existing steel bridges. In this paper, a data-based SHM approach for damage detection in steel ... -
Design and deployment of a monitoring system on a long-span suspension bridge
Petersen, Øyvind Wiig; Frøseth, Gunnstein Thomas; Øiseth, Ole Andre (Journal article, 2021)Monitoring systems have become a standard component for many landmark bridges. This paper describes the design of a new monitoring system for the Hålogaland bridge, a suspension bridge has a main span of 1145 m located in ... -
Design of a monitoring system for a long-span suspension bridge: optimal sensor placement
Petersen, Øyvind Wiig; Øiseth, Ole Andre; Frøseth, Gunnstein Thomas (Chapter, 2020)The design of systems for structural health monitoring is an exercise that requires careful planning of optimal sensor locations. The number of possible locations usually outnumbers the number of available sensors, which ... -
Development and Application of a Vision-Based System for Structural Monitoring of Railway Catenary System
Jiang, Tengjiao (Doctoral theses at NTNU;2021:280, Doctoral thesis, 2021)With the continuous increase of train speed and the expansion of the railway network, health monitoring and predictive maintenance of railway infrastructure are becoming increasingly important. The increasing investments ... -
The Effects of Spatially Distributed Damping on the Contact Force in Railway Pantograph-Catenary Interactions
Song, Yang; Jiang, Tengjiao; Rønnquist, Anders; Nåvik, Petter Juell; Frøseth, Gunnstein Thomas (Peer reviewed; Journal article, 2021)According to field measurements, the damping ratio of a railway catenary varies along the span length and shows an inherent uncertainty. In numerical simulations, it is common to assume a constant damping ratio. Herein, a ... -
Evaluation of the Consistent Load Model for Norwegian Railway Bridges Subjected to Fatigue Considering Track Curvature and Non-Standard Influence Lines
Skagestad, Ane Bræin; Sørbel, Ingvild (Master thesis, 2021)Omtrent en tredjedel av dagens norske jernbanenettverk består av stålbruer bygget før 1960. Etter disse ble bygget, har utmatting vist seg å være den ledende årsaken til brudd i stålkonstruksjoner. For en jernbanebru gir ... -
Evolution of load conditions in the Norwegian railway network and imprecision of historic railway load data
Frøseth, Gunnstein Thomas; Rønnquist, Anders (Journal article; Peer reviewed, 2018)This article describes historic load conditions in the Norwegian railway network to improve estimates of the remaining service life of bridges. Data on rolling stock, traffic and infrastructure throughout the history of ... -
Fatigue life estimation of Norwegian railway bridges
Hollevik, Lars Jørgen (Master thesis, 2021)Denne avhandlingen presenterer resterende livstidsberegning med hensyn på utmattelse for 3 bruer på det norske jernbane systemet ved hjelp av en ny lastmodell foreslått i Frøseth. Dette er gjort for å om den nye lastmodellen, ... -
Genetic algorithm for identifying train causing greatest fatigue damage in railway bridges
Bø, Anita; Knudsen, Nora (Master thesis, 2019)Den norske naturen, med sine mange fjell, daler og fjorder, gjør broer til viktige komponenter i landets jernbanenettverk. Jernbanebroene er påkjent av gjen- tatte dynamiske laster, som en følge av at tog kjører over ... -
Improved finite element model updating of a full-scale steel bridge using sensitivity analysis
Svendsen, Bjørn Thomas; Petersen, Øyvind Wiig; Frøseth, Gunnstein Thomas; Rønnquist, Anders (Journal article; Peer reviewed, 2021)There are many uncertainties related to existing bridges that are approaching or have exceeded their original design life. Lifetime extension analysis of bridges should be based on validated numerical models that can be ... -
Influence line extraction by deconvolution in the frequency domain
Frøseth, Gunnstein Thomas; Rønnquist, Anders; Cantero, Daniel; Øiseth, Ole (Journal article; Peer reviewed, 2017)This paper proposes a new method for extracting static influence lines from measurements on bridges. The response of a structure is the convolution of the load and the influence line. Previous research has not embraced the ... -
Konsekvent lastmodell for utmatting av jernbanebruer
Romstad, Knut Melhus (Master thesis, 2021)Jernbanenettet i Norge består av et stort antall stålbruer som sto ferdige for over 60 år siden. Teknologisk utvikling og befolkningsvekst har ført til at bruene er dimensjonert for helt andre trafikksituasjoner enn det ... -
Numerical Analysis of the Dynamic Response of Existing Railway Bridges.
Frøseth, Gunnstein Thomas (Master thesis, 2014)The railway is an important part of the infrastructure in todays society and there is a need to increase the capacity and verify the existing railway network to face the challenges of tomorrow. To meet todays and the future ...