Endre søk
Begrens søket
12 51 - 53 of 53
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 51. Thun, Håkan
    et al.
    Ohlsson, Ulf
    Elfgren, Lennart
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Fatigue Capacity of Small Railway Concrete Bridges: Prevision of the Results of Swedish Full-scale Tests. Comparison and Analyses2000Rapport (Annet vitenskapelig)
    Abstract [en]

    In this report results and analyses are presented from a full-scale fatigue test on a typical Swedish railway concrete bridge. The tests were performed at Luleå University of Technology in 1996. The purpose of the test was to study static and fatigue behaviour of the bridge under increased load in order to check its remaining life length. The bridge was originally situated in Lautajokk about 200 km northwest of Luleå along the iron ore line between Luleå and Narvik in Norway. The bridge had a length of 6,1 m and a width of 4,1 m and had the shape of a trough. It was built in 1967 and had been in service for 20 years. In the tests, the bridge was exposed to 6 million load cycles between 50 and 360 kN. No failure occurred even though the Swedish Concrete code BBK 94 indicated that. Especially the connection between the slab and the longitudinal beams was in a critical state according to the code.A study regarding the fatigue shear capacity with the Swedish code and the present Eurocode EC2 (1991) has shown that the codes are conservative and that further studies are needed in this area.Methods are proposed that can be used to estimate the remaining life length (Strain/deflection criterion and Wöhler curves). An analysis using a fracture mechanics approach is presented as well as studies regarding concrete strength development for Swedish Railway concrete bridges.Measurements of deflections and strains have also been carried out on four railway bridges during passing of trains

  • 52. Thun, Håkan
    et al.
    Ohlsson, Ulf
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Elfgren, Lennart
    Tensile fatigue capacity of concrete2007Inngår i: Nordic Concrete Research, ISSN 0800-6377, Vol. 36, nr 1-2, s. 48-64Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Results and analyses are presented from cyclic uniaxial tensile tests on plain cylindrical concrete cores. The influence of the load amplitude and the mean load level were studied with so called factorial design. It was found that both factors were important but that neither of them could be established to be more important than the other. Further, the deformation rate was studied. It appears that a certain fatigue limit exists below which a clearly greater number of load cycles is required for failure. From this research the exact limit cannot be predicted, but for tests with a mean load level of 40% of fpeak and an amplitude of 40% of fpeak, a very low deformation rate has been obtained. Finally, the test results have been compared with other Wöhler curves proposed for cyclic load in tension.

  • 53.
    Wang, Chao
    et al.
    Southeast University, Nanjing.
    Wang, Zhilan
    Southeast University, Nanjing.
    Zhang, Jiwen
    Southeast University, Nanjing.
    Tu, Yong-Ming
    Southeast University, Nanjing.
    Grip, Niklas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och brand.
    Ohlsson, Ulf
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och brand.
    Elfgren, Lennart
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och brand.
    FEM based research on the dynamic response of a concrete railway arch bridge2016Inngår i: IABSE CONGRESS, STOCKHOLM, 2016: Challenges in Design and Construction of an Innovative and Sustainable Built Environment / [ed] Elfgren, Lennart; Jonsson, Johan; Karlsson, Mats; Rydberg-Forssbeck, Lahja; Sigfid, Britt2016, CH - 8093 Zürich, Switzerland, 2016, s. 2472-2479Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The dynamic response of a concrete railway arch bridge is studied through a case study of the bridge over Kalix River, situated at Långforsen on the railway line between Kalix and Morjärv in northern Sweden. A simplified beam-element model, a spatial grillage-beam model and a refined shell-element model were built to analyze the bridge structure. A methodology was applied where measured static and dynamic responses were used to update finite element models of Långforsen Bridge. A multi-response objective function was presented, and the finite element method was proved feasible by comparison of predicted and measured response. In the paper comparative analyses were made of the time history displacement of three finite element models under three measured load cases. A standard train model from EUROCODE, HSLM-A 1, was applied and the dynamic responses under different speeds were studied. The results showed that a refined shell element model could accurately analyze dynamic responses of the concrete railway arch bridge in a better way than beam element and spatial grillage models. The dynamic analysis based on this type of shell model can give an optimized suggestion for the railway operation as well as for the design of high-speed railway bridges.

12 51 - 53 of 53
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf