Blar i UiS Brage på forfatter "Ersdal, Gerhard"

Viser treff 1-15 av 15

    • Buckling capacity of simulated patch corroded tubular columns – laboratory tests 

      Vo, Tri Minh; Hestholm, Kristoffer; Ersdal, Gerhard; Oma, Narve; Sivertsvik, Matias (Peer reviewed; Journal article, 2019)
      This paper presents the experimental test results for the buckling capacity of tubular columns exposed to simulated unsymmetrical patch corrosion damage. These tests were performed to investigate how the results of these ...

    • Capacity of Concrete Structures with Corroded Reinforcement and Prestressing Tendons 

      Sigvaldsen, Marie; Ersdal, Gerhard; Markeset, Gro; Samarakoon, Mudiyansele Samindi Manjula K; Langeteig, Magne (Peer reviewed; Journal article, 2021)
      The main degradation mechanism for concrete structures is corrosion of the reinforcement and prestressing tendons. Management of structures with such degradation requires detailed understanding of their remaining strength ...

    • Crack Arresting using Cutout Repair in Tubular Offshore Joints 

      Attaya, Mostafa (PhD thesis UiS;, Doctoral thesis, 2023)
      Finding efficient repair methods for cracked tubular joints in offshore structures is important, both as a permanent or temporary repair solution. The exploration of such methods and techniques includes the use of hole ...

    • Experimental and numerical study of the elastic SCF of tubular joints 

      Atteya, Mostafa; Mikkelsen, Ove; Wintle, John; Ersdal, Gerhard (Peer reviewed; Journal article, 2021-07)
      This paper provides data on stress concentration factors (SCFs) from experimental measurements on cruciform tubular joints of a chord and brace intersection under axial loading. High-fidelity finite element models were ...

    • Experimental assessment of cracked tubular joints repaired with crack-deflecting holes and weld-toe grinding 

      Riise, Simen; Atteya, Mostafa Ahmed; Mikkelsen, Ove; Ersdal, Gerhard (Peer reviewed; Journal article, 2023)
      Tubular joints in offshore structures for energy production are exposed to cyclic loading and may experience fatigue cracking. Presently, the inspection method commonly used for such structures will primarily detect whether ...

    • Experimental evaluation of the axial capacity of cracked tubular member 

      Riise, Simen (Bachelor thesis, 2021)
      This thesis experimentally investigated the compressive axial capacity of cracked tubular members. Then compared it to NORSOK N-004 (Standard Norge 2004) formulae. Further, the test results were compared with other analytical ...

    • Inspection planning for fatigue cracks in offshore structures by Monte Carlo simulations 

      Neeraas, Håkon; Ersdal, Gerhard; Oma, Narve; Hellevig, Nils-Christian (Peer reviewed; Journal article, 2019)
      Probability-informed inspection planning has traditionally a tendency to produce longer inspection intervals for older structures in contrast with the intuitive assumption that shorter inspection intervals are needed. In ...

    • Investigation of updating methods for probability-informed inspection planning for offshore structures 

      Ersdal, Gerhard; Oma, Narve (Peer reviewed; Journal article, 2019)
      The paper presents a novel process for probability-informed inspection planning based on the following principles. 1) A description of the strength of knowledge about a problem shall be included and be accounted for in the ...

    • Life extension of ship-shaped floating production units 

      Schøn, Iselin Violet Kjelland (Masteroppgave/UIS-TN-IMBM/2020;, Master thesis, 2020-06)
      In the last two decades, the number of floating, production, storage, and offloading units (FPSOs) deployed internationally has increased rapidly. Many of them are still young but have already started ageing. The objective ...

    • Momentkapasitet av slakkarmerte og spennarmerte betongkonstruksjoner med korrosjonsskader 

      Sigvaldsen, Marie (Master thesis, 2021)
      I Norge finnes en rekke kystnære bruer med varierende grad av korrosjon. I kapasitetsberegninger av disse eldre konstruksjonene er normalt bare prosentvis reduksjon av bærekapasiteten tilsvarende prosentvis korrosjonstap ...

    • Remaining capacity of deteriorated I-section structural steel members 

      Yared, Ermias (Masteroppgave/UIS-TN-IMBM/2018;, Master thesis, 2018-06)
      Abstract Steel have many design and functional advantages as a material in the construction process and in structures in use. However, deterioration of steel e.g. due to corrosion is one of the drawbacks for steel ...

    • Sprekkvekst og inspeksjonsplanlegging 

      Neraas, Håkon (Masteroppgave/UIS-TN-IMBM/2019;, Master thesis, 2019)
      Hensikten med denne oppgaven er å undersøke behovet for inspeksjoner for å oppdage sprekkvekst i et kritisk knutepunkt på en offshore jacket underlagt syklisk bølgebelastning. Det er studert hvor ofte det er nødvendig med ...

    • Statistical evaluation of fatigue lives of offshore tubular joints. 

      Alvarez, Alejandro (Master thesis, 2021)
      Fatigue design in offshore structures is based on S-N curves derived from tests on tubular joints where failure is defined as penetration of wall thickness. However, in practice, fatigue cracks are likely to continue to ...

    • Statistical evaluation of tubular joint SCFs from test data and finite element analyses 

      Ersdal, Gerhard; Atteya, Mostafa Ahmed; Mikkelsen, Ove (Peer reviewed; Journal article, 2023)
      Stress concentration factors (SCF) derived from both FEA and measurements from laboratory experiments are associated with uncertainties. To understand these uncertainties, SCF values can be determined from a series of tests ...

    • Structural reliability and optimal design of fixed jacket of offshore wind turbine 

      Alalawi, Hamad (Master thesis, 2021)
      The assessment of structural reliability for offshore wind turbines (OWTs) is challenging. The environmental conditions and loads on a wind turbine have large variability. Wind and wave act simultaneously on the structures, ...