Sökning: "Lennart Elfgren"

Hittade 5 avhandlingar innehållade orden Lennart Elfgren.

  1. 1. Reinforced concrete beams loaded in combined torsion, bending and shear : a study of the ultimate load-carrying capacity

    Författare :Lennart Elfgren; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structural Engineering; Konstruktionsteknik;

    Sammanfattning : .... LÄS MER

  3. 2. Models for analysis of young cast and sprayed concrete subjected to impact-type loads

    Författare :Lamis Ahmed; Anders Ansell; Richard Malm; Lennart Elfgren; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Young concrete · Shotcrete · Rock · Impact-type vibration · Finite element method · Fracture mechanics model · Crack width;

    Sammanfattning : The strive for a time-efficient construction process naturally put focus on the possibility of reducing the time of waiting between stages of construction, thereby minimizing the construction cost. If recently placed concrete, cast or sprayed, is exposed to impact vibrations at an early age while still in the process of hardening, damage that threatens the function of the hard concrete may occur. LÄS MER

  4. 3. Characterization of train-induced aerodynamic loads on high-speed railway vertical noise barriers

    Författare :Dongyun Liu; Gabriel Sas; Chao Wang; Jaime Gonzalez; Lennart Elfgren; Yongming Tu; Paolo Zampieri; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aerodynamic pressure; Computational fluid dynamics; Train geometry; High-speed railway; High-speed train; Load calculation model; Vertical noise barrier; Byggkonstruktion; Structural Engineering;

    Sammanfattning : High-Speed Railway (HSR) technology requires the deployment of noise barriers to mitigate noise pollution affecting nearby residents. As train speeds increase, so does the magnitude of aerodynamic effects such as aerodynamic noise and the pressure on these barriers, meaning that these structures require robust sound insulation and structural load-bearing capacities. LÄS MER

  5. 4. Anchorage in Concrete Structures : Numerical and Experimental Evaluations of Load-Carrying Capacity of Cast-in-Place Headed Anchors and Post-Installed Adhesive Anchors

    Författare :Rasoul Nilforoush; Lennart Elfgren; Norbert Randl; Karin Lundgren; Manouchehr Hassanzadeh; Richard Malm; Lars-Erik Persson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Headed anchor; Anchor bolt; Adhesive anchor; Concrete cone breakout; Concrete splitting; Pullout loading; Size effect; Member thickness; Anchor head size; Orthogonal surface reinforcement; Concrete Strength; High-strength concrete; Cracked concrete; Steel fiber-reinforced concrete; Sustained loading; Creep behavior; Structural Engineering; Konstruktionsteknik;

    Sammanfattning : Various anchorage systems including both cast-in-place and post-installed anchors have been developed for fastening both non-structural and structural components to concrete structures. The need for increased flexibility in the design of new structures and strengthening of existing concrete structures has led to increased use of various metallic anchors in practice. LÄS MER

  7. 5. Railway bridge response to passing trains : Measurements and FE model updating

    Författare :Johan Wiberg; Raid Karoumi; Lennart Elfgren; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Civil engineering and architecture; Samhällsbyggnadsteknik och arkitektur;

    Sammanfattning : Today’s railway bridges are analysed in more detail for moving loads due to the increase in speeds and axle loads. However, these numerical analyses are very time consuming as they often involve many simulations using different train configurations passing at different speeds and many considerations to take into account. LÄS MER