Sökning: "structural vibrations"

Visar resultat 16 - 20 av 85 avhandlingar innehållade orden structural vibrations.

  1. 16. Numerical Methods for Conceptual Structural Design

    Författare :Vedad Alic; Byggnadsmekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Conceptual design is the first phase in the design process in which all the requirements and design objectives are synthesized into conceptual alternatives. In practice today, major decisions regarding the buildings geometry, massing, and overall form are usually made during the first phase. LÄS MER

  3. 17. A fixed-lag smoother for solving joint input and state estimation problems in structural dynamics

    Författare :Ulrika Lagerblad; Artem Kulachenko; Thomas Abrahamsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Joint input-state estimation; Fixed-lag smoother; Structural dynamics; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : In this thesis we have investigated different numerical filters for joint input and state estimation, with the aim of designing a robust algorithm capable of monitoring the continuous motion and loading in a truck chassis. The algorithm has to be able to use sparse measurements of the motion on different parts of the truck as it is excited by road induced vibrations, and transform this data into knowledge of the state in the entire system. LÄS MER

  4. 18. Analysis of Structural Dynamic Properties and Active Vibration Control Concerning Machine Tools and a Turbine Application

    Författare :Henrik Åkesson; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active Vibration Control; Structural dynamics; Nonlinearities; Turning; Milling;

    Sammanfattning : Vibration in metal cutting is a common problem in the manufacturing industry, especially when long and slender tool holders or boring bars are involved in the manufacturing process. Vibration has a detrimental effect on machining. In particular the surface finish is likely to suffer, but tool life is also most likely to be reduced. LÄS MER

  5. 19. Search for efficient time integration methods in structural dynamics for finite element meshes with large variations of properties

    Författare :Annika Moström; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structural Engineering; Konstruktionsteknik;

    Sammanfattning : Direct time integration methods are the most commonly used solution algorithms for analysis of non-linear transient phenomena in finite element computations. One major disadvantage with these methods is that stability and accuracy of the computation are governed by the smallest element in the mesh assuming all other properties constant. LÄS MER

  7. 20. 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