Sökning: "Prestressed elasticity"

Hittade 5 avhandlingar innehållade orden Prestressed elasticity.

  1. 1. Analysis and Implementation of Preconditioners for Prestressed Elasticity Problems : Advances and Enhancements

    Författare :Ali Dorostkar; Maya Neytcheva; Thomas Huckle; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; FEM; Saddle point matrix; Preconditioning; Schur complement; Generalized Locally Toeplitz; Prestressed elasticity; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : In this work, prestressed elasticity problem as a model of the so-called glacial isostatic adjustment (GIA) process is studied. The model problem is described by a set of partial differential equations (PDE) and discretized with a mixed finite element (FE) formulation. LÄS MER

  3. 2. Assessment of Long-Term Losses in Prestressed Concrete Structures - Application for Nuclear Reactor Containments

    Författare :Peter Lundqvist; Avdelningen för Konstruktionsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; KstrConcrete; Nuclear reactor containments; prestressed concrete; prestress losses; bonded tendons; creep; shrinkage; relaxation; prediction models; resonance frequency; acoustoelasticity.;

    Sammanfattning : Most nuclear reactors, both in Sweden and worldwide, are enclosed by a prestressed concrete containment. The main purpose of the containment is to prevent any radioactive discharge to the environment in the event of a major internal accident. LÄS MER

  4. 3. Mechanical anchorage of prestressed CFRP tendons : theory and tests

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

    Sammanfattning : Fibre Reinforced Polymers (FRPs) are slowly becoming important materials to consider also for a structural engineer. They are light-weight, insensitive to corrosion and have highly modifiable mechanical properties. LÄS MER

  5. 4. Bridge Monitoring to Allow for Reliable Dynamic FE Modelling : A Case Study of the New Årsta Railway Bridge

    Författare :Johan Wiberg; Håkan Sundquist; Raid Karoumi; Björn Paulsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bridge monitoring; FE modelling; signal analysis; torsion; warping; modulus of elasticity; natural frequency; damping; finite differences; Civil engineering and architecture; Samhällsbyggnadsteknik och arkitektur;

    Sammanfattning : Today’s bridge design work in many cases demands a trustworthy dynamic analysis instead of using the traditional dynamic amplification factors. In this thesis a reliable 3D Bernoulli-Euler beam finite element model of the New Årsta Railway Bridge was prepared for thorough dynamic analysis using in situ bridge monitoring for correlation. LÄS MER

  7. 5. Quasi-instantaneous and Long-term Deformations of High-Performance Concrete with Some Related Properties

    Författare :Bertil Persson; Avdelningen för Byggnadsmaterial; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Shrinkage; Relative humidity; Long-term; Hydration; High-Performance Concrete; Elastic modulus; Deformations; Creep; Concrete; Cement; Quasi-instantaneous; Strength; Building construction; Byggnadsteknik;

    Sammanfattning : This report outlines an experimental and numerical study on quasi-instantaneous and long-term deformations of High-Performance Concrete, HPC, with some related properties. For this purpose about two hundred small cylinders and about one thousand cubes of eight types of HPC were cast. The age at loading varied between 18h and 28 days. LÄS MER