Sökning: "relaxation testing"

Visar resultat 1 - 5 av 42 avhandlingar innehållade orden relaxation testing.

  1. 1. Corrosion testing of heat exchanger tubing

    Författare :Ulf Kivisäkk; KTH; []
    Nyckelord :corrosion testing; heat exchanger; stainless steels; general corrosion; immersion testing; activation; stress corrosion cracking; constant load; u-bends; relaxation; dewpoint corrosion;

    Sammanfattning : Heat exchanger tubes are commonly made from stainless steel.In a heat exchanger both the process fluid and the cooling orheating media can be corrosive. It is therefore important to beable to select materials that do not suffer from corrosion.Current methods in this area, however, suffer from limitationsand shortcomings. LÄS MER

  3. 2. Effect of Stress Relief Annealing: Part Distortion, Mechanical Properties, and Microstructure of Additively Manufactured Austenitic Stainless Steel

    Författare :Emil Edin; Marta-Lena Antti; Pia Åkerfeldt; Fredrik Svahn; Magnus Neikter; Paul Åkerström; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser powder bed fusion; stainless steel; residual stress; heat treatment; tensile testing; relaxation testing; Materialteknik; Engineering Materials;

    Sammanfattning : Additive manufacturing (AM) processes may introduce large residual stresses in the as-built part, in particular the laser powder bed fusion process (L-PBF). The residual stress state is an inherent consequence of the heterogeneous heating and subsequent cooling during the process. LÄS MER

  4. 3. MUSCLE TONE IMBALANCE IN HUMAN UPPER EXTREMITY An experimental study of muscle adaptation to altered tension

    Författare :Fredrik Einarsson; Göteborgs universitet; []
    Nyckelord :muscle biopsy; freeze storage; upper extremity; shoulder; human muscle; sarcomere; stress-strain relationship; stress relaxation; stiffness; elasticity; mechanical testing; morphology; spasticity; obstetric brachial plexus palsy; rotator cuff tear; tendon transfer;

    Sammanfattning : Aim: The aim of this thesis was to improve outcome after tendon transfer and rotator cuff surgery by investigating the impact on response to passive mechanical testing and change in structural characteristics associated with longstanding changes in the tension of skeletal muscle in the human upper extremities in vivo. Patients and methods: The investigational method was in vitro assessment of human upper extremity muscles. LÄS MER

  5. 4. 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

  7. 5. Static and Dynamic Correlation Effects in Atoms

    Författare :Nils-Erik Dahlen; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetic and optical properties; electrical; Condensed matter:electronic structure; relaxation; magnetic resonance; supraconductors; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; Atom- och molekylärfysik; Atomic and molecular physics; spektroskopi; magnetisk resonans; egenskaper elektriska; supraledare; magnetiska och optiska ; variational energies; double ionization; Electron correlation; laser-atom interaction; Fysicumarkivet A:2002:Dahlen; conserving approximations; Green s functions; GW-approximation;

    Sammanfattning : The thesis considers the effects of electron correlation by studying the two opposite limits of atoms in the ground state and atoms in strong laser pulses. Computational methods and theoretical approaches differ significantly due to the different physical processes that are studied in these two cases. LÄS MER