Search for dissertations about: "creep"

Showing result 1 - 5 of 195 swedish dissertations containing the word creep.

  1. 1. Creep Behavior of High Temperature Cast Materials for Exhaust Applications

    Author : Christian Öberg; Stefan Jonsson; Baohua Zhu; John Hald; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; Creep; creep behaviour; creep damage; ductile cast iron; high-alloyed austenitic cast steel; thermal cycling; tensile testing; stress relaxation; oxidation; precipitation.; Materials Science and Engineering; Teknisk materialvetenskap;

    Abstract : This thesis focuses on creep of four cast materials intended for exhaust manifolds in heavy-duty truck engines. Two of the materials are ferritic ductile cast irons, SiMo51 and SiMo1000, one is an austenitic ductile cast iron, D5S, and another one is an austenitic cast steel, HK30. READ MORE

  2. 2. Mechanical Properties of Welds at Creep Activation Temperatures

    Author : Henrik C.M. Andersson-Östling; Rolf Sandström; Kamran Nikbin; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; creep; creep crack propagation; OFHC copper; welds; nuclear waste disposal; creep modeling; Materials science; Teknisk materialvetenskap;

    Abstract : Welds in materials intended for service at temperatures above the creep activation temperature often develop damage before the base metal. The weld is a discontinuity in the material and stresses and strains often accumulate in the weld. Knowledge of the properties of the weld is essential to the safe operation of the component containing the weld. READ MORE

  3. 3. Numerical simulation of weldment creep response

    Author : Peter Segle; KTH; []
    Keywords : ABAQUS; constraint effect; continuum damage mechanics; creep; creep crack growth; design; design code;

    Abstract : In-service inspections of high temperature pressureequipment show that weldments are prone to creep and fatiguedamage. It is not uncommon that severely damaged weldments arefound even before the design life of the component has beenreached. READ MORE

  4. 4. Time-dependent crack growth and fracture in concrete

    Author : Fan Ping Zhou; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; creep; rupture test; sustained loading; deformationer; betong; brottmekanik; sprickor; sprickbildning; sprickmodeller; krypning; spänningar; brottenergi; brottspänningar; beräkningsmodeller; finita element; teori; laboratorieförsök; creep rupture; tidsberoende; fracture mechanics; Fictitius Crack Model; finite element method; visco-elastic fracture; time-dependent fracture; creep crack growth; concrete; tensile fracture; crack model;

    Abstract : The objectives of this thesis are to study time-dependent fracture behaviour in concrete. The thesis consists of an experimental study, constitutive modelling and numerical analysis... READ MORE

  5. 5. Concrete creep and thermal stresses : new creep models and their effects on stress development

    Author : Gustaf Westman; Luleå tekniska universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structural Engineering; Konstruktionsteknik;

    Abstract : This thesis deals with the problem of creep in concrete and its influence on thermal stress development. New test frames were developed for creep of high performance concrete and for measurements of thermal stress development. Tests were performed on both normal strength and high performance concretes. READ MORE