Search for dissertations about: "Gunnar Härkegård"

Found 3 swedish dissertations containing the words Gunnar Härkegård.

  2. 1. Aspects of creep-fatigue in gas turbine hot parts

    Author : Magnus Hasselqvist; Gunnar Härkegård; Linköpings universitet; []
    Keywords : creep; fatigue; TMF; gas turbine; modelling; life assessment; ageing; micro-structure; solute drag; back stress; Haynes 230; IN792;

    Abstract : The goal is reliable creep-fatigue lifing methodology for industrial gas turbines.A literature study on high temperature materials used in gas turbines reveals that:• Most testing/modelling work has focused on characterisation and modelling of material response in isothermal standard tests, i.e. creep, tensile and LCF tests. READ MORE

  4. 2. Fatigue crack growth experiments and analyses - from small scale to large scale yielding at constant and variable amplitude loading

    Author : Pär Ljustell; Fred L. Nilsson; Bo Alfredsson; Gunnar Härkegård; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fracture mechanics; fatigue crack growth; finite elements analysis; small scale yielding SSY ; large scale yielding LSY ; low cycle fatigue LCF ; crack tip opening displacement CTOD ; crack closure; potential drop method; constant amplitude load; variable amplitude load; inconel 718; stainless steel 316L;

    Abstract : This thesis is on fatigue crack growth experiments and assessments of fatigue crack growth rates. Both constant and variable amplitude loads in two different materials are considered; a nickel based super-alloy Inconel 718 and a stainless steel 316L. READ MORE

  5. 3. Experiments, Computations and Models for Probabilistic HCF Design

    Author : Daniel Sandberg; Mårten Olsson; Gunnar Härkegård; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Abstract : High Cycle Fatigue (HCF) failure is a common failure type for many mechanical components. Traditional HCF design is based on the deterministic safety factor approach, typically used in conjunction with the point stress method. READ MORE