Sökning: "crack propagation"

Visar resultat 1 - 5 av 165 avhandlingar innehållade orden crack propagation.

  1. 1. Thermo-mechanical Fatigue Crack Propagation in Inconel 718

    Författare :Lars Jacobsson; Materialteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; crack closure; image analysis; potential drop; in-situ scanning elecron microscopy; crack propagation experiments; Thermo-mechanical fatigue; Inconel 718;

    Sammanfattning : Thermo-mechanical fatigue crack propagation in Inconel 718 has been studied with different methods. In-situ observations with a scanning electron microscope (SEM) were performed, the crack propagation process was followed cycle by cycle and the influences from load, temperature, and microstructure on the crack growth were analyzed. LÄS MER

  2. 2. Numerical simulation of crack propagation and wear in rails

    Författare :Jim Brouzoulis; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wear; Rolling Contact Fatigue; crack propagation; railway mechanics;

    Sammanfattning : This thesis is concerned with rail deterioration due to Rolling Contact Fatigue (RCF) and wear. Focus lies primarily on numerical modelling and prediction, with the long-term objective of developing tools to be used for specifications and planning of rail maintenance. LÄS MER

  3. 3. Modelling of large deformation crack propagation based on the extended finite element method

    Författare :Martin Fagerström; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; crack propagation; strong discontinuities; material crack driving force; FEM; cohesive zone;

    Sammanfattning : This thesis is concerned with the finite element modelling of large deformation crack propagation, based on the extended finite element methodology. The benefit from this approach is the possibility of locally enriching the finite element space, i.e. to add a priori knowledge about the local behaviour of the solution in order to improve accuracy. LÄS MER

  4. 4. Fatigue of Spot Welded Joints: Experiments and Life Predictions

    Författare :Hans-Fredrik Henrysson; Chalmers University of Technology; []
    Nyckelord :crack closure; crack propagation; crack initiation; finite element method; damage accumulation; variable amplitude; fracture mechanics; fatigue; spot welds;

    Sammanfattning : Methods to assess the fatigue strength of spot welds in built-up structures are used on a daily basis in the automotive industry. Efficient and reliable numerical methods make it possible to achieve designs with low weight, low manufacturing costs and good durability within short development cycles, since the number of prototypes built can be reduced. LÄS MER

  5. 5. Modelling of ultrasonic scattering from a crack in a pipe

    Författare :Jacob Rubenson; Chalmers University of Technology; []
    Nyckelord :Non-Destructive Testing; Cylindrical Geometry; Pipe; Crack; Wave propagation;

    Sammanfattning : This thesis considers elastic wave scattering in an infinitely long cylindrical pipe with an infinitely long internal axial crack. The method used in this thesis is called a hypersingular integral equation method since it starts with an integral representation and by using the Green's tensor of the pipe it can be manipulated to a hypersingular equation for the crack-opening displacement (COD). LÄS MER