Advanced search

Showing result 1 - 5 of 266 swedish dissertations matching the above criteria.

  2. 1. Crack growth paths in rolling contact fatigue — Numerical predictions

    Author : Mohammad Salahi Nezhad; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vector crack tip displacement; Crack face friction; Crack growth direction; Crack propagation; Rolling contact fatigue;

    Abstract : Rolling contact fatigue (RCF) cracks in railway wheels and rails are costly and complex to deal with. Despite the extensive research efforts that have been put into understanding the mechanisms and developing appropriate predictive models for RCF crack growth, there are still a lot of open questions. READ MORE

  4. 2. Behaviour of fracture process zones in concrete influenced by simultaneously applied normal and shear displacements

    Author : Manouchehr Hassanzadeh; Avdelningen för Byggnadsmaterial; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; softening; mixed mode; fictitious crack model; concrete; deformationer; betong; brottmekanik; hållfasthet; brotthållfasthet; spänningar; skjuvspänningar; sprickor; beräkningsmodeller; brottenergi; teori; laboratorieförsök; interlock; crack path; diagonal crack; microcracking; instability; fracture energy; fracture mechanics; shear; tension; process zone;

    Abstract : The thesis deals with the determination of the post peak behaviour of concrete in pure tension, and combined tension (compression) and shear. A test arrangement has been developed in order to determine the post peak behaviour of concrete expressed as stress - displacement curves. READ MORE

  5. 3. Constitutive Modelling and Finite Element Analysis of Concrete Structures with Regard to Environmental Influence

    Author : Ola Dahlblom; Byggnadsmekanik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Finite Elemente Method; Constitutive model; Concrete; Environment; Moisture; Drying; Temperature; Fracture; Fictitious crack model; Smeared Crack; Creep; Shrinkage; Pickett Effect;

    Abstract : A constitutive model for concrete is formulated. Tensile fracture is described using a smeared crack approach where the fracrure energy is considered and the shear stiffneess in the cracked region is gradually reduced as crackling develops. READ MORE

  6. 4. Modelling of TMF Crack Growth in Polycrystalline Gas Turbine Alloys : Accounting for Crack Closure Effects

    Author : Jordi Loureiro-Homs; Kjell Simonsson; Robert Eriksson; Daniel Leidermark; Tomas Månsson; Linköpings universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : The main objective of the work presented in this Licentiate of Engineering thesis is to investigate and model the fatigue crack propagation behaviour of the nickel-based superalloy Inconel 792, with special attention to the industrial lifing of high-temperature components. In-phase (IP) crack propagation tests have been performed at different temperatures and loading regimes, including extended hold times. READ MORE

  7. 5. Control of Cracking due to Imposed Strains in Concrete Structures

    Author : Dan Pettersson; Avdelningen för Konstruktionsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hydraulic engineering; Civil engineering; Friction.; Restraint; Shrinkage; Imposed deformations; Minimum reinforcement; Crack widths; Reinforced concrete; Crack development; Crack control; offshore technology; soil mechanics; Väg- och vattenbyggnadsteknik;

    Abstract : This thesis is concerned with crack control due to imposed deformations in concrete structures. The objective of crack control may either be to prevent cracking or to limit the crack widths. The aim here is to increase the knowledge in both fields for some common structures. Five papers are included and the three last concern crack development. READ MORE