Search for dissertations about: "crack propagation"
Showing result 1 - 5 of 185 swedish dissertations containing the words crack propagation.
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1. Crack growth paths in rolling contact fatigue — Numerical predictions
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
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2. Contact fatigue and crack propagation studies of sintered PM steel
Abstract : Gears made of PM steel are of interest for the automotive industry because from the press/sinter route, complex geometries can be produced to near net shape with only a few processing steps while keeping the material and energy usage at a minimum. However, the PM steels of today have significant performance limitations caused by the inherent porosity which impairs the mechanical properties by acting as stress raisers in the material. READ MORE
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3. Rolling Contact Fatigue of Railway Rails with Emphasis on Crack Initiation
Abstract : Increased traffic density and the heavier axle loads of modern trains have led to severe problems with rolling contact fatigue (RCF) which cause initiation of surface cracks in railheads. In this thesis, a specific type of surface crack, the head check, is studied numerically with emphasis on fatigue crack initiation. READ MORE
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4. Thermo-mechanical Fatigue Crack Propagation in Inconel 718
Abstract : 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. READ MORE
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5. Numerical simulation of crack propagation and wear in rails
Abstract : 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. READ MORE