Sökning: "Fatigue crack propagation."
Visar resultat 1 - 5 av 103 avhandlingar innehållade orden Fatigue crack propagation..
1. Contact fatigue and crack propagation studies of sintered PM steel
Sammanfattning : 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. LÄS MER
2. Rolling Contact Fatigue of Railway Rails with Emphasis on Crack Initiation
Sammanfattning : 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. LÄS MER
3. Fatigue of Spot Welded Joints: Experiments and Life Predictions
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
4. Failure of thermal barrier coatings under thermal and mechanical fatigue loading : microstructural observations and modelling aspects
Sammanfattning : Industrial and air-borne gas turbine hot components suffer from creep, oxidation, corrosion and microstructural degradation if not shielded from the hot and aggressive combustion gases. Two major strategies commercially available are adopted; film cooling by pressurised air and application of protective coatings. LÄS MER
5. Thermo-mechanical Fatigue Crack Propagation in 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