Search for dissertations about: "crack propagation experiments"

Showing result 1 - 5 of 48 swedish dissertations containing the words crack propagation experiments.

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

   Author : Lars Jacobsson; Materialteknik; []
   Keywords : 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;

   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

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

   Author : Hans-Fredrik Henrysson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; crack closure; crack propagation; crack initiation; finite element method; damage accumulation; variable amplitude; fracture mechanics; fatigue; spot welds;

   Abstract : 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. READ MORE

5. 3. Rolling Contact Fatigue of Railway Rails with Emphasis on Crack Initiation

   Author : Jonas Ringsberg; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; variable amplitude; crack closure; rolling contact fatigue; crack propagation; railway rails; damage accumulation; critical plane approach; crack initiation; plasticity; multiaxial fatigue;

   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

6. 4. Railway Wheel Flats. Martensite Formation, Residual Stresses, and Crack Propagation

   Author : Johan Jergeus; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sliding contact; metallographic investigation; crack propagation; thermal shock; constitutive modelling; phase transformations; railway wheel flats; full-scale field experiments; transformation plasticity; tread damage; residual stresses; spalling; martensite formation;

   Abstract : A railway wheel flat is a flat spot on the rolling surface of a wheel caused by its unintentional sliding on the rail. The reason for the sliding may be poorly adjusted, frozen or defect brakes, or too high braking forces in relation to the available wheel/rail adhesion. READ MORE

7. 5. Small-scale Experiments for Blast-induced Damage: Exploring crack propagation through Digital Image Correlation

   Author : Carlota Rodriguez San Miguel; Changping Yi; Nikolaos Petropoulos; Daniel Johansson; Pablo Segarra Catasus; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Small-scale experiments; Blast-induced cracks; Digital Image Correlation; Crack propagation behavior; Mining and Rock Engineering; Gruv- och berganläggningsteknik;

   Abstract : Blasting plays a crucial role in several engineering applications, from mining and tunneling to demolition projects. One of the remaining challenges of this process is that it can significantly affect the integrity of the rock mass by inducing damage in the form of cracks. READ MORE