The aim of this thesis was to analyze the formation of defects in a given casting of ductile cast iron EN - GJS - 600-3 cast in sand molds bentonite, which is formed jolting with coining and then find a solution to remedy these defects. To resolve this issue, the influence of the composition of the sand mixture, the effect of metal flow in a cavity forms and the influence of deoxidation of metal in the presence of defects. Obtained results showed the importance of the influence Reoxidation metal cavity mold. Specifically, in this case succeeded in reducing the incidence of PINHOLES. Removal of PINHOLES to achieve deoxidation aluminum melt. This has reduced the production of nonconforming castings under 3% from the original 6.5%.

The thesis aimed to identify fracture strain for multiaxial loading for laminate material of Al and LDPE that is mostly used in the food packing technology specially in liquid packaging industry. These materials are thin and flexible which make it difficult to handle and test it. The investigation was through applying new Nakajima test setup on such a material by designing a custom setup and 3D printing the Nakajima setup prototype to be able to use it in this study. DIC technique was used to get the results from the Nakajima test and the software used to apply the DIC technique is GOM correlate. As a validation for measurement from such a technique, a tensile test has been done and measured strains were compared with those from the specimen from the Nakajima that has smallest width as it was close to a uniaxial loading. One more validation technique was by creating a FE-model using (Abaqus software) for the biaxial loading and comparing it to the biaxial loading results that obtained from the DIC analysis.

The aim of the project is to develop a model, which is going to be used for mass reduction of a standard profile of aluminium seat rails in Aircraft structure. Using nonlinear analysis including plasticity and material failure laws the effect of changes in geometry vs. ultimate load is analysed (ABAQUS 6.11). First, the non-linear model used is validated with experimental testing: Boundary conditions and material properties are adjusted based on load displacement curves, strain gauges information and failure patterns. Less than 1% deviation is achieved between simulation and testing. An inclusion of material imperfection led to a 5% improvement of the results. Using the validated algorithm, a mass reduction is performed via geometry variation. / Ziel der Studie ist es ein adäquates Simulationsmodell zu entwickeln, welches zur Gewichtsreduzierung einer Standardprofil Aluminium Sitzschiene im Flugzeug verwendet werden kann. In einer nichtlinearen Analyse unter Berücksichtigung der Plastizität des Materials und von Materialfehlern wird die Auswirkung der Geometrieänderungen auf die maximale Traglast analysiert (ABAQUS 6.11). Zunächst wird das nicht-lineare Modell mit experimentell ermittelten Daten überprüft: Randbedingungen und Materialeigenschaften werden basierend auf Lastverschiebungskurven, Informationen von Dehnungsmessstreifen und Versagensmustern angepasst. Dabei wurden weniger als 1% Abweichung zwischen Simulation und Test erzielt. Die Berücksichtigung von Materialfehlern führte zu einer 5%-igen Verbesserung der Ergebnisse. Mit dem validierten Modell wird abschließend eine Gewichtsreduzierung mittels Geometrievariation durchgeführt.

Nucleation of dislocation loop at the crack tip in a material subjected to uniaxial loading is investigated. Analytical expression for the total energy of rectangular dislocation loop at the crack tip is found. Depencence of the nucleation energy barrier on dislocation loop shape and stress intensity factor at the crack tip is determined. It is established that the energetic barrier for nucleation of dislocation loop strongly depends on the stress intensity factor. Nucleation of dislocation loop is very sensitive to stress field modifiers (forest dislocations, precipitates, clusters of point defects, etc.) in the crack tip vicinity.

This thesis presents a 40Ar/39Ar geochronological analyses of biotite from thin ductile shear zones in Paleoproterozoic granulite-facies gneisses from the Ellesmere-Devon crystalline terrane, Nunavut, Canada. The gneisses are part of the Paleoproterozoic Thelon tectonic zone. U-Pb dates of zircon show that the gneisses have magmatic protolith ages ranging from 2007–1958 Ma. The quartzofeldspathic gneisses in southeast Ellesmere Island display centimeter-scale E- to NE-striking sinistral and dextral mylonite zones offsetting pegmatitic dikes that are the last stage of ductile deformation of the basement rocks. Samples were taken from nearshore outcrops at Hayes Fiord, Pim Island, NE of the Leffert Glacier and NW of Cape Isabella. Biotite clusters replace orthopyroxene as the result of post-granulite facies metamorphism in the gneisses. Biotite in mylonitic and ultramylonitic fabrics is found as flattened clusters and also as individual crystals defining shear bands related to mylonitization. Eight samples were dated, including biotite from five mylonites, one deformed pegmatite, one tonalite and muscovite from a pegmatite. Major element X-ray maps demonstrate that the biotite is chemically homogenous. Backscattered electron images and electron dispersive spectroscopy via scanning electron microscopy confirm that biotite lacks intercrystalline layering with other K phases. Step-heating analysis of mica at the University of Vermont yielded Paleoproterozoic 40Ar/39Ar ages. The apparent age spectra form plateau ages in all but one mylonite sample. Biotite from a protomylonite was 2051 ± 26 Ma, older than the protolith ages obtained from U-Pb zircon geochronology, and most likely indicates excess Ar. Pegmatitic muscovite was 1977 ± 35 Ma. Biotite dates range from 1874 ± 13 Ma to 1838 ± 14 Ma for the five mylonites without excess Ar. Biotite dated from ductile shear zones signals the latest deformation in the basement, which was active as early as 1887 Ma.

Intercritically austempered ductile iron (IADI) with a matrix microstructure of ferrite plus metastable austenite has an excellent combination of strength and toughness. The high strength and good ductility of this material is due to the transformation of metastable austenite to martensite during deformation. In the present study, the transformation of austenite to martensite for intercritically austempered ductile irons of varying alloy chemistry (varying amounts of nickel and/or manganese) were examined using in-situ neutron diffraction under strain-controlled loading at VULCAN at the Spallation Neutron Source at Oak Ridge National Laboratory (ORNL). Both diffraction and tensile data were collected and synced using the VDRIVE software (a proprietary ORNL software package). The single peak fit method was employed in the analysis of the diffraction data. In this thesis, the stress and strain for the start of the transformation of metastable austenite to martensite were determined. The development of residual stresses during deformation and the elastic diffraction constants for both the ferrite and austenite phases were also determined. The material was characterized using optical microscopy, backscattered imaging in the scanning electron microscopy, energy dispersive spectroscopy and transmission electron microscopy. / Master of Science

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Burrs are rough protrusions that form along the edge of a component during processing and are commonly produced during machining. Generally, the presence and severity of a burr directly impacts the final part quality. Thus, burrs need to be removed in subsequent processes to avoid injury when handling a part and/or negatively impacting the part's functionality. The size, shape, and nature of the attachment of the burr to the cutting edge are highly dependent on the material, tooling, and process parameters used during machining. This research aimed to develop two new approaches to minimize and/or eliminate burr formation during the drilling of ductile materials. The first new method outlined in this thesis relates to injecting materials in different forms at high pressures under the workpiece on the side from which the drilling tool exits to support the drilling thrust force and thereby minimize exit burr formation. The second method introduced a novel technique for designing and testing highly effective step drills based on the workpiece material and cutting parameters, using commercial drills. Testing the two approaches showed promising results for producing comparatively smaller exit burrs. / Thesis / Master of Applied Science (MASc)

Ductile braced frames are often used to resist lateral earthquake loads in steel buildings; however the presence of a brace element can sometimes interfere with architectural features. One common type of ductile braced frame system sometimes used to accommodate architectural features is the eccentrically braced frame (EBF). In order to dissipate seismic forces, EBF beam regions (called links) must sustain large inelastic deformations. EBF links with column connections must transmit large moments and shear forces to facilitate link rotation. Experiments have shown that welded link-to-column connections tend to fracture in the link flange prior to large link rotations. This study investigated methods for improving EBF link-to-column connection performance, and proposed an alternative ductile braced frame system for accommodating architectural features. Several EBF links with reduced web and flange sections were analytically investigated using validated finite element models in ABAQUS. Results indicated that putting holes in the link web reduced stress and strain values in the link flanges at the connection, but increased the plastic strain and stress triaxiality in the web at the edges of holes. Removing area from the link flanges had little effect on connection stresses and strains. Thus, the reduced web section and reduced flange section methods are not a promising solution to the EBF link-to-column connection problem. The alternative braced frame system proposed in the dissertation used ductile beam splices and buckling-restrained braces in eccentric configurations (BRBF-Es) to accommodate architectural features. Design considerations for the BRBF-Es were determined and dynamic BRBF-E performance was compared with EBF performance. BRBF-E system and component performance was determined using multiple finite element methods. Inter-story drifts and residual drifts for the BRBF-Es were similar to those for EBFs. Results indicated that BRBF-Es are a viable alternative to the EBF, and may result in better design economy than EBFs. With the BRBF-E, damage was isolated within the brace, and in the EBF, damage was isolated within the link, indicating simpler repairs with the BRBF-E. Shop welding of BRBF-E members may replace the multiple field welds required in EBF construction.