The modern trends in lubrication aim at reducing the oil quantity in tribological applications. As a consequence, the film thickness in the contact zone decreases significantly and can reach the order of magnitude of a few nanometres. Hence, the surface separation is ensured by very few lubricant molecules. Atomistic simulations based on the Molecular Dynamics method are used to analyze the local behavior of these severely confined films. A particular attention is paid to the occurrence of wall slip: predictive models and analytical laws are formulated to quantify and predict this phenomenon as a function of the surface-lubricant pair or the local operating conditions in a contact interface. Then, the coupling between Molecular Dynamics simulations and macroscopic models is explored. The classical lubrication theory is modified to include slip effects characterized previously. This approach is employed to study an entire contact featuring a nano-confined lubricant in its center, showing a severe modification of the film thickness and friction. Finally, the lubricant quantity reduction is pushed to the limits up to the occurrence of local film breakdown and direct surface contact. In this scenario, atomistic simulations allow to understand the relationship between the configuration of the last fluid molecules in the contact and the local tribological behavior.

La dynamique granulaire amenant à l'état critique présente un intérêt dans la compréhension de la déstabilisation menant à l'avalanche. Son étude permet d'avoir des pistes de compréhension sur des mécanismes plus complexes telles les catastrophes géophysiques (séismes, glissements de terrain, éboulements). Ainsi, lorsqu'un milieu granulaire tridimensionnel sous gravité est quasi-statiquement incliné, des précurseurs sont observés à partir d'une dizaine de degrés avant l'avalanche. Ces précurseurs correspondent à des réarrangements collectifs de grains observés à la surface qui apparaissent pseudo-périodiquement avec l'angle d'inclinaison. Cette thèse fournit une caractérisation expérimentale des précurseurs détectés à la surface par méthode optique et dans le volume par méthodes acoustiques (linéaire et non linéaire). Tout d'abord, de bonnes corrélations sont trouvées entre les réarrangements à la surface et dans le volume. Dans un second temps, l'étude est poursuivie avec une liste non exhaustive de paramètres influant sur les propriétés des précurseurs. L'état de surface des grains est crucial pour la dynamique des précurseurs. Puis, une tentative de description de la déstabilisation est réalisée avec notamment la mesure de la variation des paramètres élastiques. Les précurseurs d'avalanches correspondent à des pertes successives de rigidité du système, suivies du renforcement de ce dernier.

In 2004, students at the University of Guelph designed and constructed an all-wheel-drive Formula SAE vehicle for competition. It utilized an electronically-controlled, hydraulic-actuated limited slip center coupling from Haldex Traction Ltd, to transfer torque to the front wheels. The initial control system design was not comprehensively conceived, so there was a need for a thoroughly developed control system for the all-wheel-drive actuator augmented with commonly available sensors and a low cost controller. This thesis presents a novel all-wheel-drive active torque transfer controller using a neural network estimated slip angle velocity. This controller specifically targets a racing vehicle by allowing rapid direction changes for maneuverability but damping slip angle changes for increased controllability. The slip angle velocity estimate was able to track the actual simulated value it was trained against with excellent phase matching but with some offsets and phantom spikes. Using the estimated slip angle velocity for control realized smooth control output, excellent stability, and a fast turn-in yaw response on par with rear-wheel-drive configurations. A full vehicle simulation with software-in-the-loop testing for control software was also developed to aid the system design process and avoid vehicle run time for tuning. This design flow should significantly decrease development time for controls algorithm work and help increase innovation within the team.

The upper 8-12 km of the Alpine Fault, South Island, New Zealand, accommodates relative Australia-Pacific plate boundary motion through coseismic slip accompanying large-magnitude earthquakes. Earthquakes occur due to frictional instabilities on faults, and their nucleation, propagation, and arrest is governed by tectonic forces and fault zone properties. A multi-disciplinary dataset is presented on the lithological, microstructural, mineralogical, geochemical, hydrological, and frictional properties of Alpine Fault rocks collected from natural fault exposures and from Deep Fault Drilling Project (DFDP-1) drillcore. Results quantify and describe the physical and chemical processes that affect seismicity and slip accommodation. Oblique dextral motion on the central Alpine Fault in the last 5-8 Myr has exhumed garnet-oligoclase facies mylonitic fault rocks from depths of up to 35 km. During the last phase of exhumation, brittle deformation of these mylonites, accompanied by fluid infiltration, has resulted in complex mineralogical and lithological variations in the fault rocks. Petrophysical, geochemical, and lithological data reveal that the fault comprises a central alteration zone of protocataclasites, foliated and nonfoliated cataclasites, and fault gouges bounded by a damage zone containing fractured ultramylonites and mylonites. Mineralogical results suggest that at least two stages of chemical alteration have occurred. At, or near, the brittle-to-ductile transition (c. >320 °C), metasomatic alteration reactions resulted in plagioclase and feldspar replacement by muscovite and sausserite, and biotite (phlogopite), hornblende (actinolite) and/or epidote replacement by chlorite (clinochlore). At lower temperatures (c. >120°C), primary minerals were altered to kaolinite, smectite and pyrite, or kaolinite, smectite, Fe-hydroxide (goethite) and carbonate, depending on redox conditions. Ultramylonites, nonfoliated and foliated cataclasites, and gouges in the hanging wall and footwall contain the high-temperature phyllosilicates chlorite and white mica (muscovite/illite). Brown principal slip zone (PSZ) gouges contain the low-temperature phyllosilicates kaolinite and smecite, and goethite and carbonate cements. The frictional and hydrological properties of saturated intact samples of central Alpine Fault surface-outcrop gouges and cataclasites were investigated in room temperature experiments conducted at 30-33 MPa effective normal stress (σn') using a double-direct shear configuration and controlled pore fluid pressure in a triaxial pressure vessel. Surface-outcrop samples from Gaunt Creek, location of DFDP-1, displayed, with increasing distance (up to 50 cm) from the contact with footwall fluvioglacial gravels: (1) an increase in fault normal permeability (k = 7.45 x 10⁻²⁰ m² to k = 1.15 x 10⁻¹⁶ m²), (2) a transition from frictionally weak (μ=0.44) fault gouge to frictionally strong (μ=0.50’0.55) cataclasite, (3) a change in friction rate dependence (a–b) from solely velocity strengthening to velocity strengthening and weakening, and (4) an increase in the rate of frictional healing. The frictional and hydrological properties of saturated intact samples of southern Alpine Fault surface-outcrop gouges were also investigated in room temperature double-direct shear experiments conducted at σn'= 6-31 MPa. Three complete cross-sections logged from outcrops of the southern Alpine Fault at Martyr River, McKenzie Creek, and Hokuri Creek show that dextral-normal slip is localized to a single 1-12 m-thick fault core comprising impermeable (k=10⁻²⁰ to 10⁻²² m²), frictionally weak (μ=0.12 – 0.37), velocity-strengthening, illite-chlorite and trioctahedral smectite (saponite)-chlorite-lizardite fault gouges. In low velocity room temperature experiments, Alpine Fault gouges tested have behaviours associated with aseismic creep. In a triaxial compression apparatus, the frictional properties of PSZ gouge samples recovered from DFDP-1 drillcore at 90 and 128 m depths were tested at temperatures up to T=350°C and effective normal stresses up to σn'=156 MPa to constrain the fault's strength and stability under conditions representative of the seismogenic crust. The chlorite/white mica-bearing DFDP-1A blue gouge is frictionally strong (μ=0.61–0.76) across a range of experimental conditions (T=70–350°C, σn'=31.2–156 MPa) and undergoes a stability transition from velocity strengthening to velocity weakening as T increases past 210°C, σn'=31.2–156 MPa. The coefficient of friction of smecite-bearing DFDP-1B brown gouge increases from μ=0.49 to μ=0.74 with increasing temperature and pressure (T=70–210°C, σn'=31.2–93.6 MPa) and it undergoes a transition from velocity strengthening to velocity weakening as T increases past 140°C, σn'=62.4 MPa. In low velocity hydrothermal experiments, Alpine Fault gouges have behaviours associated with potentially unstable, seismic slip at temperatures ≥140°C, depending on mineralogy. High-velocity (v=1 m/s), low normal stress (σn=1 MPa) friction experiments conducted on a rotary shear apparatus showed that the peak coefficient of friction (μp) of Alpine Fault cataclasites and fault gouges was consistently high (mean μp=0.69±0.06) in room-dry experiments. Variations in fault rock mineralogy and permeability were more apparent in experiments conducted with pore fluid, wherein the peak coefficient of friction of the cataclasites (mean μp=0.64±0.04) was higher than the fault gouges (mean μp=0.24±0.16). All fault rocks exhibited very low steady state coefficients of friction (μss) (room-dry mean μss=0.18±0.04; saturated mean μss=0.10±0.04). Three high-velocity experiments conducted on saturated smectite-bearing principal slip zone (PSZ) fault gouges had the lowest peak friction coefficients (μp=0.13-0.18), lowest steady state friction coefficients (μss=0.02-0.10), and lowest breakdown work values (WB=0.07-0.11 MJ/m²) of all the experiments performed. Lower strength (μ < c. 0.62) velocity-strengthening fault rocks comprising a realistically heterogeneous fault plane represent barrier(s) to rupture propagation. A wide range of gouges and cataclasites exhibited very low steady state friction coefficients in high-velocity friction experiments. However, earthquake rupture nucleation in frictionally strong (μ ≥ c. 0.62), velocity-weakening material provides the acceleration necessary to overcome the low-velocity rupture propagation barrier(s) posed by velocity-strengthening gouges and cataclasites. Mohr-Coulomb theory stipulates that sufficient shear stress must be resolved on the Alpine Fault, or pore fluid pressure must be sufficiently high, for earthquakes to nucleate in strong, unstable fault materials. A three-dimensional stress analysis was conducted using the average orientation of the central and southern Alpine Fault, the experimentally determined coefficient of friction of velocity-weakening DFDP-1A blue gouge, and the seismologically determined stress tensor and stress shape ratio(s). Results reveal that for a coefficient of friction of μ ≥ c. 0.62, the Alpine Fault is unfavourably oriented to severely misoriented for frictional slip.

A combined experimental and computational investigation of the deformation behavior of pure magnesium single crystal at the micron length scale has been carried out. Employing the recently exploited method of microcompression testing, uniaxial microcompression experiments have been performed on magnesium single crystals with [0001], [2-1-12], [10-11], [11-20] and [10-10] compression axes. The advantage of the microcompression method over conventional mechanical testing techniques is the ability to localize a single crystalline volume which is characterizable after deformation. The stress-strain relations resulting from microcompression experiments are presented and discussed in terms of orientation dependent slip activity, twinning mechanisms and an anisotropic size effect. Such a mechanistic picture of the deformation behavior is revealed through SEM, EBSD and TEM characterization of the deformation structures, and further supported by 3D discrete dislocation dynamics simulations. The [0001], [2-1-12], and [10-11] compression axes results show dislocation plasticity. Specifically, the deformation due to [0001] compression is governed by pyramidal slip and displays significant hardening and massive unstable shear at stresses above 500MPa. In the case of the two orientations with compression along an axis 45 degrees to the basal plane, unsurpringly it is found that basal slip dominates the deformation. In contrast, compression along the [11-20] and [10-10] directions show deformation twinning in addition to dislocation plasticity. In the case of compression along [11-20], the twinning leads to easy basal slip, while the twin resultant during compression along [10-10] does not lead to easy basal slip. In all cases, a size effect in the stress-strain behavior is observed; the flow stress increases with decreasing column diameter. Furthermore, the extent of the size effect is shown to depend strongly on the number of active slip systems; compression along the [0001] axis is associated with 12 slips systems and displays a saturation of the size effect at a diameter of 10μm, while the other orientations still show a significant size effect at this diameter. The experimental evidence of an orientation-dependent deformation behavior in flow stress has been investigated by 3D discrete dislocation dynamics simulations. Here, the code TRIDIS was modified for hcp structure and c/a ratio of Mg. By matching the simulation results to experimental results, some proper constitutive material parameters such as initial dislocation density, dislocation source length, the critical resolved shear stress were suggested. For the case of [0001] and [2-1-12] orientation, dislocation feature in the pillar during the deformation was exhibited and strain burst was discussed.

Baigiamajame magistro darbe atliekami eksperimentiniai gelžbetoninių sijų, sustiprintų pneumatiniu montažiniu pistoletu mechaniškai tvirtinama anglies pluošto juosta, elgsenos tyrimai, nagrinėjama jungių skaičiaus ir išdėstymo įtaka sijos elgsenai. Darbą sudaro: įvadas, trys pagrindiniai skyriai, pasiūlymai ir išvados, literatūros sąrašas. Įvade aptariama tiriamoji problema, darbo aktualumas ir naujumas, pristatomas darbo objektas, formuluojami tikslai ir uždaviniai, pateikiama tyrimų metodika. Pirmajame skyriuje pateikiamos bendros žinios apie sijų stiprinimą, apžvelgiama stiprinimo metodų raida, aptariamos statybiniams kompozitams gaminti naudojamos medžiagos ir aprašomi populiariausi metodai, naudojami statybiniais kompozitais sustiprintų sijų skaičiavimui. Antrajame skyriuje plačiau aptariamas sluoksnių skaičiavimo metodas, atliekama jo parametrinė analizė. Trečiajame skyriuje plačiai aprašomas bandinių paruošimas ir jų bandymo metodika, pateikiami eksperimentinių tyrimų rezultatai, jie palyginami su teoriniais skaičiavimais bei kitų autorių gautais rezultatais. Darbo pabaigoje pateikiami sijų stiprinimo pneumatiniu montažiniu pistoletu mechaniškai tvirtinama anglies pluošto juosta pasiūlymai, formuluojamos išvados. Darbo apimtis – 69 p. teksto be priedų, 33 paveikslai, 5 lentelės, 32 bibliografiniai šaltiniai. / This thesis presents the analysis based on experimental testing of reinforced concrete beams, strengthened by mechanically fastened fiber reinforced polymer strips, when high pressure air powered pinner was used to fasten the strips. The influence of the number and arrangement of fasteners is investigated. Thesis consists of introduction, three main chapters, recommendations and conclusions, literature list. The introduction presents an overview, objectives, scope, methodology and significance of thesis. The first chapter shows the development of beam strengthening, introduces composite materials and methods used for calculating beams strengthened using FRP strips. In the second chapter the chosen calculation method is described in detail and its parametric analysis is performed. Third chapter gives a detailed description on the test specimen preparation and the methodology of testing. Experimental results and their comparison with theoretically obtained values and values obtained by other researchers are given here. The recommendations on the technology of strengthening the beams using mechanically fastened fiber reinforced polymer strips are given and the conclusions are drawn. Thesis contains 69 pages. There are 33 pictures, 5 tables and 32 references in the thesis.

The geometry, deformation mechanism and kinematics of the S&uuml / rg&uuml / Fault Zone is investigated by using remotely sensed data including Landsat TM and ASTER imagery combined with SRTM, and stereo-aerial photographs. They are used to extract information related to regional lineaments and tectono-morphological characteristics of the SFZ. Various image processing and enhancement techniques including contrast enhancement, PCA, DS and color composites are applied on the imagery and three different approaches including manual, semi automatic and automatic lineament extraction methods are followed. Then the lineaments obtained from ASTER and Landsat imagery using manual and automatic methods are overlaid to produce a final lineaments map. The results have indicated that, the total number and length of the lineaments obtained from automatic is more than other methods while the percentages of overlapping lineaments for the manual method is more than the automatic method which indicate that the lineaments from automatic method does not discriminate man made features which result more lineaments and less overlapping ratio with respect to final map. It is revealed from the detail analysis that, the SFZ displays characteristic deformation patterns of strike-slip faults, such as pressure ridges, linear fault controlled valleys, deflected stream courses, rotated blocks and juxtaposition of stratigraphical horizons in macroscopic scale. In addition to these, kinematic analyses carried out using fault slip data indicated that the S&uuml / rg&uuml / Fault Zone is dextral strike-slip fault zone with a reverse component of slip and cumulative displacement along the fault is more than 2 km.

Carbon nanotubes are molecular-scale tubes of graphitic carbon that possess many unique properties. They have high tensile strength and elastic modulus, are thermally and electrically conductive, and can be structurally modified using well established carbon chemistries. There is global interest in taking advantage of their unique combination of properties and using these interesting materials as components in nanoscale devices and composite materials. The goal of this research was the correlation of the mechanical properties of coiled carbon nanotubes with their chemical structure. Individual nanocoils, grown by chemical vapor deposition, were attached to scanning probe tip using the arc discharge method. Using a scanning probe microscope the nanocoils are repeatedly brought into and out of contact with a chemically-modified substrate. Precise control over the length (or area) of contact with the substrate is achievable through simultaneous monitoring the cantilever deflection resonance, and correlating these with scanner movement. The mechanical response of nanocoils depended upon the extent of their compression. Nonlinear response of the nanocoil was observed consistent with compression, buckling, and slip-stick motion of the nanocoil. The chemical structure of the nanocoil and its orientation on the tip was determined using scanning and transmission electron microscopy. The mechanical stiffness of eighteen different nanocoils was determined in three ways. In the first, the spring constant of each nanocoil was computed from the slope of the linear response region of the force-distance curve. The assumptions upon which this calculation is based are: 1) under compression, the cantilever-nanocoil system can be modeled as two-springs in series, and 2) the nanocoil behaves as an ideal spring as the load from the cantilever is applied. Nanocoil spring constants determined in this fashion ranged from 6.5x10-3 to 5.16 TPa for the CCNTs understudy. In the second, the spring constant of the nanocoil was computed from measuring the critical force required to buckle the nanocoil. The critical force method measured the force at the point where the nanocoil-cantilever system diverges from a linear region in the force curve. Nanocoil spring constants determined in this fashion ranged from 1.3x10-5 to 10.4 TPa for the CCNTs understudy. In the third, the spring constant of each nanocoil was computed from the thermal resonance of the cantilever-nanocoil system. Prior to contact of the nanocoil with the substrate, the effective spring constant of the system is essentially that of the cantilever. At the point of contact and prior to buckling or slip-stick motion, the effective spring constant of the system is modeled as two springs in parallel. Nanocoil spring constants determined in this fashion ranged from 2.7x10-3 to 0.03 TPa for the CCNTs understudy. Using the thermal resonance of the cantilever system a trend was observed relating nanocoil structure to the calculated modulus. Hollow, tube-like nanostructures had a higher measured modulus than solid or fibrous structures by several orders of magnitude. One can conclude that the structure of carbon nanocoils can be determined from using their mechanical properties. This correlation should significantly contribute to the knowledge of the scientific and engineering community. It will enable the integration of carbon nanocoils in microelectromechanical (MEMS) or nanoelectromechanical systems (NEMS) as resonators, vibration dampers, or any other application in which springs are used within complex devices.

Mining induced seismic activity and rockbursting are critical concerns for many underground operations. Seismic activity may arise from the crushing of highly stressed volumes of rock around mine openings or from shear motion on planes of weakness. Shear-slip on major planes of weakness such as faults, shear zones and weak contacts has long been recognized as a dominant mode of failure in underground mines. In certain circumstances, it can generate large seismic events and induce substantial damage to mine openings. The Big Bell Gold mine began experiencing major seismic activity and resultant damage in 1999. Several seismic events were recorded around the second graphitic shear between April 2000 and February 2002. It is likely that the seismic activity occurred as a result of the low strength of the shear structure combined with the high level of mining induced stresses. The stability of the second graphitic shear was examined in order to gain a better understanding of the causes and mechanisms of the seismic activity recorded in the vicinity of the shear structure as mining advanced. The data were derived from the observation of the structure exposures, numerical modelling and seismic monitoring. The numerical modelling predictions and the interpreted seismic monitoring data were subsequently compared in order to identify potential relationships between the two. This thesis proposes the Incremental Work Density (IWD) as a measure to evaluate the relative likelihood of shear-slip induced seismic activity upon major planes of weakness. IWD is readily evaluated using numerical modelling and is calculated as the product of the average driving shear stress and change in inelastic shear deformation during a given mining increment or step. IWD is expected to correlate with shear-slip induced seismic activity in both space and time. In this thesis, IWD was applied to the case study of the second graphitic shear at the Big Bell mine. Exposures of the second graphitic shear yielded information about the physical characteristics of the structure and location within the mine. Numerical modelling was used to examine the influence of mining induced stresses on the overall behaviour of the shear structure. A multi-step model of the mine was created using the three- dimensional boundary element code of Map3D. The shear structure was physically incorporated into the model in order to simulate inelastic shear deformation. An elasto-plastic Mohr-Coulomb material model was used to describe the structure behaviour. The structure plane was divided into several elements in order to allow for the comparison of the numerical modelling predictions and the interpreted seismic data. Stress components, deformation components and IWD values were calculated for each element of the shear structure and each mining step. The seismic activity recorded in the vicinity of the second graphitic shear was back analysed. The seismic data were also gridded and smoothed. Gridding and smoothing of individual seismic moment and seismic energy values resulted in the definition of indicators of seismic activity for each element and mining step. The numerical model predicted inelastic shear deformation upon the second graphitic shear as mining advanced. The distribution of modelled IWD suggested that shear deformation was most likely seismic upon a zone below the stopes and most likely aseismic upon the upper zone of the shear structure. The distribution of seismic activity recorded in the vicinity of the shear structure verified the above predictions. The seismic events predominantly clustered upon the zone below the stopes. The results indicated that the seismic activity recorded in the vicinity of the second graphitic shear was most likely related to both the change in inelastic shear deformation and the level of driving shear stress during mechanical shearing. Time distribution of the seismic events also indicated that shear deformation and accompanying seismic activity were strongly influenced by mining and were time-dependant. Seismic activity in the vicinity of the second graphitic shear occurred as a result of the overall inelastic shear deformation of the shear structure under mining induced stresses. A satisfactory relationship was found between the spatial distribution of modelled IWD upon the shear structure and the spatial distribution of interpreted seismic activity (measured as either smoothed seismic moment or smoothed seismic energy). Seismic activity predominantly clustered around a zone of higher IWD upon the second graphitic shear as mining advanced. However, no significant statistical relationship was found between the modelled IWD and the interpreted seismic activity. The lack of statistical relationship between the modelled and seismic data may be attributed to several factors including the limitations of the techniques employed (e.g. Map3D modelling, seismic monitoring) and the complexity of the process involved.

Made available in DSpace on 2014-06-11T19:28:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-08Bitstream added on 2014-06-13T19:58:20Z : No. of bitstreams: 1 silva_lh_me_sjc.pdf: 2510222 bytes, checksum: 9b0884b924775ed48bb9667a27133675 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste estudo foi desenvolver um novo formato de pilar protético estético em zircônia (3Y-TZP) visando suprimir a utilização do parafuso trespassante utilizado no formato convencional de pilares protéticos em zircônia. Inicialmente foi feita a caracterização do material utilizado na técnica de colagem de barbotina (slip casting) através da confecção de uma barra que teve suas propriedades mecânicas, módulo de elasticidade (E) e coeficiente de Poisson (), grau de contração e dimensão de suas partículas após sinterização avaliados pelos métodos de frequências naturais de vibração e microscopia eletrônica de varredura (MEV), respectivamente. Previamente à confecção do pilar protótipo, este teve seu comportamento mecânico avaliado e comparado a um pilar de 3YTZP convencional com parafuso trespassante pela análise por elementos finitos (FEA) durante sua instalação em implante e recebendo carga oblíqua simulando força de mastigação (210,5 N). O protótipo foi confeccionado pela técnica de colagem de barbotina em um molde de gesso obtido a partir de uma duplicata ampliada em cera. A densidade final foi avaliada pelo método de Archimedes em água. Obteve-se o módulo de elasticidade de 187,97 ± 4,84 GPa e coeficiente de Poisson de 0,19 ± 0,04 para o material. O grau de contração de sinterização foi de 58 vol% e o tamanho do grão foi de 0,705 ± 0,424 μm. Na análise por FEA verificou-se concentrações de tensões na região inicial da rosca para ambos os pilares, e durante o carregamento foram observadas tensões de tração no lado em que incidiu a carga, com presença de tensões de compressão no lado oposto. Ainda, observou-se durante o carregamento do pilar protético convencional concentração de tensão na região do pescoço do parafuso trespassante. A densidade final obtida para o pilar protótipo em 3Y-TZP foi de 95,68% em... / The purpose of this study was to develop a new esthetic zirconia (3YYTZP) implant abutment shape to suppress the use of the fixing screw commonly used by the conventional zirconia abutments. A material characterization, Young’s modulus (E), Poisson’s rate (), shrinkage and particles dimensions after sintering was performed for a bar shape specimen obtained by slip casting evaluated by the natural torsional and flexural vibration frequencies and scanning electron microscope (SEM), respectively. Previously to the prototype abutment confection, its mechanical behavior was evaluated and compared to a conventional zirconia abutment with a fixing screw by finite element analisys (FEA) simulating the abutment installation and oblique loading (210.5 N). The prototype was confectioned by the slip casting technique using a gypsum mould obtained from a wax expanded replica. The abutment had its density measured by Archimedes’ method. Through the natural vibration frequencies a Young’s modulus of 187.97 ± 4.84 GPa and a Poisson’s rate of 0.19 ± 0.04 were obtained for the material. The shrinkage was 58 vol% and the grain size was 0,705 ± 0,424 μm . The FEA showed stress concentration at the first thread pitch for both abutments, and tensile stress concentration were observed at the side that received the oblique load with compressive stress at the opposite side. Whereas, for the conventional abutment model a stress concentration was observed at the screw’s stem. The final density for the zirconia prototype abutment was 95.68% from the theoretical density (6.12 g.cm-3). The zirconia abutment obtained by slip casting presented satisfactory physical properties. The suppressing of the fixing screw could provide better performance to the abutment due to the lack of stress concentration in the screw when an oblique load is applied, when evaluated by FEA