This thesis presents a framework for a virtual laboratory for material testing, called Virlab. A virtual laboratory is an open and flexible environment that is used to simulate a set of experiments using a computer. It is beneficial and valuable for researcher and educators to simulate real problems and to conquer some challenges such as a weightless body. The virtual laboratory for material testing contributes both to the field of mechanics of materials and the field of software engineering. In the field of material mechanics Virlab can be used for material testing education and research. Students can rapidly investigate many experiments for materials and the difference between kinematics quantities and stress measures. Virlab also offers a convenient platform for researchers to investigate and test new constitutive equation and implement their new algorithms. Virlab also encourages unambiguous definitions of mechanics terms and principles. In the field of software engineering the contribution is to provide an example of the application of software engineering approaches to an important scientific computing problem. By showing the successful application of software engineer­ing methodologies for a virtual laboratory, it is hoped that software engineering ideas will spread to other scientific applications. In terms of software engineering methodologies, this thesis presents a component-based design for the virtual laboratory for material testing. In this thesis we conduct a commonality analysis for material testing, decompose the system into modules with the information hiding principle, provide an easy way to identify components from the module decompo­sition, and build the component-based system architecture. In this procedure we apply the concept of design through documentation at each stage. / Thesis / Master of Applied Science (MASc)

No description available.

No description available.

Orientador: Eloi Dezan Junior / Banca: Luciano Tavares Angelo Cintra / Banca: Maria Angélica Marciano da Silva / Banca: Juliane Maria Guerreiro Tanomaru / Banca: Francine Benetti / Resumo: Introdução: O tratamento endodôntico visa manter ou restabelecer a saúde do periodonto através do preparo biomecânico, utilizando instrumentos de níquel- titânio automatizados e associados com insertos ultrassônicos para potencializar a ação dos irrigantes. Os materiais empregados na endodontia que permanecerão em contato com tecidos devem apresentar biocompatibilidade e preferencialmente ser biomineralizador, a fim de selar comunicações (fisiológicas/iatrogênicas), isolando o sistema de canais radiculares. Objetivos: 1- Avaliar a resistência à fadiga cíclica das limas reciprocantes Genius e EdgeFile X1 Small, comparados à lima WaveOne Gold Primary; 2- Avaliar a capacidade de limpeza de um inserto ultrassônico de níquel titânio em ativação da irrigação de forma contínua e passiva; 3- Avaliar a biocompatiblidade e biomineralização do cimento reparador MTA Flow. Material e Métodos: Para avaliar a resistência à fadiga cíclica dos sistemas Genius, EdgeFile e WaveOne Gold, 80 instrumentos foram utilizados (n=20), divididos em 4 grupos experimentais: Genius 25.04, Genius 30.04; EdgeFile X1 Small e Wave One Gold Primary, acionados em um canal artificial de aço inoxidável com ângulo de curvatura de 60º e raio de curvatura de 5 mm. O tempo decorrido da ativação do motor foi gravado em um cronômetro digital e parado assim que a fratura foi detectada. O número de ciclos até a falha (NCF) e o tempo para fratura (TF) foram calculados e os comprime... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Introduction: The endodontic treatment aims to maintain or restore periodontal health through biomechanical instrumentation with nickel-titanium automatized instruments, associated with an ultrasonic tip to activate the irrigant, enhancing cleanness. Materials used in endodontics that will remain in contact with tissues, should demonstrate properties as biocompatibility and biomineralization ability, in order to seal communications (physiological/iatrogenic) isolating the root canal system. Objectives: 1- Evaluate the cyclic fatigue resistance of reciprocating Genius and EdgeFile X1 Small instruments compared to Waveone Gold Primary instruments; 2- Evaluate the cleaning effectiveness of a nickel-titanium ultrasonic tip in continuous and passive irrigant activation; 3-Evaluate the biocompatibility and biomineralization of MTA Flow repair cement. Materials and Methods: To evaluate the cyclic fatigue resistance of Genius, EdgeFile and WaveOne Gold, 80 instruments were used (n = 20), divided into 4 experimental groups: Genius 25.04, Genius 30.04; EdgeFile X1 Small and Wave One Gold Primary, reciprocating in a stainless steel artificial canal with a 60° angle of curvature and 5mm radius of curvature. The elapsed time of the motor activation was recorded in a digital timer and stopped as soon as the fracture was detected. The number of cycles to fracture (NCF) and time to fracture (TF) were calculated and the fractured segments lengths measured. To evaluate the ultrasonic tip clean... (Complete abstract click electronic access below) / Doutor

The structural performance of Rounded Dovetail Connections (RDC) has been studied experimentally and numerically to provide information needed for connection structural design. RDC are mainly used to transfer vertical shear forces, but test results show that they can carry considerable load in tension and bending. Geometric parameters, such as dovetail flange angle and dovetail height are shown to significantly effect affect the structural performance of RDC. Results show that it is impractical to determine a set of empirical equations to describe the structural performance of RDC based on basic wood material properties. RDC manufactured and tested with low and constant moisture content outperformed those evaluated under other climatic conditions, and test results demonstrate that RDC should be produced at low machine speed and with minimal a gap between the connecting members. RDC in laminated strand lumber have higher capacity and fail under larger deformations compared to RDC in western hemlock. A three-dimensional finite element method model is presented and validated with experimental tests. Good agreement is achieved between the load deformation response predicted by the model and the experimentally observed load deformation response. Therefore the model is deemed suitable for estimating the stresses needed to develop failure criteria. A failure criterion for the analysis of RDC is presented taking into account size effect in the strength of wood. Based on the experimental and numerical studies, a design equation for RDC is presented that provides the engineering community with a new design tool. Finally, self tapping screws as reinforcement have been studied and are shown to significantly improve the structural performance of RDC under vertical shear loading.

The structural performance of Rounded Dovetail Connections (RDC) has been studied experimentally and numerically to provide information needed for connection structural design. RDC are mainly used to transfer vertical shear forces, but test results show that they can carry considerable load in tension and bending. Geometric parameters, such as dovetail flange angle and dovetail height are shown to significantly effect affect the structural performance of RDC. Results show that it is impractical to determine a set of empirical equations to describe the structural performance of RDC based on basic wood material properties. RDC manufactured and tested with low and constant moisture content outperformed those evaluated under other climatic conditions, and test results demonstrate that RDC should be produced at low machine speed and with minimal a gap between the connecting members. RDC in laminated strand lumber have higher capacity and fail under larger deformations compared to RDC in western hemlock. A three-dimensional finite element method model is presented and validated with experimental tests. Good agreement is achieved between the load deformation response predicted by the model and the experimentally observed load deformation response. Therefore the model is deemed suitable for estimating the stresses needed to develop failure criteria. A failure criterion for the analysis of RDC is presented taking into account size effect in the strength of wood. Based on the experimental and numerical studies, a design equation for RDC is presented that provides the engineering community with a new design tool. Finally, self tapping screws as reinforcement have been studied and are shown to significantly improve the structural performance of RDC under vertical shear loading.

Orientador: Paulo Sérgio Cerri / Resumo: Modificações nos cimentos endodônticos tem sido frequentemente realizada a fim da obtenção de um material biocompatível e que favoreça a reparação dos tecidos periodontais. Assim, o GuttaFlow bioseal (GFB) foi lançado no mercado a partir de uma modificação do cimento à base de silicone GuttaFlow; no GFB foi adicionado ao cimento partículas de vidro cerâmico bioativo. Por outro lado, o MTA Fillapex (MTAF), um cimento à base de silicato tricálcico, também teve a substituição do agente radiopacificador óxido de bismuto pelo tungstato de cálcio. O nosso propósito foi avaliar a biocompatibilidade dos cimentos GFB e o MTAF (contento tungstato de cálcio), em subcutâneo de ratos. Tubos de polietileno foram preenchidos com os respectivos materiais GFB (n=20), MTAF (n=20) e Endofill (EF; n=20) e implantados no subcutâneo de ratos. No grupo controle GC (n=20), foram implantados tubos vazios. Após 7, 15, 30 e 60 dias, os tubos implantados com os tecidos circundantes foram removidos e incluídos em parafina. O número de células inflamatórias (CI) e a espessura das cápsulas foram obtidos a partir de cortes corados com HE. Alguns cortes foram corados com tricrômico de Masson para verificar a formação de colágeno nas cápsulas enquanto o método de von Kossa foi realizado para detectar depósitos de cálcio. A interleucina-6 (IL-6), uma citocina pró-inflamatória, e fator de crescimento endotelial vascular (VEGF) foram detectados por meio de reações imuno-histoquímicas. O número de células IL-6-im... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Endodontic cements have been often modified in attempt to obtain biocompatible materials, which are able to promote the repair of periodontal tissues. GuttaFlow bioseal (GFB) was launched on the market from a modification of GuttaFlow silicone cement, containing bioactive glass ceramic. In the MTA Fillapex (MTAF), a tricalcium silicate-based material, the bismuth oxide radiopacifying agent was replaced by calcium tungstate. The purpose of this study was to evaluate the tissue reactions promoted by GFB and MTAF in comparison with Endofill (EF), a zinc oxide eugenol-based root-filling material, which has a long clinical track record. Polyethylene tubes filled with GFB (n=20), MTAF (n=20) or EF (n=20) were implanted into rat subcutaneous. In the control group (CG; n=20), empty tubes were implanted. After 7, 15, 30 and 60 days, the implanted tubes surrounded by connective tissue were fixed and embedded in paraffin. The number of inflammatory cells (IC) and the capsule thickness were obtained in the HE-stained sections. Some sections were stained with Masson's trichrome for the collagen evaluation while the von Kossa method was performed for detection of calcium deposits. Interleukin-6 (IL-6), a pro-inflammatory cytokine, and vascular endothelial growth factor (VEGF) were detected by immunohistochemical reactions. The number of IL-6-immunopositive cells was estimated in the capsules. Data were analyzed by two-way ANOVA and Tukey post-test (p≤0.05). From 7 to 60 days, all groups sh... (Complete abstract click electronic access below) / Mestre

The structural performance of Rounded Dovetail Connections (RDC) has been studied experimentally and numerically to provide information needed for connection structural design. RDC are mainly used to transfer vertical shear forces, but test results show that they can carry considerable load in tension and bending. Geometric parameters, such as dovetail flange angle and dovetail height are shown to significantly effect affect the structural performance of RDC. Results show that it is impractical to determine a set of empirical equations to describe the structural performance of RDC based on basic wood material properties. RDC manufactured and tested with low and constant moisture content outperformed those evaluated under other climatic conditions, and test results demonstrate that RDC should be produced at low machine speed and with minimal a gap between the connecting members. RDC in laminated strand lumber have higher capacity and fail under larger deformations compared to RDC in western hemlock. A three-dimensional finite element method model is presented and validated with experimental tests. Good agreement is achieved between the load deformation response predicted by the model and the experimentally observed load deformation response. Therefore the model is deemed suitable for estimating the stresses needed to develop failure criteria. A failure criterion for the analysis of RDC is presented taking into account size effect in the strength of wood. Based on the experimental and numerical studies, a design equation for RDC is presented that provides the engineering community with a new design tool. Finally, self tapping screws as reinforcement have been studied and are shown to significantly improve the structural performance of RDC under vertical shear loading. / Forestry, Faculty of / Graduate

No description available.

Historic truss bridges are examined in this thesis through material characterization of wrought iron and structural evaluation of an early 20th century pony truss bridge. The mechanical properties of wrought iron from six 19th century truss bridges were evaluated through mechanical testing that includes hardness and tension tests. The main findings of this work are: 1) That hardness is a poor predictor of yield and ultimate stress but has some ability in screening iron for iron with low ductility, 2) there is a statistically significant difference in the distribution of yield and ultimate stresses between material samples from different bridges, and 3) that a size effect is present in the material that results in lower yield and ultimate stresses for larger members. Load tests were conducted on an early 20th century pony truss bridge where member axial strains and truss deflections are measured, which were then simulated in computer models. The key observations are: 1) that connection type between truss members has little effect on computer model results, 2) that a significant difference was observed between measured axial forces and those predicted in the computer models for certain members, and 3) that although the bridge response is best modeled with a pin-roller support condition, compressive forces measured in the bottom chord members from temperature change indicate the supports have some lateral resistance, thus are not a true pin-roller.