The effects of high loading rates (HLR), and nano reinforcement on the mechanical response of adhesively-bonded SLJs with composite adherends, subjected to different loading (strain) rates are systematically investigated. The results are then compared to those of neat thermoset resin and thermo-plastic adhesive. More specifically, nano-reinforced and neat resin bonded joints mating carbon/epoxy and glass/epoxy adherends were subjected to tensile loadings under 1.5 and 3 mm/min and tensile impacts at a loading rate of 2.04E+5 mm/min. In some cases, additional tests were conducted under 15, 150, and 1500 mm/min to obtain additional properties gained using the nano-reinforcements for use in the further numerical investigations. The HLR tests were conducted, using a modified instrumented pendulum equipped with a specially designed impact load transfer apparatus. The dispersion of nanoparticles was facilitated using a mechanical stirrer and a three-roll mill machine. The failure mechanisms were studied with a scanning electron microscope.

An experimental program was conducted to investigate some aspects of in-plane behaviour of masonry infilled steel frames. Eight concrete masonry infilled steel frames, consisting of three fully grouted and five partially grouted infills, were tested under combined lateral and axial loading. All specimens were constructed using one-third scale concrete masonry units. The in-plane lateral load was gradually increased at the frame top beam level until the failure of the specimen while an axial load was applied to the top beam and held constant. The parameters of the study included axial load, extent of grouting, opening, and aspect ratio of the infill. The experimental results were used, along with other test results from the literature, to evaluate the efficacy of stiffness and strength predictions by some theoretical methods with a focus on Canadian and American design codes. Cracking pattern, stiffness, failure mode, crack strength, and ultimate strength of the specimens were monitored and reported. Presence of axial load was found to increase the ultimate strength of the infilled frame but had no marked effect on its stiffness. Two specimens exhibited “splitting failure” due to axial load. Partially grouted specimens developed extensive diagonal cracking prior to failure whereas fully grouted specimens showed little or no cracking prior to failure. An increase in grouting increased the ultimate strength of the frame system but reduced its ductility. Presence of opening reduced the ultimate strength of the infilled frame and increased its ductility but its effect on the stiffness of the frame system was not significant. A review of current Canadian and American design codes showed that the Canadian code significantly overestimates the stiffness of infilled frames whereas the American code provides improved predictions for stiffness of these frame systems. Both design codes underestimate the strength of masonry infilled steel frames but grossly overestimate the strength of masonry infilled RC frames. / Masonry infilled steel frames tested under combined axial and lateral loading. Behaviour as affected by axial load, grouting, aspect ratio and openings discussed. Correlation between axial load level and the infill lateral resistance examined. Efficacy of the Canadian and American masonry standards on infill design was examined.

The Finite Element Method of stress analysis is employed in axisymmetric, two and three-dimensional forms, to investigate the mechanical behaviour of dental structures under simulated oral loading conditions. Stress distributions which are examined, include those occuring in the crowns of normal teeth due to masticatory loading and in restored teeth as a consequence of the restoration's setting and thermal expansions. The force distributions occuring on roots of individual teeth and on teeth used as abutments for various bridge constructions are also investigated for both axial and non-axial loading and various alveolar bone support conditions. The instantaneous centres of rotation of teeth when subjected to orthodontic loading are also determined. The Finite Element Method is employed to examine various published hypotheses which attempt to correlate the mechanical behaviour of bone structures with that tissue's biological response characteristics. The cases examined include the remodelling of the alveolar process subsequent to orthodontic treatment and the remodelling or so-called straightening of the malaligned long bone. Utilising published experimental data, the Finite Element Method is also employed in a reverse mode to enable some hitherto unknown mechanical properties of the periodontal membrane and cortical bone tissues to be determined. Indeed, due to the flexibility of the method, it was possible to represent these tissues as orthotropic materials. The work is presented in two volumes. While the first volume contains all the results of the analyses, the second contains an outline of the relevant finite element theory. Nevertheless, where the theory has been extended, in particular in the area of non-isotropic material analysis, it is developed in greater depth. The second volume also contains both a thorough description and a listing of all the computer programs developed.

SILVA, Francisca Gleiciane da. Condutividade hidráulica do solo saturado e fluxo preferencial em amostras confinadas de terra. 2015. 64 f. Dissertação (Mestrado em agronomia)- Universidade Federal do Ceará, Fortaleza-CE, 2015. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-08-30T20:09:46Z No. of bitstreams: 1 2015_dis_fgsilva.pdf: 1737179 bytes, checksum: 358ee3fc0ff3e673a09ab8f32131e84a (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2016-08-31T23:41:15Z (GMT) No. of bitstreams: 1 2015_dis_fgsilva.pdf: 1737179 bytes, checksum: 358ee3fc0ff3e673a09ab8f32131e84a (MD5) / Made available in DSpace on 2016-08-31T23:41:15Z (GMT). No. of bitstreams: 1 2015_dis_fgsilva.pdf: 1737179 bytes, checksum: 358ee3fc0ff3e673a09ab8f32131e84a (MD5) Previous issue date: 2015 / Understanding the processes related to the movement of water in soil profile is relevant to the management of soil and water resources. Hydraulic conductivity is an important soil property that affects this movement, but its determination in laboratory conditions requires that samples are contained in cylinders which can cause the presence of preferential flow through the soil wall interface. So, the goal of this work was to test the effect of increasing perimeter and height of the sample on saturated hydraulic conductivity in confined soil samples of different textures. Soil samples were collected and the following physical analyzes were performed: particle density, particle-size, water dispersed clay, soil porosity, and saturated hydraulic conductivity (Ko). Experimental data were analyzed in a randomized design for all variables, adopting a 4 x 5 factorial arrangement (four diameters x five heights of the cylinders), with six replications. The Shapiro- Wilk test was used to verify the normality of the data, F test for analysis of variance, and Tukey´s test for comparison of means (p<0.05). Classical descriptive statistics and multivariate analysis techniques were also employed. It was conclude that: a) the results support the hypothesis that the increase of the perimeter causes an increase of the saturated hydraulic conductivity; b) for the same increase of preferential flow area, the effect on the saturated hydraulic conductivity was higher for clay soil; c) the hypothesis that increased water path causes a change in the Ko values was rejected; d) for both soil classes increased water path did not affect the values of the saturated hydraulicconductivity. / A compreensão dos processos relacionados ao movimento da água no perfil do solo é relevante para o manejo do solo e dos recursos hídricos. A condutividade hidráulica é um importante atributo do solo que interfere nesse movimento, sendo que sua determinação na condição de laboratório requer que as amostras estejam confinadas em cilindros, o que pode causar a presença de fluxo preferencial pela interface solo/parede do cilindro. Objetivou-se nesse trabalho testar o efeito do aumento do perímetro e da altura da amostra sobre a condutividade hidráulica do solo saturado em amostras confinadas de terra de diferentes texturas. Foram coletadas amostras de terra para realização das análises físicas, a saber: densidade de partículas, granulometria, argila dispersa em água, porosidade do solo e condutividade hidráulica do solo saturado (Ko). Os dados experimentais foram analisados em delineamento inteiramente casualizado para todas as variáveis, adotandose o esquema fatorial 4 x 5 (quatro diâmetros e cinco alturas dos cilindros), com seis repetições. Foram aplicados os testes de Shapiro-Wilk para verificar a normalidade dos dados, o F para análise de variância e o de Tukey para a comparação da médias (todos a 5% de probabilidade). Também foi empregada a estatística descritiva clássica para algumas variáveis e técnicas multivariadas de análises. Conclui-se que a) aceita-se a hipótese de que o aumento do perímetro da amostra provoca aumento nos valores de condutividade hidráulica do solo saturado; b) para o mesmo aumento de área de fluxo preferencial, o efeito sobre a condutividade hidráulica do solo saturado para o solo argiloso foi maior; c) a hipótese de que o aumento do percurso da água causa alteração nos valores de Ko foi refutada; d) para ambas as classes de solos o aumento do percurso da água não foi determinante nos valores obtidos para condutividade hidráulica do solo saturado.

Em virtude da presença cada vez mais frequente de solicitações cíclicas nas estruturas de engenharia e do aprimoramento da análise de projetos, os ensaios em solos sob carregamentos cíclicos tiveram seu interesse renovado nos últimos anos. Os ensaios de laboratório são realizados de forma que simulem, da melhor maneira possível, as condições observadas em campo. Tais condições auxiliam na escolha dos ensaios a serem conduzidos para a determinação de parâmetros geotécnicos relevantes a cada situação observada em campo. Dentre os ensaios empregados na Engenharia Geotécnica, destaca-se o simple shear. Este ensaio é conhecido e utilizado para medir a resistência ao cisalhamento e a rigidez de solos. Este é o único ensaio de laboratório capaz de submeter uma amostra a condições de deformação plana sob volume constante e permitir a rotação das tensões principais. Tais condições são frequentemente representativas em diversas situações em campo como, por exemplo, o modo de cisalhamento adjacente ao fuste de uma estaca ou sob plataformas offshore com base gravitacional. Nesse contexto, um equipamento foi desenvolvido para a realização de ensaios do tipo simple shear. O aparato conta com uma câmara, na qual é aplicada pressão à amostra de solo. Diferenciando-se do equipamento comercial para tais ensaios, que emprega uma membrana com anéis metálicos, a amostra de solo neste equipamento é envolta por uma membrana de látex, o que possibilita a consolidação de forma isotrópica ou anisotrópica. Quanto ao carregamento, o equipamento desenvolvido permite que o carregamento seja realizado de forma monotônica ou clíclica. Quando do carregamento cíclico, este pode ainda ser realizado de forma a se manter a tensão controlada ou a deformação. Foram conduzidos ensaios de calibração e validação do equipamento empregando-se uma areia fina de granulometria uniforme cujas propriedades são amplamente conhecidas através de outros ensaios. Os resultados obtidos foram então comparados com estudos no mesmo material em equipamentos triaxiais, cisalhamento direto e outro simple shear. Os resultados mostraram-se satisfatórios, validando o equipamento desenvolvido. / In view of the ever more frequent presence of the cyclic solicitations on Engineering structures and the enhancement of design analysis, the soil testing under cyclic loading conditions had its interest renewed in the last years. The laboratory tests are conduced in a way that simulates, in the best way possible, the observed field conditions. Said conditions aid on the choice of the tests to be conducted in order to determinate the relevant geomechanics parameters.to each situation observed on the field. Among the employed tests in Geotechnical Engineering, it is highlighted the simple shear. This test is known and used to measure the shear strength and soil righty. This is the only laboratory test capable of submitting the sample to plane strain conditions under constant volume and allows the main stress rotations. Said conditions are frequently representative in many field situations, such as, the adjacent shear mechanism to the shaft of a pile or, under offshore platforms with gravitational base. In this context, a equipment was developed to perform simple shear tests. The apparatus has a chamber, in which it is applied confining pressure to the soil sample. Contrasting from the commercial equipment for said tests, that uses a membrane with metallic rings, in this equipment the soil sample is involved by a latex membrane, allowing the consolidation being carried out isotropically or anisotropically. The loading on this equipment can be conduced on monotonic or cyclic conditions. The cyclic loading can even be conduced by controlling the deformation or the stress. Calibration and validation testes where conduced on the equipment using a fine sand of uniform granulometry which properties are largely known through other tests. The obtained results where then compared to other tests carried out on the same material in triaxial tests, direct shear and other simple shear, The results obtained were considered satisfactory, validating the developed equipment.

Em virtude da presença cada vez mais frequente de solicitações cíclicas nas estruturas de engenharia e do aprimoramento da análise de projetos, os ensaios em solos sob carregamentos cíclicos tiveram seu interesse renovado nos últimos anos. Os ensaios de laboratório são realizados de forma que simulem, da melhor maneira possível, as condições observadas em campo. Tais condições auxiliam na escolha dos ensaios a serem conduzidos para a determinação de parâmetros geotécnicos relevantes a cada situação observada em campo. Dentre os ensaios empregados na Engenharia Geotécnica, destaca-se o simple shear. Este ensaio é conhecido e utilizado para medir a resistência ao cisalhamento e a rigidez de solos. Este é o único ensaio de laboratório capaz de submeter uma amostra a condições de deformação plana sob volume constante e permitir a rotação das tensões principais. Tais condições são frequentemente representativas em diversas situações em campo como, por exemplo, o modo de cisalhamento adjacente ao fuste de uma estaca ou sob plataformas offshore com base gravitacional. Nesse contexto, um equipamento foi desenvolvido para a realização de ensaios do tipo simple shear. O aparato conta com uma câmara, na qual é aplicada pressão à amostra de solo. Diferenciando-se do equipamento comercial para tais ensaios, que emprega uma membrana com anéis metálicos, a amostra de solo neste equipamento é envolta por uma membrana de látex, o que possibilita a consolidação de forma isotrópica ou anisotrópica. Quanto ao carregamento, o equipamento desenvolvido permite que o carregamento seja realizado de forma monotônica ou clíclica. Quando do carregamento cíclico, este pode ainda ser realizado de forma a se manter a tensão controlada ou a deformação. Foram conduzidos ensaios de calibração e validação do equipamento empregando-se uma areia fina de granulometria uniforme cujas propriedades são amplamente conhecidas através de outros ensaios. Os resultados obtidos foram então comparados com estudos no mesmo material em equipamentos triaxiais, cisalhamento direto e outro simple shear. Os resultados mostraram-se satisfatórios, validando o equipamento desenvolvido. / In view of the ever more frequent presence of the cyclic solicitations on Engineering structures and the enhancement of design analysis, the soil testing under cyclic loading conditions had its interest renewed in the last years. The laboratory tests are conduced in a way that simulates, in the best way possible, the observed field conditions. Said conditions aid on the choice of the tests to be conducted in order to determinate the relevant geomechanics parameters.to each situation observed on the field. Among the employed tests in Geotechnical Engineering, it is highlighted the simple shear. This test is known and used to measure the shear strength and soil righty. This is the only laboratory test capable of submitting the sample to plane strain conditions under constant volume and allows the main stress rotations. Said conditions are frequently representative in many field situations, such as, the adjacent shear mechanism to the shaft of a pile or, under offshore platforms with gravitational base. In this context, a equipment was developed to perform simple shear tests. The apparatus has a chamber, in which it is applied confining pressure to the soil sample. Contrasting from the commercial equipment for said tests, that uses a membrane with metallic rings, in this equipment the soil sample is involved by a latex membrane, allowing the consolidation being carried out isotropically or anisotropically. The loading on this equipment can be conduced on monotonic or cyclic conditions. The cyclic loading can even be conduced by controlling the deformation or the stress. Calibration and validation testes where conduced on the equipment using a fine sand of uniform granulometry which properties are largely known through other tests. The obtained results where then compared to other tests carried out on the same material in triaxial tests, direct shear and other simple shear, The results obtained were considered satisfactory, validating the developed equipment.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Understanding the processes related to the movement of water in soil profile is relevant to the management of soil and water resources. Hydraulic conductivity is an important soil property that affects this movement, but its determination in laboratory conditions requires that samples are contained in cylinders which can cause the presence of preferential flow through the soil wall interface. So, the goal of this work was to test the effect of increasing perimeter and height of the sample on saturated hydraulic conductivity in confined soil samples of different textures. Soil samples were collected and the following physical analyzes were performed: particle density, particle-size, water dispersed clay, soil porosity, and saturated hydraulic conductivity (Ko). Experimental data were analyzed in a randomized design for all variables, adopting a 4 x 5 factorial arrangement (four diameters x five heights of the cylinders), with six replications. The Shapiro- Wilk test was used to verify the normality of the data, F test for analysis of variance, and TukeyÂs test for comparison of means (p<0.05). Classical descriptive statistics and multivariate analysis techniques were also employed. It was conclude that: a) the results support the hypothesis that the increase of the perimeter causes an increase of the saturated hydraulic conductivity; b) for the same increase of preferential flow area, the effect on the saturated hydraulic conductivity was higher for clay soil; c) the hypothesis that increased water path causes a change in the Ko values was rejected; d) for both soil classes increased water path did not affect the values of the saturated hydraulicconductivity. / A compreensÃo dos processos relacionados ao movimento da Ãgua no perfil do solo à relevante para o manejo do solo e dos recursos hÃdricos. A condutividade hidrÃulica à um importante atributo do solo que interfere nesse movimento, sendo que sua determinaÃÃo na condiÃÃo de laboratÃrio requer que as amostras estejam confinadas em cilindros, o que pode causar a presenÃa de fluxo preferencial pela interface solo/parede do cilindro. Objetivou-se nesse trabalho testar o efeito do aumento do perÃmetro e da altura da amostra sobre a condutividade hidrÃulica do solo saturado em amostras confinadas de terra de diferentes texturas. Foram coletadas amostras de terra para realizaÃÃo das anÃlises fÃsicas, a saber: densidade de partÃculas, granulometria, argila dispersa em Ãgua, porosidade do solo e condutividade hidrÃulica do solo saturado (Ko). Os dados experimentais foram analisados em delineamento inteiramente casualizado para todas as variÃveis, adotandose o esquema fatorial 4 x 5 (quatro diÃmetros e cinco alturas dos cilindros), com seis repetiÃÃes. Foram aplicados os testes de Shapiro-Wilk para verificar a normalidade dos dados, o F para anÃlise de variÃncia e o de Tukey para a comparaÃÃo da mÃdias (todos a 5% de probabilidade). TambÃm foi empregada a estatÃstica descritiva clÃssica para algumas variÃveis e tÃcnicas multivariadas de anÃlises. Conclui-se que a) aceita-se a hipÃtese de que o aumento do perÃmetro da amostra provoca aumento nos valores de condutividade hidrÃulica do solo saturado; b) para o mesmo aumento de Ãrea de fluxo preferencial, o efeito sobre a condutividade hidrÃulica do solo saturado para o solo argiloso foi maior; c) a hipÃtese de que o aumento do percurso da Ãgua causa alteraÃÃo nos valores de Ko foi refutada; d) para ambas as classes de solos o aumento do percurso da Ãgua nÃo foi determinante nos valores obtidos para condutividade hidrÃulica do solo saturado.

Provas de carga dinâmicas em sete tubulões, de oito metros de comprimento e 0,60 m de diâmetro de fuste, sendo quatro com 1,5 m de base alargada, são apresentadas. Resistências mobilizadas determinadas pelo PDA e pela utilização de métodos que empregam medidas de repique elástico, em particular, os métodos de CHELLIS-VELLOSO e UTO et al. (1985) são comparadas. Várias seqüências de carregamento foram efetuadas, de modo a se ter uma ideia da influência de carregamentos sucessivos no comportamento dos tubulões. Constatou-se que o método de CHELLIS-VELLOSO apresentou resultados sofríveis em relação às resistências encontradas pelas análises CAPWAP, mas que melhoram à medida que sucessivos carregamentos são impostos aos tubulões, por causa do gradual comportamento de tubulões escavados em tubulões \"cravados\", pelo acúmulo de tensões residuais de cravação. Este fato pode ser corroborado pela aplicação do Princípio de Hamilton aos tubulões, fazendo crer que a realização de um ensaio de carregamento dinâmico em elementos de fundação moldados in loco necessita de uma suficiente penetração líquida deste elemento no terreno - da ordem do seu diâmetro, se este for de seção uniforme -, ou seja, sua transformação em um elemento de comportamento \"cravado\". Em alguns tubulões, provas de carga dinâmicas foram efetuadas com o solo em estado natural e inundado, a fim de se determinar a influência da colapsibilidade na resistência mobilizada, conforme o nível de energia aplicado. Verificou-se que em um tubulão submetido a uma inundação prévia do terreno por 48 h, as resistências mobilizadas foram inferiores às encontradas nos demais, para um mesmo nível de energia, muito provavelmente pela ação deletéria da água na colapsibilidade do solo em tela. / Dynamic Loading Tests (DLT) on seven caissons 8 m length and 0,60 m shaft diameter are presented, being four caissons with 1,5 m enlarged base diameter. Mobilized resistances determined both through PDA and rebound measurement methods as CHELLIS-VELLOSO and UTO et al. (1985) are compared. SeveraI successive loadings were performed in order to obtain assessment of the influence of the loading sequence in the caisson behavior. It was observed what CHELLIS-VELLOSO method showed very poor agreement with the obtained resistances through the CAPWAP analysis. Nevertheless, it was noted what the more the caissons are submitted to successive loadings, the closer are the results between CAPWAP analysis and CHELLIS-VELLOSO method, because the cast-in-place caisson is gradually switched to a driving caisson due to driving residual stress accumulations. To allow this to happen, it is necessary to have a net set value close to the shaft diameter in caisson without enlarged base. These facts were confirmed through the application Hamilton\'s Principle to tested caissons. In some caissons DLT were performed with natural and soaked soil conditions in order to know the collapsible influence in the mobilized resistances. lt was verified what 48 hours previous soaked soil resulted in lowest resistances than observed in the other caissons to the same energy level. This fact may justify the harmful action of the water in the reduction of resistance in collapsible soils.

A simple method has been developed to determine amino acid loading in solid phase peptide synthesis. The method is applicable for the most common type of synthesis, which use FMOC as protective group and piperidine as a deprotecting agent. Both products of deprotection reaction are separated by HPLC and determined using an UV detector; an internal standard is added. The method gives true values that have been verified by an independent method. The RSD is 1.52%. The method is more accurate than the published methods and allows the determination from the waste of synthesis. The employing of the internal standard eliminated the necessity of dilution accuracy or known volumes.

The aim of the research is to investigate the effect of increased axle loading on saturated and unsaturated railway foundation materials for heavy haul applications. The research methodology comprises of a literature review to identify the lacuna in the scientific knowledge, finite element modelling for characterisation of railway cyclic loading, development of a cyclic triaxial apparatus for laboratory testing and experimental work, followed by analysis, interpretation and discussion of results and lastly the formulation of conclusions and recommendations. The axle loading of interest start with a base load of 20 tonnes per axle for general freight followed by increased axle loading of 26, 30, 32.5 and 40 tonnes per axle for heavy haul. The test materials used in the experimental work are representative of the subballast and subgrade layers in a railway substructure. As a reproduction of the climatic conditions in the field and the loading from passing trains, experimental testing was carried out on saturated samples under undrained conditions and unsaturated samples under constant water content. Unsaturated samples were prepared to matric suctions of 50, 100 and 225 kPa via axis translation. Monotonic and cyclic tests were conducted to investigate the behaviour of railway foundation materials. Critical state theory for saturated and unsaturated soils is used as a method of analysis in establishing the failure criterion and the failure envelope. Various parameters, such as stress states, strains, resilient modulus, pore water pressure and matric suction are also utilised in investigating trends and behaviours. Based on the monotonic test results, the shear strength of unsaturated samples was found to be greater than that of saturated samples, attributed mainly to strain hardening caused by the unsaturated soil conditions, with the presence of a peak deviator stress when plotted on the stress-strain graph. However, unsaturated samples were also found to be prone to load-collapse during monotonic shear, even when the water content and confining stress remained constant, which resulted in brittle behaviour with the sudden rupture and formation of multiple bifurcation shear bands and slip planes. Based on the cyclic tests on saturated materials, it was discovered that increased axle loading can result in phase-transition in soil behaviour, based on the stress states in the soil relative to the critical state line plotted in the effective stress space. Stress states below the critical state line resulted in a no-phase transition with dilation behaviour. Stress states on the critical state line resulted in a single-phase transition from dilation to contraction. Stress states above the critical state line resulted in a double-phase transition from dilation to contraction behaviour and then strain-softening. It is therefore concluded that increased axle loading can only be sustained by materials which presented dilation and no phase-transition in soil behaviour, which occurred at axle loading of 20 and 26 tonnes per axle for the subballast and subgrade materials. Based on the cyclic tests on unsaturated materials, it was established that increased axle loading did not cause material failure for all load axle cases and materials. The stress states of all tests plotted well below the failure envelope in the net stress space, which is indicative of resilient and elastic behaviour. Increased axle loading instead resulted in decreased permanent strain, until the critical level of repeated deviator stress of 32.5 tonnes per axle was found, where the permanent strain increased. It is therefore concluded that, as a result of the increased shear strength from the strain hardening property of unsaturated materials, an increased axle loading of 32.5 tonnes per axle can be safely sustained by the tested materials provided the matric suction in the soil is greater than 50 kPa. / Thesis (PhD)--University of Pretoria, 2020. / Civil Engineering / PhD / Unrestricted