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Numerické modely pro posuzování stability zemního svahu / Numerical Patterns for Evaluation of the Stability SlopeEkr, Jan January 2012 (has links)
The master’s thesis deals with numerical patterns for evaluation of the stability slopes. Solutions have been made with finite element method for different design situations with using programme system ANSYS. The results were compared with conventional approaches determining of the slope safety factor.
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Odhad životnosti železobetonových mostů / Life-cycle analysis of reinforced concrete bridgesDoležel, Jiří January 2016 (has links)
With increasing age of the concrete road bridges, the highly topical question is to determine their reliability and load-bearing capacity level required for the residual life of the structure. Doctoral thesis presents a comprehensive methodology for assessing the reliability of reinforced and prestressed concrete bridges based on non-linear finite element method damage and failure virtual simulations at both deterministic and stochastic levels. Load-bearing capacity values are specified by the structure’s design load capacity estimation by global safety factor methods or they are based on a fully probabilistic load capacity analysis using the direct resistance estimation. For the fully probabilistic calculations, the simulation technique Latin Hypercube Sampling is used.
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[pt] ANÁLISE DE RUPTURA DE ENCOSTA E INTERAÇÃO COM ESTRUTURAS USANDO MÉTODO DO PONTO MATERIAL / [en] SLOPE RUPTURE AND INTERACTION WITH STRUCTURES ANALYSIS USING THE MATERIAL POINT METHODTHALITA COSTA DE MORAES 08 February 2021 (has links)
[pt] Essa pesquisa usa o Método do Ponto Material (MPM), para avaliar diferentes aspectos de deslizamentos de encosta. Esse tema é de suma importância, visto que os deslizamentos de terra são o desastre natural que mais causa perdas humanas no Brasil. Esse método numérico foi verificado a fim de que fosse encontrado o fator de segurança e a superfície de ruptura em um talude infinito com solo representado pelo modelo constitutivo de Drucker-Prager. Além disso, foi validado para calcular a força de impacto em um anteparo, sendo o volume impactante um objeto qualquer elástico ou um solo com modelo de Drucker-Prager. Os cálculos foram executados com o código desenvolvido pela PUC-Rio e produziram excelentes resultados. Foi observada uma grande dependência dos resultados com a malha, e assim como no Método dos Elementos Finitos, o refinamento da malha gera convergência para um resultado. O método foi considerado satisfatório para cálculo de uma parede de retenção em locais de risco. / [en] This research uses a numerical method, the Material Point Method, to evaluate different aspects of slope landslides. This theme is of paramount importance since landslides are the natural disaster that shows the highest number of deaths in Brazil. The method was verified so that it could find the safety factor and rupture surface in an infinite slope with soil represented by the Drucker-Prager constitutive model. In addition, the method was validated to calculate impact force in a bulkhead; the impacting volume could be any elastic object or soil with the Drucker-Prager model. The calculations were performed using the code developed by PUC-Rio and showed excellent results. It was observed high dependence on the mesh discretization, as well as the Finite Element Method, the refinement of the mesh generates convergence for a result. The method was considered satisfactory for calculating a retention wall at risk locations.
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[en] ANALYSIS OF THE DISPLACEMENT FIELD IN THE STABILITY OF HIGH-RISE MINING SLOPES / [pt] ANÁLISE DO CAMPO DE DESLOCAMENTOS PARA ESTABILIDADE DE TALUDES DE GRANDE ALTURA EM MINERAÇÃO / [es] ANÁLISIS DEL CAMPO DE DESLOCAMIENTOS PARA ESTABILIDAD DE TALUD DE GRANDE ALTURA EN MINERACIÓNHERNAN RENATO GAVILANES JIMENEZ 16 February 2001 (has links)
[pt] A avaliação da estabilidade do talude da Mina Robert
(Canadá) é feita através do campo de deslocamentos de
marcos superficiais e subsuperficiais e possíveis
mecanismos de ruptura obtidos a partir da análise tensão-
deformação usando-se o programa computacional FLAC (V.
3.30). Adotando-se o emprego dos modelos constitutivos
elástico perfeitamente plástico e elasto-plástico com
amolecimento, são calculados o fator de segurança e a
porcentagem da região de plastificação, e são definidas as
características de comportamento cinemático do talude sob
condições de carregamento gravitacional.
Apresenta-se um estudo de sensibilidade considerando-se
tensões cisalhantes e deslocamentos acumulados em função da
variação dos parâmetros do maciço rochoso e da inclinação
do talude, além de se analisar fatores associados à
definição dos mecanismos de ruptura em termos de tensão-
deformação.
Finalmente, são apresentadas as comparações entre os
fatores de segurança calculados em função dos resultados da
simulação numérica (FLAC) e os fatores de segurança
calculados por equilíbrio limite considerando-se as
superfícies potenciais de ruptura provenientes da modelagem
computacional. / [en] The evaluation of the stability of the Robert Pit Mine
(Canada) is made through the field of
displacements of superficial and ground marks and possible
rupture mechanisms obtained
from the results of tension-deformation analysis by using
the program computational FLAC
(V. 3.30). Two constitutive models, the elastic perfectly
plastic model and elastic-plastic with
strain softening model, are used for the determination of
safety's factor and plastification area.
This work also defines the characteristics of cinematic
behavior of the rock slope under
gravitat ional condit ions.
A sensibility study is realized considering shear stress
and displacements in function of the
variation of the rock parameters and of the inclination of
the slope. The analysis of the factors
associated to the definition of the rupture mechanisms in
tension-deformation terms is also
done.
Finally, the comparisons are presented among safety's
factors calculated in function of the
results of the numerical analysis (FLAC) and safety's
factors calculated by limit equilibrium
methods in function of the potential rupture surfaces of
the computational model. / [es] La evaluación de estabilidad del talud de la Mina Robert (Canadá) se realiza a través del campo de deslocamientos
de marcos superficiales y subsuperficiales y posibles mecanismos de ruptura obtenidos a partir del análisis
tensión-deformación utilizando el programa computacional FLAC (V. 3.30). Se adopta el empleo de los modelos
constitutivos elástico perfectamente plástico y elasto-plástico con ablandamiento. Se calculan el factor de
seguridad y el portentaje de la región de plastificación, y son definidas las características de comportamiento
cinemático del talud bajo condiciones de recarga gravitacional. Se presenta un estudio de sensibilidad
considerando las tensiones cisallantes y deslocamientos acumulados en función de la variación de los parámetros
del macizo rocoso y de la inclinación del talud, además de nalisa factores asociados a la definición de los
mecanismos de ruptura en términos de tensión - deformación. Finalmente, se presentan las comparaciones entre
los factores de seguridad calculados en función de los resultados de la simulación numérica (FLAC) y los factores
de seguridad calculados por equilibrio límite considerando las superfícies potenciales de ruptura provenientes del
modelo computacional.
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[en] DETERMINATION OF SAFETY FACTOR IN SLOPE STABILITY USING LIMIT ANALYSIS AND SECOND ORDER CONIC PROGRAMMING / [pt] DETERMINAÇÃO DO FATOR DE SEGURANÇA EM ESTABILIDADE DE TALUDES UTILIZANDO ANÁLISE LIMITE E PROGRAMAÇÃO CÔNICA DE SEGUNDA ORDEMLUIS FERNANDO CHAHUA CRUZ 21 November 2018 (has links)
[pt] O presente trabalho tem como principal objetivo mostrar a aplicabilidade prática da análise limite pelo método de elementos finitos na avaliação de problemas de estabilidade de talude, sendo este colocado como um problema de programação matemática, no qual se precisa realizar um processo de otimização
para a solução do problema. Apresenta-se um método para obter a solução do problema de estabilidade de taludes utilizando para isso a programação matemática, e fazendo ênfase na utilidade da programação cônica da segunda ordem (SOCP). Inicialmente faz uma revisão das formulações da análise limite, via o método de elementos finitos, encontradas na literatura existente. A seguir é descrita a formulação da análise limite numérica partindo do principio do trabalho virtual para sua formulação, e utilizando a ferramenta dos elementos finitos para realizar a implementação numérica. São propostas diferentes formas de trabalhar com o critério de resistência do material, sendo a de melhor desempenho, em termos de tempo de processamento a forma cônica quadrática que permite acoplar a programação cônica da segunda ordem (SOCP) na ferramenta numérica. É acoplada a técnica da redução dos parâmetros de resistência do material com a finalidade de encontrar o fator de segurança da estrutura do talude (FS). Finalmente são apresentados exemplos de validação e aplicação, os quais permitem visualizar a eficiência da ferramenta desenvolvida em termos de tempo de processamento ao utilizar a programação cônica da segunda ordem (SOCP). Os resultados sugerem viabilidade da utilização da técnica estudada na solução de problemas relacionada à estabilidade de taludes. / [en] The main objective of this work is to show the practical applicability of limit analysis by finite element method in the evaluation of slope stability problems, and this placed as a mathematical programming problem, which you need to perform an optimization process to solve the problem. We present a method to obtain the solution of the problem of slope stability using for this mathematical programming, and making emphasis on the usefulness of the second order conic programming (SOCP). Initially, a review of formulations Limit Analysis via Finite Element Method, found in the existing literature. Then is described the Numerical Limit Analysis formulation starting from virtual work principle their formulation, and using Finite Element Method as a tool to carry out the numerical implementation. We propose different ways of working with the yield criterion of the material, being the best performing in terms of processing time the conic quadratic form that allows to coupling to the second order conic programming (SOCP) in numerical implementation. It is coupled to the technique of reducing the strength parameters of the material in order to find the safety factor of the slope of the structure (FS). Finally, examples are presented for validation and application, which allow you to view the efficiency of the developed implementation in terms of processing time with the use of second order conic programming (SOCP). The results suggest the feasibility of using the technique studied in the solution of problems related to Slope Stability.
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Posouzení kyvných podpěr turbíny z hlediska vzniku MS deformační stability / Stability analysis of swinging props turbinesBukovský, Petr January 2012 (has links)
Master thesis deals with a computing simulation of two props turbines lines. The thesis output is gaining maximum possible load, at which a commencement of deformation stability critical state for various geometrical imperfections has not arisen yet. The calculation has been done by FEM in two different ways: linear solution (using a calculation conversion into eigenbuckling) and nonlinear solution (using a FEM deformation option). Result analysis compares both methods outcomes. Safety factor for the props operation has been proposed taking into consideration known influences on operating state.
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Grip, slip, petals, and pollinators : linking the biomechanics, behaviour and ecology of interactions between bees and plantsPattrick, Jonathan Gilson January 2018 (has links)
The ability to grip on petal surfaces is of crucial importance for the interactions between bees and flowers. In this thesis, I explore the biomechanics of attachment and morphological diversity of bee attachment devices, linking this to the behavioural ecology of bee interactions with flowers. Attachment devices come in two main kinds: claws or spines, and adhesive pads. Claw functioning is poorly described, particularly in terms of how their performance depends on body size, claw geometry, and surface roughness. Claw attachment performance was investigated using several insect species, each covering a large range of body masses. Weight-specific attachment forces decreased with body size, with claw sharpness seemingly playing a role. In bees there is considerable interspecific variation in tarsal claw morphology. This variation, and arolia presence/absence, was categorised for the large bee family Apidae. Cleft/bifid claws were shown to be present in the majority of the Apidae, often with differences between sexes and clades. Using Bombus terrestris, there was no evidence that cleft claws are important for pollen collection; however, I found that the inner tooth of cleft claws can act as a backup if the main tooth breaks. Although this may be one function of cleft claws, there are clearly other unresolved functions well worth further exploration. Investigations were undertaken to explore how petal surface roughness affects bee foraging behaviour. Lab-based foraging trials on B. terrestris visiting artificial flowers varying in slope, surface texture and sugar reward revealed a trade-off between the biomechanical difficulty of visiting and handling the ‘flowers’ and the quality of the reward offered. Flowers that were difficult to grip were often avoided even if they offered a higher reward. To further investigate reward preferences of bees, the effect of sucrose concentration on honey stomach offloading times was also explored. Although the majority of petals do have a rough surface, some have slippery petals. In the field, bumblebees avoided landing on slippery hollyhock petals in favour of the easy-to-grip staminal column. In contrast, honey bees, which are smaller and have larger adhesive pads, landed on both the staminal column and the petals. Slippery petals may be an adaptation to increase contact with plant reproductive structures. Grip is also important to allow the honey bee parasite Varroa destructor to climb on to their host. Attachment forces experiments found that V. destructor could support > 300 times their body mass on honey bees, giving them strong attachment even when bees attempt to remove them through grooming. A grooming-based device for treating V. destructor was tested in an apiary trial. The device was ineffective, providing valuable information for beekeepers considering using this product. In summary, this thesis improves our understanding of the biomechanics of attachment as well as identifying several important aspects of grip in bee-plant interactions.
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Avaliação de ferramenta de simulação da transmissão sonora para projetos de isolamento acústico em edificações habitacionaisSilva, Renata Costa da 19 July 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In July, 2013, Brazil s new standard, NBR15575:2013, began to require minimum
thermal, luminal, structural and acoustical performance levels in new constructions of
residential dwellings. Thus, computer programs that simulate the sound transmission
in buildings, can serve as important tools for professionals, enabling the verification of
virtual acoustic performance of projects, quickly and economically. By being widely used
in European countries, they have the database of existing elements and building systems
in Europe. From this, this study aimed to evaluate a computational tool of simulation of
sound transmission on the reality of Brazilian buildings. Twenty households were selected
in the city of Santa Maria - RS, to be measured in situ and then simulated to airborne and
impact noise. The residences were chosen according to standard and types of building
systems. For greater representation of Brazilian buildings, residences of low, medium
and high standards were chosen. The building systems chosen were structural masonry,
structural walls with concrete or ceramic block; and reinforced concrete, with walls of
hollow brick; all with massive concrete slab. The software used for the simulations was
the SONarchitect and all the features and building elements used were entered into the
software s database. The values of Ln,T , Dn,T , and RT per frequency band, and their
weighted values Ln,T,w, Dn,T,w and mean RT were obtained through measurements and
simulation. The weighted measured and simulated values were similar, on the other hand,
the values obtained by frequency band showed disagreement with the lower frequencies
precisely, from 50 Hz to 100 Hz. There was also a relationship of impact sound transmission
loss with the area size of the partition, in which there is a significant increase in sound
insulation in partitions with larger areas. In addition, coefficients and safety factors were
determined for each standard and building system to be applied in the spectra of the
simulations, aiming to bring the simulated values closer to the measured ones. Parallel
with the evaluation of the computational tool, questionnaires with 150 professionals who
develop acoustic projects in the country were applied. This step had as main objective
to find out what tools and methods are mostly used by professionals in the development
of these projects. From 31 received responses, it was determined that 20.88% of the
professionals use a computational tool to develop designs. It was also possible to discover
some features such as field of expertise and graduation year, which regions they are
located, what kind of projects they develop and if they have already developed projects
based on the new standard. / Com a entrada em vigor, em julho de 2013, da nova norma brasileira, NBR
15575:2013, passaram a ser exigidos nas novas construções de uso multifamiliar, níveis
mínimos de desempenho, tais como térmico, ilumínico, estrutural e acústico. Dessa
maneira, programas computacionais que simulam a transmissão sonora em edificações,
podem servir como ferramentas importantes aos profissionais, permitindo a verificação
do desempenho acústico virtual dos projetos, de forma rápida e econômica. Por serem
amplamente utilizados nos países europeus, possuem banco de dados dos elementos e
sistemas construtivos existentes na Europa. A partir disso, esse trabalho teve como
objetivo a avaliação de uma ferramenta computacional, de simulação da transmissão
sonora, para a realidade das construções brasileiras. Foram selecionadas 20 residências,
na cidade de Santa Maria - RS, para serem medidas in loco e depois simuladas, aos ruídos
aéreo e de impacto. As residências foram escolhidas, de acordo com padrão e sistemas
construtivos. Para maior representatividade das construções brasileiras, foram escolhidas
residências do padrão baixo, médio e alto. Os sistemas construtivos escolhidos foram
alvenaria estrutural, com paredes de bloco estrutural de concreto ou cerâmico; e concreto
armado, com paredes de tijolo vazado; todos com laje maciça de concreto. O programa
utilizado para as simulações foi o SONarchitect e todas as características, dos elementos
construtivos utilizados, foram inseridos no banco de dados do software. Foram obtidos
os valores de Ln,T , Dn,T,, e TR por banda de frequência, e seus valores ponderados de
Ln,T,w, Dn,T,w e TR médio, nas medições e simulações. Os valores ponderados medidos
e simulados foram similares, por outro lado os valores obtidos por banda de frequência
apresentaram divergência em relação às frequências mais baixas, precisamente de 50 Hz
a 100 Hz. Verificou-se também uma relação da perda de transmissão sonora ao ruído de
impacto com o tamanho da área da partição, na qual ocorre um aumento significativo no
isolamento sonoro em partições com áreas maiores. Além disso, foram determinados
coeficientes e fatores de segurança, para cada padrão e sistema construtivo, a serem
aplicados nos espectros das simulações. Com o objetivo de aproximar os valores simulados
dos valores medidos. Paralelamente à avaliação da ferramenta computacional, foram
aplicados questionários com 150 profissionais que desenvolvem projetos acústicos no país.
Essa etapa tinha como objetivo principal descobrir quais ferramentas e métodos são
mais utilizados pelos profissionais no desenvolvimento desses projetos. A partir de 31
questionários respondidos, foi possível determinar que 20,88% dos profissionais utilizam
alguma ferramenta computacional para desenvolver os projetos. Também foi possível
descobrir algumas características desses profissionais como curso e ano de formação, quais
as regiões que estão inseridos, que tipo de projetos desenvolvem e se já desenvolveram
projetos baseados na nova norma.
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Návrh zajištění hlubokého zářezu / The Design of Deep Cut SecuringŠtainerová, Lenka January 2015 (has links)
The aim is to design economical and above all safe securing a deep notch, both in the construction phase and throughout the use of the building. In the first part of the thesis Background research will be given an idea of the construction of the geotechnical point of view. The second part will contain the geotechnical design calculation. The third part will be proposed safety recommendations in terms of geotechnical monitoring.
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Pevnostní kontrola zařízení Vodní výklopník a optimalizace jeho konstrukčního řešení / Design optimisation and strenght checking of Water tiltable devicesMach, Jan January 2013 (has links)
This master’s thesis is about possibility of fruit and vegetable process from agricultural raw material to food. The first part of thesis include information about machinery, devices and process line and describe how this devices work. The second part solve water tiltable device, this part explain what water tiltable device do, how work and describe structure of each subassembly. Next step solve the device by kinematics aspect and aspect of load analysis. Calculation is included in annex one. Results of annex one are used for FEM (finite element method) simulation of frame. Output of FEM simulation can be used for finding safety factor of displacement and strain, output data are used for optimization of device.
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