Dissertations / Theses on the topic 'Steel ties'

Doctor of Philosophy
Civil Engineering
Robert J. Peterman
A study was conducted to determine the effect of different concrete properties and prestressing steel indentation types on development length and flexural capacity of pretensioned members. Wires and strands commonly used in the manufacturing of prestressed concrete railroad ties worldwide were selected for the study. Thirteen different 5.32-mm-diameter prestressing wire types and six different strands (four, seven-wire strands and two, three-wire strands) were used to cast prisms with a square cross section. The ratio of concrete to prestressed steel in the test prism’s cross section was representable of typical concrete railroad ties. Thus, geometrical and mechanical properties of test prisms were representative of actual ties in the railroad industry. To understand the effect of concrete-release strengths and slumps on development length, all parameters were kept constant in the prisms except concrete-release strength and slump. To manufacture prisms with different release strengths, all four wires/strands were pulled and detensioned gradually when the concrete compressive strength reached 3500 (24.13 MPa), 4500 (31.03 MPa), and 6000 (41.37 MPa) psi. To determine the effect of different slumps on development length, prisms with different slumps of 3 in. (7.6 cm), 6 in. (15.2 cm), and 9 in. (22.9 cm) were manufactured and all other parameters were kept constant in prisms. All prisms were tested in three-point bending at different spans to obtain estimations of development length based on type of reinforcement, concrete-release strength, and concrete slump. Lastly, a design equation was developed based on experimental data for prediction of development length. In the last phase of load tests, cyclic-loading tests were conducted on the prisms manufactured with wires to evaluate the bond performance of wires with different indentation types under cyclic loading. A total of 210 load tests, including 14 cyclic tests, were conducted. The monotonic-load tests revealed a large difference in the development length of pretensioned concrete members manufactured with different wire/strand types and different concrete-release strengths. Also, the cyclic-load tests revealed a significant difference in bond performance of different wire types under cyclic loading compared to monotonic loading.

Doctor of Philosophy
Department of Industrial & Manufacturing Systems Engineering
Chih-Hang John Wu
Quality is a result of product design and production control. Product design must maximize the ability to function across variations in production and environment. Production control must monitor and maintain the key design characteristics necessary for the intended function. Failure to do so results in premature part failure and increased costs. This has occurred in the production of modern cross ties. By designing quality into the product and production process, performance is maximized. This research presents a methodology for incorporating quality into the product design and production process. For product design, a relationship between product performance and design parameters is established by modeling techniques. These models provide a means to redesign the product to maximize performance and to understand the sensitivity of the design to fluctuation in production and environment. These models also establish the key design parameters that are critical for sustaining quality. For production, a method of monitoring the key design parameters is presented that provides an affordable means of automated inspection. Automated inspection removes operator error from the inspection process and allows for greater sampling rates to be achieved. The methodology presented allows for a potential of 100% inspection to be achieved with minimal impact to production costs. The research is applied to the analysis and quality control of pre-stressing steel reinforcement for concrete cross-ties. This application provides an opportunity to test and verify the research findings on a real world problem. Novel automated 3D spatial analysis algorithms are presented. This research furthers the state of the art of performing Geometrical Dimensioning and Tolerancing (GD&T). A cost effective method of non-contact surface profiling was developed with high resolution and high density surface profiles. The combined research findings present a methodology of achieving quality by design.

After the second world war, cavity walls became a widespread external wall type in the North Western Europe including the Netherlands. Cavity walls consist of two leaves separated by a hollow space (cavity). The leaves are commonly made by masonry bricks, blocks, and wall ties. Wall ties are used to connect the two leaves of a cavity wall and are installed during construction. The ties are meant to withstand wind pressure mostly. Recently in the north of the Netherlands induced earthquakes took place. As consequence, many cavity walls may fail due to the crisis of the ties subjected to seismic solicitations for which they were not designed. The present work investigate numerically the behaviour of cavity masonry wall systems with or without wall ties. The models were implemented taking into account the physical and geometric nonlinearities. Both nonlinear static and dynamic analyses have been performed by means of the �nite element software DIANA.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
Os Polímeros Reforçados com Fibras (PRF) são materiais compósitos constituídos por fibras unidas por uma matriz polimérica. São leves, não corrosivos, possuem alta resistência à tração e são de simples execução. O PRF em forma de tecido é utilizado para envolver o pilar de concreto armado promovendo a restrição das deformações laterais pelo efeito de membrana. Nos pilares com seção transversal circular, esse efeito de membrana é desenvolvido ao longo de todo o seu perímetro. Já para seções quadradas ou retangulares, esse efeito de membrana se desenvolve apenas nos cantos arredondados, reduzindo, assim, a eficiência do confinamento. Por conta dessa limitação, esta pesquisa propõe a utilização de um mecanismo auxiliar constituído por tirantes transversais de aço ancorados por perfis longitudinais, que juntamente com o PRF vão promover o confinamento nos maiores lados de seções de pilares retangulares. Foram realizados ensaios experimentais de dez pilares de concreto, cujos resultados confirmaram o maior incremento de força e ductilidade nos pilares devido à presença dos tirantes, verificando também que os perfis longitudinais contribuem diretamente com a força axial no pilar. Por meio da análise numérica em elementos finitos foi possível observar o acréscimo de regiões de concreto efetivamente confinado devido à presença dos tirantes. Com a análise paramétrica realizada foram identificados os parâmetros e como eles influenciam no comportamento dos pilares reforçados com a técnica: a relação entre os lados da seção transversal, a taxa de PRF; a taxa de tirantes de aço e a rigidez do perfil de ancoragem. Por fim, foi desenvolvido um modelo analítico que possibilita calcular a parcela de força resistida pelo concreto confinado e pelos perfis de ancoragem de modo independente, indicando boas correlações com os resultados experimentais e numéricos.
Fiber Reinforced Polymers (FRP) are composite materials consisting of fibers bonded by a polymer matrix. They are lightweight, non-corrosive, have high tensile strength and simple to apply. The FRP jacket is used to wrap the concrete column and restrict the lateral expansion by the membrane effect. In columns with circular cross section, the membrane effect is developed along its entire perimeter. However, in square or rectangular sections this effect is only developed at the rounded corners, resulting in a decrease of the confinement efficiency. Due this limitation, this research proposes the use of an auxiliary mechanism made up of transverse steel ties anchored by longitudinal bars, which together with the FRP, promote confinement on the biggest sides of rectangular sections of columns. Experimental tests were carried out on ten concrete columns, whose results confirmed the greatest force increase and ductility due to the presence of the steel ties and that the anchor bars contribute directly with the axial force. Through the numerical analysis in finite elements methods it was possible to observe the effective confined concrete regions due to the presence of the ties. With the parametric analysis performed some parameters were identified and how they influence in behavior of columns reinforced with this technique: the relationship between the sides of the cross section; the PRF rate; the steel ties rate and the stiffness of the anchor bar. Finally, an analytical model was developed allowing calculate the force resisted by the confined concrete and the anchor bars forces independently, indicating good correlations with the experimental and numerical results.
O arquivo contém 11 páginas em branco, mas que não interfere no conteúdo da tese.

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 93-96).
The primary contributions of this thesis include the first stages of development of a 2D, finite-volume, non-hydrostatic, [sigma]-coordinate code and beginning to apply the Dynamically Orthogonal field equations to study the sensitivity of internal tides to perturbations in the density field. First, we ensure that the 2D Finite Volume (2DFV) code that we use can accurately capture non-hydrostatic internal tides since these dynamics have not yet been carefully evaluated for accuracy in this framework. We find that, for low-aspect ratio topographies, the z-coordinate mesh in the 2DFV code produces numerical artifacts near the bathymetry. To ameliorate these stair-casing effects, and to develop the framework towards a moving mesh with free-surface dynamics, we have begun to implement a non-hydrostatic [sigma]-coordinate framework which significantly improves the representation of the internal tides for low-aspect ratio topographies. Finally we investigate the applicability of stochastic density perturbations in an internal tide field. We utilize the Dynamically Orthogonal field equations for this investigation because they achieve substantial model order reduction over ensemble Monte-Carlo methods.
by Sydney Glass Sroka.
S.M.

Extensive use of steel belted radial tires made it necessary to investigate the rubber-brass adhesion. Surface analysis techniques were used to give a better understanding of this bond, After about a decade of research, investigators have been successful in optimizing many of the parameters to obtain a bond of high strength. However there are still certain areas in which more work has to be done to make better quality tires. One such area is the effect of compound formulation on adhesion. Compound formulations still to a large extent are empirical. The purpose of this work is to give a scientific basis for formulating the rubber compound for best possible adhesion.
Master of Science

Thesis (Ph. D.)--Washington State University, August 2009.
Title from PDF title page (viewed on Aug. 4, 2009). "Department of Civil and Environmental Engineering." Includes bibliographical references (p. 110-111).

This study investigated the potential use of wide skidder tires for forest harvesting operations on steep slopes. During the summer of 1984, field tests were conducted to compare the performance characteristics of 24.5-32 and 66-43 rubber tires on a JD-640 grapple skidder loaded with tree length material. The skidder was operated on 20%, 25% and 30% slopes on Piedmont soils near Rome, Georgia.

Video recorders were used to document the field measurements and observations of machine travel time and wheel slip over defined courses. Soil compaction was evaluated by comparing soil cone penetrometer readings taken in the wheel tracks of the test lanes to those taken in undisturbed adjacent areas. Skidder lateral stability was analyzed using the mathematical model developed in this study.

Based on the results of statistical analyses of the data and field observations obtained under the test conditions, the skidder equipped with wide tires generally attained higher average speeds, tended to cause less wheel slip, resulted in smaller increases in soil cone penetrometer readings, and had significantly greater stability on sideslopes than the skidder equipped with the narrow tires. The stability model developed in this study predicted the critical sideways tipping angle for a JDâ 64O grapple skidder to be approximately 32° when fitted with the 24.5-32 tires, and 44° when fitted with the 66-43 tires.

Master of Science

The research conducted was sponsored by JVI of Pittsfield, Massachusetts. JVI has developed a steel embedded connection, referred to as a shooter. The shooter is provided in capacities, a 40 kip capacity shooter and a 50 kip capacity shooter. This steel connection is embedded near the end of a double-tee prestressed girder. Double-tee prestressed girders are a primary component used in the construction of parking garages. Typical double-tee lengths are 60 to 75 feet; however, for this research 20 ft long segments were cast and tested with the shooter installed.

This project had three main goals. The first goal was to develop a preliminary design for the reinforcement around the shooter and test the shootersâ capacity in the laboratory to determine if the stated capacity was correct. Four different designs were created, two designs for the 40 kip capacity shooter and 2 designs for the 50 kip capacity shooter. Each design was placed in one stem of the double-tee and tested at the laboratory. Results from these tests indicate that that each specimen achieved the stated capacity. However, failure was not a connection failure but a shear bond failure.

The second goal was to take the information gathered from testing and develop a design model that could be used for other situations for this type of connection. The design model was created according to the guidelines in the ACI 318-08 code. Two different methods were used, a strut-and-tie model and a modified ACI code approach. From these designs it was determined that the strut-and-tie model should be used for the design of these connections; however, more research needs to be done before using the modified ACI code approach.

The final goal was to determine if finite element analysis could be used to determine if the load at which large cracks that immediately proceed failure occur could be predicted. From this analysis it was determined that a load range could be predicted in which a crack could form as well as a range of what the transfer length of the strands could be.
Master of Science

Following some incidents in high-rise buildings, such as Ronan Point London 1968, in which collapse of a limited number of structural elements progressed to a failure disproportionate to the initial cause, consideration of robustness was introduced in British Standard. The main method of preventing progressive collapse for providing robustness to steel framed buildings with precast concrete floor slabs focuses on the allowable tying forces that the reinforcement in between the slabs and in hollowcores should carry. However there are uncertainties about the basis of the practical rules associated with this method. This thesis presents the results of numerical and analytical studies of tie connection behaviour between precast concrete floor slabs (PCFS). It is shown that under current design regulations the tie connection is not able to resist the accidental load limit applied on the damaged floor slabs. By establishing the capability of a finite element model to depict and predict the behaviour of concrete members in situations such as arching and catenary action against several experimental tests, an extensive set of parametric studies was conducted in order to identify the effective parameters in enhancing the resistance of the tie connection between PCFSs. These parameters include: tie bar diameter, position, length, yield stress and ultimate strain; the slab’s height, length; and the compressive strength of the grouting concrete in between the slabs that encases the tie bar. Recommendations are made based on the findings of this parametric study in order to increase the resistance of the tie connection. Based on the identified effective parameters in the parametric study a predictive analytical relationship is derived which is capable of determining the maximum vertical displacement and load that the tie connection is able to undergo. This relationship can be used to enable the connection to capture the accidental limit load on a damaged slab. The identified parameters are examined in a three dimensional finite element model to assess their effect when columns of the structure are lost in different locations such as an edge, corner or internal column. Based on the findings of this study methods for improving the connections performance are presented. Also the effect of alternative transverse tying method is evaluated and it is concluded that although this kind of tie increases the load carrying capacity of the connection, its effect on the catenary action is not significant.

COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
Com base na regressão numérica de séries históricas associadas à produção de quatro produtos destacados no ranking mundial de produção (cimento, aço, pneus e carroceria de ônibus), a presente pesquisa de mestrado avalia os impactos econômicos decorrentes do processo da certificação. Considerada instrumento econômico de mercado que permite diferenciar produtos e fornecer incentivos para consumidores e produtores, o processo de certificação é um mecanismo formal que assegura qualidade e conformidade do produto a especificações técnicas previamente estabelecidas, permitindo disponibilizar um certificado que efetivamente denota conformidade do produto e sua adequação ao uso, criando condições mercadológicas favoráveis para facilitar sua comercialização em mercados externos mais competitivos. Como contribuição do trabalho são também analisadas as interfaces da certificação com a metrologia, com a normalização e com a avaliação da conformidade, entendidas como funções complementares da tecnologia industrial, a serviço do desenvolvimento da competitividade e da melhoria contínua de serviços e produtos, da redução do desperdício, da agregação de maior eficácia técnica e econômica e da redução de barreiras técnicas ao comércio, assim preconizando a máxima um único ensaio, baseado numa única norma, documentada por um único certificado, de credibilidade e aceitação mundial. Tendo em vista a abundante evidência teórica que considera a certificação uma ferramenta de competitividade e de intercâmbio tecnológico no nível macroeconômico da produção, o estudo empírico conduzido, beneficiando-se de um método estatístico de regressão processado pelo clássico programa econométrico EViews, inclui a certificação como uma variável dummy no processo de regressão, permitindo a mensuração dos impactos econômicos desejados. Foi demonstrado que a certificação possui influência positiva na produção, permitindo-se assegurar, com um nível de significância de 0,05, ou seja, com uma probabilidade de 95 por cento, que o processo de certificação no Brasil impactou: (i) 41,6 por cento na produção de cimento (de 1970 a 2002, tendo a certificação sido implementada em junho/1994), (ii) 15,2 por cento na produção de aço (de 1980 a 2002, tendo a certificação sido implementada em janeiro/1997); (iii) 20,8 por cento na produção de pneus (de 1970 a 2002, tendo a certificação sido implementada em maio/1996); (iv) 31,4 por cento na produção de carrocerias de ônibus (de 1980 a 2002, tendo a certificação sido implementada em janeiro/1993); e assim ficando demonstrado o impacto da certificação avaliada pelo método estatístico de regressão, que também caracteriza o desempenho dos produtos investigados.
Based on a numerical regression of time series associated to the production of four products highly ranked in the production world market (steel, cement, bus shell and tires), the present Master research evaluates the economic impacts associated with the process of certification. Considered an effective economic instrument, useful to differentiate products and to provide incentives to consumers and producers, the certification process is a formal instrument that assures quality and conformity of the product to technical specifications previously established, making available a certificate that effectively denote conformity of the product and its adequacy to the use, creating favorable marketing conditions and facilitating its commercialization in more competitive external markets. As an indirect contribution, the thesis also analyze the interfaces of the certification with metrology, documentary standarization and with conformity assessment, understood as complementary functions of the basic industrial technology, serving the development of the competitiveness and the continuous improvement of services and products, the reduction of wastefulness, the aggregation of greater technical and economic effectiveness and of the reduction of technical barriers to trade, thus underpinning the well accepted principle a single test, based on a single documentary standard, documented in a single certificate, internationally accepted. In view of the abundant theoretical evidence that considers the certification a tool of competitiveness and technological interchange in the macroeconomic level of the production, the lead empirical study, benefiting itself of a statistical method of regression processed for the classic econometrical program EViews, it includes the certification as an variable dummy in the regression process, allowing the quantitative evaluation of the desired economic impacts. It was demonstrated that the certification possess positive influence in the production, allowing itself to assure with a level of significance of 0,05, that is, with a 95 percent probability, that the process of certification in Brazil has impacted: (i) 15.2 percent in the steel production (since 1980 to 2002, having the certification been implemented in January/1997); (ii) 20.8 percent in the production of tires (since 1970 to 2002, having the certification been implemented in May/1996); (iii) 31.4 percent in the production of bus shells (since 1980 to 2002, having the certification been implemented in January/1993); e (iv) 41.6 percent in the cement production (since 1970 to 2002, having the certification been implemented in June/1994), thus being demonstrated the impact of the certification evaluated by the regression method used, characterizing the performance of the investigated products.

Resumo: O bom comportamento das estruturas de concreto armado é assegurado pelo fenômeno da aderência existente entre o aço e o concreto, garantindo que os materiais trabalhem em conjunto formando, assim, um conjunto solidário. Esse trabalho apresenta os resultados dos ensaios de tração direta, segundo a ABNT/NBR 7477 e de arrancamento normalizado pela CEB RC6 e referido também na ASTM C-234, realizados com concreto convencional e com concreto contendo 10% de resíduo de borracha em substituição a areia, em volume, nas idades de 28 e 90 dias. As barras de aço utilizadas neste trabalho foram do tipo nervuradas e com os diâmetros variando entre 10, 12,5 e 16 mm. Com a introdução dos resíduos de borracha no concreto, foi avaliado o comportamento das mesmas em sua composição e a viabilidade da utilização estrutural desse tipo de concreto como material de construção, em substituição ao concreto convencional. Os resultados obtidos através dos ensaios de aderência confirmam ma viabilidade da utilização do resíduo de borracha em substituição ao agregado miúdo em concreto, segundo a composição adotada.
Abstract: The good behavior of the structures of concrete reinforced is assured by the phenomenon of the existing bond between the steel and the concrete, guaranteeing that the materials work in set forming, thus, a solidary set. This work presents the results of the assays of direct traction, according to ABNT/NBR 7477 and of pulling up normalized for CEB RC6 and also related in the ASTM C-234, carried through with conventional concrete and concrete I contend 10% of rubber residue in substitution the sand, volume, the ages of 28 and 90 days. The used bars of steel in this work had been of the type with rib and with the diameter varying between 10, 12,5 and 16 mm. With the introduction of the rubber residues in the concrete, it was evaluated the behavior of same in its composition and viability of the structural use of this type of concrete as material of construction, in substitution to the conventional concrete. The results gotten through the bond assays confirm me the viability of the use of the rubber residue in substitution to the small aggregate in concrete, following the adopted composition.
Orientador: Mônica Pinto Barbosa
Coorientador: Jorge Luis Akasaki
Banca: Vitor Antonio Ducatti
Banca: Haroldo de Mayo Bernardes
Mestre

The subject of master’s thesis is a structural analysis of a bearing structure of an existing historical single-track railway bridge over the Vltava river in a direction from Prague Modřany to Vrané nad Vltavou. The riveted steel bridge carries rail traffic across five fields. A part of the master’s thesis is focused on a disposal of a variant of the longest field by using a modern arch construction.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Araca Renovadora de Pneus
Cesp
Holcim do Brasil S.A
O bom comportamento das estruturas de concreto armado é assegurado pelo fenômeno da aderência existente entre o aço e o concreto, garantindo que os materiais trabalhem em conjunto formando, assim, um conjunto solidário. Esse trabalho apresenta os resultados dos ensaios de tração direta, segundo a ABNT/NBR 7477 e de arrancamento normalizado pela CEB RC6 e referido também na ASTM C-234, realizados com concreto convencional e com concreto contendo 10% de resíduo de borracha em substituição a areia, em volume, nas idades de 28 e 90 dias. As barras de aço utilizadas neste trabalho foram do tipo nervuradas e com os diâmetros variando entre 10, 12,5 e 16 mm. Com a introdução dos resíduos de borracha no concreto, foi avaliado o comportamento das mesmas em sua composição e a viabilidade da utilização estrutural desse tipo de concreto como material de construção, em substituição ao concreto convencional. Os resultados obtidos através dos ensaios de aderência confirmam ma viabilidade da utilização do resíduo de borracha em substituição ao agregado miúdo em concreto, segundo a composição adotada.
The good behavior of the structures of concrete reinforced is assured by the phenomenon of the existing bond between the steel and the concrete, guaranteeing that the materials work in set forming, thus, a solidary set. This work presents the results of the assays of direct traction, according to ABNT/NBR 7477 and of pulling up normalized for CEB RC6 and also related in the ASTM C-234, carried through with conventional concrete and concrete I contend 10% of rubber residue in substitution the sand, volume, the ages of 28 and 90 days. The used bars of steel in this work had been of the type with rib and with the diameter varying between 10, 12,5 and 16 mm. With the introduction of the rubber residues in the concrete, it was evaluated the behavior of same in its composition and viability of the structural use of this type of concrete as material of construction, in substitution to the conventional concrete. The results gotten through the bond assays confirm me the viability of the use of the rubber residue in substitution to the small aggregate in concrete, following the adopted composition.

Content diploma work, work is proposal and static review elements trojlodniho in-store object. Further is elaboration contract documents crimping with from technical news, layout drawing, production drawing and piece list materials.

The purpose of this dissertation is to take into consideration the design and the steel structure assessment of the hangar for small propeller aircraft type Cessna. The platform dimensions are 40,0 by 60,0 metres. Headroom is around 10,0 metres. The object’s location is in Brno. The main structural material is steel S355J2. There are two initial geometric alternatives, in other words structural modifications of desired solution. These are spatial truss arc tie beam and garland tie beam. The two alternatives were tentatively designed according to their dimensions and the main supporting elements of both alternatives were also assessed and considered. The alternatives were finally evaluated and one option was selected for detailed processing. In turn of the chosen option, there had been drawing of detailed analysis of the main load bearing parts of the construction with joints and some other details included. Furthermore there is drawing documentation and supervisor’s technical report attached. The valid standards CSN EN were used in processing of this dissertation.

Les structures en béton armé sont amenées à répondre à différentes exigences pouvant dépasser la simple résistance mécanique. Pendant le processus de fissuration, les contraintes dans le béton armé sont progressivement redistribuées entre l'acier et le béton via l'interface entre ces deux matériaux. Cette redistribution de contraintes a un impact direct sur l'état de fissuration final et doit donc être prise en compte dans la modélisation. Il existe différents modèles numériques capables de représenter les effets de la liaison acier-béton. Cependant, leur usage est, pour l'instant, incompatible avec les applications concernant les structures de grandes dimensions (difficultés de maillage, coût de calcul...). Dans ce cadre d'application, l'hypothèse de liaison parfaite entre l'acier et le béton (déplacement identique) est donc toujours utilisée. On se propose ici de développer un nouveau modèle éléments finis de liaison acier-béton qui soit à la fois représentatif des phénomènes physiques se produisant à l'interface entre les deux matériaux et compatible avec les contraintes de modélisation des structures de grandes dimensions. Ce travail de thèse se découpe en trois grandes parties : - le développement d'un modèle élément fini de liaison acier-béton adapté aux contraintes de modélisation des structures de grandes dimensions. Ce modèle numérique permet ainsi de tenir compte des interactions mécaniques entre le béton et les armatures d'acier représentées à l'aide d'éléments barres. - la caractérisation du comportement de la liaison acier-béton. Un modèle de loi d'adhérence (évolution de la contrainte d'adhérence en fonction du glissement) basé sur des observations expérimentales (campagne expérimentale de pull-out menée au cours de la thèse et données bibliographiques) est proposé. Il permet en particulier de différencier le cas d'une rupture par arrachement, d'une rupture par éclatement en tenant compte des caractéristiques matériaux et géométriques de la structure. - l'application du modèle proposé à un élément structurel (poutre). Un essai de poutre en flexion quatre points visant à caractériser l'évolution de la fissuration (évolution de l'ouverture de fissure mesurée à l'aide de la technique de corrélation d'images notamment) a ainsi été proposé. Ces résultats ont ensuite été comparés à ceux de simulations numériques tenant compte de la liaison acier-béton d'une part ou de l'hypothèse de liaison parfaite d'autre part. Les deux modélisations donnent une bonne approximation du comportement extérieur de la structure (comportement global et ouvertures de fissure des surfaces extérieures de la poutre). Le modèle de liaison acier-béton apporte cependant une meilleure caractérisation de la phase de fissuration active (apparition des fissures) et modifie plus particulièrement le comportement local de la structure à proximité directe des armatures (limitant le développement de l'endommagement du béton le long des renforts).

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
This work presents an evaluation of the structural behavior of steel plane frames infilled with structural masonry of blocks of autoclaved aerated concrete, regarding the contribution of the masonry to the structure global stiffening, through the strut-and-tie model. Case studies were evaluated taking into account three steel plane frames and, subsequently, the model was applied to the project of steel buildings with four, six, and eight stories. First and second-order numerical analyses (nonlinear geometrical analysis) were performed to braced steel frames with bracing elements formed for bars of steel and masonry panels. The masonry panels were considered across strut-and-tie model. It is presented comparisons of the lateral displacements and the solicitant forces in the bars of strut-and-tie model to first and second-order analyses. The solicitant forces on the strut and tie were also compared to the structural resistance on these bars aiming to achieve the structural dimension of the masonry panel. Through the results obtained it is concluded that it is possible to substitute the bracing metal bars for the masonry panels until determined numbers of stories. This numbers depends on factors such as the stiffness of the frame and masonry panels, and the intensity applied.
Neste trabalho apresenta-se uma avaliação do comportamento estrutural de pórticos planos de aço preenchidos com alvenaria estrutural de blocos de concreto celular autoclavado, considerando a contribuição da alvenaria na rigidez global da estrutura, por meio de um modelo de bielas e tirantes. Para realização dos estudos de caso, foram avaliados três pórticos planos de aço e, posteriormente, o modelo foi aplicado ao projeto de edifícios de aço com quatro, seis e oito pavimentos. Foram realizadas análises numéricas de primeira e segunda ordem (análise não-linear geométrica) de pórticos de aço contraventados com elementos de contraventamentos formados por barras de aço e por painéis de alvenaria. Os painéis de alvenaria foram considerados por meio do modelo de bielas e tirantes. São apresentadas comparações dos deslocamentos laterais e dos esforços solicitantes nas barras do modelo de bielas e tirantes para as análises de primeira e de segunda ordem. Os esforços solicitantes nas bielas e nos tirantes também foram comparados com os esforços resistentes nessas barras, com vistas a efetuar o dimensionamento estrutural do painel de alvenaria. Os resultados obtidos permitem concluir que é possível substituir as barras de contraventamento metálico por painéis de alvenaria até um determinado número de pavimentos. Este número depende de fatores como a rigidez dos pórticos e dos painéis de alvenaria e a intensidade das ações aplicadas.

Main concern of the thesis is a structural design of main load bearing elements of steel, four-storey high administration building. Designed building has 36 m long and 24 m wide rectangular footprint. Roof is shaped into a hyperbolic paraboloid surface. Main load bearing structure is consisting of six main cross sections formed by truss columns, and generally curved roof truss beams, accompanied by storey supporting frames with composite slabs. Overall shape of the roof is defined by warped surface. Cladding of the building is consisting of aluminium facade system.

The diploma thesis deals with design and assessment of steel arched bridge with the semi through bridge deck placed on the third-class road. This steel structure is drawn up to bridge water barrier – the river Olše in Návsí. The distance between axes lay on abutments is 48,5 meters. The bridge´s supporting structure consists of two steel arches angled towards each other and fastened to the foundation blocks. The supporting beam of the bridge deck is tied to the arch by tie-rods. The tie-rods are designed to the V-shaped system.

El objetivo de esta investigación es proponer recuperar y usar el acero que es parte de un neumático, el cual se encuentra en desuso, como una alternativa para poder incrementar la resistencia de la losa de concreto frente a los esfuerzos de flexo tracción, y así poder mitigar la formación de grietas producto de la acción de cargas externas, específicamente en el diseño y construcción de pavimentos. Con esta finalidad, se procedió a realizar un estudio del comportamiento mecánico del concreto reforzado con fibras de acero, las que fueron obtenidas previamente del reciclado de neumáticos usados, las que a su vez fueron obtenidas de reencauchadoras provenientes de distintas partes de la ciudad de Lima. Se prepararon una serie de muestras cilíndricas y prismáticas, estas posteriormente fueron curadas mediante inundación en una poza durante periodos de 3 días, 14 días y 28 días. Con la finalidad de poder evaluar la evolución de las resistencias del concreto con el tiempo, los especímenes fueron analizados en distintas edades, estas fueron específicamente 3, 7 y 28 días. Los resultados obtenidos muestran que las fibras de acero tuvieron un efecto directo en el módulo de rotura a la flexo tracción, lográndose incrementos promedios de hasta el 48.1%, el cual contiene acero en longitudes de 45mm (fibras) cuyo peso que equivale al 3%, brindando un aporte estructural a losas de concreto hidráulico Finalmente, se determinó que es posible obtener losas con resistencias a la flexo tracción equivalentes a losas de espesores menores usando este acero en desuso en el concreto.
In this work, the use of steel fibers obtained from recycled tires has been proposed, as an alternative to increase the resistance of the concrete slab against flexo tracción efforts, and thus be able to mitigate the formation of cracks caused by the action of external loads, specifically in the design and construction of pavements. To this end, a study of the mechanical behavior of steel fiber reinforced concrete was carried out, which were previously obtained from the recycling of used tires, which in turn were obtained from retreads from different parts of the city of Lima. A series of cylindrical and prismatic specimens (concrete beams) were prepared, which were subsequently cured by flooding in a pool for periods of 3 days, 14 days and 28 days. In order to be able to evaluate the evolution of concrete resistances over time, the specimens were analyzed at different ages, these were specifically 3, 7 and 28 days. The results obtained show that the steel fibers had a direct effect on the flexo tracción modulus of rupture, achieving average increases of up to 48%, with a dosage of 3% of steel fibers by weight. providing a structural contribution to hydraulic concrete slabs. Finally, it was found that it is possible to obtain slabs with tensile bending strengths equivalent to slabs of smaller thicknesses, by applying steel fibers from recycled tires.
Tesis

Le comportement des structures en béton armé peut s’avérer extrêmement complexe en cas de dépassement de la limite de fissuration du béton. Le caractère composite du béton armé doit être représenté finement. Pour la simulation des structures industrielles, les modèles numériques employés supposent une relation parfaite entre le béton et les armatures qui non seulement ne prennent pas en compte la complexité de la relation entre les deux matériaux mais aussi ne permet pas de présenter finement les caractéristiques de la fissuration étant directement liée à celle des aciers. Dans la littérature, plusieurs méthodes numériques sont proposées pour étudier finement les caractéristiques de la liaison acier-béton, mais toutes ces méthodes posent des difficultés pour les calculs de structures complexes en 3D. En partant des résultats obtenus dans le cadre de la thèse de Torre-Casanova (2012), une nouvelle formation d’un modèle de liaison acier-béton a été développée pour améliorer les performances et la représentativité (comportement cyclique). Ce nouveau modèle a été validé sur un tirant par comparaison avec une solution analytique et des résultats expérimentaux et également testé à l’échelle structurelle pour simuler le comportement d’un voile en cisaillement. Compte tenu de la difficulté pour caractériser numériquement l’ouverture de fissure en cas de fissuration complexe, une nouvelle méthode de post-traitement a également été développée. Finalement, le développement du comportement cyclique de la loi d’adhérence avec enveloppe non-réduite est intégré dans le modèle de liaison acier-béton pour prendre en compte l’irréversibilité du glissement et le boucle d’hystérésis lors du chargement en charge-décharge ou du chargement cyclique. L’application sur un tirant et sur un voile en cisaillement est également effectuée afin d’investiguer le comportement global et local
Reinforced concrete structure behavior can be extremely complex in the case of exceeding the cracking threshold. The composite characteristics of reinforced concrete structure should be finely presented. In order to compute the industrial structures, a perfect relation hypothesis between steel and concrete is supposed in which not only the complex phenomenon of the two-material relation is not taken into account, but it is also unable to predict the crack characteristics, which is directly linked to the steel. In literature, several numerical methods are proposed in order to finely study the concrete-steel bond behavior, but these methods give many difficulties in computing complex structures in 3D. With the results obtained in the thesis framework of Torre-Casanova (2012), the new concrete-steel bond model has been developed to improve performances (iteration numbers and computational time) and the representation (cyclic behavior) of the initial one. The new model has been verified with analytical solution of steel-concrete tie and validated with the experimental results and equally tested with the structural scale to compute the shear wall behavior. Because of the numerical difficulty in post-processing the crack opening in the complex crack formation, a new crack opening method is also developed. Finally, the cyclic behavior of the bond law with the non-reduced envelope is adopted and integrated in the new bond model in order to take into account the slip irreversibility and the hysteresis during the cyclic load. The application of the model is carried out on a steel-concrete tie and a shear-wall

Este trabalho descreve um dormente monobloco de concreto protendido, o qual foi projetado para atender as características de uma via ferroviária brasileira. O dormente apresentou comportamento e resistência semelhantes aos dormentes de concreto comumente fabricados em vários países. A fim de verificar e aprovar o projeto, o dormente foi submetido a ensaios estáticos e dinâmicos, segundo as especificações da norma americana AREMA. Verificado e aprovado o projeto, dezoito dormentes foram fabricados sem e com fibras de aço, no teor de 60 kg/'M POT.3' (aproximadamente 0,75 % por volume). Ensaios estáticos e dinâmicos foram realizados em dormentes com e sem fibras de aço, com o objetivo de quantificar o benefício das fibras de aço à resistência estrutural do dormente. As fibras aumentaram o momento fletor de primeira fissura e o momento último, aumentaram significativamente a força de início de escorregamento dos fios de protensão e reduziram o espaçamento e a abertura das fissuras. As fibras também acrescentaram grande ductilidade aos dormentes e diminuíram a tensão nos fios de protensão, nos estágios mais avançados do carregamento. Sob ação dinâmica, as fibras reduziram a tensão nos fios de protensão mais tracionados em aproximadamente 100%, o que elevou significativamente a resistência do dormente à fadiga. Dormentes fabricados com menor força de protensão apresentaram excelente comportamento plástico e grande ductilidade, especialmente o dormente com fibras
This work describes a prestressed concrete monoblock railway sleeper designed according to a brazilian railway track. The sleeper was tested according to the Arema specifications in order to verify the project. The sleeper presented a structural behavior similar to the concrete railway sleepers used worldwide. After the preliminary tests, eighteen sleepers were manufactured without and with steel fibers contents of 60 Kg/'M POT.3' (about 0.75% by volume) and they were tested under static and dynamic loading to evaluate the fiber contribution on the resistance. Steel fibers increased the first crack and ultimate bending moments, reduced the deflection under ultimate load and increased significantly the slip force of the prestressing tendons. Reinforcing the sleeper with fibers also reduced the crack width and the spacing between cracks, adding higher ductility to the sleepers and decreasing the stress in the prestressing tendons under higher loads. The fibers increased significantly the fatigue strength under cyclic loading, decreasing the stress in the prestressing tendons in about 100%. The test results showed that sleepers manufactured with lower prestressed force have higher toughness, especially those reinforced with steel fibers

Diploma thesis develops comprehensive documentation of the new building construction of residential house on the level of the implementation of the project construction. Proposal emphasizes layout of linked to ensure the technical design, structural, fire safety, protection against noise, energy saving, safety in use. Work is performed in an electronic format using AutoCAD and Microsoft Word (PDF Creator).

碩士
國立臺灣科技大學
營建工程系
105
Previous short column tests show that the so-called combined tie is able to provide noticeable confinement to the outskirt concrete. in this study, encased concrete-filled steel box column specimens are tested under prescribed cyclic loading to investigate the effectiveness of the combined tie on the ductility of the encased concrete-filled box columns. Width-to-thickness ratio is the main parameter in this study, base on the test results, the ratio is proposed to be smaller than 37: 　　Elastic analysis results shows that: (1) In the elastic region, the stiffness of the combined ties is related to the width-to-thickness ratio. 　　Experimental results shows that: (1) Combined tie is effective to be used in the design.(2) In providing confinement to concrete, the combined tie has a similar function to the tie used in the reference specimen. (3) In this experiment, the ductility of concrete-filled steel box columns is not significantly affected by the width-to-thickness ratio. (4) For a conservative design, the diameter of supplementary longitudinal reinforcement must not be smaller than 1/6 times the hoop spacing.

碩士
國立臺灣科技大學
營建工程系
100
In this study, a total of nine large scale concrete-filled box column (CFBC) specimens were tested under cyclic loading to study their seismic behavior. Among the nine specimens, six of them were facilitated with tie rods to enhance the ductility of the columns. The influence of high axial load to the flexural strength and ductility was studied. ASTM A572 Gr. 50 steel and concrete with specified compressive strength of 420 kgf/cm2 were used to fabricate the specimens. Test results showed that the width-to-thickness ratio requirement in the building code may result in insufficient ductility of CFBC columns when axial load applied to the column reaches 40% of the nominal axial strength of the column. Use of properly arranged tie rods is proved to be able to enhance moment capacity, plastic hinge rotation capacity, ductility, and energy dissipation of the CFBCs. A design method of tie rods to provide sufficient confining effect to the CFBC in plastic hinge zone was proposed.

碩士
國立中山大學
材料科學研究所
92
IF Steel to be used in this thesis which only have 50ppm carbon is approach Iron. It to be part of BCC. Because BCC material have much slip system when increase the cycle will induce to create multiple slip system. The dislocation structure often to become cell. We observation the same result of SEM and TEM in low cycle fatigue. The cell size is small in high plastic strain amplitude. The cell size is big in low strain amplitude. The difference of dislocation structures in front of crack tip which obtained under propagation rates o f 10-4, 10-5, 10-6 and 10-7 mm/cycle is the volume percentage occupied by the dislocation structures viz. misorientation cell, cell, wall, PSBs.

Global catastrophes such as the COVID-19 crisis raise individual and collective anxiety among faith communities. Fears about the well-being of loved ones, grief over the hiatus of corporate worship services, and uncertainty about the sustainability of local churches loom large. A significant challenge surrounding preaching during a pandemic is the need to speak a word to and for this anxiety. But psychotherapists know an important thing about anxiety: it contains no information. It is no more than “a noisy gong or a clanging cymbal,” to use St Paul’s words. To reassure it away from the pulpit is tantamount to colluding with it. What if instead of attempting to soothe away anxiety in troubling times like these, the preacher and the congregation collide head-on with the feeling that resides on the other side of the anxiety? What comes into view then? This paper will bring the central tenets of dynamic psychotherapy to bear on the task of preaching amidst global catastrophe. By relying on how therapists move past anxiety to directly address the deep feelings of patients, we raise ideas for preaching sermons that go past anxiety, fear, and helplessness and steer into the storm of emotions stirring among the faith community.

碩士
國立中山大學
材料科學研究所
94
In this thesis, we use IF Steel to be the matrix which composition of carbon is 50ppm approaches Iron and belongs to the part of BCC structure. After we use the load 350kgf precrack, while the propagation rate approaching 2x10-5~3x10-5mm/cycle, we immediately drop the stress intensity factor(Δk) to a level which is determined by the propagation rate of 9x10-7mm/cycle. Then we record the cycle number as P1, and after the crack tip continues to propagate, we record the cycle number again as P2, and between the period of (P2 – P1), we take 4 sample which marks are 0.25(P2 –P1), 0.5(P2 –P1), 0.75(P2 –P1), (P2 –P1). By this way, we can find out the difference of microstructure of the crack tip from a high load level to a low one. On this experiment, we observation the vein structure, dislocation walls, and so on. It proves that the same phenomenon could also be happened on BCC material, just like FCC material. As time goes by, after drop load, the stored energy is more and more strong. And the vein structure of reverse evolution would become the structure of dislocation cells of normal evolution. Then the crack would continue to propagate on the circumstances.

碩士
國立中央大學
土木工程研究所
94
According to ACI318-02, the behavior of deep beam is defined as the ratio of shear span to effective depth a/d 2.5. Strut-and-tie model analytical method can be adopted to the shear strength evaluation of the deep beams. The main purpose of the research is to see the validity of strut-and-tie model applied to analysis of rectangular and T-sectional beams. The comparison of analytical results between rectangular and T-section beams are discussed. Experimental works were made on testing five rectangle and five T-sectional RC beams, where no stirrup was used. Specimens were controlled by different shear span ratio, a/d. From the experimental result, the proposed strut-and-tie model for analyzing T-sectional and rectangle beams is fairly accurate. The largest difference in analyzing is that T-sectional beams have offered more discrepancy such as flange parts. However, the proposed model is more rational than previous researchers adopted using different softened strut-concrete behaviors.

碩士
國立臺灣科技大學
營建工程系
100
ABSTRACT The development of High Strength Concrete (HSC) and High Strength Steel (HSS) facilitate the realization of high-rise building especially in seismic region to resist earthquake excitation. Innovative multi-spiral shear reinforcement which is designed for square cross section column offers technical and cost advantages comparing to conventional tied column stirrup. This research has objective to recognize the shear behavior of two types of stirrups with high strength steel and concrete under low axial load. The square hoops columns and multi-spiral columns are tested under 20% and 10% axial load ratio, respectively. Concrete compressive strength (70 MPa and 100 MPa) and spacing of the transverse reinforcement are two parameters that will be examined. Longitudinal and transversal reinforcements with specified yield strengths of 685 MPa and 785 MPa, respectively, are considered. Critical crack angle; shear strain and curvature; stress of transverse reinforcement; effect of axial compression load of six large-scale columns will be explained. Test results show that the maximum strength of columns appears before the yielding of stirrups. Thus, stress at transverse reinforcement that can be predicted from drift ratio and stress at hoops relationship derived from test result becomes important as the limitation for design calculation. Moreover, smaller critical crack angle, stiffer column and higher lateral strength will be occurred from higher axial load application. Current codes provisions in shear strength provide the conservative estimation as 45 degrees of crack angle applied. On the other hand, models proposed by researchers overestimate the measured strength.

碩士
國立臺灣大學
機械工程學研究所
100
In this study, the effect of different quenching cooling rates and tempering holding times on the mechanical properties of hot work tool steels was investigated. SKD61 and its modified steels were used as experimental materials. Quenching temperature and holding time are fixed at 1030℃ and 1hr, respectively. There are two kinds of cooling rate during quenching. After quenching, specimens were dipped in a 590℃ salt bath for tempering, with four different holding times of 0.5, 3, 6 and10 hours. All specimens were tempered twice. Then the hardness and impact toughness of these specimens were measured. In addition, the microstructure and chemical compositions were examined using OM, SEM and EPMA, and the relationships between different heat treatment parameters and mechanical properties were revealed. As results, the specimens which were cooled faster during quenching have higher hardness and impact toughness mostly, and the specimens which contained more carbon, chromium and manganese possess higher hardness value. We found out that there are three main factors affecting the impact toughness value: (1) Impact toughness increases due to the decrease of hardness. (2) Impact toughness decreases because of the precipitation of carbides on the grain boundaries, when the tempering holding time gets longer or the quenching rate becomes slower. (3) the influence of alloy element on the toughness during tempering. The effect of the three factors will vary with the tempering holding time.

Modern manufacturing systems need new types of scheduling methods. While traditional scheduling methods are primarily concerned with sequencing of jobs, modern manufacturing environments provide the additional possibility to process jobs in batches. This adds to the complexity of scheduling. There are two types of batching namely: (i) serial batching (jobs may be batched if they share the same setup on a machine and one job is processed at a time. The machine which processes jobs in this manner is called as discrete processor) and (ii) parallel batching (several jobs can be processed simultaneously on a machine at a time. The machine which processes jobs in this manner is called as batch processor or batch processing machine). Parallel batching environments have attracted wide attention of the researchers working in the field of scheduling. Particularly, taking inspiration from studies of scheduling batch processors in semiconductor manufacturing [Mathirajan and Sivakumar (2006b) and Venkataramana (2006)] and in steel casting industries [Krishnaswamy et al. (1998), Shekar (1998) and Mathirajan (2002)] in the Management Studies Department of Indian Institute of Science, this thesis addresses a special problem on scheduling batch processor, observed in the steel casting manufacturing. A fundamental feature of the steel casting industry is its extreme flexibility, enabling castings to be produced with almost unlimited freedom in design over an extremely wide range of sizes, quantities and materials suited to practically every environment and application. Furthermore, the steel casting industry is capital intensive and highly competitive. From the viewpoint of throughput and utilization of the important and costly resources in the foundry manufacturing, it was felt that the process-controlled furnace operations for the melting and pouring operations as well as the heat-treatment furnace operations are critical for meeting the overall production schedules. The two furnace operations are batch processes that have distinctive constraints on job-mixes in addition to the usual capacity and technical constraints associated with any industrial processes. The benefits of effective scheduling of these batch processes include higher machine utilization, lower work-in-process (WIP) inventory, shorter cycle time and greater customer satisfaction [Pinedo (1995)]. Very few studies address the production planning and scheduling models for a steel foundry, considering the melting furnace of the pre-casting stage as the core foundry operation [Voorhis et al. (2001), Krishnaswamy et al. (1998) and Shekar (1998)]. Even though the melting and pouring operations may be considered as the core of foundry operations and their scheduling is of central importance, the scheduling of heat-treatment furnaces is also of considerable importance. This is because the processing time required at the heat treatment furnace is often longer compared to other operations in the steel-casting foundry and therefore considerably affects the scheduling, overall flow time and WIP inventory. Further, the heat-treatment operation is critical because it determines the final properties that enable components to perform under demanding service conditions such as large mechanical load, high temperature and anti-corrosive processing. It is also important to note that the heat-treatment operation is the only predominantly long process in the entire steel casting manufacturing process, taking up a large part of total processing time (taking up to a few days as against other processes that typically take only a few hours). Because of these, the heat-treatment operation is a major bottleneck operation in the entire steel casting process. The jobs in the WIP inventory in front of heat-treatment furnace vary widely in sizes (few grams to a ton) and dimensions (from 10 mm to 2000 mm). Furthermore, castings are primarily classified into a number of job families based on the alloy type, such as low alloy castings and high alloy castings. These job families are incompatible as the temperature requirement for low alloy and high alloy vary for similar type of heat-treatment operation required. These job families are further classified into various sub-families based on the type of heat treatment operations they undergo. These sub-families are also incompatible as each of these sub-families requires a different combination of heat-treatment operation. The widely varying job sizes, job dimensions and multiple incompatible job family characteristic introduce a high degree of complexity into scheduling heat-treatment furnace. Scheduling of heat-treatment furnace with multiple incompatible job families can have profound effect on the overall production rate as the processing time at heat-treatment operation is very much longer. Considering the complexity of the process and time consumed by the heat treatment operation, it is imperative that efficient scheduling of this operation is required in order to maximize throughput and to enhance productivity of the entire steel casting manufacturing process. This is of importance to the firm. The concerns of the management in increasing the throughput of the bottleneck machine, thereby increasing productivity, motivated us to adopt the scheduling objective of makespan. In a recent observation of heat-treatment operations in a couple of steel casting industries and the research studies reported in the literature, we noticed that the real-life problem of dynamic scheduling of heat-treatment furnace with multiple incompatible job families, non-identical job sizes, non-identical job dimensions, non-agreeable release times and due dates to maximize the throughput, higher utilization and minimize the work-in-process inventory is not at all addressed. However, there are very few studies [Mathirajan et al. (2001, 2002, 2004a, 2007)] which have addressed the problem of scheduling of heat-treatment furnace with incompatible job families and non-identical job sizes to maximize the utilization of the furnace. Due to the difference between the real-life situation on dynamic scheduling of heat-treatment furnace of the steel casting manufacturing and the research reported on the same problem, we identified three new class of batch processor problems, which are applicable to a real-life situation based on the type of heat-treatment operation(s) being carried out and the type of steel casting industry (small, medium and large scale steel casting industry) and this thesis addresses these new class of research problems on scheduling of batch processor. The first part of the thesis addresses our new Research Problem (called Research Problem 1) of minimizing makespan (Cmax) on a batch processor (BP) with single job family (SJF), non-identical job sizes (NIJS), and non-identical job dimensions (NIJD). This problem is of interest to small scale steel casting industries performing only one type of heat treatment operation such as surface hardening. Generally, there would be only a few steel casting industries which offer such type of special heat-treatment operation and thus the customer is willing to accept delay in the completion of his orders. So, the due date issues are not important for these types of industries. We formulate the problem as Mixed Integer Linear Programming (MILP) model and validate the proposed MILP model through a numerical example. In order to understand the computational intractability issue, we carry out a small computational experiment. The results of this experiment indicate that the computational time required, as a function of problem size, for solving the MILP model is non-deterministic and non-polynomial. Due to the computational intractability of the proposed MILP model, we propose five variants of a greedy heuristic algorithm and a genetic algorithm for addressing the Research Problem 1. We carry out computational experiments to obtain the performance of heuristic algorithms based on two perspectives: (i) comparison with optimal solution on small scale instances and (ii) comparison with lower bound for large scale instances. We choose five important problem parameters for the computational experiment and propose a suitable experimental design to generate pseudo problem instances. As there is no lower bound (LB) procedure for the Research Problem1, in this thesis, we develop an LB procedure that provides LB on makespan by considering both NIJS and NIJD characteristics together. Before using the proposed LB procedure for evaluating heuristic algorithms, we conduct a computational experiment to obtain the quality of the LB on makespan in comparison with optimal makespan on number of small scale instances. The results of this experiment indicate that the proposed LB procedure is efficient and could be used to obtain LB on makespan for any large scale problem. In the first perspective of the evaluation of the performance of the heuristic algorithms proposed for Research Problem 1, the proposed heuristic algorithms are run through small scale problem instances and we record the makespan values. We solve the MILP model to obtain optimal solutions for these small scale instances. For comparing the proposed heuristic algorithms we use the performance measures: (a) number of times the proposed heuristic algorithm solution equal to optimal solution and (b) average loss with respect to optimal solution in percentage. In the second perspective of the evaluation of the performance of the heuristic algorithms, the proposed heuristic algorithms are run through large scale problem instances and we record the makespan values. The LB procedure is also run through these problem instances to obtain LB on makespan. For comparing the performance of heuristic algorithms with respect to LB on makespan, we use the performance measures: (a) number of times the proposed heuristic algorithm solution equal to LB on makespan (b) average loss with respect to LB on makespan in percentage, (c) average relative percentage deviation and (d) maximum relative percentage deviation. We extend the Research Problem 1 by including additional job characteristics: job arrival time to WIP inventory area of heat-treatment furnace, due date and additional constraint on non-agreeable release time and due date (NARD). Due date considerations and the constraint on non-agreeable release times and due date (called Research Problem 2) are imperative to small scale steel casting foundries performing traditional but only one type of heat treatment operation such as annealing where due date compliance is important as many steel casting industries offer such type of heat treatment operations. The mathematical model, LB procedure, greedy heuristic algorithm and genetic algorithm proposed for Research Problem 1, including the computational experiments, are appropriately modified and\or extended for addressing Research Problem 2. Finally, we extend the Research Problem 2 is by including an additional real life dimension: multiple incompatible job families (MIJF). This new Research Problem (called Research Problem 3) is more relevant to medium and large scale steel casting foundries performing more than one type of heat treatment operations such as homogenizing and tempering, normalizing and tempering. The solution methodologies, the LB procedure and the computational experiments proposed for Research Problem 2 are further modified and enriched to address the Research Problem 3. From the detailed computational experiments conducted for each of the research problems defined in this study, we observe that: (a) the problem parameters considered in this study have influence on the performance of the heuristic algorithms, (b) the proposed LB procedure is found to be efficient, (c) the proposed genetic algorithm outperforms among the proposed heuristic algorithms (but the computational time required for genetic algorithm increases as problem size keeps increasing), and (d) in case the decision maker wants to choose an heuristic algorithm which is computationally most efficient algorithm among the proposed algorithms, the variants of greedy heuristic algorithms : SWB, SWB(NARD), SWB(NARD&MIJF) is relatively the best algorithm for Research Problem 1, Research Problem 2 and Research Problem 3 respectively.

This study focuses on Bruegel's parodic legacy in the picaresque tradition. It is based, on the one hand, on visual rhetoric, visual parody, and the poetics of epideictic rhetoric; and, on the other, on the interaction between epideictic rhetoric's salient features and the Bruegelian themes of camivalisation, the satirising of human folly, and the ontic order of the World Upside Down topos as organising principles. The relationships between the above themes are chronologically traced in various disguises in pictures by representative picaresque artists from the sixteenth to the twentieth centuries: i.e., in Bruegel, Steen, Hogarth, Daumier, and Grosz. Each of these picaresque artists battled with their own times, parodying the paradigmatic targets of the high mode, in both social and genre hierarchy, and in doing so revealed the complexities of the above themes at work within an ever changing context-bound rhetoricity.
Art History, Visual Arts & Musicology
Thesis (D.Litt. et Phil.)

Dissertação de mestrado em Structural Analysis of Monuments and Historical Constructions
Anthropological reasons apart, earthquakes are one of the most devastating causes of damage to monuments and historical constructions, and, as a consequence, lead to significant cultural, human, and economical losses. Protection of such structures against seismic excitations is thus an important factor regarding life safety and the conservation of our historical heritage. Efficient connections between structural elements can highly reduce the seismic vulnerability of masonry buildings by enhancing the out of plane behaviour of the walls regarding lateral loads which are presented as the principal cause of failure in this type of structure. In spite of the importance of structural connections regarding the global behaviour of historical constructions under seismic actions, research in this field is almost nonexistent and needs to be developed. The objective of this thesis is to study the seismic response to a ductile connection used to connect tie-rods to masonry walls in the scope of seismic retrofitting of historical constructions and to analyse its behaviour in comparison to the behaviour of the other structural elements. In seismic vulnerability assessment, numerical models are of great importance and providing characterizations of such connections would be of considerable interest to architects and engineers in order to more accurately design a seismic retrofit and thus be able to predict and avoid expected damage. Using a preliminary numerical model as a bench mark, the prototype was tested under monotonic and cyclic loading in order to reproduce similar excitations encountered during an earthquake. Based on the experimental campaign, a numerical model was developed and calibrated using the FE method. The comparison between the updated model and the experimental results helped to understand the fact that to a greater extent than the plasticization of the material, the parameter dissipating energy during the cycles is the friction between the plate and the walls. It was concluded that this innovative ductile connexion was not as effective as had been expected in terms of seismic behaviour on account of the large residual displacements observed after a cyclic loading. Therefore, an alternative solution is proposed as well as implementation recommendations.
À parte das razões antropológicas, os sismos são uma das maiores causas de dano para os monumentos e construções históricas, levando a perdas significativas a nível económico, cultural e humano. A proteção deste tipo de estruturas face às ações sísmicas é um fator relevante para a segurança e conservação do património histórico. A eficiência das ligações entre elementos estruturais pode amplamente reduzir a vulnerabilidade sísmica dos edifícios, através do melhoramento do comportamento para fora do plano das paredes de alvenaria, atenuando o principal modo de colapso destas estruturas quando sujeitas a ações horizontais. Apesar da importância das ligações estruturais no contexto do comportamento global de construções históricas quando sujeitas a ações sísmicas, a investigação neste campo é escassa e necessita de ser claramente ampliada. Para avaliação da vulnerabilidade sísmica a utilização de modelos numéricos é de grande importância. A caracterização e a definição do comportamento real a nível numérico são fundamentais para os projetistas, uma vez que estes necessitam de uma previsão adequada do comportamento das ligações e da sua influência no comportamento estrutural para evitar o dano. O objetivo da presente dissertação é estudar a resposta de uma ligação dúctil (placa de ancoragem) utilizada para ligar tirantes a paredes de alvenaria, passível de ser utilizada no reforço sísmico de construções históricas, analisando o seu comportamento sísmico de uma forma integrada com o comportamento dos restantes elementos estruturais. Partindo de um modelo numérico preliminar desenvolvido de raiz e usando-o como um ponto de referência, foram realizados ensaios monotónicos e cíclicos para a caracterização estrutural da ligação. Com base na campanha experimental, o modelo numérico foi calibrado. A comparação entre o modelo calibrado e os resultados experimentais ajudou a compreender a resposta estrutural da ligação, o mecanismo de colapso, a dissipação de energia durante os ciclos, entre outros. Com a presente dissertação concluiu-se que a ligação dúctil estudada, em termos de comportamento sísmico, não teve a resposta estrutural esperada, uma vez que foram observadas das grandes deformações residuais, tendo sido apresentada uma solução alternativa, bem como recomendações para a sua implementação.
Sans parler des raisons anthropologiques, les tremblements de terre sont une des causes les plus dévastatrices des dégâts occasionnés aux monuments et constructions historiques, ce qui engendre en conséquence d’importantes pertes en termes humain, culturel et économique. Protéger ces structures est, par conséquent, un facteur de grande importance vis-à-vis de la sécurité de la population et de la conservation de notre patrimoine culturel. La vulnérabilité séismique des bâtiments en maçonnerie peut être réduite de manière conséquente en connectant efficacement les différents éléments structuraux ce qui a pour conséquence d’améliorer le comportement des murs vis-à-vis des déformations hors du plan. Malgré l’importance de ces connexions au regard du comportement global des constructions historiques soumises à une action séismique, la recherche dans ce domaine est presque inexistante et nécessite d’être développé. L’objectif de cette thèse est d’étudier la réponse séismique d’une connexion flexible, utilisé pour ancrer les tirants aux murs de maçonnerie, dans le but d’un renforcement séismique de bâtiments historique et de comparer son comportement vis-à-vis des autres éléments structuraux. Les model numériques sont d’une grande importance au regard des études de vulnérabilité séismique et la définition des caractéristiques de telles connexions pourrait être d’une grande contribution pour les architectes et ingénieur afin d’être plus proche de la réalité dans leur démarche de conception et en conséquence prévoir et éviter de nombreux dégâts. En se servant d’un modèle numérique préliminaire comme repère, le prototype a été testé sous un chargement cyclique afin de reproduire une excitation similaire à celle ressentie lors d’un tremblement de terre. Basé sur cette campagne expérimentale, le modèle numérique a ensuite été développé et calibré utilisant la méthode des EF. La comparaison entre le modèle final et les tests menés a permis de démontrer qu’à plus grande échelle que la plastification de l’acier, le paramètre permettant de dissiper de l’énergie était la friction entre l’assiette ductile et le mur. Pour conclure, il est démontré que cette connexion innovatrice ne fonctionne pas aussi bien que prévu au regard de son comportement séismique du fait des grandes déformations résiduelles observées après chaque cycle de charge.