Thesis (Ph.D.)--McMaster University, 2005. / Supervisor: A. Ghobarah. Also available online.

Thesis (M. Eng.(Mechanical Engineering))--University of Pretoria, 2002. / Summaries in Afrikaans and English. Includes bibliographical references.

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Mechanical and Aerospace Engineering." Includes bibliographical references (p. 77-80).

Extreme event populations are encountered in all domains of civil engineering. The classical and Bayesian statistical approaches for describing these populations are described and compared. Bayesian frameworks applied to such populations are reviewed and critiqued. The present Bayesian framework is explained from both theoretical and computational points of view. Engineering judgement and regional analyses can be used to yield a distribution on a parameter set describing a population of extremes. Extraordinary order events, as well as known data, can be used to update the prior parameter distribution through Bayes theorem. The resulting posterior distribution is used to form a compound distribution, the basis for estimation. Quantile distributions are developed as are linear transformations of the parameters. Examples from several domains of civil engineering illustrate the flexibility of the computer program which implements the present method. Suggestions are made for further research. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

El Perú presenta diversas eventualidades como las lluvias, que retrasan distintas actividades que promueven el crecimiento económico del país. Las zonas urbanas necesitan una mejora continua del entorno con mejores infraestructuras para promover el crecimiento y reducir los accidentes. En la actualidad, se necesita fomentar por el medio local soluciones innovadoras para la evacuación de altas precipitaciones. El concreto permeable es un tipo de concreto cuya tecnología permite que el agua discurra a través de su estructura por la alta porosidad que posee a diferencia del concreto tradicional. Es fabricado de agregado grueso y material cementante, con un bajo porcentaje de finos de hasta el 10%. Esta investigación consiste en proponer un diseño de mezcla de concreto permeable de f’c=175kg/cm² aplicado en veredas que satisfaga distintos requerimientos establecidos por las normas CE010 de Pavimentos Urbanos, ACI 211.3R, ACI 522R-10 y los propios de la zona de aplicación. Para ello se realizó una batería de 12 diseños de mezcla con relaciones a/c 0.30, 0.35 y 0.38; agregados de HUSO 7 y 67; cementos portland tipo 1 Sol y Quisqueya; y aditivo Z fluidizante SR. Se realizaron ensayos en estado fresco: Slump, peso volumétrico y contenido de vacíos; y en estado endurecido: Resistencia a la compresión y flexión, y permeabilidad. Finalmente se realizó un prototipo con el diseño que presentó mejores características con el propósito de validar la investigación y se realizo un comparativo entre las veredas de concreto permeable y tradicional. / Peru presents various eventualities such as rainfall, which delay different activities that promote the country's economic growth. Urban areas need continuous improvement of the environment with better infrastructure to promote growth and reduce accidents. At present, innovative solutions for the evacuation of high rainfall need to be promoted through the local environment. Permeable concrete is a type of concrete whose technology allows water to flow through its structure due to the high porosity it possesses, unlike traditional concrete. It is made of coarse aggregate and cementitious material, with a low percentage of fines of up to 10%. This research consists in proposing a permeable concrete mix design of f'c = 175kg / cm² applied in sidewalks that satisfies different requirements established by the CE010 standards of Urban Pavements, ACI 211.3R, ACI 522R-10 and those of the area of application. For this, a battery of 12 mixing designs with a / c ratios of 0.30, 0.35 and 0.38; aggregates of HUSO 7 and 67; portland cements type 1 Sol and Quisqueya; and fluidizing Z additive SR. Fresh tests were performed: Slump, volumetric weight and void content; and in a hardened state: resistance to compression and flexion, and permeability. Finally, a prototype was made with the design that presented better characteristics with the purpose of validating the research and a comparison was made between the permeable and traditional concrete sidewalks. / Tesis

La presente investigación corresponde a la evaluación de las propiedades mecánicas de la madera contralaminada (CLT) elaborados con una especie de mediana densidad mediante ensayos de resistencia para mejorar su comportamiento como muros estructurales en edificaciones. La aplicación de la madera laminada cruzada denominada también CLT (Cross Laminated Timber) como material estructural en la construcción de edificaciones permitiría un mejor aprovechamiento del potencial forestal de muchos países, haciendo que este sector sea más sostenible. Esta aplicación es factible siempre en cuando el material a emplear cumpla con las solicitaciones de resistencia que demanda su uso estructural y su proceso industrial sea compatible con las condiciones y la oferta existente en el entorno. Para lograr este propósito, se elaboraron prototipos de paneles CLT con madera Cachimbo, especie de mediana densidad denominado científicamente como Cariniana doméstica perteneciente a la familia Lecythidaceae. Se realizaron ensayos para determinar las propiedades mecánicas de resistencia a esfuerzos de compresión perpendicular y paralela a las fibras de las capas exteriores, esfuerzo de flexión y resistencia al corte. Los procedimientos fueron realizados siguiendo normativas de madera contralaminada como la española EN16351, el EC5 y la E.010 de madera. Los resultados obtenidos dan cuenta que los paneles CLT elaborados con Cachimbo son capaces de resistir los requerimientos de carga que podría demandar una edificación de mediana altura y cumple con los requisitos básicos especificados en las normativas. Las resistencias alcanzadas son similares a las obtenidas con maderas de tipo coníferas en estudios realizados en otros países, siguiendo los mismos criterios y normatividad. / The present investigation corresponds to the evaluation of the mechanical properties of the Cross Laminated Timber (CLT) made with medium density species by means of resistance tests to improve its behavior as structural walls in buildings. The application of the cross laminated wood also called CLT (Cross Laminated Timber) as structural material in the construction of buildings would allow a better use of the existing forest potential in many countries, making this sector more sustainable. This application is feasible as long as the material to be used complies with the stresses of resistance that its structural use demands, and its industrial process is compatible with the conditions and the existing offer in the environment. To achieve this purpose, prototypes of CLT panels were made with Cachimbo wood, a medium-density species scientifically called Carinianadomestic belonging to the Lecythidaceae family. Tests were carried out to determine the mechanical properties of resistance to perpendicular and parallel compression stresses to the fibers of the outer layers, bending stress and shear strength. The procedures were carried out following norms of contra-laminated wood such as the Spanish EN16351, the EC5 and the Peruvian E.010 wood regulations. The results obtained show that the CLT panels made with Cachimbo can withstand the load requirements that a medium-height building could demand and meets the basic requirements specified in the regulations. The strengths achieved are similar to obtained with coniferous woods in studies carried out in other countries, following the same criteria and regulations. / Trabajo de investigación

En la presente tesis se analiza el problema torsional extremo de un edificio en esquina de cuatro pisos y un semisótano. Los edificios en esquinas comúnmente presentan un diseño arquitectónico comercial, que aprovecha el perímetro colindante con la calle para poner ventanas y mamparas. Sin embargo, este diseño arquitectónico no toma en cuenta irregularidades estructurales. Una de las irregularidades es la torsional. La torsión es consecuencia de las excentricidades entre el Centro de Masa (CM) y el Centro de Rigidez (CR) en ambos ejes. Para la presente tesis se plantea la siguiente hipótesis: “El caso en estudio presenta irregularidad torsional extrema dada su arquitectura y su ubicación en esquina. Esta irregularidad no está permitida según Norma en Edificaciones categoría “C” y con zonificación 4, por lo que se deberá aumentar la rigidez en zonas críticas. Esta rigidez no depende del incremento de gran longitud de placas sino de su espesor y su ubicación dentro de la estructuración, para su demostración se proponen cinco modelos que se analizan sísmicamente empleando la Norma Técnica E030-2016 teniendo como punto de partida, los planos de arquitectura y una estructuración base; para luego escoger uno de los cinco modelos y realizar el correspondiente diseño estructural de todos los elementos de la edificación”. Además, la tesis tiene como valor añadido el análisis torsional bajo tres normas técnicas de Sismoresistencia de los años 2003, 2016 y 2018, con el objetivo de encontrar diferencias sustanciales entre ellas. Además, se plantea realizar el respectivo análisis Tiempo-Historia del modelo solución. / In this thesis the extreme torsional problem of a four-story corner building and a basement is analyzed. The buildings in controlled corners have a commercial architectural design, which takes advantage of the perimeter adjacent to the street to put windows and screens. However, this architectural design does not take into account structural irregularities. One of the irregularities is the torsional one. The torsion is a consequence of the eccentricities between the Mass Center (CM) and the Rigidity Center (CR) in both axes. For the present thesis, the following hypothesis is proposed: “The case under study presents extreme torsional irregularity given its architecture and its corner location. This irregularity is not allowed according to Standard in Buildings category "C" and with zoning 4, so the rigidity in critical areas will be increased. This rigidity does not depend on the increase of large length of plates but on its thickness and its location within the structuring For its demonstration, five models are proposed, which are analyzed seismically using Technical Standard E030-2016, taking as a starting point the architectural plans and a basic structuring; then choose one of the five models and make the corresponding structural design of all the elements of the building”. In addition, the thesis has as an added value the torsional analysis under three technical standards of earthquake resistance of the years 2003, 2016 and 2018, with the objective of finding substantial differences between them. In addition, it is proposed to perform the respectful Time-History analysis of the solution model. / Tesis

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The aim of this article is to use artificial neural networks (ANN) to perform the structural design of confined masonry buildings. ANN is easy to operate and allows to reduce the time and cost of seismic designs. To generate the artificial neural network, training models (traditional confined masonry designs) are used to identify the input and output parameters. From this, the final architecture and activation functions are defined for each layer of the ANN. Finally, ANN training is carried out using the backpropagation algorithm to obtain the matrix of weights and thresholds that allow the network to operate and provide preliminary structural designs with a 10% margin of error, with respect to the traditional design, in the dimensions and reinforcements of the structural elements.

No description available.

Switched reluctance motors (SRMs) possess many desirable qualities for the long-term sustainability of electrified transportation such as cheap production costs and simple, robust configurations. However, high acoustic noise and torque ripple are two performance imperfections that have prevented the widespread implementation of SRMs. This thesis investigates design techniques to reduce the acoustic noise produced by an 8/6 SRM while also analyzing the impact each design has on the motor’s performance. The fundamentals of SRMs are discussed including the operating principles, modelling and control strategies. The multiphysics finite element analysis (FEA) toolchain used to accurately model acoustic noise and vibrations of SRMs is described. Using the network of FEA tools, nodal forces and natural frequencies of a four phase 8/6 SRM are analyzed to study the acoustic noise and vibration behaviours. The FEA process is validated experimentally by matching measured vibration modes and acoustic noise sound pressure level (SPL) with FEA numerical results. Through inspiration from an extensive literature review, various design techniques are applied to a baseline four phase 8/6 SRM and compared for both acoustic noise reduction and EM performance criteria. The investigated designs were split into two categories, stator-housing modifications that aim to increase the stiffness of the assembly and rotor modifications that aim to reduce the magnitude of radial forces while preserving performance. The best design strategies as determined by the comparative analysis were then further optimized to combine the best techniques together for the 8/6 SRM. The proposed structural improvements included the modifications of the stator yoke shape along with increasing the number of fastening components involved in the assembly. Additionally, an iterative procedure for the parametric modelling of windows introduced to the rotor poles is outlined. The best design considerations are combined to create the design of a novel 8/6 SRM which significantly reduces the acoustic noise produced by the motor with little impact to performance. / Thesis / Master of Applied Science (MASc)