Today the most prosperous interface of architectural design and representation has become the architectural model both in its digital and physical forms. There has been a shift in the design medium from the physical modeling processes to computer-aided design, by way of which the computational design methods have established a much more dynamic, complex, and continual design. In this process, the digital design model now accompanies the whole design as a single entity, contrary to conventional analog modeling techniques where design is compartmentalized into linear phases. By the embracement of computer-aided manufacturing (CAM) in company of computeraided design (CAD), physical modeling has gained another dimension in the interwoven relationship of the digital and physical. The aim of this study is to explore the novel conceptual and computational changes which mark the departure of this new mode of design from the old. There has always been a hierarchy of presence between the virtual space of representations and architecture&rsquo / s materiality. Within this context, the emphasis of the study is on the relationship between the virtuality of conception and modeling processes, and the materiality of construction, production and fabrication.

Laboratory experiments were performed to study and improve longshore sediment transport rate predictions. Measured total longshore transport in the laboratory was approximately three times greater for plunging breakers than spilling breakers. Three distinct zones of longshore transport were observed across the surf zone: the incipient breaker zone, inner surf zone, and swash zone. Transport at incipient breaking was influenced by breaker type; inner surf zone transport was dominated by wave height, independent of wave period; and swash zone transport was dependent on wave period. Selected predictive formulas to compute total load and distributed load transport were compared to laboratory and field data. Equations by Kamphuis (1991) and Madsen et al. (2003) gave consistent total sediment transport estimates for both laboratory and field data. Additionally, the CERC formula predicted measurements well if calibrated and applied to similar breaker types. Each of the distributed load models had shortcomings. The energetics model of Bodge and Dean (1987) was sensitive to fluctuations in energy dissipation and often predicted transport peaks that were not present in the data. The Watanabe (1992) equation, based on time-averaged bottom stress, predicted no transport at most laboratory locations. The Van Rijn (1993) model was comprehensive and required hydrodynamic, bedform, and sediment data. The model estimated the laboratory cross-shore distribution well, but greatly overestimated field transport. Seven models were developed in this study based on the principle that transported sediment is mobilized by the total shear stress acting on the bottom and transported by the current at that location. Shear stress, including the turbulent component, was calculated from the wave orbital velocity. Models 1 through 3 gave good estimates of the transport distribution, but underpredicted the transport peak near the plunging wave breakpoint. A suspension term was included in Models 4 through 7, which improved estimates near breaking for plunging breakers. Models 4, 5 and 7 also compared well to the field measurements. It was concluded that breaker type is an important variable in determining the amount of transport that occurs at a location. Lastly, inclusion of the turbulent component of the orbital velocity is vital in predictive sediment transport equations.

abstract: Digital sound synthesis allows the creation of a great variety of sounds. Focusing on interesting or ecologically valid sounds for music, simulation, aesthetics, or other purposes limits the otherwise vast digital audio palette. Tools for creating such sounds vary from arbitrary methods of altering recordings to precise simulations of vibrating objects. In this work, methods of sound synthesis by re-sonification are considered. Re-sonification, herein, refers to the general process of analyzing, possibly transforming, and resynthesizing or reusing recorded sounds in meaningful ways, to convey information. Applied to soundscapes, re-sonification is presented as a means of conveying activity within an environment. Applied to the sounds of objects, this work examines modeling the perception of objects as well as their physical properties and the ability to simulate interactive events with such objects. To create soundscapes to re-sonify geographic environments, a method of automated soundscape design is presented. Using recorded sounds that are classified based on acoustic, social, semantic, and geographic information, this method produces stochastically generated soundscapes to re-sonify selected geographic areas. Drawing on prior knowledge, local sounds and those deemed similar comprise a locale's soundscape. In the context of re-sonifying events, this work examines processes for modeling and estimating the excitations of sounding objects. These include plucking, striking, rubbing, and any interaction that imparts energy into a system, affecting the resultant sound. A method of estimating a linear system's input, constrained to a signal-subspace, is presented and applied toward improving the estimation of percussive excitations for re-sonification. To work toward robust recording-based modeling and re-sonification of objects, new implementations of banded waveguide (BWG) models are proposed for object modeling and sound synthesis. Previous implementations of BWGs use arbitrary model parameters and may produce a range of simulations that do not match digital waveguide or modal models of the same design. Subject to linear excitations, some models proposed here behave identically to other equivalently designed physical models. Under nonlinear interactions, such as bowing, many of the proposed implementations exhibit improvements in the attack characteristics of synthesized sounds. / Dissertation/Thesis / Ph.D. Electrical Engineering 2013

Tendo em vista a importância das obras portuárias e costeiras no desenvolvimento do país e a complexidade dos fenômenos que regem os Processos Litorâneos, torna-se relevante a utilização de modelos físicos, como os canais de ondas, para otimização destes projetos. Neste sentido, os principais objetivos desta Tese são o desenvolvimento de um sistema de controle para o gerador de ondas do Laboratório de Hidráulica da Escola Politécnica da Universidade de São Paulo - LHEPUSP, capaz de gerar ondas irregulares, baseadas em espectros de energia da agitação, bem como, a partir de um estudo com caso de um molhe de berma, avaliar do ponto de vista técnico o procedimento de dimensionamento de quebra-mares com base no ensaio da estrutura frente a ondas regulares com as características da onda significativa de projeto. Uma das contribuições desta Tese é o novo sistema de controle da geração de ondas do LHEPUSP, que é capaz de gerar ondas regulares, irregulares e randômicas. A outra contribuição, referente ao estudo de caso, permitiu concluir que o emprego de ondas regulares na otimização em modelo físico de projetos de quebra-mares pode levar a dimensionamentos conservadores, e portanto de custo mais alto, principalmente no dimensionamento de obras dispostas em profundidades inferiores aos 10 m, onde foram encontradas diferenças para mais no recuo da estrutura, comparativamente com a ação de ondas irregulares de mesma altura significativa. / Considering the harbour and coastal structures significance for the Country development and the complex Littoral Processes phenomena, is an important requirement the physical models use, like wave flumes, to improve these designs. Following this context, the Thesis main purposes are to develop a wave maker control system for the Laboratório de Hidráulica da Escola Politécnica da Universidade de São Paulo - LHEPUSP wave fume able to generate irregular waves, based on wave energy spectra, and also, from a berm jetty case study, evaluate, from the technical point of view, the breakwater design procedure based on structure tests with design significative regular waves. One of the Thesis contribution is the new wave maker control system for the LHEPUSP wave fume able to generate regular, irregular and randomic waves. The other contribution, about the case study, showed as conclusion that the regular waves use for breakwaters design physical model improvement may suggest conservative results, inducing high cost structures, mainly for those ones in depths lower than 10 m, being observed larger structural backward response differences, comparing with irregular waves action with the same significative height.

Orientador: Joerg Dietrich Wilhelm Schleicher / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências / Made available in DSpace on 2018-08-21T13:15:48Z (GMT). No. of bitstreams: 1 Marcondes_PauloEduardoPasquini_M.pdf: 15230137 bytes, checksum: 6a3ec19ac833d41b7e0e630fdfdcd247 (MD5) Previous issue date: 2012 / Resumo: Nos reservatórios de hidrocarbonetos, a caracterização das falhas e fraturas é de extrema importância devido a seu papel ora como barreiras ao fluxo, ora canais condutores. Os efeitos da anisotropia causada por fraturas alinhadas têm sido objeto de muitos trabalhos e experimentos de modelagem sísmica. No entanto, devido a complexidade exibida por meios fraturados anisotrópicos, a caracterização desse tipo de meio nem sempre é possível. Nestas condições, através da adoção de modelos e geometrias simplificados, bem como da adequada escolha dos parâmetros é que a modelagem física da propagação de ondas sísmicas através de meios fraturados permite estimar a influência destas características das fraturas de forma mais confiável. Modelamos fraturas preenchidas por material de baixa resistência ao cisalhamento usando inclusões de neoprene, que possui esta característica. Foram efetuadas medidas de transmissão acústica de ondas P e S em um modelo de referência sem inclusões e em outro modelo com inclusões discóides de neoprene. Os dados ultrassônicos foram adquiridos usando transdutores de ondas P com frequência central de 120 kHz e de ondas S com 90 kHz. Estudamos o comportamento destes dois meios anisotrópicos sob compressão uniaxial. Também estudamos o efeito destas inclusões sobre os parâmetros anisotrópicos de um meio cujo arcabouço já apresentava comportamento anisotrópico polar. Ambos os modelos foram submetidos a compressão uniaxial com tensões de 3 até 15,8 MPa. O completo fechamento das fraturas ocorre ao nível de tensão de 14,6 MPa. Nossa análise aponta a existência de diferentes regimes para o comportamento das inclusões, observados tanto no parâmetro densidade de fraturas quanto sob sua razão de aspecto. Estes resultados sugerem uma dependência da razão de aspecto para baixos níveis de tensão uniaxial diferente do que se tem reportado na literatura. Outros resultados obtidos dizem respeito à caracterização dos meios anisotrópicos devido ao fraturamento a partir dos coeficientes elásticos derivados a partir das velocidades sísmicas. Apesar de não exaustivos, nossos resultados mostram que abordagens experimentais simples podem fornecer conhecimento valioso do comportamento de rochas fraturadas aos níveis de tensão existentes nos reservatórios / Abstract: Fault and fracture characterization is very important for hydrocarbon reservoirs, due to it being either a flow barrier or conduit. Elastic anisotropy due to aligned cracks has been the subject of many seismic physical modeling experiments. However, due to the complexity exhibited by fractured anisotropic media, fully characterizing these kind of media is not always possible. Under these conditions, the adoption of simplified models and geometries as well as adequate parameter choices permits characterizing these media using physical seismic modeling in a reliable way. We modeled fractures with a low shear modulus filling using neoprene rubber discs as inclusions, because of neoprene's low shear modulus. We carried out pulse transmission measurements of P- and S-wave velocities in a reference model without inclusions and in a model with penny-shaped neoprene inclusions. The reference model is an anisotropic matrix that consists of stacked plexiglass plates. Rubber discs were used as inclusions in that anisotropic matrix leading to secondary anisotropy, this is our second model. We recorded ultrasonic seismic data using P-wave transducers with central frequency 120 kHz and S-wave transducers with 90 kHz. We compressed the physical models using pressures ranging from 3 to 15.8MPa. Full crack closure occurs at stress 14.6MPa normal to model faces. Our analysis indicates different regimens for the behavior of the inclusions when observed via its crack densities and aspect ratios. These results suggest a different dependence of the crack aspect ratio on uniaxial stress at the low state of stress than usually described in the literature. Other results point that it might be possible to characterize a fractured medium though its elastic coefficients. Though our results are not extensive, they show that simple experimental approaches might provide valuable insight into the behavior of cracked rocks at reservoir stress levels / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

Ce mémoire est centré sur l’application de la technique d’optimisation de type Space Mapping dans le cadre du dimensionnement d’actionneurs électriques pris en compte par des modélisations multi-physiques. L’intérêt particulièrement recherché de ce type de méthode est la réduction potentiellement forte du coût du dimensionnement optimal. Cette volonté de réduction du coût de l’approche optimale s’explique par plusieurs considérations. En premier lieu, la modélisation des actionneurs tend à considérer de plus en plus de phénomènes physiques (tels que les phénomènes magnétiques, électriques, thermiques, mécaniques …) afin de décrire au mieux les phénomènes observés et mesurés. En second lieu il devient alors nécessaire de tenir compte des couplages entre ces physiques afin de traduire au plus juste l’interdépendance de ces phénomènes. Dans ce cadre, un travail particulier a été réalisé concernant la prise en compte des aspects thermiques dans les machines électriques. C’est ainsi qu’un modèle thermique à constantes localisées d’une machine synchrone à aimants permanents a été construit. Pour valider les résultats de calcul et préciser la définition de certain de ses éléments, une démarche expérimentale a été réalisée. Tous ces points, traduits dans le plan numérique, haussent le coût de l’évaluation des performances des actionneurs, et donc celui de leurs dimensionnements. De là, l’utilisation des techniques d’optimisation basées sur des modèles substituts permet d’envisager des réductions significatives des coûts de dimensionnement. La technique de Space Mapping est utilisée dans ce travail comme solution pour trouver un compromis entre la qualité des solutions trouvées et le temps de calcul. Plus particulièrement, elle est utilisée pour résoudre un problème de dimensionnement optimal d’une machine synchrone à aimants permanents assurant la fonction de démarreur dans une application de véhicule hybride. L’approche d’optimisation par Space Mapping a été comparée à celle, plus classique, n’utilisant qu’une seule modélisation de l’actionneur à dimensionner, c’est-à-dire sans modèle substitut. Il est montré que les techniques de Space Mapping sont à même de trouver des solutions de dimensionnement similaires à celles issues d’une approche classique, mais de manière beaucoup plus efficace, i.e. en utilisant un nombre plus faible d’évaluations de la modélisation multi-physique de l’actionneur. / This thesis focuses on the application of the Space Mapping optimization technique in the case of the sizing of electrical actuators taking into account a multi-physical modeling. The main interest in this type of optimization method is to considerably reduce the cost of optimal sizing. The need to use such optimization approach is due to several considerations. First, electrical actuators modeling tends to increasingly require the consideration of several physical phenomena (such as magnetic, electrical thermal and mechanical phenomena) in order to better describe observed and measured phenomena. Besides, it becomes necessary to take into account couplings between the different physical phenomena to precisely calculate the interdependencies between these phenomena. In this context, taking into account the thermal aspect in the case of electrical machines is particularly highlighted. A lumped parameter model of a permanent magnet synchronous machine is built. An experimental procedure has been followed to validate calculation results and define some elements of the proposed model. When implemented numerically, all points mentioned above increase the cost of the calculation of the performances of the electrical actuator, and then the cost of the optimal sizing. Thus, the use of an optimization technique based on surrogate models permits to reduce the optimal sizing cost. Space Mapping technique was used in this work as a solution to find a compromise between the quality of the found results and the calculation time. It is particularly used to solve an optimal sizing problem of a permanent magnet synchronous machine used as starter in a hybrid vehicle application. The Space Mapping optimization approach was compared to a classical one using a unique modeling of sized the electrical actuator : no surrogate model is used in the classical approach. Il is demonstrated that the Space Mapping techniques find optimization results that are similar to those found by the classical approach, yet, in a much more efficiently. Space Mapping techniques require only few calculations of the multi-physical model of the actuator.

This study examined the differences between normal vocal fold vibration and the movement patterns of vocal folds with mass lesions by means of a synthetic model. The experimenter molded and cast three sets of vocal folds, representing normal structure, small nodules, and larger nodules. Acoustic, aerodynamic, and digital video signals were recorded and analyzed in order to quantify air flow and pressure, measure vibratory stability, and visually assess closure patterns across the three structural conditions. Statistical analysis revealed that the presence of vocal nodules resulted in a significantly higher onset pressure, fundamental frequency, airflow at onset, and offset pressure. However, the results were inconclusive with regard to vocal stability, and it remains unclear whether the current models of nodules are sufficiently similar to the human system to adequately model the type of mass lesions typically seen in a clinical context.

Formula SAE (FSAE) vehicle systems are very complex. Understanding how subsystems effect the overall vehicle is essential for making design trade-offs. FSAE is a competitive environment. Teams need to have reliable and high performing vehicles to do well in competition. The Virginia Tech (VT) FSAE team has produced a prototype electric powertrain (EPT) vehicle, VTM16e, and will take their first EPT vehicle, VTM17e, to competition in 2017. The use of model-based design (MBD) for an EPT FSAE vehicle is investigated through this thesis. The goal of the research is to build the framework of a full vehicle simulation to take knowledge gained from the VTM16e prototype vehicle, and apply it to the VTM17e competition vehicle. A top-down, bottom-up approach is taken to build a full vehicle model of an EPT FSAE vehicle. A full vehicle simulation is built with subsystems to establish an overall structure and subsystem interactions. Individual subsystems are then focused on for testing and validation. Breaking the vehicle down into subsystems allows the overall model to be incrementally improved. The battery subsystem is focused on in this thesis. Extensive testing is performed on the batteries to characterize their performance. Computer models are generated from empirical data through parameter estimation techniques. Validation of the battery models is performed and the resulting model is incorporated into the overall vehicle model. Performance limits of the vehicle are determined through model exploration, and design modifications to increase the reliability and performance for the VTM17e vehicle are proposed. / Master of Science

As climate change escalates and the demands for energy resources increase, modern geotechnical engineering must tackle critical challenges to ensure sustainable development and enhance the resilience of infrastructure in society. The coupled chemo-hydro-mechanical processes in multiphase materials present significant challenges in geotechnical engineering, particularly for applications like carbon sequestration, geological disposal of nuclear waste, and hydraulic fracturing with reactive fluids, all of which involve highly heterogeneous and strongly anisotropic multiphysics environments. This dissertation introduces a multiphysical computational framework specifically designed to address the challenges associated with these unconventional applications. In this dissertation, we consider not only the local multiphysical coupling effects in the constitutive model but also the nonlocal effects arising from pore fluid flow, chemical species convection and diffusion, chemical reactions occurring in both solid and fluid constituents, and damage due to fluid pressure acting on fractures in the solid. We have integrated all these physical processes and developed a single unified model capable of handling the complex hydro-chemo-mechanical responses of geomaterials under varying geochemical conditions, confining pressures, and external loading scenarios. This computational framework offers a comprehensive simulation tool to investigate the long-term stability of geomaterials, which is determined by the intensity of chemical reactions under specific temperature and pressure conditions (assuming an isothermal condition in this dissertation), as well as the sustainability of geotechnical infrastructure in erosive environments driven by both mechanical and chemical processes. Three key aspects of engineering applications related to the effects of chemical reactions in geotechnical engineering are addressed. Firstly, we have integrated a complete calcite reaction system into poromechanics to couple pore geochemistry with poroelasticity theory. This integration is capable of predicting the geomechanical response essential for long-term stability analysis in \ch{CO2} sequestration engineering. Key features of this model include a multi-field finite element approach, local-equilibrium explicit geochemistry characterization of the calcite dissolution/precipitation reaction system, a robust algorithm for sequentially coupling pore geochemistry with poromechanics, and strategies to enhance the computational efficiency of solvers. Secondly, for applications involving acid working fluids in hydraulic fracturing, we have extended and adapted previous models within the phase field method framework. This extended integration effectively addresses the effects of chemically assisted fracturing in hydraulic fracturing operations. The key innovations of this model are the implementation of the phase field method to capture crack behaviors with poromechanics, the modeling of acid fluid transport in porous media and fractures, and its application to multiple mineral reaction systems. Thirdly, we have proposed a constitutive model that incorporates pore geochemistry and the pressure dissolution effect into internal variables, effectively capturing the chemical reactions contributing to softening in geomaterials. This model effectively illustrates and predicts chemically induced weathering or damage in granular porous media, such as sinkholes and subsidence. Derivations of a thermodynamically-based degradation index consider the influences of pore geochemistry and contact forces between grains and bonds. The model also proposes cross-scale relationships that consider reaction effects from individual particle sizes to particle aggregates. Furthermore, these relationships are incorporated into classical Cam-Clay-type models, along with the derivation of a consistent tangent modulus. / Dissertation / Doctor of Philosophy (PhD) / This thesis presents the comprehensive behaviors of geomaterials under mechanical, fluid, and chemical interactions, which result in displacement and cracking. Since there is no existing software or simulation tool that includes all the physical behaviors considered in this dissertation, the development and implementation of these physical mechanisms, followed by testing and analysis for engineering problems, constitutes the main contribution of this work. The newly developed simulation tool ranges from simulating the mechanical behavior of porous media saturated with water and reactive fluid to modeling the seepage of water/reactive fluid that triggers damage (cracks) in the porous media. This simulation tool can effectively analyze engineering problems that focus on the interactions between the working fluid and the host solid matrix under complex solution conditions. Examples include modeling carbon sequestration in saline aquifers and the storage of nuclear waste in subsurface repositories etc. The simulation tool proposed in this thesis incorporates rigorous mathematical derivations, efficient and accurate multiscale discretization techniques, robust non-iterative and iterative numerical coupling strategies, and thorough comparisons between numerical results and experimental/laboratory data. Simultaneously, it is important to recognize the model's limitations. Although the model assumes local equilibrium and interactions between physical mechanisms, it cannot fully capture all behaviors under these assumptions due to the restrictions in our understanding and potential constraints of numerical methods.

Les structures offshores sont conçues pour résister à des chargements environnementaux sévères. Des études expérimentales et numériques de la fondation d’une éolienne offshore soumise à des chargements statiques monotones/cycliques sont présentées dans ce manuscrit. Des pieux isolés (diamètre de 1,8 m et 40 m de longueur) et une structure en treillis fondée sur 4 pieux ont été testés à 100×g en centrifuge dans un massif de sable de Fontainebleau dense. Le comportement du pieu isolé a été identifié à travers des essais de chargement axial monotone. Différentes méthodes de mise en place de pieu ont été adoptées (installation à 1×g et à 100×g) et leur influence sur la capacité portante a été mesurée. Le diagramme de stabilité du pieu a été construit à partir des résultats des essais cycliques, des essais CPT ont été réalisés et l’influence des contraintes initiales a été étudiée. Des résultats expérimentaux de la fondation jacket soumise à des chargements latéraux cycliques sont enfin présentés. La méthode des éléments finis et un macro-élément pour des pieux ont été utilisés pour reproduire numériquement les résultats expérimentaux. Les lois de comportement adoptées sont basées sur la théorie d’hypo-plasticité et les contraintes initiales dans le sol sont issues de la méthode ICP-05. Les résultats numériques sont confrontés aux résultats expérimentaux et aux résultats analytiques obtenus à partir de la norme API. / Offshore structures are designed to resist to severe environmental loads. This manuscript presents experimental and numerical studies on offshore wind turbine pile foundations submitted to static monotonic/cyclic loads. Isolated piles (diameter of 1.8 m and embedded length of 40m) and a four-legged truss structure installed in dense Fontainebleau sand have been tested at 100×g in a geotechnical centrifuge. The behavior of the isolated piles has been characterized under monotonic axial load. The piles have been jacketed at 1×g and 100×g and the influence of the setup method on the bearing capacity has been measured. The stability diagram of a pile has been constructed using cyclic tests, CPT experiments have been performed and the influence of the initial stresses has been studied. Finally, experimental results of the jacket foundation submitted to lateral cyclic loadings are presented. The finite element method and a macro-element for piles have been used to numerically reproduce the experimental results. Constitutive laws are based on the hypoplasticity theory and the initial stresses in the soil have been calculated using the IC-05 method. The numerical results are compared with the experimental and the analytical results from the API standards.