The CubeSat Program has provided access to space for many universities, private companies, and government institutions primarily due to the low cost of CubeSat satellite development. While these costs are orders of magnitude lower than similarly capable nano-satellite missions, they are still outside of the budgetary constraints of many potential developers including university and high school clubs. Using 3D printed plastics in the production of CubeSat structures and mechanisms presents a large cost savings opportunity that will allow these institutions to participate in the development of these satellites, expanding the educational and scientific impact of the CubeSat Program. Five rapid prototype plastics manufactured with four different 3D printing technologies were studied to determine their survivability when subjected to the required vibration testing and thermal bakeout that all CubeSats are must pass through before integration and launch. ASTM D638 Type V tensile bar samples of each plastic were procured and subjected to a thermal bakeout and tensile testing to determine the thermal and outgassing effects on their mechanical properties. This information was used to design a concept structure for use in a low budget CubeSat mission. Finite Element Analysis in Abaqus was then utilized to test the integrity of this structure under a worst case load condition derived from the ELaNa 6 launch vibration profile. Results from the analysis show that Objet FullCure720 photopolymer resin, DSM Somos Prototherm 12120 photopolymer resin, and Windform XT carbon fiber filled nylon all provide adequate strength to survive the environmental testing conditions required for this system to proceed through flight integration and launch.

O presente trabalho propõe a execução de ensaios de medição do número de swirl em bancada de fluxo em regime permanente, com a utilização de um dispositivo modular e dutos de admissão do cabeçote de um motor diesel produzidos via prototipagem rápida (PR). A medição do número de swirl com dutos produzidos via PR, traz como principais vantagens: reprodutibilidade dos ensaios, facilidade de simular e mensurar o número de swirl dos potenciais desvios no processo de fundição ou usinagem, além da redução no tempo para o desenvolvimento de novas geometrias dos dutos de admissão. O trabalho é experimental e uma unidade do cabeçote estudado foi encaminhado para o laboratório da EPUSP e o número de swirl medido para posterior comparação dos dados. Após a fase inicial de aquisição de dados e ajustes no projeto do dispositivo, essa unidade do cabeçote foi seccionada e digitalizada para que a geometria interna fosse reproduzida via prototipagem rápida. Os dutos de admissão foram montados no dispositivo modular para a realização dos testes em bancada. Todos os testes foram realizados no mesmo equipamento e com o mesmo sistema de controle, com o intuito de reduzir o número de variáveis externas na aquisição de dados. Quando realizou-se a comparação das médias dos resultados do número de swirl do cabeçote e do dispositivo modular com o uso de prototipagem rápida não foram encontradas diferenças estatisticamente significantes. O método proposto representou o escoamento de ar da admissão do modelo de cabeçote analisado. / The present work proposes to execute steady state bench test, swirl number measurements, using a modular device and cylinder head intake ports from a diesel engine manufactured via rapid prototype (RP) techniques. Swirl number measurements with intake ports produced by RP, bring as main advantages: Tests reproducibility, easy to measure the swirl number variances in consequence of potential casting or machining process deviations besides of time reduction to the development of new intake ports geometry. The research is experimental and one sample of the investigated cylinder head was sent to the laboratory and the swirl number was measured for later results comparison. After the early development phase of data acquisition and design improvements, this cylinder head sample was then sectioned and digitalized as to know to have the same internal geometry in the intake ports produced via rapid prototype. The intake ports were assembled in the modular device to perform bench tests. All tests were performed in the same rig and with the same control system with aiming to reduce the external variables during data acquisition. When the mean results analysis was performed in order to compare the results between cylinder head and modular device using rapid prototype, no statistically significant changes were found. The proposed method represented the investigated cylinder head´s intake air flow.

Nowadays, with the development of electronic and communication technologies, more and more low-cost vehicles such as small, light-weight aircraft are widely applied in all kinds of fields. Ground Station is an essential part of low cost vehicles for the operator to control and monitor the vehicles. In this thesis, Ground Station Display and Flight Management System for Low-Cost Vehicles have been developed.The major objective of this project is to design an intuitive and easy operative Human Machine Interface for displaying and monitoring the flight data and traffic information on ground. Meanwhile, a Graphic User Interface for the Flight Management System has been developed for realizing the waypoints input and flight plan for the vehicles. To fulfill this task, a low-cost hardware and software architecture is presented. Moreover, some COTS tools such as VAPS and MATLAB are applied for the software development because of their Object-Oriented and Rapid Prototype design methods. At the end of project, simulation has been done for the display HMI to test the behaviours of objects and the impacts of display. The trajectory simulation of flight management control panel is also implemented to test the waypoints creation, trajectory generation and smoothing.

A novel method was developed to design and fabricate nozzles capable of producing low-divergence fluid jets. Nozzle apertures were elliptical, and jets exhibited elliptical cross-sections with divergence varying predictably between 0 and 13°. Nozzle aperture aspect ratios varied from 1.00 to 2.45, area was equivalent to that of a 6mm diameter circle. An elliptical jet was developed with 0.4° and 0.9° divergence in the major and minor axes, respectively. Performance of this elliptical nozzle was compared to that of a circular nozzle via profiled creep-feed grinding trials. Results indicate the circular nozzle performs similarly to the horizontal ellipse; the vertical ellipse frequently caused wheel breakdown. Optimized cutting parameters: wheel speed 23m/s, cut depth 1.78mm, feed rate 200mm/min, jet pressure 3.21MPa or greater. Experiments were performed on a Blohm Planomat 408 CNC grinding machine using CimTech 310 cutting fluid. Nozzle experiments used a Brix concentration of 6.1%, grinding experiments used 3.1%.

O presente trabalho propõe a execução de ensaios de medição do número de swirl em bancada de fluxo em regime permanente, com a utilização de um dispositivo modular e dutos de admissão do cabeçote de um motor diesel produzidos via prototipagem rápida (PR). A medição do número de swirl com dutos produzidos via PR, traz como principais vantagens: reprodutibilidade dos ensaios, facilidade de simular e mensurar o número de swirl dos potenciais desvios no processo de fundição ou usinagem, além da redução no tempo para o desenvolvimento de novas geometrias dos dutos de admissão. O trabalho é experimental e uma unidade do cabeçote estudado foi encaminhado para o laboratório da EPUSP e o número de swirl medido para posterior comparação dos dados. Após a fase inicial de aquisição de dados e ajustes no projeto do dispositivo, essa unidade do cabeçote foi seccionada e digitalizada para que a geometria interna fosse reproduzida via prototipagem rápida. Os dutos de admissão foram montados no dispositivo modular para a realização dos testes em bancada. Todos os testes foram realizados no mesmo equipamento e com o mesmo sistema de controle, com o intuito de reduzir o número de variáveis externas na aquisição de dados. Quando realizou-se a comparação das médias dos resultados do número de swirl do cabeçote e do dispositivo modular com o uso de prototipagem rápida não foram encontradas diferenças estatisticamente significantes. O método proposto representou o escoamento de ar da admissão do modelo de cabeçote analisado. / The present work proposes to execute steady state bench test, swirl number measurements, using a modular device and cylinder head intake ports from a diesel engine manufactured via rapid prototype (RP) techniques. Swirl number measurements with intake ports produced by RP, bring as main advantages: Tests reproducibility, easy to measure the swirl number variances in consequence of potential casting or machining process deviations besides of time reduction to the development of new intake ports geometry. The research is experimental and one sample of the investigated cylinder head was sent to the laboratory and the swirl number was measured for later results comparison. After the early development phase of data acquisition and design improvements, this cylinder head sample was then sectioned and digitalized as to know to have the same internal geometry in the intake ports produced via rapid prototype. The intake ports were assembled in the modular device to perform bench tests. All tests were performed in the same rig and with the same control system with aiming to reduce the external variables during data acquisition. When the mean results analysis was performed in order to compare the results between cylinder head and modular device using rapid prototype, no statistically significant changes were found. The proposed method represented the investigated cylinder head´s intake air flow.

A prosthetic socket worn by an amputee must serve a wide variety of functions, from stationary support to the transfer of forces necessary to move. Fit and comfort are important factors in determining the therapeutic effectiveness of a socket. A socket that does not fit the subject well will cause movement problems and potentially long-term health issues. Because a subject's residual limb changes volume throughout the day, it is desirable that the socket adapt to accommodate volume changes to maintain fit and comfort. This thesis presents research to manufacture adaptive sockets using selective laser sintering (SLS). This additive manufacturing process allows freedom to design a socket that has both compliant areas that can adapt to changes to the residual limb, as well as rigid regions to provide necessary support for the limb. A variety of concepts are discussed that are intended for manufacture by SLS, and that feature flexible inner membranes in various configurations. For each concept the membrane will be inflated or deflated to match the limb’s change in volume and the thesis also presents a study to determine SLS machine parameters for optimal build results. A series of experiments was created to understand the ability of SLS manufactured plastics to be inflated and the possible performance. / text

O trabalho trata do estudo do processo de impressão tridimensional e desenvolvimento de uma impressora para a produção de corpos-de-prova cerâmicos. A técnica de impressão tridimensional pertence ao grupo de prototipagem rápida e consiste na obtenção de um corpo sólido a partir de um modelo digital de três dimensões, através do fatiamento do modelo tridimensional e da impressão seqüencial de suas respectivas fatias. Durante o processo de impressão, deposita-se um ligante sobre camadas sucessivas de pó e em cada camada, o ligante consolida o pó no formato bidimensional da fatia, que por fim soma-se as outras fatias subseqüentes, consolidando assim o formato tridimensional do modelo. Os equipamentos convencionais de impressão 3D utilizam pós a base de gesso e acrílico, onde o ligante, a base de água, fornece a primeira adesão química; posteriormente é infiltrada uma resina para fornecer uma ligação com o pó de acrílico. Na impressão de cerâmica a base de alumina ou zircônia, o desenvolvimento de ligantes tem de ser realizado visando à adesão química e orgânica combinadas antes da sinterização. Neste projeto, uma mini impressora 3D para corpos de prova foi desenvolvida e com ela foram produzidos corpos de geometria simples e seção constante, cujo projeto, custo, manutenção simplificada e econômica possibilita também o emprego de materiais agressivos nos ligantes, com risco de danificação de componentes, a exemplo de ácido fosfórico, porém com baixo custo de recuperação. Foram analisados diversos tipos pelo dimensionamento de seus aglomerados, fluidez e densidade. Obteve-se pó a base de gesso por R$15,00 o kilograma. Corpos de prova foram analisados com relação à resistência mecânica por flexão de três pontos, densidade, porosidade aparente e imagens por microscopia ótica e microscopia eletrônica de varredura (MEV). Um protótipo de uma mini-impressora foi idealizado, projetado e fabricado, soluções originais e econômicas foram propostas e na sua validação alguns conceitos necessitam de melhorias, ainda assim foram obtidos resultados promissores. Foi desenvolvida uma formulação de pó baseado em gesso que teve o custo de aproximadamente 5% do produto importado. / The work studies the three-dimensional printing process and the development of a 3D printer to produce ceramic specimen. The 3D printing technique belongs to the rapid prototype group and consists in obtaining a solid body from a three-dimensions digital model, through the slicing of the three-dimensional model and the sequential printing of their respective slices. During the printing process, a binder is deposited upon successive powder layers, and in each layer, the binder consolidates the powder into the bi-dimensional shape of the slice, which ultimately adds to the other slices that followed, consolidating the three-dimensional shape model. The conventional 3D printing equipments uses powder based in gypsum and acrylic, where the water-based binder, provides the first chemical bind; subsequently is infiltrated a resin to provide a binding with the acrylic powder. In the ceramic printing based on alumina or zirconia, the development of binders must be accomplished looking for a organic and chemical bind before sintering. In this project, a mini 3D printer for ceramic specimens was developed and built, with it were be produced bodies of simple geometry and constant section, which design, cost and simplified maintenance and cost also enable the use of aggressive materials in binders, with the risk of components damage, such as phosphoric acid, but with low cost to recovery. Were analyzed several types of powders by the sizing of its clusters, fluidity and density. Were obtained gypsum powder for $ 7.00 a kilogram. The specimen were analyzed in relation to the mechanical strength by three-point bending, density, apparent porosity and images by optical microscopy and scanning electron microscopy (SEM). A prototype of a mini 3D printer was designed, engineered and manufactured, unique and economical solutions have been proposed and in its validation some concepts need of improvement, yet promising results were obtained. It was developed a powder formulation based on gypsum that has cost about 5% of the imported product.

O trabalho trata do estudo do processo de impressão tridimensional e desenvolvimento de uma impressora para a produção de corpos-de-prova cerâmicos. A técnica de impressão tridimensional pertence ao grupo de prototipagem rápida e consiste na obtenção de um corpo sólido a partir de um modelo digital de três dimensões, através do fatiamento do modelo tridimensional e da impressão seqüencial de suas respectivas fatias. Durante o processo de impressão, deposita-se um ligante sobre camadas sucessivas de pó e em cada camada, o ligante consolida o pó no formato bidimensional da fatia, que por fim soma-se as outras fatias subseqüentes, consolidando assim o formato tridimensional do modelo. Os equipamentos convencionais de impressão 3D utilizam pós a base de gesso e acrílico, onde o ligante, a base de água, fornece a primeira adesão química; posteriormente é infiltrada uma resina para fornecer uma ligação com o pó de acrílico. Na impressão de cerâmica a base de alumina ou zircônia, o desenvolvimento de ligantes tem de ser realizado visando à adesão química e orgânica combinadas antes da sinterização. Neste projeto, uma mini impressora 3D para corpos de prova foi desenvolvida e com ela foram produzidos corpos de geometria simples e seção constante, cujo projeto, custo, manutenção simplificada e econômica possibilita também o emprego de materiais agressivos nos ligantes, com risco de danificação de componentes, a exemplo de ácido fosfórico, porém com baixo custo de recuperação. Foram analisados diversos tipos pelo dimensionamento de seus aglomerados, fluidez e densidade. Obteve-se pó a base de gesso por R$15,00 o kilograma. Corpos de prova foram analisados com relação à resistência mecânica por flexão de três pontos, densidade, porosidade aparente e imagens por microscopia ótica e microscopia eletrônica de varredura (MEV). Um protótipo de uma mini-impressora foi idealizado, projetado e fabricado, soluções originais e econômicas foram propostas e na sua validação alguns conceitos necessitam de melhorias, ainda assim foram obtidos resultados promissores. Foi desenvolvida uma formulação de pó baseado em gesso que teve o custo de aproximadamente 5% do produto importado. / The work studies the three-dimensional printing process and the development of a 3D printer to produce ceramic specimen. The 3D printing technique belongs to the rapid prototype group and consists in obtaining a solid body from a three-dimensions digital model, through the slicing of the three-dimensional model and the sequential printing of their respective slices. During the printing process, a binder is deposited upon successive powder layers, and in each layer, the binder consolidates the powder into the bi-dimensional shape of the slice, which ultimately adds to the other slices that followed, consolidating the three-dimensional shape model. The conventional 3D printing equipments uses powder based in gypsum and acrylic, where the water-based binder, provides the first chemical bind; subsequently is infiltrated a resin to provide a binding with the acrylic powder. In the ceramic printing based on alumina or zirconia, the development of binders must be accomplished looking for a organic and chemical bind before sintering. In this project, a mini 3D printer for ceramic specimens was developed and built, with it were be produced bodies of simple geometry and constant section, which design, cost and simplified maintenance and cost also enable the use of aggressive materials in binders, with the risk of components damage, such as phosphoric acid, but with low cost to recovery. Were analyzed several types of powders by the sizing of its clusters, fluidity and density. Were obtained gypsum powder for $ 7.00 a kilogram. The specimen were analyzed in relation to the mechanical strength by three-point bending, density, apparent porosity and images by optical microscopy and scanning electron microscopy (SEM). A prototype of a mini 3D printer was designed, engineered and manufactured, unique and economical solutions have been proposed and in its validation some concepts need of improvement, yet promising results were obtained. It was developed a powder formulation based on gypsum that has cost about 5% of the imported product.

Previous studies have shown that many drivers are unable to provide the right amount of steering torque when facing an imminent collision with an upcoming obstacle. In some cases, drivers under-react i.e., they provide too low steering inputs and thus collide with the obstacle in front; in other cases, drivers might apply a higher steering input than necessary, potentially resulting in the vehicle leaving the road or losing stability. The EMA function is an active safety feature which has the sole objective of providing steering torque interference when performing such a manoeuvre. The motivation for the thesis work is to overcome some limitations of the existing MA function which does not incorporate the ability to differentiate driver reactions. In this thesis, an Evasive Manoeuvre Assist (EMA) function is designed to adapt to both types of the drivers, by an optimised steering torque overlay. The existing current EMA function is always amplifying the driver steering inputs using a feed-forward controller. The focus of this thesis work is to identify and dene a proper steering sequence reference model for closed-loop feedback control design. A simple single-point preview model is designed first to calculate the reference steering angle. A few test scenarios are set-up using the IPG CarMakerTMsimulation tool. The reference model is then tuned with respect to the amplitude and frequency by batch simulations to obtain the optimal steering prole. A feedback controller is then designed using this reference model. The controller is implemented in a real-time environment, using a Volvo rapid-prototype test vehicle. Preliminary variation tests have shown that the developed controller can enhance both an over-reacting and under-reacting driver's performance during an evasive manoeuvre, by applying assistance/resistance EPAS torque timely. The designed EMA function is shown to accommodate different driver reactions and provide intuitive torque interference. As opposed to the earlier notion that the EMA function only assists the driver with an additional steering wheel torque, it was shown that the optimal steering torque overlay might be in the form of assistance or resistance.

No description available.