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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Ferramenta pneumática para movimentação de carrocerias rodoviárias em linhas de montagem / Pneumatic tool to drive road vehicles on assembly lines

Taborda, Gustavo Gomes January 2009 (has links)
Este trabalho apresenta um estudo de caso na indústria de implementos e veículos rodoviários para solução do processo específico de movimentação de veículos e carrocerias rodoviárias nas linhas de montagem. A solução é o desenvolvimento do projeto de uma ferramenta pneumática para atender os parâmetros identificados no processo de movimentação utilizando uma metodologia de projeto. A metodologia adotada é uma composição de modelos sugeridos por autores mostrando uma sequência clara e objetiva do ciclo de vida do projeto, estruturada em quatro fases principais: Projeto Informacional, Projeto Conceitual, Projeto Executivo e Otimização de Projeto. A identificação das informações relevantes ao processo de movimentação dos produtos deu início ao Projeto Informacional. Com a finalidade de conhecer melhor as características dos processos dos potenciais usuários da ferramenta, foram levantadas as características e os parâmetros do processo. Os parâmetros abordam as principais grandezas envolvidas no sistema e suas limitações. Os dados resultantes do levantamento foram analisados gerando uma síntese de todos os parâmetros identificados para o desenvolvimento das próximas fases. No projeto conceitual, houve a evolução da solução através do detalhamento de um conceito, escolhido mediante a proposição de alternativas durante a geração de conceitos. O detalhamento é apresentado através de desenhos, segundo a diretriz de projeto orientado ao computador, com base na estrutura funcional de funcionamento da ferramenta, salientando os principais sistemas e suas configurações. Os dimensionamentos são apresentados no projeto executivo e contemplam dois tipos de análise: a análise cinemática e a análise estrutural do sistema. Na análise cinemática são apresentadas duas propostas de configuração para o motor pneumático que será utilizado na ferramenta. As propostas são expostas através de desenhos de montagem, desenhos explodidos e gráficos dos parâmetros do motor pneumático para cada uma das configurações adotadas. Nesta fase também é mostrada a construção do protótipo. Os resultados do projeto são obtidos através da realização de teste em bancada e em campo para confirmação dos parâmetros estabelecidos. Completando o ciclo de vida do projeto, propõem-se as tendências evolutivas, analisando as possíveis melhorias para a ferramenta. As conclusões do trabalho são baseadas nos resultados apresentados nos testes realizados com a ferramenta, na eficiência da metodologia adotada para o desenvolvimento do projeto e na análise do cumprimento dos objetivos definidos no trabalho. / This paper presents a case study in industry of road road vehicles for solution of the specific handling of road vehicles and truck trailers in assembly lines. The solution is to develop the design of a pneumatic tool to meet the criteria identified in the move process using a design methodology. The methodology used is a composite of models suggested by the authors showed a clear sequence and objective of the life cycle of the project, divided into four main phases: Informational Design, Conceptual Design, Executive Design and Optimization Project. The identification of information relevant to the process of transferring products initiated the Informational Design. In order to better understand the nature of the processes of potential users of the tool has been raised the characteristics and process parameters. The parameters to approach the main quantities involved in the system and its limitations. Data from the survey were analyzed by generating a synthesis of all parameters identified for the development of the next phases. In conceptual design, was the evolution of the solution through the details of a concept, chosen by proposing alternatives for the generation of concepts. The detail is presented through drawings, according to the guideline of design aided computer based functional structure operating the tool, highlighting the major systems and their configurations. The detail is presented in the executive project and includes two types of analysis: kinematic analysis and structural analysis of the system. In the kinematic analysis are presented two proposals for setting for the air motor to be used in the tool. The proposals are exposed through the assembly drawings, exploded drawings and graphics of the parameters of the air motor for each of the configurations adopted. This stage is also shown a prototype. The project results are obtained by performing test bench and field tests to confirm the established parameters. Completing the life cycle of the project, propose to the changing trends, and review possible improvements to the tool. The conclusions of the study are based on the results presented in the tests with the tool, the efficiency of the methodology used to develop the design and analysis of compliance with the defined objectives at work.
12

Ferramenta pneumática para movimentação de carrocerias rodoviárias em linhas de montagem / Pneumatic tool to drive road vehicles on assembly lines

Taborda, Gustavo Gomes January 2009 (has links)
Este trabalho apresenta um estudo de caso na indústria de implementos e veículos rodoviários para solução do processo específico de movimentação de veículos e carrocerias rodoviárias nas linhas de montagem. A solução é o desenvolvimento do projeto de uma ferramenta pneumática para atender os parâmetros identificados no processo de movimentação utilizando uma metodologia de projeto. A metodologia adotada é uma composição de modelos sugeridos por autores mostrando uma sequência clara e objetiva do ciclo de vida do projeto, estruturada em quatro fases principais: Projeto Informacional, Projeto Conceitual, Projeto Executivo e Otimização de Projeto. A identificação das informações relevantes ao processo de movimentação dos produtos deu início ao Projeto Informacional. Com a finalidade de conhecer melhor as características dos processos dos potenciais usuários da ferramenta, foram levantadas as características e os parâmetros do processo. Os parâmetros abordam as principais grandezas envolvidas no sistema e suas limitações. Os dados resultantes do levantamento foram analisados gerando uma síntese de todos os parâmetros identificados para o desenvolvimento das próximas fases. No projeto conceitual, houve a evolução da solução através do detalhamento de um conceito, escolhido mediante a proposição de alternativas durante a geração de conceitos. O detalhamento é apresentado através de desenhos, segundo a diretriz de projeto orientado ao computador, com base na estrutura funcional de funcionamento da ferramenta, salientando os principais sistemas e suas configurações. Os dimensionamentos são apresentados no projeto executivo e contemplam dois tipos de análise: a análise cinemática e a análise estrutural do sistema. Na análise cinemática são apresentadas duas propostas de configuração para o motor pneumático que será utilizado na ferramenta. As propostas são expostas através de desenhos de montagem, desenhos explodidos e gráficos dos parâmetros do motor pneumático para cada uma das configurações adotadas. Nesta fase também é mostrada a construção do protótipo. Os resultados do projeto são obtidos através da realização de teste em bancada e em campo para confirmação dos parâmetros estabelecidos. Completando o ciclo de vida do projeto, propõem-se as tendências evolutivas, analisando as possíveis melhorias para a ferramenta. As conclusões do trabalho são baseadas nos resultados apresentados nos testes realizados com a ferramenta, na eficiência da metodologia adotada para o desenvolvimento do projeto e na análise do cumprimento dos objetivos definidos no trabalho. / This paper presents a case study in industry of road road vehicles for solution of the specific handling of road vehicles and truck trailers in assembly lines. The solution is to develop the design of a pneumatic tool to meet the criteria identified in the move process using a design methodology. The methodology used is a composite of models suggested by the authors showed a clear sequence and objective of the life cycle of the project, divided into four main phases: Informational Design, Conceptual Design, Executive Design and Optimization Project. The identification of information relevant to the process of transferring products initiated the Informational Design. In order to better understand the nature of the processes of potential users of the tool has been raised the characteristics and process parameters. The parameters to approach the main quantities involved in the system and its limitations. Data from the survey were analyzed by generating a synthesis of all parameters identified for the development of the next phases. In conceptual design, was the evolution of the solution through the details of a concept, chosen by proposing alternatives for the generation of concepts. The detail is presented through drawings, according to the guideline of design aided computer based functional structure operating the tool, highlighting the major systems and their configurations. The detail is presented in the executive project and includes two types of analysis: kinematic analysis and structural analysis of the system. In the kinematic analysis are presented two proposals for setting for the air motor to be used in the tool. The proposals are exposed through the assembly drawings, exploded drawings and graphics of the parameters of the air motor for each of the configurations adopted. This stage is also shown a prototype. The project results are obtained by performing test bench and field tests to confirm the established parameters. Completing the life cycle of the project, propose to the changing trends, and review possible improvements to the tool. The conclusions of the study are based on the results presented in the tests with the tool, the efficiency of the methodology used to develop the design and analysis of compliance with the defined objectives at work.
13

Desenvolvimento de um sistema de atuação magnética para excitação de sistemas rotativos / Development of a magnetic actuation system to rotating system excitation

Mendes, Ricardo Ugliara, 1987- 17 August 2018 (has links)
Orientadores: Kátia Lucchesi Cavalca Dedini, Luiz Otávio Saraiva Ferreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-17T15:03:09Z (GMT). No. of bitstreams: 1 Mendes_RicardoUgliara_M.pdf: 2835811 bytes, checksum: c8cae753b116c3893246e25fb64fdf4c (MD5) Previous issue date: 2011 / Resumo: Máquinas rotativas apresentam um vasto campo de aplicação como aeronaves, fábricas, laboratórios e usinas de energia. Estas aplicações contêm eixos girando a altas velocidades que devem ter alto nível de confiabilidade. Assim, a análise do comportamento dinâmico destas bombas e turbinas é necessária para estabelecer padrões de funcionamento do equipamento. Ultimamente, com projetos feitos com auxílio de computador, modelos de elementos finitos de eixos incluindo mancais, discos, selos e acoplamentos têm sido desenvolvidos. Através destes modelos, o comportamento das máquinas pode ser previsto, permitindo projetos otimizados baseados nos cálculos de velocidades críticas e simulações de instabilidades do filme de óleo. Estas informações fornecem a base para o desenvolvimento de controladores para reduzir vibrações durante a partida de máquinas, assim como aceleração ou desaceleração através das velocidades críticas, ou ainda para controlar instabilidades do filme de óleo. Uma das técnicas aplicadas na identificação de parâmetros de máquinas e estruturas é a análise modal, a qual consiste em aplicar uma força de perturbação no sistema e, então, medir sua resposta. Entretanto, há uma dificuldade que traz limitações à excitação de sistemas com eixos rotativos, quando utilizando martelos de impacto ou shakers, uma vez que, devido ao atrito, forças tangenciais e ruídos indesejados podem ser aplicados ao sistema. Portanto, o estudo de uma técnica de excitação externa sem contato se torna de grande interesse. Neste sentido, o presente trabalho trata do estudo e desenvolvimento de um modelo em elementos finitos de máquinas rotativas integrado ao modelo de um atuador magnético como fonte de excitação externa, focando na resposta do modelo e sua interação com o atuador. Também é apresentada uma comparação entre simulações numéricas e testes práticos obtidos de uma bancada experimental / Abstract: Rotating machines have a wide range of application such as airplanes, factories, laboratories and power plants. These applications contain shafts rotating at high speeds that must have high trust levels. Thus, the dynamic behavior analysis of these pumps and turbines is required to establish operational patterns of the equipment. Lately, with computer aid design, shafts finite element models including bearings, discs, seals and couplings have been developed. Through these models the machines behavior can be predicted, allowing optimized design based on the critical speeds calculus and oil instabilities simulations. These informations provide the basis for controller development in order to reduce vibrations during the machines start-up and acceleration or deceleration through the critical speeds, or even to control oil instabilities. One of the technique es applied in parameters identification of machines and structures is the modalanalysis, which con sists of applying a perturbation force into the system and then to measure its response. However, there is a difficulty that brings limitations to the excitation of systems with rotating shafts when using impact hammers or shakers, due to friction, undesired tangential forces and noise that can be applied to the system. Therefore, the study of a non-contact technique of external excitation becomes of high interest. In this sense, the present work deals with the study and development of a finite element model for rotating machines using a magnetic actuator as source of external excitation, focusing on the model response and its interaction with the actuator. It is also presented a comparison between the numerical simulations and practical tests obtained from a rotor test rig / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica
14

Design optimization and testing of electrical connector for low voltage transmission cabinets : In collaboration with ABB AB Kabeldon

Chandrappa Kori, Vinay Kumar, Radhakrishnan Ganesan, Gowtham Prasath January 2019 (has links)
Abstract: This thesis work was a part of Halmstad University’s Mechanical Masterprogramme curriculum done in favour of ABB Alingsås. Our industrial partnerproduces and manufactures low voltage electrical distribution cabinets, connectorsand switch gears. This project is focused on specific electrical connector used inABB’s trademark cabinets. These electrical connectors serve as both the input and output points for thedistribution cabinets. The product under scope is an extension connector calledADI3M which is used in conjunction with the large sized cable connectors(AD300). This is a sequential design optimization activity performed after theredesigning of the AD300 to ensure interface compatibility and also aimed atopportunistic cost reduction. The ADI3M should provide design compatibility withboth old and new AD300 connector designs along with the comfortable interfacinginside the CDC and SDC cabinets. With the design process and concepting knowledge gained from the course work inHalmstad university along with the ABB’s industrial exposure towards the powersupply networks we proposed four different design concepts. These design conceptswere then evaluated against interface compatibility, cost aspects, manufacturingreadiness, mechanical strength, heat generation and electricity conductionproperties. Among the product development techniques, we applied QFD processto generate the concepts, waterfall method to frame the engineering design processflow and morphological matrix to select the generated concepts. We then changedthe raw material from brass to aluminium and extrusion process due to its beneficialproperties compared to brass and copper with various other reasons explainedclearly in the thesis content. For the plastic cover we preferred poly-carbonate dueto requirements such as transparency, stiffness, etc. Two of the best feasibleconcepts were selected and the design proposals were prototyped using 3D printingtechnology. The 3D printing method used was fused deposition modelling (FDM).Later machined aluminium prototypes were then produced for the metalsubcomponents to do real time strength analysis and interface checks. Weperformed a theoretical product strength analysis using ANSYS19.2. Then resultswere then evaluated, and the final concept was chosen according to the factors suchas cost impact, easy installation and comfortable inter-component clearance.Finally, the prototypes were tested for IP rating fulfilment and compatible interfaceswith adjacent components. The consecutive activities to be done out of thesis scope is to conduct mechanicaland tests and record the performance. The future scope of this project is to developa hybrid design combining the AD300 and ADI3M connectors which would enableeasy product handling, simplified functionality and further reduce cost.
15

Object Oriented CAE Software for the Exploration and Design of Microstructures

Sintay, Stephen D. 23 November 2005 (has links) (PDF)
Through the use of generalized spherical harmonic basis functions a spectral representation is used to model the microstructure of cubic materials. This model is then used to predict the macroscopic elastic and plastic properties of materials with cubic crystal symmetry and various sample symmetry including triclinic and axial—symmetric. Building on the work of citeN{Barnett-FractureMechanics} the influence that anisotropy has on the fatigue response of the material is also modeled. This is accomplished through using the effective elastic stiffness tensor in the computation of crack extension force G. The resulting material model and macroscopic property calculations are the foundation for a software package which provides an interface to the microstructure. The Microstructure Sensitive Design interface (MDSi) enables interaction with the material design process and provides tools needed to incorporate material parameters with traditional design, optimization, and analysis software. Therefore the microstructure model can be optimized concurrently with a geometric model to further increase the overall design space. The software is then be used to explore how changes in the microstructure affect the performance of a turbine disc. The additional design space afforded by inclusion of the material parameters show that the total mass of the disk can be lowered by 9.5%. Additionally when the same geometry and loading conditions are considered and only the texture of the material is modified G is reduced be more than an order of magnitude.
16

The Mechanical Design of a Suspension Parameter Identification and Evaluation Rig (SPIdER) for Wheeled Military Vehicles

Wagner, Timothy Paul 16 December 2011 (has links)
No description available.
17

Mechanical Redesign and Fabrication of a 12 DOF Orthotic Lower Limb Exoskeleton and 6 Axis Force-Torque Sensor

Goodson, Caleb Benjamin 27 October 2020 (has links)
This thesis details several modifications to the mechanical design of the Orthotic Lower Limb Exoskeleton (OLL-E) that improve upon the functionality and manufacturability of parts and their assemblies. The changes made to these parts maintain or improve the factor of safety against yield and fatigue failure as compared to the original designs. Design changes are verified by FEA simulations and hand calculations. The changes included in this thesis also allowed parts that were previously difficult or impossible to manufacture using traditional methods to be made in house or outsourced to another machine shop. In addition to the mechanical design changes, this thesis also details the design and implementation of a six axis force-torque sensor built into the foot of OLL-E. The purpose of this sensor is to provide feedback to the central control system and allow OLL-E to be self-balancing. This foot sensor design is calibrated and initial results are discussed and shown to be favorable. / Master of Science / Recent developments in the fields of robotics and exoskeleton design have increased their feasibility for use in medical rehabilitation and mobility enhancement for persons with limited mobility. The Orthotic Lower Limb Exoskeleton (OLL-E) is an exoskeleton specifically designed for enhancing mobility by allowing users with lower limb disabilities such as spinal cord injuries or paraplegia to walk. The research detailed in this thesis explains the design and manufacturing processes used to make OLL-E as well as providing design details for a force sensor built into the exoskeleton foot. Before manufacturing could take place some parts needed to be redesigned and this thesis provides insight into the reasons for these changes. After the manufacturing and design process was completed the OLL-E was assembled and the project can now move forward with physical testing.
18

Design and Implementation of Articulated Robotic Tails to Augment the Performance of Reduced Degree-of-Freedom Legged Robots

Saab, Wael 24 April 2018 (has links)
This dissertation explores the design, and implementation of articulated robotic tail mechanisms onboard reduced degree-of-freedom (DOF) legged robots to augment performance in terms of stability and maneuverability. Fundamentally, this research is motivated by the question of how to improve the stability and maneuverability of legged robots. The conventional approach to address these challenges is to utilize leg mechanisms that are composed of three or more active DOFs that are controlled simultaneously to provide propulsion, maneuvering, and stabilization. However, animals such as lizards and cheetahs have been observed to utilize their tails to aid in these functionalities. It is hypothesized that by using an articulated tail mechanism to aid in these functionalities onboard a legged robot, the burden on the robot's legs to simultaneously maneuver and stabilize the robot may be reduced. This could allow for simplification of the leg's design and control algorithms. In recent years, significant progress has been accomplished in the field of robotic tail implementation onboard mobile robots. However, the main limitation of this work stems from the proposed tail designs, the majority of which are composed of rigid single-body pendulums that provide a constrained workspace for center-of-mass positioning, an important characteristics for inertial adjustment applications. Inspired by lizards and cheetahs that adjust their body orientation using flexible tail motions, two novel articulated, cable driven, serpentine-like tail mechanisms are proposed. The first is the Roll-Revolute-Revolute Tail which is a 3-DOF mechanism, designed for implementation onboard a quadruped robot, that is capable of forming two mechanically decoupled tail curvatures via an s-shaped cable routing scheme and gear train system. The second is a the Discrete Modular Serpentine Tail, designed for implementation onboard a biped robot, which is a modular two-DOF mechanism that distributes motion amongst links via a multi-diameter pulley. Both tail designs utilize a cable transmission system where cables are routed about circular contoured links that maintain equal antagonistic cable displacements that can produce controlled articulated tail curvatures using a single active-DOF. Furthermore, analysis and experimental results have been presented to demonstrate the effectiveness of an articulated tail's ability to: 1) increase the manifold for center-of-mass positioning, and 2) generate enhanced inertial loading relative to conventionally implemented pendulum-like tails. In order to test the tails ability to augment the performance of legged robots, a novel Robotic Modular Leg (RML) is proposed to construct both a reduced-DOF quadrupedal and bipedal experimental platform. The RML is a modular two-DOF leg mechanism composed of two serially connected four-bar mechanisms that utilizes kinematic constraints to maintain a parallel orientation between it's flat foot and body without the use of an actuated ankle. A passive suspension system integrated into the foot enables the dissipation of impact energy and maintains a stable four point-of-contact support polygon on both flat and uneven terrain. Modeling of the combined legged robotic systems and attached articulated tails has led to the derivation of dynamic formulations that were analyzed to scale articulated tails onboard legged robots to maximize inertial adjustment capabilities resulting from tail motions and design a control scheme for tail-aided maneuvering. The tail prototypes, in conjunction with virtual simulations of the quadruped and biped robot, were used in experiments and simulations to implement and analyze the methods for maneuvering and stabilizing the proposed legged robots. Results successfully demonstrate the tails' ability to augment the performance of reduced-DOF legged robots by enabling comparable walking criteria with respect to conventional legged robots. This research provides a firm foundation for future work involving design and implementation of articulated tails onboard legged robots for enhanced inertial adjustment applications. / Ph. D.
19

Shooting Target - Konstruktion : Product Development

Bergkvist, Marcus, Åkerblom, Christopher January 2014 (has links)
The shooting sport is one of the most widespread sports in the world and it is being practice in most countries. Based on their own experiences, in competition - and hobby shooting, the client M4Solutions found a demand and need for a shooting target that is manufactured in Sweden. The purpose of the project has been to develop, with the help of Marcus Walldén, two shooting targets from idea to finished product. These two shooting targets, Plate Rack Target and Dueling Tree, would each be equipped with a mechanical resetting system but will in the future have the ability to be provided with an electronic resetting system. The project from the client was divided into two theses. One of these two, written by Marcus Walldén, focused on the tripod parts and the overall design work for both Plate Rack Target and Dueling Tree. The thesis that is presented in this report have focused on resetting systems, the design of protective plates and other peripherals for both shooting targets. This work has primarily been in CAD environment where design, construction and development has been given free rein. Calculations, test shootings and choice of materials has been made in order to reach the best possible solutions. The thesis resulted in two complete 3D models and two full-scale prototypes of steel.
20

Projeto de máquina de usinagem de esferas cerâmicas verdes / Design of a grinding machine of green ceramic balls

Pedroso, Marcos Paulo Gonçalves 28 August 2015 (has links)
O presente trabalho trata do projeto e da fabricação de uma mini máquina para usinagem de esferas cerâmicas verdes. Esferas de cerâmicas avançadas encontram grande aplicação em componentes de alta precisão como rolamentos híbridos ou como a cabeça de próteses de quadril. A grande demanda pelas esferas de cerâmicas avançadas nesses componentes se deve à combinação única de suas propriedades tais como: alta estabilidade dimensional, alta dureza, baixo coeficiente de expansão térmica, biocompatibilidade (bioinerte) e alta resistência mecânica à compressão. No entanto o alto desempenho só será alcançado se as esferas tiverem tolerâncias estreitas (dimensão e forma) e acabamento superficial ultrafino. Esse trabalho objetiva o projeto e a fabricação de um protótipo de mini máquina para usinagem de esferas cerâmicas prensadas de até 30 mm de diâmetro. O desenvolvimento do projeto foi dirigido por uma metodologia de projeto mecânico e após definição do conceito foi gerado um pré-projeto virtual seguido da fabricação de um protótipo, o conceito é composto por três rebolos, sendo dois de arraste que, tendo velocidades e direções de giro variáveis, promovem a variação do eixo de giro das esferas, parâmetro necessário para atingir baixo desvio de esfericidade. Blanks esféricos em zircônia foram conformados por prensagem isostática e usinados no protótipo construído. As esferas passaram pela caracterização metrológica através da medição de esfericidade, circularidade e acabamento superficial. / This work deals with the design and manufacturing of a mini machine for grinding of green ceramic balls. Balls of advanced ceramics find wide application in high-precision components such as hybrid bearings or as bearings of hip prostheses. The large demand for advanced ceramic balls in these components is due to their unique combination of properties such as high dimensional stability, high hardness, low coefficient of thermal expansion, biocompatibility (bio inert) and high compressive strength. However the high performance can only be achieved if the balls have narrow tolerances (size and shape) and ultra-fine surface finish. This work aims to design and manufacture a mini prototype machine to obtain a green ceramic balls up to 30 mm in diameter. The project development was driven by a mechanical design methodology and after the concept generation a virtual pre-design has been generated followed by manufacturing a prototype, the initial concept is composed of three wheels, two of drag that having variables turning speeds and directions, promote a random orbital effect in the balls necessary to reduce the sphericity error. Spherical zirconia blanks were shaped by isostatic pressing and machined in the built prototype. The balls were characterized by measuring sphericity error and surface roughness.

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