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Hybrid modelling of machine tool axis drives.Whalley, R., Ebrahimi, Kambiz M., Abdul-Ameer, A.A. January 2005 (has links)
No / The x-axis dynamics of a milling machine where the workpiece and saddle are mounted on supporting slides is considered. A permanent magnet motor, lead screw, ball nut and bearings are employed as the machine, traverse actuator mechanism. Hybrid, distributed¿lumped parameter methods are used to model the machine tool x-axis drive system. Inclusion of the spatial configuration of the drive generates the incident, travelling and reflected vibration signature of the system. Lead screw interactive torsion and tension loading, which is excited by cutting and input disturbance conditions, is incorporated in the modelling process. Measured and results from simulation exercises are presented in comparative studies enabling the dynamic characteristics of the machine to be identified under, no load and with the application of cyclic, cutting force disturbances. The effect of the lead screw length, cutting speed and hence the load disturbance frequency are examined and the resulting performance accuracy is commented upon.
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Tool wear in titanium machining / Förslitning av skärverktyg vid svarvning av titanOdelros, Stina January 2012 (has links)
The present work was performed at AB Sandvik Coromant as a part in improving the knowledge and understanding about wear of uncoated WC/Co cutting tools during turning of titanium alloy Ti-6Al-4V. When machining titanium alloys, or any other material, wear of the cutting tools has a huge impact on the ability to shape the material as well as the manufacturing cost of the finished product. Due to the low thermal conductivity of titanium, high cutting temperatures will occur in narrow regions near the cutting edge during machining. This will result in high reaction and diffusion rates, resulting in high cutting tool wear rates. To be able to improve titanium machining, better knowledge and understanding about wear during these tough conditions are needed. Wear tests were performed during orthogonal turning of titanium alloy and the cutting tool inserts were analysed by SEM, EDS and optical imaging in Alicona InfiniteFocus. Simulations in AdvantEdge provided calculated values for cutting temperatures, cutting forces and contact stresses for the same conditions as used during wear tests. It was found that turning titanium alloy with WC/Co cutting tools at cutting speeds 30-60 m/min causes chamfering of the cutting tool edge and adhesion of a build-up layer (BUL) of workpiece material on top of the rake face wear land. The wear rate for these low cutting speeds was found to be almost unchanging during cutting times up to 3 minutes. During cutting speeds of 90-115 m/min, crater wear was found to be the dominating wear mechanism and the wear rate was found to have a linear dependence of cutting speed. An Arrhenius-type temperature dependent wear mechanism was found for high cutting speeds, between 90 and 115 m/min.
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Geostrategy and the doctrines function : A case study of the Swedish doctrines MSD12 and MSD16Jungestrand, Michael January 2018 (has links)
In the field of war studies there is an ongoing debate about the understanding of the doctrine. A common understanding of the doctrine is important not only within the field of research but also because it creates a common language among its users which reduces the risk of misunderstandings. Harald Høiback, an important player in the matter, claims that a nations prolonged geostrategic situation predicts its doctrines content with regard to its function. These functions are to act as tools of command, education and change. The main aim of this essay is to make a contribution to the debate by testing Høiback´s predication. In a case study of the Swedish strategic doctrines MSD12 and MSD16, Høiback´s predication is tested using qualitative text analysis. The main finding of this essay is that a doctrine can change its function as tool of command faster than Høiback's assertion predicts.
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Návrh kompaktního stroje pro třískové obrábění klíčů / Entwurf einer Kompaktmaschine zur SchlüsselbearbeitungŽůrek, František January 2017 (has links)
This master thesis Design of a machine tool for a safety keys production deals with concept of a machine tool for production of safety keys. Solution variants are methodically elaborated, mainly concerning their achieved tact times and machine dimensions. A computation diagram for fast comparison of concepts in case of different customer key specification is presented. Chosen concept version is then detailed designed. The result fills a hole on the market of specific machine tools for machining of safety keys.
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Escolha de ferramentas na quebra de cocos por macacos-prego (Sapajus spp.): Efeitos da forma das ferramentas / Tool selection for nut cracking by capuchin monkeys (Sapajus spp.): tool\'s shape effectsArdila, Andrés David Ballesteros 02 February 2015 (has links)
Existe ampla evidência do nível de seletividade exibido por macacos-prego (Sapajus sp) em situações de escolha de ferramentas para a quebra de frutos encapsulados; indicando que as características dos martelos (material, peso e distância de transporte), assim como as características físicas próprias dos indivíduos, afetam a eficiência do na quebra e determinam o processo individual de tomada de decisões no uso de ferramentas. Considerando a predição de que também é provável que a eficiência na quebra seja dependente do controle do macaco sobre a pedra e do ângulo de impacto; o presente trabalho teve como objetivo avaliar experimentalmente se a forma das ferramentas afeta a eficiência na quebra e é levada em consideração pelos macacos-prego, na hora de escolher as ferramentas a serem usadas. Para tal, testamos a escolha de pedras por cinco macacos-prego semilivres usuários de ferramentas - fazendo uso de pedras artificiais e realizando tentativas discretas de escolha com participação livre dos indivíduos - através de um delineamento fatorial de medidas repetidas com oito condições experimentais, correspondentes às possíveis combinações de três variáveis independentes em dois níveis: forma dos martelos (possibilidades de pegada e superfície potencial de contato), peso (leve e pesado) e distância de transporte exigida (perto e longe das bigornas). Avaliamos a seletividade exibida, os comportamentos manipulativos exploratórios e a proficiência natural de quebra de cada sujeito, visando elucidar os fatores determinantes do processo de escolha de ferramentas para a quebra de frutos. Os resultados apontam preferência dos macacos-prego pelos martelos que fornecem maior eficiência, pedras com maior possibilidade de pegada e maior superfície potencial de contato no golpe, aumentando os benefícios e diminuindo os custos do uso. Não encontramos um efeito evidente das variáveis de custo (peso e distância de transporte) sobre a preferência pelas características da forma, nem foi encontrada uma relação entre a preferência exibida em condições experimentais com o engajamento e proficiência natural dos indivíduos na quebra de cocos. Finalmente, verificamos que os macacos-prego baseiam suas escolhas principalmente a partir das dicas visuais, não obstante exibirem comportamentos manipulativos exploratórios que possivelmente permitem ganhar informação adicional sobre as propriedades da forma das ferramentas para realizar a escolha / Evidences point out that capuchin monkeys select stone tools for nut cracking based on the physical characteristics of tools (material, weight, transporting distance) in relation to their own physical characteristics (size, weight), and that selectivity seems to affect the efficiency of nut cracking, determining individual decision making in tool use. Considering the prediction that nut crack efficiency is affected by individual control, the stone and the impact angle; this study aimed to evaluate experimentally if the tools shape affect nut crack efficiency, and if this is considered in individual tool selection. We tested the choices of five semi-free individuals using artificial designed tools in eight different experimental conditions, manipulating hammers weight, shape and distance to the anvil, to determine the factors involved in tool selection process for nut cracking. The results shows the monkeys prefer hammers that increase cracking nut efficiency, with more holding possibility, and higher potential contact surface in the bites. There was no evidence for effect of variables related with costs (hammer weight and transporting distance) on the shape preference, and there was no relation between preferences in experimental conditions and engage or efficiency in baseline. We found that the capuchin monkeys based their tool choices in visual characteristics and exhibit manipulative exploratory behaviors that allow them to gain information about the tools shape to make choices
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Design and analysis of integrally-heated tooling for polymer compositesAbdalrahman, Rzgar January 2015 (has links)
Tooling design is crucial for the production of cost-effective and durable composite products. As part of the current search for cost reduction (by reducing capital investment, energy use and cycle time), integrally-heated tooling is one of the technologies available for ‘out-of-autoclave’ processing of advanced thermoset polymer composites. Despite their advantages, integrally-heated tools can suffer from uneven distribution of temperature, variability in heat flow rate and inconsistency in heating/cooling time. This research, therefore, investigates a number of design variables such as shape and layout of heating channels in order to improve the heating performance of an integrally-heated tool. Design of Experiments (DoE) has been carried out using Taguchi’s Orthogonal Array (OA) method to set several combinations of design parameters. Each of these design combinations has been evaluated through numerical simulation to investigate heating time and mould surface temperature variation. The simulation results suggest that the layout of the channels and their separation play a vital role in the heating performance. Signal-to-Noise (S/N) ratio and analysis of variance (ANOVA) have been applied to the results obtained to identify the optimal design combination of the integrally-heated tool. Statistical analysis reveals that the heating performance of an integrally-heated tool can be significantly improved when the channels’ layout is parallel. The shape of the channels has negligible effect and the distance between the channels should be determined based on the production requirement. According to the predicted optimal design, a developed integrally water-heated tool is manufactured. The actual thermal properties of the constituent materials of the produced tool are also measured. Then a numerical model of the experimental tool model is simulated in ANSYS software, with setting the actual material properties and boundary condition to define the temperature uniformity and heating rate of the experimental tool. Comparison of the experimental and numerical results of the experimental tool confirmed the well assigning of the boundary conditions and material properties during simulation the heated tool. The experimental results also confirmed the predicted optimal design of the integrally heated tool. Finally, in order to define its thermomechanical behaviour under the effective (in service) thermal loads, a tool model is simulated. Numerical results presented that the produced extremes of thermal deformation, elastic strain, normal and plane shear stresses, under the effective thermal loading, are within the allowable elastic limits of the participated materials.
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Tool Life Characterization in Refill Friction Stir Spot WeldingBelnap, Ruth Guadalupe 20 June 2024 (has links) (PDF)
As light-weighting becomes a priority for the automotive industry, refill friction stir spot welding emerges with enormous potential to supplement or replace conventional spot joining processes. This thesis addresses the limitations of current tooling options by examining materials beyond steel for use in RFSSW. Contained herein is an analysis of weld quality as a function of tool material, a production evaluation of RFSSW using various tool materials, and an assessment of long-term performance of a tungsten carbide tool. Over the course of this research, tungsten carbide emerged as a viable candidate for long-lasting RFSSW tooling.
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Correlation between chainsaw type and tool marks in sectioned boneMoore, Gregory 22 January 2016 (has links)
This research determined if the patterns resulting from different chainsaw chain types impacting bone leave tool marks are dissimilar enough from one another to determine which type of chainsaw was used in dismemberment mimicking homicide cases. Multiple styles of commercially available chainsaw chains were used. The long bones of adult white tailed deer (Odocoileus virginianus) were cut to produce false start cuts and complete sectioning to mimic typical human dismemberment. The cut areas were examined macroscopically and microscopically to note features common to each chain. The chains were compared to one another to note differences. It was proposed that each chainsaw would leave different tool marks. It was found that the style of tooth significantly affects the size of the exit chipping, size of the breakaway notch, angling of the kerf floor, and the mass of bone wastage produced. The most significant differences were produced with a standard tooth. The skip of the chainsaw did not create significant differences. This research has applications in forensic anthropology through the additional information on tool marks and the ability to identify specific tool types. The information is also useful to law enforcement investigations involving dismemberments.
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Scoreboard ToolSrinivasan, Anush January 1900 (has links)
Master of Science / Department of Computing and Information Sciences / Daniel A. Andresen / Scoreboard tool is a web application developed to provide a platform where administrators can conduct quizzes (typically in an organization) or employees can take a quiz (individually or in a team). These quizzes are generally conducted to improve the knowledge of the users (typically employees) taking the quiz.
This project is a tool where the user can take online quizzes which comprise of various categories like technology, science, math etc . The categories have various sub-categories. The admin can also perform CRUD on teams. The quizzes are created by the admin using a database which has the questions for the quizzes. The quizzes are basically divided into quizzes with multiple choice questions and timed quizzes where a user has a specified time to complete the quiz. Once a user logs in he can view his quiz history where he can view the scores of the various quizzes taken and also the time and date when taken. At the end of the quiz the user is given the option of rating the quiz and also entering his/her opinion of the quiz. The users will also have an option to view their scores graphically and compare their scores with other teams in the form of reports and also as graphs.
The important feature of this application is that the scores will be reported using reporting services. And another important feature is instead of manually testing the application test cases will be written for automated testing.
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The application of computer simulation to the development of manufacturing strategiesSmith, James Martin January 1997 (has links)
No description available.
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