Orientador: Celso Kazuyuki Morooka / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-23T20:08:04Z (GMT). No. of bitstreams: 1 Mendes_JoseRicardoPelaquim_M.pdf: 6979997 bytes, checksum: cb7b7cacbcb91fb76e57ca2cad3585fc (MD5) Previous issue date: 1998 / Resumo: Uma série de trabalhos desenvolvidos com o uso do conceito de Sistemas Inteligentes Distribuídos, criando agentes de raciocínio fornecido por especialistas em diversas áreas do Petróleo, implementadas em um shell específico (Kards), tem vislumbrado um grande potencial do uso desta tecnologia no ramo do Petróleo. Na seleção de brocas para a perfuração de poços de Petróleo, o objetivo é alcançar um mínimo custo métrico, sendo a seleção na prática realizada através de poços de correlação e na própria experiência do engenheiro de perfuração. O uso de métodos analíticos geralmente necessitam de informações expendiosas além de ser uma tarefa árdua devido a complexibilidade do problema. Nesta dissertação é apresentado um método de preservação do conhecimento especializado no processo de seleção de brocas tricônicas através de redes neurais, lógica nebulosa e ferramentas disponíveis no Sistema Kards. Este trabalho serviu de base para arquitetar um Sistema Inteligente para o auxílio de seleção de brocas tricônicas, sendo útil também em termos de treinamento de novos engenheiros / Abstract: A series of works developed using the concept of Distributed Intelligent Systems, creating agents of reasoning provided by experts in several areas of Petroleum, structured in a specific shell (Kards), has glimpsed a great potencial of this technology in Petroleum sector. ln the bit selection to drill oil well, the objective is to obtain a minimum metric cost, being the selection in practice realized using correlation wells and in drilling engineers experience. The use of analytical methods usually needs extensive informations and moreover it is hard job owing to complexity of the problem. ln the thesis is presented a method of preservations of specialized knowledge jn triconics drills selection process using neural nets, fuzzy logic and available tools in the Kards System. This work was a base to construct an lntelligent System for the assistance of triconics drills selection, being also useful to fit to training of engineers / Mestrado / Mestre em Engenharia de Petróleo

Improvement of manufacturing productivity is dependent on the successful automation of manufacturing processes, the success of which is based in turn upon the availability of information which describes the state of manufacturing operations. Acoustic Emission (AE) signals related to the cutting process and tool wear have been recently applied to monitor manufacturing processes, and various AE parameters can be used to provide process information. For example, when cutting tools become worn, AE energy generated at the interface of tool flank and work piece increases. This study is thus an experimental investigation of the AE spectrums representing AE signals energy distribution to determine the possibility of extracting useful parameters to provide on-line information about drilled-hole quality and drill-bit wear. An experiment conducted using a radial-arm drilling machine was employed to collect on-line AE drilling process spectrums, yielding eight indicator parameters. Drill wear states were measured using a machine vision system. Assessment of the drilled hole quality was based on tolerances established in Geometric Dimensioning and Tolerancing (GD&T). Correlations among drill wear, drilled-hole quality measurements, and the AE spectrum indicator parameters were examined by regression analysis. A forward-stepwise variable selection procedure was used to select the best-fit regression model for each drilled hole quality measurement associated with the set of one AE parameter raised to different powers. According to quality measurements, drilled holes were categorized as either "acceptable" or "unacceptable" holes, using cluster analysis with a group-averaging method. The usage of AE parameters to decide to which group a drilled hole belonged was also examined. From the experimental evidence, it was observed that there are strong relationships between AE parameters and drill-wear state and the quality measurements of drilled holes. AE parameters could be useful predictor variables to provide information to controller/operators to evaluate current drilling processes. Based on the status information of drill wear and the quality measurements, drilling processes can be adjusted accordingly. / Graduation date: 1997

In the aerospace industry, burr removal is a very important part of the manufacturing process. Stacks of material on sections of an aircraft are assembled and drilled by hand. Due to extensive burr formation the sheets must be destacked so that burrs can be removed and then the stacks are reassembled and fastened together. If burrs are minimized in the drilling process, this would reduce the necessity for the sheets to be destacked and deburred. One approach to minimizing burrs is to lower the thrust force in drilling through suitable modification of the drill geometry such as the use of a step drill. Although prior researchers have analyzed different drill geometries such as step drills and their effect on hole exit burr formation in the drilling process through experimentation, no work has been reported on modeling and analysis of step drilling forces and their relationship to burr formation as a function of the step drill geometry parameters. Consequently, this thesis focuses on the modeling of the thrust force and torque for step drills and analyzes their relationship with burr size as a function of the step drill geometry parameters. In the first step, a mechanistic model for thrust and torque in drilling is implemented for a standard twist drill. This mechanistic model is then adapted to predict the thrust and torque for a step drill. Subsequently, experiments are performed to validate the mechanistic model and to evaluate burr formation with standard and step drills. The influence of thrust and torque on hole exit burr formation is analyzed for different step drill geometries and experimental feeds and speeds. The results show that the predicted thrust and torque values for both drill geometries are in good agreement with measured values, although the torque model consistently underpredicts. For standard drill geometry in the calibration tests, the average error in the thrust prediction is 7.09% and the average error in the torque prediction is -18.05%. In validation tests, the average error for predicted thrust is 2.29% and the average error for predicted torque is -18.46%. For the step drill model the average error in thrust is 0.72% while the average error in torque is -8.72%. In addition, a reduction in the predicted thrust force for a step drill relative to the standard twist drill is found to correlate well with a reduction in the measured burr size. However, further reduction in the thrust force by varying the step angle and diameter ratio do not correlate well with the measured burr size. Likely reasons for these results are presented in this thesis.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 230-235). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 230-235). Also available on the Internet.

No description available.

No description available.

Drilling is one of the most commonly used material removal processes for producing holes in the manufacturing industry. Despite the long history of design and developments of hole making tools, the modern twist drill, which undertakes most of the hole making tasks, is largely based on Morse’s geometrical design patented in 1863. however, considerable improvements in the technological performance of drilling operations as assessed by the forces, power, drill-life and hole quality have been achieved through the use of stronger and more wear resistant tool materials, better selection of the salient drill point features and improvements in drill manufacturing methods involving increased automation and geometrical control of drill variability. A variety of drill point modifications and designs have also been proposed and made commercially available although the modern conventional general purpose twist drill design still remains the standard product of drill manufacturers commonly available in stock. The improvement of the technological performance of twist drills has traditionally been the domain of the drill manufacturers who provide technical information and advice often in the form of machining feed and speed recommendations for use in practice. Such machining recommendations or data may also be found in special handbooks which sometimes include drilling performance data such as thrust, torque and power requirements or the expected drill-life in the form of tables, monographs or empirical equations which include the obvious process variables such as the feed and speed. (For complete introduction open document)

Thesis (Professional Degree)--University of Missouri, School of Mines and Metallurgy, 1921. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed May 13, 2009)

Thesis (Ph. D.)--West Virginia University, 2005 / Title from document title page. Document formatted into pages; contains xiii, 124 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 109-112).