Modern production systems have to allow high performance cutting processes in a flexible production system environment at a high level of accuracy. The final workpiece accuracy is mainly influenced by the thermo-elastic behavior of the machine tool and can be improved by additional measures, compensation strategies and an optimized machine design. These measures are often implemented as stand-alone solutions. According to the Industry 4.0 all information should be connected in a single model of the actual machine state to increase machining accuracy. It is therefore necessary to integrate upcoming smart fluid power systems into the machine network.

Para lidar com o aumento dos custos de energia nos sistemas de produção e ações para minimizar impactos ambientais relacionados à geração de eletricidade através de combustíveis fósseis, o tema \"consumo de energia\" tornou-se um dos mais discutidos na indústria nos últimos anos (LI, 2015). Portanto, a redução do consumo de energia elétrica nos processos de fabricação é assunto fundamental para o segmento industrial nos dias atuais. Tal ação requer conhecimento sobre as demandas de energia de máquinas e todos os equipamentos envolvidos em um processo. Reduzir o consumo de energia nos processos de usinagem pode melhorar significativamente a produção de um modo sustentável (SCHUDELEIT; ZÜST; WEGENER, 2017). Para diminuir a demanda energética em processos de usinagem particularmente em máquinas-ferramentas (MFs), dados de consumo de energia devem ser obtidos para ajudar no planejamento de processos e também contribuir para melhorar a eficiência energética da máquina como um todo. Além disso, para atender à crescente demanda do mercado por máquinas mais eficientes e a competitividade global no setor de manufatura, fabricantes de MFs estão enfrentando grandes desafios para melhorar a produtividade e reduzir o consumo de energia (BEN JDIDIA et al., 2018). Considerando o aumento do preço da energia e a sustentabilidade industrial, o presente trabalho apresenta um estudo detalhado do consumo de energia em um centro de torneamento e sugere estratégias para reduzir o consumo de energia nas MFs. Os resultados obtidos, até agora, indicam que adaptar o comportamento operacional das MFs por meio de modos de operação inteligentes, adaptando a demanda de energia aos requisitos do processo específico parece ser um bom procedimento para reduzir o consumo de energia, tornando os processos e máquinas mais eficientes, melhorando assim a sustentabilidade dos processos de usinagem. / To deal with rising energy costs in production system and significant demands for minimizing environmental impacts related to the electricity generation using fossil fuels, the theme \"energy consumption\" has become one of the most discussed topics in the manufacturing industry in recent years (LI, 2015). Therefore, the reduction of energy consumption in manufacturing processes is a fundamental issue for the industrial segment nowadays. Such subject requires knowledge about the energy requirements from machines and all the involved equipment. Reducing energy consumption in machining processes can significantly improve sustainability in manufacturing (SCHUDELEIT; ZÜST; WEGENER, 2017). To reduce energy demand in machining processes, particularly in machine tools (MTs), energy consumption data must be obtained to help process-planning and contribute to improve machine efficiency. Moreover, to meet growing market demand for more efficient machines and global competitiveness in the manufacturing sector, MTs manufacturers are facing major challenges to improve productivity and reduce energy consumption (BEN JDIDIA et al., 2018). Considering the increasing energy requirements and industrial sustainability, the present research presents a comprehensive study of energy consumption in a Two-spindle Turning center and suggests strategies to reduce energy consumption in MTs as a whole. The results obtained, so far, indicates that optimizing the operational behavior of MTs through smart operation modes by adapting the power demand to the current production requirements seems to be a good procedure to reduce the energy consumption, making the processes and machines more efficient as well as improving environmental performance of machining processes.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Bibliography: leaves 164-168. / by Joseph Githu Kimemia. / Ph.D.

Para lidar com o aumento dos custos de energia nos sistemas de produção e ações para minimizar impactos ambientais relacionados à geração de eletricidade através de combustíveis fósseis, o tema \"consumo de energia\" tornou-se um dos mais discutidos na indústria nos últimos anos (LI, 2015). Portanto, a redução do consumo de energia elétrica nos processos de fabricação é assunto fundamental para o segmento industrial nos dias atuais. Tal ação requer conhecimento sobre as demandas de energia de máquinas e todos os equipamentos envolvidos em um processo. Reduzir o consumo de energia nos processos de usinagem pode melhorar significativamente a produção de um modo sustentável (SCHUDELEIT; ZÜST; WEGENER, 2017). Para diminuir a demanda energética em processos de usinagem particularmente em máquinas-ferramentas (MFs), dados de consumo de energia devem ser obtidos para ajudar no planejamento de processos e também contribuir para melhorar a eficiência energética da máquina como um todo. Além disso, para atender à crescente demanda do mercado por máquinas mais eficientes e a competitividade global no setor de manufatura, fabricantes de MFs estão enfrentando grandes desafios para melhorar a produtividade e reduzir o consumo de energia (BEN JDIDIA et al., 2018). Considerando o aumento do preço da energia e a sustentabilidade industrial, o presente trabalho apresenta um estudo detalhado do consumo de energia em um centro de torneamento e sugere estratégias para reduzir o consumo de energia nas MFs. Os resultados obtidos, até agora, indicam que adaptar o comportamento operacional das MFs por meio de modos de operação inteligentes, adaptando a demanda de energia aos requisitos do processo específico parece ser um bom procedimento para reduzir o consumo de energia, tornando os processos e máquinas mais eficientes, melhorando assim a sustentabilidade dos processos de usinagem. / To deal with rising energy costs in production system and significant demands for minimizing environmental impacts related to the electricity generation using fossil fuels, the theme \"energy consumption\" has become one of the most discussed topics in the manufacturing industry in recent years (LI, 2015). Therefore, the reduction of energy consumption in manufacturing processes is a fundamental issue for the industrial segment nowadays. Such subject requires knowledge about the energy requirements from machines and all the involved equipment. Reducing energy consumption in machining processes can significantly improve sustainability in manufacturing (SCHUDELEIT; ZÜST; WEGENER, 2017). To reduce energy demand in machining processes, particularly in machine tools (MTs), energy consumption data must be obtained to help process-planning and contribute to improve machine efficiency. Moreover, to meet growing market demand for more efficient machines and global competitiveness in the manufacturing sector, MTs manufacturers are facing major challenges to improve productivity and reduce energy consumption (BEN JDIDIA et al., 2018). Considering the increasing energy requirements and industrial sustainability, the present research presents a comprehensive study of energy consumption in a Two-spindle Turning center and suggests strategies to reduce energy consumption in MTs as a whole. The results obtained, so far, indicates that optimizing the operational behavior of MTs through smart operation modes by adapting the power demand to the current production requirements seems to be a good procedure to reduce the energy consumption, making the processes and machines more efficient as well as improving environmental performance of machining processes.

Esta tese assume como pressuposto teórico que crescimento e desenvolvimento econômicos são processos dinâmicos que ocorrem a partir da co-evolução da tecnologia, da estrutura industrial e das instituições. A trajetória do processo de industrialização por substituição de importações (PISI) brasileiro foi marcada pela ênfase na acumulação de capacidade produtiva, e menor disposição das empresas na acumulação de capacidade inovativa. As empresas optaram pelo licenciamento externo de tecnologia, enquanto uma minoria de empresas institucionalizou e complementou esses esforços inovativos através de investimentos em P&D e/ou outros tipos de aprendizados tecnológicos. Embora a capacidade produtiva seja importante para materialização do progresso técnico, o mesmo apenas é conseguido através da P&D e a partir da cooperação entre produtor-usuário, fornecedores e universidades. A proteção da concorrência externa gerou demanda suficiente para o crescimento do setor de máquinas-ferramenta, mas também poucas empresas desenvolveram capacidade inovativa. Ademais, chama atenção o caráter contraditório do arcabouço regulatório e competitivo do PISI para o setor de bens de capital: as importações foram estimuladas por taxas de câmbio diferenciadas, importações sem cobertura cambial e isenções fiscais, enquanto se protegia a produção nacional com barreiras tarifárias e não tarifárias. Essa ‘dinâmica’ institucional configurou a especialização do setor de máquinas-ferramenta em produtos com menor conteúdo tecnológico relativamente às importadas. Os ramos industriais capitaneados pelas empresas estrangeiras após 1956 também contribuíram para configurar tal quadro, pois as mesmas requeriam máquinas-ferramenta de elevado conteúdo tecnológico que deslocava a procura para o mercado externo. A mudança do paradigma tecnológico nas décadas de 1970/1980 e a abertura econômica na década de 1990 configuraram a trajetória e o processo de reestruturação empreendido pelo setor no momento seguinte. As empresas com maior capacidades tecnológicas conseguiram acessar os novos conhecimentos requeridos para entrarem e se manterem na nova trajetória tecnológica. O profundo processo de reestruturação baseou-se na reorganização, especialização e aumento da eficiência produtiva. Com a consolidação produtiva e tecnológica das empresas líderes houve aumento da já existente heterogeneidade competitiva entre os fabricantes. Tal heterogeneidade decorre não apenas dos distintos esforços inovativos entre os fabricantes, mas também é devida à estrutura da demanda e do grau de sofisticação do usuário. / This thesis assumes as a theoretical basis that the economic growth and development are dynamic processes that occur from the co-evolution of technology, industrial structure and institutions. The trajectory of the Brazilian industrialization process was characterized by the accumulation of productive capacity and not the accumulation of innovative capacity. Companies preferred to license foreign technology, while a minority of companies institutionalized and complemented these efforts through investments in innovative R&D and/or other types of technological know-how. Although the production capacity is important for the materialization of technical progress, it is only achieved through R&D and from the cooperation between user-producer, suppliers and universities, etc. Protection from foreign competition generated enough demand for the growth of the machine tool, but few companies have developed innovative capacity. Furthermore, our attention is called to the contradictory nature of the regulatory framework and competitive PISI for the capital goods sector: imports were stimulated by different exchange rates, imports without hedging and tax exemptions, while protecting domestic production with tariffs and nontariff barriers. This 'dynamic' institutional sector specialization configured machine tool products with lower technological content compared with the imported ones. The industries led by foreign companies after 1956 also contributed to set up such a framework because they required machine tools with high technological content which shifted the demand for the foreign market. The technological paradigm shift in the decades of 1970/1980 and economic opening in the 1990s shaped the trajectory and the restructuring process undertaken by the sector in the next moment. Firms with greater technological capabilities gained access to the new knowledge required to enter and remain in the new technological trajectory. The profound restructuring process was based on the reorganization, specialization and increased production efficiency. With the productive and technological consolidation of the leading, the was an increase in the existing competitive heterogeneity among manufacturers. Such heterogeneity arises not only from different innovative efforts between manufacturers, but it is also due to the structure of demand and the degree of sophistication of the end user.

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in fulfilment of the requirements for the degree of Master of Science in Engineering. Johannesburg 2016 / The quantity and particle size distribution of pulverised coal supplied to combustion equipment downstream of coal pulverising plants are critical to achieving safe, reliable and efficient combustion. These two key performance indicators are largely dependent on the mechanical condition of the pulveriser. This study aimed to address the shortfalls associated with conventional time-based monitoring techniques by developing a comprehensive online pulveriser condition monitoring philosophy. A steady-state Mill Mass and Energy Balance (MMEB) model was developed from first principles for a commercial-scale coal pulveriser to predict the raw coal mass flow rate through the pulveriser. The MMEB model proved to be consistently accurate, predicting the coal mass flow rates to within 5 % of experimental data. The model proved to be dependent on several pulveriser process variables, some of which are not measured on a continuous basis. Therefore, the model can only function effectively on an industrial scale if it is supplemented with the necessary experiments to quantify unmeasured variables. Moreover, a Computational Fluid Dynamic (CFD) model based on the physical geometry of a coal pulveriser used in the power generation industry was developed to predict the static pressure drop across major internal components of the pulveriser as a function of the air flow through the pulveriser. Validation of the CFD model was assessed through the intensity of the correlation demonstrated between the experimentally determined and numerically calculated static pressure profiles. In this regard, an overall incongruity of less than 5 % was achieved. Candidate damage scenarios were simulated to assess the viability of employing the static pressure measurements as a means of detecting changes in mechanical pulveriser condition. Application of the validated pulveriser CFD model proved to be highly advantageous in identifying worn pulveriser components through statistical analysis of the static pressure drop measured across specific components, thereby demonstrating a significant benefit for industrial application. / MT2016

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Despite a large demand from industry, a realistic chatter modeling for hard turning has not been available due to the complexity of the problem, which is mainly caused by flank wear and nonlinearity in hard turning. This thesis attempts to develop chatter models for predicting chatter stability conditions in hard turning with the considerations of the effects of flank wear and nonlinearity. First, a linear model is developed by introducing non-uniform load distribution on a tool tip to account for the flank wear effect. Second, a nonlinear model is developed by further incorporating nonlinearity in the structure and cutting force. Third, stability analysis based on the root locus method and the describing function approach is conducted to determine a critical stability parameter. Fourth, to validate the models, a series of experiment is carried out to determine the stability limits as well as certain characteristic parameters for facing and straight turning. From these, it is shown that the nonlinear model provides more accurate predictions than the linear model, especially in the high-speed range. Furthermore, the stabilizing effect due to flank wear is confirmed through a series of experiments. Fifth, to fully account for the validity of linear and nonlinear models, an empirical model is proposed to fit in with the experimental stability limits in the full range of cutting speed. The proposed linear and nonlinear chatter models will help to improve the productivity in many manufacturing processes. In addition, chatter experimental data will be useful to develop other chatter models in hard turning.

M. Tech. Industrial Engineering. / Discusses the main objectives of this research are to; analyse the current state of press brakes technology ; develop a press brake concept using the Screw Jack System applying DFM (designing for manufacturability) principles and to fabricate a mini prototype Screw Jack Press Brake.

D. Tech. Industrial Engineering. / Aims to develop new optimized press brake concepts using Reconfigurable Manufacturing System (RMS) principles. The objectives of the research are articulated as follows: Research and identify part/ product families currently being manufactured on existing bending press tools and the respective technologies used. Design new press brake concepts and possible reconfigurations to be incorporated in future bending press tools based on part/ product families. To design the library of modules for the bending press tools based on new concepts and reconfiguration mechanisms formulated. To manufacture prototype(s) based on new concepts and perform experimental tests to evaluate performance of the designs.