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The 21st century demand for innovation is leading towards a revolution in the way products are perceived. This will have a major impact on manufacturing technologies as current product innovation is constrained by the available manufacturing processes, which function independently. One of the most significant developments is the emergence of hybrid manufacturing technologies integrating various individual manufacturing processes. Hybrid processes utilise the advantages of the independent processes whilst minimising their weaknesses as well as extending application areas. Despite the fact that the drawbacks of the individual processes have been significantly reduced, the application of state of the art hybrid technology has always been constrained by the capabilities of their constituent processes either from technical limitations or production costs. In particular, it is virtually impossible to machine complex parts due to limited cutting tool accessibility. By contrast, additive manufacturing (AM) techniques completely solve the tool accessibility issue, but this increased flexibility and automation is achieved by compromising on part accuracy and surface quality. Furthermore, the shape and size of raw materials have to be specific for each hybrid process. More importantly, process planning methods capable of effectively utilising manufacturing resources for hybrid processes are highly limited. In this research, a hybrid process, entitled iAtractive, combining additive, subtractive and inspection processes is proposed. An experimental methodology has been designed and implemented, by which a generative reactionary process planning algorithm (GRP2A) and feature-based decision-making logic (FDL) is developed. GRP2A enables a complex part to be accurately manufactured as one complete unit in the shortest production time possible. FDL provides a number of manufacturing strategies, allowing existing parts to be reused and transformed into final parts with additional features and functionalities. A series of case studies have been manufactured from zero and existing parts, demonstrating the efficacy of the iAtractive process and the developed GRP2A and FDL, which are based on a manual process. The major contribution to knowledge is the new vision for a hybrid process, which is not constrained by the capability of the individual processes and raw material in terms of shape and size. It has been demonstrated that the hybrid process together with GRP2A and FDL provides an effective solution to flexibly and accurately manufacture complex part geometries as well as remanufacture existing parts.

Orientador: Olivio Novaski / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-05T07:03:19Z (GMT). No. of bitstreams: 1 Deonisio_CarlosCesardeCastro_D.pdf: 16365372 bytes, checksum: fb0542af08c6aa67ad7bd3a1a196a1f3 (MD5) Previous issue date: 2004 / Resumo: O principal objetivo deste trabalho é caracterizar a qualidade da superfície gerada no processo de fresamento em acabamento, com fresas de topo esférico, do aço para trabalho a frio ABNT D2, endurecido. Utilizou-se o método do planejamento fatorial e as variáveis de influência foram às condições de contato entre a ferramenta e a superfície usinada, os parâmetros de corte e o desgaste de flanco da ferramenta de corte (VB). O aumento da velocidade de corte muda o mecanismo de formação do cavaco, causando a diminuição da razão entre o aumento dos esforços de usinagem e da deflexão da ferramenta de corte em relação ao aumento da velocidade de corte, decorrente da mudança na distribuição de temperatura entre a ferramenta de corte, a peça e o cavaco. Há interação entre a velocidade de corte, o sobrematerial e o avanço, em relação à deformação, encruamento e conseqüente endurecimento da superfície usinada. O desgaste da ferramenta de corte tem significativa influência na integridade da superfície gerada. A velocidade de corte e o avanço por dente influenciam na segmentação do cavaco / Abstract: The main goal of this investigation is to characterize the quality of the generated surface, in the process of finishing milling, of the hardened steel for cold work ABNT D2. The method of factorial planning was used and the variables of influence were the conditions of contact between the cutting tool and the machined surface, the cutting parameters and the cutting tool wear. The increase of the cutting speed change the mechanism of chip formation, causing the reduction of the ratio of the increase of machining forces and the deflection of the cutting tool in relation to the increase of the cut speed, because of the change in the distribution of temperature between the tool, the part and the chip. There is interaction between cutting speed, feed rate and stock removal, in relation the deformation, strain hardening and consequent hardening of the surface machining. The wear of the cutting tool has significant influence in the integrity of the generated surface. The cutting speed and the feed for tooth influence the segmentation of the chi / Doutorado / Materiais e Processos de Fabricação / Doutor em Engenharia Mecânica