Otimização do torneamento vertical de anéis de pistão de ferro fundido cinzento martensítico utilizando ferramenta de metal duro com geometria especial.

O processo de usinagem por torneamento vertical duplo do ferro fundido cinzento martensítico é de grande importância para a indústria automobilística, principalmente no processo de fabricação de anéis de pistão. O objetivo deste trabalho é demonstrar o processo de desenvolvimento de ferramentas de metal duro recobertas com vistas à maximização da taxa de produção do processo, considerando-se a máxima vida da ferramenta de corte e o mínimo custo de usinagem por peça. Utilizando-se arranjos fatoriais completos (DOE), foram testadas duas geometrias diferentes: uma ferramenta com geometria quadrada especial, formada por duas arestas e duas pontas de corte simultâneas e outra, hexagonal. Considerando-se que a geometria quadrada especial proporcionou a máxima vida, modelos quadráticos completos para as respostas de interesse foram construídos utilizando-se um arranjo composto central (CCD) para o avanço ( f ) e a rotação (n). Aplicando-se o algoritmo gradiente GRG, os objetivos da otimização propostos foram alcançados com avanço = 0,37mm/rot., rotação de 265 rpm para a utilização da ferramenta de geometria quadrada especial. Experimentos de confirmação comprovam a eficiência da abordagem adotada

Otimização do torneamento vertical de anéis de pistão de ferro fundido cinzento martensítico utilizando ferramenta de metal duro com geometria especial.

Submitted by repositorio repositorio ([email protected]) on 2018-06-06T14:12:44Z No. of bitstreams: 1 dissertacao_0038601.pdf: 3212673 bytes, checksum: 5f0e8402f44d459c9913dee0abd9c607 (MD5)Made available in DSpace on 2018-06-06T14:12:44Z (GMT). No. of bitstreams: 1 dissertacao_0038601.pdf: 3212673 bytes, checksum: 5f0e8402f44d459c9913dee0abd9c607 (MD5) Previous issue date: 2011-09O processo de usinagem por torneamento vertical duplo do ferro fundido cinzento martensítico é de grande importância para a indústria automobilística, principalmente no processo de fabricação de anéis de pistão. O objetivo deste trabalho é demonstrar o processo de desenvolvimento de ferramentas de metal duro recobertas com vistas à maximização da taxa de produção do processo, considerando-se a máxima vida da ferramenta de corte e o mínimo custo de usinagem por peça. Utilizando-se arranjos fatoriais completos (DOE), foram testadas duas geometrias diferentes: uma ferramenta com geometria quadrada especial, formada por duas arestas e duas pontas de corte simultâneas e outra, hexagonal. Considerando-se que a geometria quadrada especial proporcionou a máxima vida, modelos quadráticos completos para as respostas de interesse foram construídos utilizando-se um arranjo composto central (CCD) para o avanço ( f ) e a rotação (n). Aplicando-se o algoritmo gradiente GRG, os objetivos da otimização propostos foram alcançados com avanço = 0,37mm/rot., rotação de 265 rpm para a utilização da ferramenta de geometria quadrada especial. Experimentos de confirmação comprovam a eficiência da abordagem adotada

Entropy-Based Weighting for Multiobjective Optimization: An Application on Vertical Turning

In practical situations, solving a given problem usually calls for the systematic and simultaneous analysis of more than one objective function. Hence, a worthwhile research question may be posed thus: In multiobjective optimization, what can facilitate for the decision maker choosing the best weighting? Thus, this study attempts to propose a method that can identify the optimal weights involved in a multiobjective formulation. The proposed method uses functions of Entropy and Global Percentage Error as selection criteria of optimal weights. To demonstrate its applicability, this method was employed to optimize the machining process for vertical turning, maximizing the productivity and the life of cutting tool, and minimizing the cost, using as the decision variables feed rate and rotation of the cutting tool. The proposed optimization goals were achieved with feed rate = 0.37 mm/rev and rotation = 250 rpm. Thus, the main contributions of this study are the proposal of a structured method, differentiated in relation to the techniques found in the literature, of identifying optimal weights for multiobjective problems and the possibility of viewing the optimal result on the Pareto frontier of the problem. This viewing possibility is very relevant information for the more efficient management of processes

Entropy-Based weighting applied to normal boundary intersection approach: the vertical turning of martensitic gray cast iron piston rings case

In practical situations, solving a given problem usually calls for the systematic and simultaneous analysis of more than one objective function. Hence, a worthwhile research question may be posed thus: In multiobjective optimization, what can facilitate the decision maker in choosing the best weighting? Thus, this study attempts to propose a method that can identify the optimal weights involved in a multiobjective formulation. Our method uses functions of Entropy and Global Percentage Error as selection criteria of optimal weights. To demonstrate its applicability, we employed this method to optimize the machining process for vertical turning martensitic gray cast iron piston rings, maximizing the productivity and the life of cutting tool and minimizing the cost, using feed rate and rotation of the cutting tool as the decision variables. The proposed optimization goals were achieved with feed rate = 0.35 mm rev-1 and rotation = 248 rpm. Thus, the main contributions of this study are the proposal of a structured method, differentiated in relation to the techniques found in the literature, of identifying optimal weights for multiobjective problems and the possibility of viewing the optimal result on the Pareto frontier of the problem. This viewing possibility is very relevant information for managing processes more efficiently. In practical situations, solving a given problem usually calls for the systematic and simultaneous analysis of more than one objective function. Hence, a worthwhile research question may be posed thus: In multiobjective optimization, what can facilitate the decision maker in choosing the best weighting? Thus, this study attempts to propose a method that can identify the optimal weights involved in a multiobjective formulation. Our method uses functions of Entropy and Global Percentage Error as selection criteria of optimal weights. To demonstrate its applicability, we employed this method to optimize the machining process for vertical turning martensitic gray cast iron piston rings, maximizing the productivity and the life of cutting tool and minimizing the cost, using feed rate and rotation of the cutting tool as the decision variables. The proposed optimization goals were achieved with feed rate = 0.35 mm rev-1 and rotation = 248 rpm. Thus, the main contributions of this study are the proposal of a structured method, differentiated in relation to the techniques found in the literature, of identifying optimal weights for multiobjective problems and the possibility of viewing the optimal result on the Pareto frontier of the problem. This viewing possibility is very relevant information for managing processes more efficiently.