Wear of cutting tools is a big concern for industrial manufacturers, because of their acquisition cost as well as the impact on the production lines when they are unavailable. Law of wear is very important in determin...Wear of cutting tools is a big concern for industrial manufacturers, because of their acquisition cost as well as the impact on the production lines when they are unavailable. Law of wear is very important in determining cutting tools lifespan, but most of the existing models don’t take into account the cutting temperature. In this work, the theoretical and experimental results of a dynamic study of metal machining against cutting temperature of a treated steel of grade S235JR with a high-speed steel tool are provided. This study is based on the analysis of two complementary approaches, an experimental approach with the measurement of the temperature and on the other hand, an approach using modeling. Based on unifactorial and multifactorial tests (speed of cut, feed, and depth of cut), this study allowed the highlighting of the influence of the cutting temperature on the machining time. To achieve this objective, two specific approaches have been selected. The first was to measure the temperature of the cutting tool and the second was to determine the wear law using Rayleigh-Ham dimensional analysis method. This study permitted the determination of a law that integrates the cutting temperature in the calculations of the lifespan of the tools during machining.展开更多
Evaluating real world situations in risky environments based on various qualitative/quantitative criteria in order to suggest a strategy/policy among available options is one of the critical challenges in inciden...Evaluating real world situations in risky environments based on various qualitative/quantitative criteria in order to suggest a strategy/policy among available options is one of the critical challenges in incident management. Such is the case when considering an eco-efficient development strategy that can minimize the risk associated with the location of gas stations in human settlements. Taking the Douala city of Cameroon as an example, four actions were evaluated, including the options of relocating the gas stations, putting in place of emergency response plan in gas stations, and relocation of households subject to a group of four criteria. Data were collected via personal communication with decision-makers using a five-point Likert scale. The market values of buildings subject to expropriation were estimated based on order No. 0082/Y. 15.1/MNUH/D of 20 November 1987 of the ministry of Housing and Urban Development, Cameroon. The financial costs incurred in establishing a gas station were an average value obtained from a sample of 80 gas stations randomly selected among those whose locations do not comply with existing regulations. These amounts were obtained from their financial records, while the value of putting in place an emergency action plan was obtained from the current market value of the equipment required. The algorithm of PROMETHEE under the usual criterion function was implemented. The results suggested that putting in place an emergency response plan could minimize relocation costs, maximize profits/welfare, and maximize environmental quality, and minimize social impacts, and was therefore considered as the most preferred alternative. Sensitivity analyses of results further confirmed that implementation of emergency response plan is the most preferred alternative.展开更多
文摘Wear of cutting tools is a big concern for industrial manufacturers, because of their acquisition cost as well as the impact on the production lines when they are unavailable. Law of wear is very important in determining cutting tools lifespan, but most of the existing models don’t take into account the cutting temperature. In this work, the theoretical and experimental results of a dynamic study of metal machining against cutting temperature of a treated steel of grade S235JR with a high-speed steel tool are provided. This study is based on the analysis of two complementary approaches, an experimental approach with the measurement of the temperature and on the other hand, an approach using modeling. Based on unifactorial and multifactorial tests (speed of cut, feed, and depth of cut), this study allowed the highlighting of the influence of the cutting temperature on the machining time. To achieve this objective, two specific approaches have been selected. The first was to measure the temperature of the cutting tool and the second was to determine the wear law using Rayleigh-Ham dimensional analysis method. This study permitted the determination of a law that integrates the cutting temperature in the calculations of the lifespan of the tools during machining.
文摘Evaluating real world situations in risky environments based on various qualitative/quantitative criteria in order to suggest a strategy/policy among available options is one of the critical challenges in incident management. Such is the case when considering an eco-efficient development strategy that can minimize the risk associated with the location of gas stations in human settlements. Taking the Douala city of Cameroon as an example, four actions were evaluated, including the options of relocating the gas stations, putting in place of emergency response plan in gas stations, and relocation of households subject to a group of four criteria. Data were collected via personal communication with decision-makers using a five-point Likert scale. The market values of buildings subject to expropriation were estimated based on order No. 0082/Y. 15.1/MNUH/D of 20 November 1987 of the ministry of Housing and Urban Development, Cameroon. The financial costs incurred in establishing a gas station were an average value obtained from a sample of 80 gas stations randomly selected among those whose locations do not comply with existing regulations. These amounts were obtained from their financial records, while the value of putting in place an emergency action plan was obtained from the current market value of the equipment required. The algorithm of PROMETHEE under the usual criterion function was implemented. The results suggested that putting in place an emergency response plan could minimize relocation costs, maximize profits/welfare, and maximize environmental quality, and minimize social impacts, and was therefore considered as the most preferred alternative. Sensitivity analyses of results further confirmed that implementation of emergency response plan is the most preferred alternative.
