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The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Tue, 23 Jul 2024 17:35:11 GMT2024-07-23T17:35:11ZExperimental Analysis and Geometrical Modeling of Cutting Conditions Effect in 5 Axis Milling with Ti6Al4V Alloy
http://hdl.handle.net/10985/7493
Experimental Analysis and Geometrical Modeling of Cutting Conditions Effect in 5 Axis Milling with Ti6Al4V Alloy
PRAT, David; DUC, Emmanuel; FROMENTIN, Guillaume; POULACHON, Gerard
The 5 axis continuous milling is an advanced technique for free-form surfaces manufacturing. In finishing, this technique uses ball-end or hemispherical milling cutter. This type of operation for 5 axis milling allows the possibility to tilt the tool with two different angles. As a consequence, a mass of geometrical configurations exists and establishing accurate parameters is quite difficult to define. A geometrical model has been developed to find the effective cutting diameters and cutting speed on the cut and the finished surface. After an experimental validation, this study proposes an analysis of several 5 axis milling configurations in order to perform this technique.
Sun, 01 Jan 2012 00:00:00 GMThttp://hdl.handle.net/10985/74932012-01-01T00:00:00ZPRAT, DavidDUC, EmmanuelFROMENTIN, GuillaumePOULACHON, GerardThe 5 axis continuous milling is an advanced technique for free-form surfaces manufacturing. In finishing, this technique uses ball-end or hemispherical milling cutter. This type of operation for 5 axis milling allows the possibility to tilt the tool with two different angles. As a consequence, a mass of geometrical configurations exists and establishing accurate parameters is quite difficult to define. A geometrical model has been developed to find the effective cutting diameters and cutting speed on the cut and the finished surface. After an experimental validation, this study proposes an analysis of several 5 axis milling configurations in order to perform this technique.Statistical tolerance analysis of over-constrained mechanisms with gaps using system reliability methods
http://hdl.handle.net/10985/9295
Statistical tolerance analysis of over-constrained mechanisms with gaps using system reliability methods
BEAUCAIRE, Paul; GAYTON, Nicolas; DUC, Emmanuel; DANTAN, Jean-Yves
One of the aims of statistical tolerance analysis is to evaluate a predicted quality level at the design stage. One method consists of computing the defect probability PD expressed in parts per million (ppm). It represents the probability that a functional requirement will not be satisfied in mass production. This paper focuses on the statistical tolerance analysis of over-constrained mechanisms containing gaps. In this case, the values of the functional characteristics depend on the gap situations and are not explicitly formulated with respect to part deviations. To compute PD, an innovative methodology using system reliability methods is presented. This new approach is compared with an existing one based on an optimization algorithm and Monte Carlo simulations. The whole approach is illustrated using two industrial mechanisms: one inspired by a producer of coaxial connectors and one prismatic pair. Its major advantage is to considerably reduce computation time.
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/10985/92952013-01-01T00:00:00ZBEAUCAIRE, PaulGAYTON, NicolasDUC, EmmanuelDANTAN, Jean-YvesOne of the aims of statistical tolerance analysis is to evaluate a predicted quality level at the design stage. One method consists of computing the defect probability PD expressed in parts per million (ppm). It represents the probability that a functional requirement will not be satisfied in mass production. This paper focuses on the statistical tolerance analysis of over-constrained mechanisms containing gaps. In this case, the values of the functional characteristics depend on the gap situations and are not explicitly formulated with respect to part deviations. To compute PD, an innovative methodology using system reliability methods is presented. This new approach is compared with an existing one based on an optimization algorithm and Monte Carlo simulations. The whole approach is illustrated using two industrial mechanisms: one inspired by a producer of coaxial connectors and one prismatic pair. Its major advantage is to considerably reduce computation time.Modeling and Analysis of Five-Axis Milling Configurations and Titanium Alloy Surface Topography
http://hdl.handle.net/10985/10958
Modeling and Analysis of Five-Axis Milling Configurations and Titanium Alloy Surface Topography
PRAT, David; DUC, Emmanuel; FROMENTIN, Guillaume; POULACHON, Gerard
Five-axis milling with a ball-end cutter is commonly used to generate a good surface finish on complex parts, such as blades or impellers made of titanium alloy. The five-axis milling cutting process is not straight forward; local cutting conditions depend a lot on the geometrical configuration relating to lead and tilt angles. Furthermore, the surface quality is greatly affected by the cutting conditions that define the milling configuration. This study presents a geometrical model of five-axis milling in order to determine the effective cutting conditions, the milling mode, and the cutter location point. Subsequently, an analysis of surface topography is proposed by using the geometrical model, local criteria, and a principle component analysis of experimental data. The results show the effects of local parameters on the surface roughness, in relation to the lead and tilt angles.
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/10985/109582016-01-01T00:00:00ZPRAT, DavidDUC, EmmanuelFROMENTIN, GuillaumePOULACHON, GerardFive-axis milling with a ball-end cutter is commonly used to generate a good surface finish on complex parts, such as blades or impellers made of titanium alloy. The five-axis milling cutting process is not straight forward; local cutting conditions depend a lot on the geometrical configuration relating to lead and tilt angles. Furthermore, the surface quality is greatly affected by the cutting conditions that define the milling configuration. This study presents a geometrical model of five-axis milling in order to determine the effective cutting conditions, the milling mode, and the cutter location point. Subsequently, an analysis of surface topography is proposed by using the geometrical model, local criteria, and a principle component analysis of experimental data. The results show the effects of local parameters on the surface roughness, in relation to the lead and tilt angles.Statistical tolerance analysis of a mechanism with gaps based on system reliability methods
http://hdl.handle.net/10985/9297
Statistical tolerance analysis of a mechanism with gaps based on system reliability methods
BEAUCAIRE, Paul; GAYTON, Nicolas; DUC, Emmanuel; DANTAN, Jean-Yves
One of the aim of statistical tolerance analysis is to evaluate a predicted quality level in the design stage. A method consists in computing the defect probability D P expressed in parts per million (ppm). It represents the probability that a functional requirement will not be satisfied in mass production. This paper focuses on the statistical tolerance analysis of over-constrained mechanism with gaps. In this case, the values of the functional characteristics depend on the gap situations, and are not explicitly formulated as a function of part deviations. To compute D P , two different methodologies will be presented and confronted. The first one is based on an optimization algorithm and Monte Carlo simulations. The second methodology uses system reliability methods. The whole approach is illustrated on a basic academic problem inspired by industrial interests.
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/10985/92972013-01-01T00:00:00ZBEAUCAIRE, PaulGAYTON, NicolasDUC, EmmanuelDANTAN, Jean-YvesOne of the aim of statistical tolerance analysis is to evaluate a predicted quality level in the design stage. A method consists in computing the defect probability D P expressed in parts per million (ppm). It represents the probability that a functional requirement will not be satisfied in mass production. This paper focuses on the statistical tolerance analysis of over-constrained mechanism with gaps. In this case, the values of the functional characteristics depend on the gap situations, and are not explicitly formulated as a function of part deviations. To compute D P , two different methodologies will be presented and confronted. The first one is based on an optimization algorithm and Monte Carlo simulations. The second methodology uses system reliability methods. The whole approach is illustrated on a basic academic problem inspired by industrial interests.Statistical tolerance analysis of a hyperstatic mechanism, using system reliability methods
http://hdl.handle.net/10985/9282
Statistical tolerance analysis of a hyperstatic mechanism, using system reliability methods
BEAUCAIRE, Paul; GAYTON, Nicolas; DUC, Emmanuel; LEMAIRE, Maurice; DANTAN, Jean-Yves
The quality level of a mechanism can be evaluated a posteriori after several months by following the number of warranty returns. However, it is more interesting to evaluate a predicted quality level in the design stage: this is one of the aims of statistical tolerance analysis. A possible method consists of computing the defect probability (PD) expressed in ppm. It represents the probability that a functional requirement will not be satisfied in mass production. For assembly reasons, many hyperstatic mechanisms require gaps, which their functional requirements depend on. The defect probability assessment of such mechanisms is not straightforward, and requires advanced numerical methods. This problem particularly interests the VALEO W.S. company, which experiences problems with an assembly containing gaps. This paper proposes an innovative methodology to formulate and compute the defect probability of hyperstatic mechanisms with gaps in two steps. First, a complex feasibility problem is converted into a simpler problem. Then the defect probability is efficiently computed thanks to system reliability methods and the m-dimensional multivariate normal distribution Um. Finally, a sensitivity analysis is provided to improve the original design. The whole approach is illustrated with an industrial case study, but can be adapted to other similar problems.
Sun, 01 Jan 2012 00:00:00 GMThttp://hdl.handle.net/10985/92822012-01-01T00:00:00ZBEAUCAIRE, PaulGAYTON, NicolasDUC, EmmanuelLEMAIRE, MauriceDANTAN, Jean-YvesThe quality level of a mechanism can be evaluated a posteriori after several months by following the number of warranty returns. However, it is more interesting to evaluate a predicted quality level in the design stage: this is one of the aims of statistical tolerance analysis. A possible method consists of computing the defect probability (PD) expressed in ppm. It represents the probability that a functional requirement will not be satisfied in mass production. For assembly reasons, many hyperstatic mechanisms require gaps, which their functional requirements depend on. The defect probability assessment of such mechanisms is not straightforward, and requires advanced numerical methods. This problem particularly interests the VALEO W.S. company, which experiences problems with an assembly containing gaps. This paper proposes an innovative methodology to formulate and compute the defect probability of hyperstatic mechanisms with gaps in two steps. First, a complex feasibility problem is converted into a simpler problem. Then the defect probability is efficiently computed thanks to system reliability methods and the m-dimensional multivariate normal distribution Um. Finally, a sensitivity analysis is provided to improve the original design. The whole approach is illustrated with an industrial case study, but can be adapted to other similar problems.