George-Christopher Vosniakos is Professor in Manufacturing Systems at the School of Mechanical Engineering, National Technical University of Athens (NTUA), Greece. He holds a first degree in Mechanical Engineering from NTUA (1986), an MSc in Advanced Manufacturing Technology (1987) from University of Manchester (formerly: UMIST). UK and a PhD in Intelligent CAD/CAPP Interfaces (1991) from UMIST, too. In the 1990s he worked in the ΙΤ industry in Germany and held a lecturer's post at UMIST. He has authored 83 journal articles, 78 conference papers, 5 book chapters and 80 technical reports in the fields of Advanced Manufacturing Technology and Intelligent Manufacturing Systems. He is member of the editorial board of Int. J. Advanced Manufacturing Technology, Int. J. of Machining and Machinability of Materials, Int. J. of Mechatronics and Manufacturing Systems and Advances in Robotics Research
This paper advocates using state-of-the-art engineering tools in design and produc- tion of ceram... more This paper advocates using state-of-the-art engineering tools in design and produc- tion of ceramic parts and the corresponding pressing and casting dies. A feature li- brary is developed for the parametric design of parts with simple geometry, focusing on concave pottery parts. A user-friendly interface is developed, so that parametric design can be achieved by technicians with no proficiency in
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2007
ABSTRACT The ultimate aim of casting simulation is to recommend process parameter values that res... more ABSTRACT The ultimate aim of casting simulation is to recommend process parameter values that result in the best possible casting quality. However, commercial casting simulation is currently used as a trial-and-error tool, mostly comparing between possible scenarios with no guarantee of realism. Three techniques are presented to overcome these discrepancies for solid investment casting of jewellery as a test bed. The first technique consists in recording temperature versus time profiles by thermocouples embedded in the casting. These profiles are used as calibration reference regarding the overall heat transfer coefficient at the melt-mould interface in simulation. The second technique consists in metallographic validation of simulation findings in terms of correlating microstructure and defects of the casting with simulation results concerning temperature distribution and porosity. The third technique consists in introducing genetic algorithms as an optimization tool. A small number of simulation sample runs link process parameters of interest, such as mould temperature and melt temperature, with results characterizing casting quality, e.g. porosity. These samples are used to train a neural network, thereby creating a generalized meta-model of the process, which is directly used as the fitness function of the genetic algorithm. Combining the three techniques described above caters for realistic and practical casting process planning using commercially available casting simulation software as a tool.
... At the basic level further detail is given, mainly with regard to element connection. ... add... more ... At the basic level further detail is given, mainly with regard to element connection. ... address in the PC memory, sample size and period, operation identification and parameter ... Paradox providesautomatic report generation, SQL query, as well as querybyexample capability and a ...
Centrifugal casting is widely used as an investment casting method for small parts of complex geo... more Centrifugal casting is widely used as an investment casting method for small parts of complex geometry. Considering that the selection of casting conditions is not a trivial process, casting simulation programs could contribute to the enhancement of the process knowledge. In order to obtain realistic results from simulation, the input pa- rameters should be correctly defined. Determination of the interfacial
This paper advocates using state-of-the-art engineering tools in design and produc- tion of ceram... more This paper advocates using state-of-the-art engineering tools in design and produc- tion of ceramic parts and the corresponding pressing and casting dies. A feature li- brary is developed for the parametric design of parts with simple geometry, focusing on concave pottery parts. A user-friendly interface is developed, so that parametric design can be achieved by technicians with no proficiency in
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2007
ABSTRACT The ultimate aim of casting simulation is to recommend process parameter values that res... more ABSTRACT The ultimate aim of casting simulation is to recommend process parameter values that result in the best possible casting quality. However, commercial casting simulation is currently used as a trial-and-error tool, mostly comparing between possible scenarios with no guarantee of realism. Three techniques are presented to overcome these discrepancies for solid investment casting of jewellery as a test bed. The first technique consists in recording temperature versus time profiles by thermocouples embedded in the casting. These profiles are used as calibration reference regarding the overall heat transfer coefficient at the melt-mould interface in simulation. The second technique consists in metallographic validation of simulation findings in terms of correlating microstructure and defects of the casting with simulation results concerning temperature distribution and porosity. The third technique consists in introducing genetic algorithms as an optimization tool. A small number of simulation sample runs link process parameters of interest, such as mould temperature and melt temperature, with results characterizing casting quality, e.g. porosity. These samples are used to train a neural network, thereby creating a generalized meta-model of the process, which is directly used as the fitness function of the genetic algorithm. Combining the three techniques described above caters for realistic and practical casting process planning using commercially available casting simulation software as a tool.
... At the basic level further detail is given, mainly with regard to element connection. ... add... more ... At the basic level further detail is given, mainly with regard to element connection. ... address in the PC memory, sample size and period, operation identification and parameter ... Paradox providesautomatic report generation, SQL query, as well as querybyexample capability and a ...
Centrifugal casting is widely used as an investment casting method for small parts of complex geo... more Centrifugal casting is widely used as an investment casting method for small parts of complex geometry. Considering that the selection of casting conditions is not a trivial process, casting simulation programs could contribute to the enhancement of the process knowledge. In order to obtain realistic results from simulation, the input pa- rameters should be correctly defined. Determination of the interfacial
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