Browse Titles - 3065 results
6.5 kV n-Channel 4H-SiC IGBT with Low Switching Loss Achieved by Extremely Thin Drift Layer
(Switzerland: Trans Tech Publications, 2016), 9 page(s)
Thin drift layers were used to realize n-channel 4H-SiC IGBTs with an extremely low switching loss. The thickness of a drift layer was 60 µm, which was designed for a blocking voltage of 6.5 kV. An on-voltage of 5.4 V was obtained at a collector current of 100 A/cm2 and the specific differential on-resistance at...
Sample
(Switzerland: Trans Tech Publications, 2016), 9 page(s)
Description
Thin drift layers were used to realize n-channel 4H-SiC IGBTs with an extremely low switching loss. The thickness of a drift layer was 60 µm, which was designed for a blocking voltage of 6.5 kV. An on-voltage of 5.4 V was obtained at a collector current of 100 A/cm2 and the specific differential on-resistance at 100 A/cm2 was 20 mOcm2 at room temperature, indicating proper bipolar operation. A switching evaluation of the SiC IGBTs was performed...
Thin drift layers were used to realize n-channel 4H-SiC IGBTs with an extremely low switching loss. The thickness of a drift layer was 60 µm, which was designed for a blocking voltage of 6.5 kV. An on-voltage of 5.4 V was obtained at a collector current of 100 A/cm2 and the specific differential on-resistance at 100 A/cm2 was 20 mOcm2 at room temperature, indicating proper bipolar operation. A switching evaluation of the SiC IGBTs was performed with a bus voltage of 3.6 kV and a load current of 10 A, and a turn-off loss of 1.2 mJ was obtained. This turn-off loss is very small compared to the values in the current literatures, and was estimated to be an over 80% reduction. The series operation of thin-drift-layer 6.5 kV SiC IGBTs can ensure a lower switching loss than the single operation of higher blocking voltage devices in power conversion systems.
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Field of Study
Global Issues
Content Type
Periodical article
Date Published / Released
2016-05, 2016
Publisher
Trans Tech Publications
Topic / Theme
Engineering
Copyright Message
Copyright © 2016 Trans Tech Publications Ltd.
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2D Barcode Identification Technology Application in Tool Management System for Workshop
(Switzerland: Trans Tech Publications, 2016), 9 page(s)
With the development of advanced automation degree industries, the requirements of network management for workshop tool become more and more urgent. A very important part in network management system is identification technology of the tool. In this paper, 2D (two-dimensional) barcode identification technology is...
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(Switzerland: Trans Tech Publications, 2016), 9 page(s)
Description
With the development of advanced automation degree industries, the requirements of network management for workshop tool become more and more urgent. A very important part in network management system is identification technology of the tool. In this paper, 2D (two-dimensional) barcode identification technology is applied in the tool information in real-time query to realize network management. The 2D barcode reading device, which is combined with...
With the development of advanced automation degree industries, the requirements of network management for workshop tool become more and more urgent. A very important part in network management system is identification technology of the tool. In this paper, 2D (two-dimensional) barcode identification technology is applied in the tool information in real-time query to realize network management. The 2D barcode reading device, which is combined with the local computer decoding software, could achieve communication between production line and the server. By using 2D barcode identification technology, it could achieve network management for workshop tool, improve production efficiency and reduce the artificial error.
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Field of Study
Global Issues
Content Type
Periodical article
Date Published / Released
2016-01, 2016
Publisher
Trans Tech Publications
Topic / Theme
Engineering
Copyright Message
Copyright © 2016 Trans Tech Publications Ltd.
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2-D Defect Profile Reconstruction from Ultrasonic Guided Wave Signals Based on Radial Wavelet Basis Function Neural Network with ELM
(Switzerland: Trans Tech Publications, 2016), 14 page(s)
The reconstruction of defect profiles based on ultrasonic guided waves means the acquisition of defect profiles and parameters from ultrasonic guided wave signals. To achieve multi-resolution approximation, this paper proposed a reconstruction approach based on Radial Wavelet Basis Function Neural Network (RWBFNN)...
Sample
(Switzerland: Trans Tech Publications, 2016), 14 page(s)
Description
The reconstruction of defect profiles based on ultrasonic guided waves means the acquisition of defect profiles and parameters from ultrasonic guided wave signals. To achieve multi-resolution approximation, this paper proposed a reconstruction approach based on Radial Wavelet Basis Function Neural Network (RWBFNN), which combines wavelet analysis and neural network. Gaussian radial basis functions and Mexican hat wavelet frames are used as scalin...
The reconstruction of defect profiles based on ultrasonic guided waves means the acquisition of defect profiles and parameters from ultrasonic guided wave signals. To achieve multi-resolution approximation, this paper proposed a reconstruction approach based on Radial Wavelet Basis Function Neural Network (RWBFNN), which combines wavelet analysis and neural network. Gaussian radial basis functions and Mexican hat wavelet frames are used as scaling functions and wavelet functions respectively. The training and testing samples contain simulation data and experimental data. The input data sets are defect echo signals, and the output data sets are 2-D profile parameters. To reduce the training time and simplify the profile reconstruction procedure without losing accuracy, Extreme Learning Machine (ELM) is adopted simultaneously. The results indicate that significant advantages can be obtained over other defect profile reconstruction schemes, and the accuracy of the predicted defect profile can be controlled by the resolution of the network with the lower computational complexity.
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Field of Study
Global Issues
Content Type
Periodical article
Date Published / Released
2016-05, 2016
Publisher
Trans Tech Publications
Topic / Theme
Engineering
Copyright Message
Copyright © 2016 Trans Tech Publications Ltd.
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2D Meso-Scale Finite Element Modeling and Simulation of Polymer-Mineral Composite Material
(Switzerland: Trans Tech Publications, 2016), 9 page(s)
Polymer-mineral composite material is prepared by using modified epoxy resin as binder and mineral particles as aggregates. Its excellent damping characteristic and low thermal expansion make it ideal in manufacturing machine tool beds. However, the properties of this material depend on its formula and structure,...
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(Switzerland: Trans Tech Publications, 2016), 9 page(s)
Description
Polymer-mineral composite material is prepared by using modified epoxy resin as binder and mineral particles as aggregates. Its excellent damping characteristic and low thermal expansion make it ideal in manufacturing machine tool beds. However, the properties of this material depend on its formula and structure, so it is very important to develop an efficient method to numerically model the materials and then to optimize their properties. In thi...
Polymer-mineral composite material is prepared by using modified epoxy resin as binder and mineral particles as aggregates. Its excellent damping characteristic and low thermal expansion make it ideal in manufacturing machine tool beds. However, the properties of this material depend on its formula and structure, so it is very important to develop an efficient method to numerically model the materials and then to optimize their properties. In this paper, 2D meso-scale finite element modeling is presented for numerical analysis of the mechanical properties of polymer-mineral composite material. The material was treated as a 2-phase composite composed of aggregates and binder which was epoxy resin mixed with fillers. Based on grading curve, the weights of aggregates were converted into the corresponding area, the aggregate particles were randomly generated and assembled with binder to produce the model. And then 2D numerical simulations were conducted under different gradations. The results show that: (1) the 2D FE model is very close to the real polymer-mineral composite material in the aspect of density and aggregate shapes and sizes, which validate the fidelity of the generated finite element model and numerical analysis method; (2) by comparing the materials' properties under four different gradations, it can be found that the materials with SAC gradation have the best mechanical property.
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Field of Study
Global Issues
Content Type
Periodical article
Date Published / Released
2016-03, 2016
Publisher
Trans Tech Publications
Topic / Theme
Engineering
Copyright Message
Copyright © 2016 Trans Tech Publications Ltd.
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3D Numerical Model of the Subsoil-Structure Interaction and Comparison of the Results with Experimentally Measured Values
(Switzerland: Trans Tech Publications, 2017), 13 page(s)
The influence of the physically-nonlinear behaviour of the structure and interaction between the upper structure and foundation are the aspects which influence the results of the subsoil-structure interaction analysis. The experimental measurement of stress and strain and monitoring of stress-strain relations by i...
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(Switzerland: Trans Tech Publications, 2017), 13 page(s)
Description
The influence of the physically-nonlinear behaviour of the structure and interaction between the upper structure and foundation are the aspects which influence the results of the subsoil-structure interaction analysis. The experimental measurement of stress and strain and monitoring of stress-strain relations by interaction of foundation structures with subsoil are also performed at the Faculty of Civil Engineering, VS?B-TU Ostrava. Numerical ana...
The influence of the physically-nonlinear behaviour of the structure and interaction between the upper structure and foundation are the aspects which influence the results of the subsoil-structure interaction analysis. The experimental measurement of stress and strain and monitoring of stress-strain relations by interaction of foundation structures with subsoil are also performed at the Faculty of Civil Engineering, VS?B-TU Ostrava. Numerical analyses of contact task was made with FEM. The test sample for the task was a steel-fibre reinforced concrete foundation slab model loaded during experimental loading test. The calculated values of the subsidence do not correspond to the measured values of foundation subsidence of existing buildings, or values measured during the experiments. Results of the solutions are also different and depend on the choice of the model of the subsoil. Using several FEM software tools were made numerical analyses. Results of FEM analyses were also confronted with the values measured during the experiment.
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Field of Study
Global Issues
Content Type
Periodical article
Date Published / Released
2017-06, 2017
Publisher
Trans Tech Publications
Topic / Theme
Engineering
Copyright Message
Copyright © 2017 Trans Tech Publications Ltd.
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3D Numerical Simulation of the Hollow Square-Typed Polymer Based on Gas-Assisted Extrusion Method
(Switzerland: Trans Tech Publications, 2016), 9 page(s)
According to the properties of hollow square-typed polymer extrudate, the three dimensional numerical simulation of hollow square-typed polymer extrudate based on gas-assisted extrusion technology was performed by using finite element method. Meanwhile, four different gas-assisted modes imposed on the outer and in...
Sample
(Switzerland: Trans Tech Publications, 2016), 9 page(s)
Description
According to the properties of hollow square-typed polymer extrudate, the three dimensional numerical simulation of hollow square-typed polymer extrudate based on gas-assisted extrusion technology was performed by using finite element method. Meanwhile, four different gas-assisted modes imposed on the outer and inner wall of hollow square-type extrudate were considered. The extrudate swell ratios and field distributions, such as pressure drop, ve...
According to the properties of hollow square-typed polymer extrudate, the three dimensional numerical simulation of hollow square-typed polymer extrudate based on gas-assisted extrusion technology was performed by using finite element method. Meanwhile, four different gas-assisted modes imposed on the outer and inner wall of hollow square-type extrudate were considered. The extrudate swell ratios and field distributions, such as pressure drop, velocities and normal stresses of four different gas-assisted modes were obtained and compared with each other. Research results show that the extrudate swell ratios and field distributions of different gas-assisted modes are completely different. For the mode of gas-assisted on the single wall, the extrudate swell or shrink phenomena are large due to the non-symmetric properties of field distributions. For the no gas-assisted mode, although the physical field values are large, the extrudate swell ratio is not large due to the interaction role of both walls. For the mode of gas-assisted on both walls, the physical field values, such as pressure drop, normal velocities and stresses are all diminished, and the extrudate swell phenomenon was completely eliminated.
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Field of Study
Global Issues
Content Type
Periodical article
Date Published / Released
2016-07, 2016
Publisher
Trans Tech Publications
Topic / Theme
Engineering
Copyright Message
Copyright © 2016 Trans Tech Publications Ltd.
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3D Topography Analysis of Ball-End Milled H-13 Die Steel Surfaces Using Wavelet Decomposition Method
(Switzerland: Trans Tech Publications, 2016), 10 page(s)
Optical profiler is employed to measure the surface topography of H-13 die steel machined by ball end cutter. By using 2D discret wavelet decomposition, the topographies of different frequency bands are obtained and the influence of cutter posture on varying frequncy bands topography is studied. The results show t...
Sample
3D Topography Analysis of Ball-End Milled H-13 Die Steel Surfaces Using Wavelet Decomposition Method
(Switzerland: Trans Tech Publications, 2016), 10 page(s)
Description
Optical profiler is employed to measure the surface topography of H-13 die steel machined by ball end cutter. By using 2D discret wavelet decomposition, the topographies of different frequency bands are obtained and the influence of cutter posture on varying frequncy bands topography is studied. The results show that cutter posture has a great influence on the whole frequency band roughness. The changing trend of roughness is roughly the same und...
Optical profiler is employed to measure the surface topography of H-13 die steel machined by ball end cutter. By using 2D discret wavelet decomposition, the topographies of different frequency bands are obtained and the influence of cutter posture on varying frequncy bands topography is studied. The results show that cutter posture has a great influence on the whole frequency band roughness. The changing trend of roughness is roughly the same under different cutter postures which increase firstly then decrease with the decrease in frequency. A surface with a small high frequency roughness may have a large median frequency roughness.
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Field of Study
Global Issues
Content Type
Periodical article
Date Published / Released
2016-05, 2016
Publisher
Trans Tech Publications
Topic / Theme
Engineering
Copyright Message
Copyright © 2016 Trans Tech Publications Ltd.
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Abnormal Grain Growth on the Surface of Cold-Rolled AA1235 Aluminum Plate during the Annealing Process
(Switzerland: Trans Tech Publications, 2017), 12 page(s)
AA1235 aluminum alloys were twin roll cast into a 7.0 mm-thick billet and further rolled into a plate with 70% reduction, followed by annealing at 500 C for 8 h. Abnormal grains were found to be formed on the plate bottom surface. SEM, EBSD, and micro X-ray diffraction were used to analyze the mechanism underlying...
Sample
(Switzerland: Trans Tech Publications, 2017), 12 page(s)
Description
AA1235 aluminum alloys were twin roll cast into a 7.0 mm-thick billet and further rolled into a plate with 70% reduction, followed by annealing at 500 C for 8 h. Abnormal grains were found to be formed on the plate bottom surface. SEM, EBSD, and micro X-ray diffraction were used to analyze the mechanism underlying the abnormal growth of these grains. Results showed that the {100} >001001
AA1235 aluminum alloys were twin roll cast into a 7.0 mm-thick billet and further rolled into a plate with 70% reduction, followed by annealing at 500 C for 8 h. Abnormal grains were found to be formed on the plate bottom surface. SEM, EBSD, and micro X-ray diffraction were used to analyze the mechanism underlying the abnormal growth of these grains. Results showed that the {100} >001< texture was formed in the surrounding normal grains adjacent to the abnormal grain. The orientation angle between the abnormal grain and its adjacent normal grains was 45°. The {100} >001< texture formed during rolling and annealing accelerated abnormal grain growth. The partially dissolved Fe precipitates were heterogeneously distributed in the plate bottom heterogeneously, which also mainly explained abnormal grain growth.
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Field of Study
Global Issues
Content Type
Periodical article
Date Published / Released
2017-06, 2017
Publisher
Trans Tech Publications
Topic / Theme
Engineering
Copyright Message
Copyright © 2017 Trans Tech Publications Ltd.
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About Formability of Ultra-Fine Grained Metallic Materials
(Switzerland: Trans Tech Publications, 2016), 9 page(s)
Ultra-fine grained (UFG) and nanostructured metallic materials obtained via severe plastic deformation typically show very high mechanical strength but low tensile ductility, which dramatically limits their practical utility. Significant efforts were made to improve uniaxial tensile ductility of ultra-fine grained...
Sample
(Switzerland: Trans Tech Publications, 2016), 9 page(s)
Description
Ultra-fine grained (UFG) and nanostructured metallic materials obtained via severe plastic deformation typically show very high mechanical strength but low tensile ductility, which dramatically limits their practical utility. Significant efforts were made to improve uniaxial tensile ductility of ultra-fine grained and nanostructured metallic materials. The developed strategies can be divided into two main groups. (1) The 'mechanical' strategies e...
Ultra-fine grained (UFG) and nanostructured metallic materials obtained via severe plastic deformation typically show very high mechanical strength but low tensile ductility, which dramatically limits their practical utility. Significant efforts were made to improve uniaxial tensile ductility of ultra-fine grained and nanostructured metallic materials. The developed strategies can be divided into two main groups. (1) The 'mechanical' strategies employ the mechanical characteristics of these materials, such as their work hardening ability and/or strain rate sensitivity. These mechanical characteristics can be varied via changing testing parameters, such as temperature and/or strain rate. (2) The 'microstructural' strategies are based on idea of intelligent microstructural design to suppress necking at early stages of plastic deformation thus improving ductility. However, not much attention was paid to the fact, that in metallforming operations, metallic materials are not deformed uniaxially, but have to undergo deformation under complex strain paths. This work aims to demonstrate that despite UFG metallic materials have low tensile ductility, they can show enhanced formability during plastic deformation in complex stress state (such as formability under biaxial stretch, which is sufficient for metalforming operations.
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Field of Study
Global Issues
Content Type
Periodical article
Date Published / Released
2016-01, 2016
Publisher
Trans Tech Publications
Topic / Theme
Engineering
Copyright Message
Copyright © 2016 Trans Tech Publications Ltd.
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About the Possibility of Applying Coloured Soil-Cement in Making Road Pavement Layers
(Switzerland: Trans Tech Publications, 2016), 9 page(s)
The issue of the urban environment decoration has continuously been the task of urban architecture authority and it is quite successfully performed. Adding pigments, using coloured filler in the content of bitumen-concrete mixtures or applying multi-coloured paving stones and mosaic rigid concrete pavements provid...
Sample
(Switzerland: Trans Tech Publications, 2016), 9 page(s)
Description
The issue of the urban environment decoration has continuously been the task of urban architecture authority and it is quite successfully performed. Adding pigments, using coloured filler in the content of bitumen-concrete mixtures or applying multi-coloured paving stones and mosaic rigid concrete pavements provide additional positive impression in the perception of intra-buildings space and modern urban landscape. The use of local materials with...
The issue of the urban environment decoration has continuously been the task of urban architecture authority and it is quite successfully performed. Adding pigments, using coloured filler in the content of bitumen-concrete mixtures or applying multi-coloured paving stones and mosaic rigid concrete pavements provide additional positive impression in the perception of intra-buildings space and modern urban landscape. The use of local materials with adding pigments for the design of residential areas can be extremely important for local communities.In order to test soil-cement mixtures with added colour pigment for road pavements on the basis of construction laboratory at Lutsk NTU, a series of experiments has been planned to answer the question of the pigment amount impact on the physical and mechanical properties of the materials and finding the best ratios for them.
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Field of Study
Global Issues
Content Type
Periodical article
Date Published / Released
2016-09, 2016
Publisher
Trans Tech Publications
Topic / Theme
Engineering
Copyright Message
Copyright © 2016 Trans Tech Publications Ltd.
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