The Experts below are selected from a list of 1065 Experts worldwide ranked by ideXlab platform
Kenichi Manabe - One of the best experts on this subject based on the ideXlab platform.
-
effects of surface roughness on micro deep drawing of circular cups with consideration of size effects
2016Co-Authors: Liang Luo, Kenichi Manabe, Zhengyi Jiang, Dongbin Wei, Xianming Zhao, Tsuyoshi FurushimaAbstract:Surface roughness, compared with tiny sizes of micro products, can be relatively large and has significant influences on micro forming processes and products' quality. In this study, a voronoi finite element model that considers size effects of material was developed. Next the surface roughness information was assigned to this voronoi model through different elemental thickness distributions. Furthermore, springback simulation was conducted for the micro deep drawn circular cups. Simulation results demonstrate that the surface roughness with consideration of size effects has significant influences on the overall springback, the Drawability represented by the minimum thickness and products' quality regarding thickness evenness and shape accuracy. This study also shows that the results from the new models are close to the experimental results concerning the diameter of cup mouth and the maximum drawing force. The developed model for the micro deep drawing is accurate and beneficial for the development of micro deep drawing process. The new FE model considers both surface roughness and size effects for micro deep drawing of circular cups.The new FE model provides more accuracy results than normal models when compared with experimental results.Surface roughness affects the springback, the Drawability and the cups' quality obviously in micro deep drawing.
-
effect of alternating blank holder motion of drawing and wrinkle elimination on deep Drawability
2007Co-Authors: Tetsuya Yagami, Kenichi Manabe, Y YamauchiAbstract:Abstract The effect of controlling blank holder motion by a newly proposed algorithm on deep-Drawability was investigated for a circular-cup deep-drawing process of a thin sheet metal, from the perspective of wrinkle behavior as well as the fracture limit. The algorithm for controlling blank holder motion, such that blank holder force is extremely low, by temporarily allowing wrinkling has been proposed by the authors for improving the deep-Drawability of thin blanks. Experimental deep drawing tests of a Cu alloy sheet were carried out to evaluate the effect of motion control on wrinkle behavior. Finite element (FE) simulations of the deep drawing process were also conducted to investigate the effect of the method on fracture damage reduction. In the previous work by FE simulation, we showed that the motion control method is effective for forming relatively thin sheet blanks, and that the performance of the control method significantly depends on control parameters, i.e., minimum and maximum allowable wrinkle heights, which are associated with wrinkle recognition. The results of the experiment indicated that wrinkle elimination can be successful if wrinkles are within the allowable height range. FE simulation results also indicated that deep-Drawability can be improved as a result of the reduction of ductile damage accumulation when using blank holder control.
-
dieless drawing process of extruded non circular aluminum alloy tubes with double hollow section
2007Co-Authors: Tsuyoshi Furushima, Kenichi ManabeAbstract:Dieless drawing technique can thin down tubes by combining locally heating and tensile deformation of tubes without dies and tools. In this study, the dieless drawing process is applied to non-circular 1100 and 3003 aluminum alloy extruded tubes with double hollow section for heat exchangers. Fundamental deformation behavior of the tubes in the dieless drawing is investigated experimentally. Multi-pass dieless drawing is performed for the tubes to obtain larger reduction in area. The limiting reduction in area of A3003 tubes is 40% larger than 35% of A1100 in a singles pass drawing. Reduction in area 57.75% is obtained by two-pass dieless drawing for A3003 tubes. Geometrical similarity law in cross section is satisfied for the aluminum extruded tubes with double-hollow-section. In addition, surface characteristic and microstructure of the tubes after the dieless drawing is observed to investigate the effect of microscopic factors on the deformation behavior and the Drawability in the dieless drawing. The results show that the surface roughness of the tubes increases with increasing reduction in area. Furthermore, the rate of increasing surface roughness depends on the grain size of initial tubes. It is found that the microstructure and the surface characteristic affect the deformation behavior and the Drawability in the dieless drawing.
-
finite element analysis of magnesium az31 alloy sheet in warm deep drawing process considering heat transfer effect
2006Co-Authors: Abdelwahab Elmorsy, Kenichi ManabeAbstract:This paper reports on the finite element analysis (FEA) of a warm deep-drawing process. The present investigation of FE analysis of warm deep-drawing process was initiated with two primary objectives. First, to have first-hand knowledge of warm deep-drawing process considering heat transfer effect between blank and die components (die and blank holder), second to investigate the improvement of Drawability and temperature distribution of magnesium alloy sheet, AZ31. In this model, both die and blank holder were heated to 300 °C while the punch was kept at room temperature by cooling water. The initial temperature of the blank is the room temperature. The effect of strain rate sensitivity index on the deformation profile was considered in this work. The FE model was performed with two punch speeds to investigate the effect of the punch speed on the temperature distribution. The simulation results were compared to those obtained from the same model without considering heat transfer. In the second model, the die, the blank, the blank holder and the punch were heated to 300 °C. The simulation results revealed that considering heat transfer is very effective for deep Drawability of Mg alloy. The blank in first model was drawn successfully without any localized thinning and the cup height is higher in contrast to the second model.
-
fuzzy adaptive control of blank holder force in circular cup deep drawing forming limit and influencing factors
1998Co-Authors: Shoichiro Yoshihara, Kenichi Manabe, Ming Yang, Hisashi NishimuraAbstract:The mechanism on improvement of the Drawability by using the fuzzy adaptive BHF (blank holder force) control has been studied in circular-cup deep-drawing process. The deep-drawing tests were carried out using aluminum alloy and cold rolled steel sheets of 1.0 mm thickness. The LDRs (limit drawing ratio) obtained from the fuzzy BHF control method and the constant BHF method in the experiment were compared and evaluated. As a result, the LDR in the case of aluminum alloy improved from 2.09 to 2.14 and in the case of the steel from 2.25 to 2.27 with the fuzzy adaptive BHF control method. The previously presented mechanism on improvement of the Drawability was proved by the observation of blank deformation process. The wrinkle at the flange part under the low BHF condition was flattened due to the increasing BHF from middle to last stage of the process and then the fracture at the punch shoulder part did not happen. Moreover, from the plastic deformation model of deep-drawing operation assuming the blank material with strain hardening and anisotropic characteristics, it was confirmed that the low F value and the high γ value have a great effect on the improvement of the LDR by using the variable BHF method.
Ken-ichiro Mori - One of the best experts on this subject based on the ideXlab platform.
-
deep Drawability and bendability in hot stamping of ultra high strength steel parts
2016Co-Authors: Ken-ichiro Mori, Tomoyoshi Maeno, Yuzo YanagitaAbstract:The deep Drawability and bendability in hot stamping of ultra-high strength steel parts were examined. Although the cold Drawability is greatly influenced by the blank shape, the limiting drawing depths for the square and circular blanks were equal for hot stamping because of small flow stress. In hot hat-shaped bending using draw-and form-type tools, the effect of the blankholder force generated with the draw-type tools on the springback was small, and the seizure for the form-type tools was smaller than that of the draw-type tools. Since both edges in contact with the electrodes are not heated for resistance heating, cracks were caused at the edges for resistance heating in the transversal directions in hot stamping of an S-rail with form-type tools, and thus it is required to control deformation of the non-heating zones.
-
cold deep drawing of commercial magnesium alloy sheets
2007Co-Authors: Ken-ichiro Mori, Hirokazu TsujiAbstract:A cold deep drawing process for commercial AZ31 magnesium alloy sheets was developed. The commercial sheets were successfully formed into circular cups at room temperature by optimising the annealing temperature of the sheets, i.e. a limiting drawing ratio of 1.75 was attained for an annealing temperature of 500 °C. The increases in elongation, n-value and r-value, and the decrease in flow stress effective in the improvement of Drawability were obtained for the annealing. The apparatus for cold deep drawing without heating becomes much simpler than that for the conventional warm deep drawing. The effects of the lubricant, the clearance between the die and the punch and the corner radius of the punch on the Drawability were examined. The limiting drawing ratio was increased by applying force onto the edge of a blank through the die corner. In addition, cold deep drawing of magnesium alloy square cups was performed. It was found that comparatively shallow magnesium alloy cups are satisfactorily formed at room temperature without heating.
-
finite element analysis of the formability of an austenitic stainless steel sheet in warm deep drawing
2003Co-Authors: Hirohiko Takuda, Ken-ichiro Mori, T Masachika, E Yamazaki, Y. WatanabeAbstract:Abstract The forming limit in warm deep drawing of a type 304 stainless steel sheet is experimentally examined and the deformation behaviour and the temperature change in the sheet are simulated by the combination of the rigid–plastic and the heat conduction finite element methods. In the simulation the deformation-induced martensitic transformation is taken into consideration. The experimental and the numerical results show the positive effect of the heating on the Drawability. The limiting drawing ratio becomes higher to 2.7 in the warm deep drawing, while the ratio is 2.0 at room temperature. The improvement in the Drawability is attained by the comparatively low heating temperature under 150 °C and by the cooling of the punch. The forming limit and the necking site are successfully predicted by the simulation.
Hyoung Seop Kim - One of the best experts on this subject based on the ideXlab platform.
-
stretchability and Drawability of twinning induced plasticity steel cored layer steel sheets
2017Co-Authors: Jungsik Kim, Seung Mi Baek, Jae Ik Yoon, Minhong Seo, Won Tae Cho, K G Chin, See Am Lee, Hyoung Seop KimAbstract:Abstracts In this work, the qualCONVERSION(0ities of sheet formability (i.e., stretchability and Drawability), of twinning-induced plasticity (TWIP), steel-cored thr$ee-layer steel sheets were investigated in terms of tensile parameters (i.e., strain hardening exponent, strain rate sensitivity, normal anisotropy, mean R -value, and total elongation). The tensile parameters of TWIP steel-cored three-layer steel sheets follow the force-based rule of mixtures. The limit drawing ratio, the measure of Drawability, of the three-layer steel sheet was proportional to the mean R -value and the strain rate sensitivity while the limit dome height (LDH), the measure of stretchability, could not be correlated with any tensile parameters. The LDH of the TWIP steel-cored layer sheet was superior to that of the single layer due to the inhibition of serration in the TWIP steel-core during the Erichsen test.
Wim Deferme - One of the best experts on this subject based on the ideXlab platform.
-
printing smart designs of light emitting devices with maintained textile properties
2018Co-Authors: Inge Verboven, Jeroen Stryckers, Viktorija Mecnika, Glen Vandevenne, Manoj Jose, Wim DefermeAbstract:To maintain typical textile properties, smart designs of light emitting devices are printed directly onto textile substrates. A first approach shows improved designs for alternating current powder electroluminescence (ACPEL) devices. A configuration with the following build-up, starting from the textile substrate, was applied using the screen printing technique: silver (10 µm)/barium titanate (10 µm)/zinc-oxide (10 µm) and poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (10 µm). Textile properties such as flexibility, drapability and air permeability are preserved by implementing a pixel-like design of the printed layers. Another route is the application of organic light emitting devices (OLEDs) fabricated out of following layers, also starting from the textile substrate: polyurethane or acrylate (10–20 µm) as smoothing layer/silver (200 nm)/poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (35 nm)/super yellow (80 nm)/calcium/aluminum (12/17 nm). Their very thin nm-range layer thickness, preserving the flexibility and drapability of the substrate, and their low working voltage, makes these devices the possible future in light-emitting wearables.
-
Printing Smart Designs of Light Emitting Devices with Maintained Textile Properties
2018Co-Authors: Inge Verboven, Jeroen Stryckers, Viktorija Mecnika, Glen Vandevenne, Manoj Jose, Wim DefermeAbstract:To maintain typical textile properties, smart designs of light emitting devices are printed directly onto textile substrates. A first approach shows improved designs for alternating current powder electroluminescence (ACPEL) devices. A configuration with the following build-up, starting from the textile substrate, was applied using the screen printing technique: silver (10 µm)/barium titanate (10 µm)/zinc-oxide (10 µm) and poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (10 µm). Textile properties such as flexibility, drapability and air permeability are preserved by implementing a pixel-like design of the printed layers. Another route is the application of organic light emitting devices (OLEDs) fabricated out of following layers, also starting from the textile substrate: polyurethane or acrylate (10–20 µm) as smoothing layer/silver (200 nm)/poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (35 nm)/super yellow (80 nm)/calcium/aluminum (12/17 nm). Their very thin nm-range layer thickness, preserving the flexibility and drapability of the substrate, and their low working voltage, makes these devices the possible future in light-emitting wearables
Y. Watanabe - One of the best experts on this subject based on the ideXlab platform.
-
finite element analysis of the formability of an austenitic stainless steel sheet in warm deep drawing
2003Co-Authors: Hirohiko Takuda, Ken-ichiro Mori, T Masachika, E Yamazaki, Y. WatanabeAbstract:Abstract The forming limit in warm deep drawing of a type 304 stainless steel sheet is experimentally examined and the deformation behaviour and the temperature change in the sheet are simulated by the combination of the rigid–plastic and the heat conduction finite element methods. In the simulation the deformation-induced martensitic transformation is taken into consideration. The experimental and the numerical results show the positive effect of the heating on the Drawability. The limiting drawing ratio becomes higher to 2.7 in the warm deep drawing, while the ratio is 2.0 at room temperature. The improvement in the Drawability is attained by the comparatively low heating temperature under 150 °C and by the cooling of the punch. The forming limit and the necking site are successfully predicted by the simulation.
