The Experts below are selected from a list of 78135 Experts worldwide ranked by ideXlab platform
Kenichi Manabe - One of the best experts on this subject based on the ideXlab platform.
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development of servo type micro hydromechanical Deep Drawing apparatus and micro Deep Drawing experiments of circular cups
Journal of Materials Processing Technology, 2015Co-Authors: Hideki Sato, Kenichi Manabe, Kikukatsu Ito, Dongbi Wei, Zhengyi JiangAbstract:Abstract A micro-hydromechanical Deep-Drawing (MHDD) apparatus for manufacturing a micro-complex-shape components and increasing of drawn cup accuracy has been developed in this study. This apparatus with simple tooling structure and forming process can achieve high dimensional accuracy using servo press mechanics with a double-action type, one-stroke forming process without transferring and positioning, force control, and fine flow rate control of the pressure medium. The developed MHDD apparatus can prevent wrinkling by applying an appropriate constant gap and stably generate the counterpressure. Micro drawn cups of 0.8 mm diameter are successfully fabricated. Also, the effects of counterpressure on drawability and dimensional accuracy at the bottom of the cup are investigated for phosphor bronze, stainless-steel, and pure titanium foils with a thickness of 50 μm. The appropriate counterpressure applied in MHDD can eliminate wrinkling and reduce the frictional Drawing force. It is concluded that the forming limit and dimensional accuracy can be improved by MHDD.
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validation of fe simulation based on surface roughness model in micro Deep Drawing
Journal of Materials Processing Technology, 2008Co-Authors: Kenichi Manabe, Hiroshi Koyama, Tetsuhide Shimizu, Ming Yang, K ItoAbstract:Metal forming technology has been paid great attention as one of the most economical mass production methods for sub-millimeter-scale microparts as well as macro-scale parts. Although tools and dies are essential for the manufacture of microformed parts, the fundamental knowledge and technological data on their fabrication have not been accumulated. Therefore, establishing design manuals and codes for tools, dies and blank materials for microforming is important for realizing high-precision forming. Particularly for miniaturization in sheet metal forming, the surface roughness of tools and blanks are thought to largely affect the processing characteristics and accuracy of products. From the standpoint of the design of tools and blank materials, this study was focused on the surface roughness of tools and blanks in the micro-Deep-Drawing process, and aimed at clarifying the effect of surface roughness on microforming characteristics. In our previous study, by finite element (FE) simulation considering surface roughness, the effect of tool surface asperity on the drawn cup surface quality in the two-stage micro-Deep-Drawing process was simulated. In this study, to verify the validity of the FE model of surface roughness in the micro-Deep-Drawing process, a new high-precision sequential blanking and Drawing setup was developed for the experiment and a microcup with 500 μm diameter was fabricated from stainless steel (SUS304) ultrathin foil of 20 μm thickness. For the evaluation of the drawn cup, the cup geometry, thickness strain distribution, and surface roughness were measured. By comparisons of the FE simulation and the experimental results, the validation of the surface roughness model was studied, and the notable influential factors at the microscale were discussed.
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finite element analysis of magnesium az31 alloy sheet in warm Deep Drawing process considering heat transfer effect
Materials Letters, 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.
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effect of blank holder force control in Deep Drawing process of magnesium alloy sheet
Journal of Materials Processing Technology, 2005Co-Authors: Shoichiro Yoshihara, Kenichi Manabe, Hisashi NishimuraAbstract:Abstract A circular cup Deep-Drawing process was investigated using a magnesium alloy material, which is the lightest practical material for use in manufacturing structural components. An improvement in the limiting Drawing ratio (LDR) at 300 °C was observed, by controlling a variable blank holder force (BHF) during the process, in comparison with the constant BHF conditions. The reason for the improvement of the LDR is that the magnesium alloy material has a low F -value, which was obtained from tensile tests when it was warmed to the elevated temperature. When the experimental conditions are not appropriate, such as when BHF is high, the experimentally drawn cup fractured at the wall part (β-rupture). The LDR of the magnesium alloy sheet was improved using the BHF control technique and verified using a finite element method (FEM) simulation. It is confirmed that the FEM simulations behaved in a similar manner to the experiments, with β-rupture being observed during the fracture at the wall part.
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formability enhancement in magnesium alloy Deep Drawing by local heating and cooling technique
Journal of Materials Processing Technology, 2003Co-Authors: Shouichirou Yoshihara, Hirokuni Yamamoto, Kenichi Manabe, Hisashi NishimuraAbstract:Abstract A new Deep Drawing process with a local heating and cooling technique was developed because sheet forming of a magnesium alloy is very difficult by the conventional method at room temperature. The objective of this study is to clarify how much the formability of a magnesium alloy sheet can be enhanced by using the new technique. A magnesium alloy sheet of 0.5 mm thickness was used. Deep Drawing experiments were conducted at a temperature of about 400 °C for the blank and Deep Drawing tool (holder and die) and at a punch speed of 200 mm/min. As a result, the drawn cup height of 115 mm was achieved by using both the local heating and cooling technique and the variable blank holder pressure (BHP) technique. It is confirmed that the Deep Drawing performance of the magnesium alloy can be considerably enhanced under the appropriate temperature distribution for the local heating and cooling technique and with variable BHP control.
Swadesh Kuma Singh - One of the best experts on this subject based on the ideXlab platform.
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experimental and numerical investigation of anisotropic yield criteria for warm Deep Drawing of ti 6al 4v alloy
Materials & Design, 2014Co-Authors: Niti Kotkunde, Aditya D Deole, Ami Gupta, Swadesh Kuma SinghAbstract:Abstract Accuracy of the finite element simulation of sheet metal forming is significantly dependent on the correctness of input properties and appropriate selection of material models. In this work, anisotropic yield criteria namely, Hill 1948, Barlat 1989, Barlat 1996, Barlat 2000 and Cazacu Barlat have been implemented for Ti–6Al–4V alloy at 400 °C. Material constants required for the yield criteria have been determined and deformation behavior in Deep Drawing process has been analyzed in finite element software. Also, Deep Drawing experiments on Ti–6Al–4V alloy have been performed at 400 °C to validate finite element simulation results. Further, comparison of yield criteria based on thickness distribution, earing profile, complexity in material parameter identification and computational time has shown Cazacu-Barlat to be well suited for Deep Drawing of Ti–6Al–4V alloy.
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failure and formability studies in warm Deep Drawing of ti 6al 4v alloy
Materials & Design, 2014Co-Authors: Niti Kotkunde, Aditya D Deole, Ami Gupta, Swadesh Kuma SinghAbstract:Abstract Deep Drawing experiments have been performed in order to study formability of Ti–6Al–4V alloy sheet at temperature ranging from room temperature to 400 °C. It is found that below 150 °C, formability of the material is very poor and above 150 °C till 400 °C, limiting Drawing ratio (LDR) is found to be 1.8 which is substantially lesser than other structural alloys. For better understanding of failures in failed cups, failure regions have been identified in neck and wall which are validated using finite element (FE) simulations. Fractured surface has been examined with scanning electron microscope (SEM) which reveals different types of shallow dimples indicating predominantly ductile failure. Additionally, in the properly drawn cups, thickness distribution has been studied over a temperature range of 150–400 °C and blank diameter 50–54 mm. In order to optimize blank diameter and temperature to obtain uniform thickness distribution of drawn cups, artificial neural network (ANN) and genetic algorithm (GA) have been employed. Thickness distribution for optimized parameters is validated using FE simulation.
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effect of process parameters on product surface finish and thickness variation in hydro mechanical Deep Drawing
Journal of Materials Processing Technology, 2008Co-Authors: Swadesh Kuma Singh, Ravi D KumaAbstract:Hydro-mechanical Deep Drawing combines the features of conventional Deep Drawing and hydroforming. In this process, the punch deforms the blank to its final shape by moving against a controlled pressurized fluid. Hydro-mechanical Deep Drawing offers several advantages over conventional Deep Drawing like higher drawability, uniform strain distribution, better surface finish and improved dimensional accuracy. The process parameters such as initial pressure in the chamber (pre-bulging pressure), the peak chamber pressure (cutoff pressure) and oil gap have strong influence on the process. In view of this, the effect of the pre-bulging pressure and the cutoff pressure on thickness distribution and surface finish in hydro-mechanical Deep Drawing were studied in this paper. Experiments have been carried out on extra-low carbon steel sheets by varying these parameters. It was found out that thickness distribution along cup wall is more uniform for intermediate pre-bulging pressures. At too low pre-bulging pressure necking takes place at punch corner (similar to the conventional Deep Drawing) and at very high pre-bulging pressure, necking shifts towards wall region. So a region of safe pressure (combination of pre-bulging and cutoff pressure) was found out in which cups of better quality in terms of uniform thickness distribution and better quality surface can be drawn successfully.
L F Menezes - One of the best experts on this subject based on the ideXlab platform.
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influence of process parameters on the Deep Drawing of stainless steel
Finite Elements in Analysis and Design, 2007Co-Authors: R Padmanabha, M C Oliveira, J L Alves, L F MenezesAbstract:Optimization of process parameters in sheet metal forming is an important task to reduce manufacturing cost. To determine the optimum values of the process parameters, it is essential to find their influence on the deformation behaviour of the sheet metal. The significance of three important process parameters namely, die radius, blank holder force and friction coefficient on the Deep-Drawing characteristics of a stainless steel axi-symmetric cup was determined. Finite element method combined with Taguchi technique form a refined predictive tool to determine the influence of forming process parameters. The Taguchi method was employed to identify the relative influence of each process parameter considered in this study. A reduced set of finite element simulations were carried out as per the Taguchi orthogonal array. Based on the predicted thickness distribution of the Deep drawn circular cup and analysis of variance test, it is evident that die radius has the greatest influence on the Deep Drawing of stainless steel blank sheet followed by the blank holder force and the friction coefficient. Further, it is shown that a blank holder force application and local lubrication scheme improved the quality of the formed part.
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effect of anisotropy on the Deep Drawing of mild steel and dual phase steel tailor welded blanks
Journal of Materials Processing Technology, 2007Co-Authors: R Padmanabhan, M C Oliveira, A J Baptista, L F MenezesAbstract:Abstract Tailor-welded blanks made of dissimilar, uniform or non-uniform thickness materials have potential applications in automobile industries. Compared to the base metal, the formability of tailor-welded blank is less due to the presence of weld area and strength mismatch between component blanks. Most sheet metals used to produce tailor-welded blanks have anisotropy induced during pre-processing stage due to large deformation. The orientation of the blank sheet rolling direction and the combination of the blank sheet materials has significant influence on the deformation behaviour. The effect of anisotropy in the tailor-welded blank and the orientation of blank sheets rolling direction during Deep-Drawing process are investigated in this study. Finite element analysis of Deep-Drawing mild steel and dual-phase steel tailor-welded blank models was carried out using research purpose FE code DD3IMP; to form a basis for tailor-welded blank design and development for a part. Anisotropy in the blank sheets has moderate influence and its contribution to increased material flow depends on the mechanical properties of the blank sheets. Appropriate combination of the blank sheets rolling direction orientation can significantly improve the formability of the tailor-welded blank in the Deep-Drawing of square cup.
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three dimensional numerical simulation of the Deep Drawing process using solid finite elements
Journal of Materials Processing Technology, 2000Co-Authors: L F Menezes, C TeodosiuAbstract:Abstract The main goal of this work is to present a three-dimensional mechanical model for the numerical simulation of the Deep-Drawing process. The model takes into account the large elastoplastic strains and rotations that occur in the Deep-Drawing process. Hill’s orthotropic yield criteria with isotropic and kinematics hardening describes the anisotropic plastic properties of the sheet. Coulomb’s classical law models the frictional contact problem treated with an augmented Lagrangian approach. This method yields a mixed system where the final unknowns of the problem are static (frictional contact forces) and kinematic (displacements) variables. To solve this problem use is made of a fully implicit algorithm of Newton–Raphson type. Three-dimensional isoparametric finite elements with a selective reduced integration are used for the spatial discretization of the deformed body. The geometry of the forming tools is modelled by Bezier surfaces. The numerical results of the Deep-Drawing of a square cup are presented to focus their good agreement with the results of experiment.
Tayla Alta - One of the best experts on this subject based on the ideXlab platform.
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evaluation of stamping lubricants in forming advanced high strength steels ahss using Deep Drawing and ironing tests
Journal of Materials Processing Technology, 2009Co-Authors: Hyunok Kim, Tayla AltaAbstract:Abstract In forming AHSS, the lubricant must reduce the friction between die and sheet as well as the effect of heat generated from deformation and friction, especially in forming at high stroking rates. In this study, the effectiveness of stamping lubricants was evaluated by using the Deep Drawing and ironing tests. Various stamping lubricants were tested in forming of DP590 GA round cup samples. In these tests, the performance of lubricants was ranked via evaluation criteria that include punch force and the geometry of tested specimens. Deep Drawing tests were conducted at two different blank holder forces, BHF (30 and 70 ton) at a constant ram speed (70 mm/s). The ironing tests were conducted to evaluate the performance of lubricants at higher tool–workpiece interface pressure than that is present in Deep Drawing. Polymer-based thin film lubricants with pressure additives (e.g. Lubricants A and B) were more effective than other lubricants as shown by the force (e.g. maximum punch force and applicable BHF without cup fracture) and geometry indicators (e.g. draw-in length, flange perimeter and sidewall thinning). The pressure and temperature distributions at the die–sheet interface were predicted by FE simulation of Deep Drawing and ironing tests. As expected, the value of interface pressure and temperature were maximum at the die corner radius.
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Deep Drawing of round cups from tailor welded blanks
Journal of Materials Processing Technology, 1995Co-Authors: Mustafa A Ahmetoglu, Dirk Ouwers, Leonid Shulki, Laure Taupi, Gary L Kinzel, Tayla AltaAbstract:Recent developments in the welding technology and the considerations regarding material cost, dimensional accuracy and weight, force automakers and appliance manufacturers to use tailor-welded blanks in their stamping operations. The welding of blanks with different thicknesses, materials and/or surface conditions introduces many challenging formability problems for process development and tool design. In cooperation with industrial partners, projects are being conducted at the ERC for Net Shape Manufacturing to study the formability of tailor-welded blanks and develop guidelines for tool design. This paper gives a summary of the preliminary work done on the Deep Drawing of round cups from tailor-welded blanks.
Hisashi Nishimura - One of the best experts on this subject based on the ideXlab platform.
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effect of blank holder force control in Deep Drawing process of magnesium alloy sheet
Journal of Materials Processing Technology, 2005Co-Authors: Shoichiro Yoshihara, Kenichi Manabe, Hisashi NishimuraAbstract:Abstract A circular cup Deep-Drawing process was investigated using a magnesium alloy material, which is the lightest practical material for use in manufacturing structural components. An improvement in the limiting Drawing ratio (LDR) at 300 °C was observed, by controlling a variable blank holder force (BHF) during the process, in comparison with the constant BHF conditions. The reason for the improvement of the LDR is that the magnesium alloy material has a low F -value, which was obtained from tensile tests when it was warmed to the elevated temperature. When the experimental conditions are not appropriate, such as when BHF is high, the experimentally drawn cup fractured at the wall part (β-rupture). The LDR of the magnesium alloy sheet was improved using the BHF control technique and verified using a finite element method (FEM) simulation. It is confirmed that the FEM simulations behaved in a similar manner to the experiments, with β-rupture being observed during the fracture at the wall part.
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formability enhancement in magnesium alloy Deep Drawing by local heating and cooling technique
Journal of Materials Processing Technology, 2003Co-Authors: Shouichirou Yoshihara, Hirokuni Yamamoto, Kenichi Manabe, Hisashi NishimuraAbstract:Abstract A new Deep Drawing process with a local heating and cooling technique was developed because sheet forming of a magnesium alloy is very difficult by the conventional method at room temperature. The objective of this study is to clarify how much the formability of a magnesium alloy sheet can be enhanced by using the new technique. A magnesium alloy sheet of 0.5 mm thickness was used. Deep Drawing experiments were conducted at a temperature of about 400 °C for the blank and Deep Drawing tool (holder and die) and at a punch speed of 200 mm/min. As a result, the drawn cup height of 115 mm was achieved by using both the local heating and cooling technique and the variable blank holder pressure (BHP) technique. It is confirmed that the Deep Drawing performance of the magnesium alloy can be considerably enhanced under the appropriate temperature distribution for the local heating and cooling technique and with variable BHP control.
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formability enhancement in magnesium alloy stamping using a local heating and cooling technique circular cup Deep Drawing process
Journal of Materials Processing Technology, 2003Co-Authors: Hirokuni Yamamoto, Kenichi Manabe, Hisashi Nishimura, Shoichiro YoshiharaAbstract:Abstract A new Deep Drawing process with a localized heating and cooling technique was developed to improve sheet forming of a magnesium alloy which is very difficult by conventional methods at room temperature. The objective of this study is to clarify how much the formability of a magnesium alloy sheet can be enhanced by using the new technique. A magnesium alloy sheet of 0.5 mm thickness was used. Deep Drawing experiments were conducted at a temperature of about 400 °C for the blank and Deep Drawing tool (holder and die) and at a punch speed of 200 mm/min. As a result, the drawn cup height of 115 mm was achieved by using both the local heating and cooling technique and the variable blank holder pressure (BHP) technique. It was confirmed that the Deep Drawing performance of the magnesium alloy can be considerably enhanced using the appropriate temperature distribution for the local heating and cooling technique and with variable BHP control.
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fuzzy adaptive control of blank holder force in circular cup Deep Drawing forming limit and influencing factors
Transactions of the Japan Society of Mechanical Engineers. C, 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.
