Investigation of Forming Cylindrical Parts in a Modified Hydrodynamic Deep Drawing Assisted by Radial Pressure With Inward Flowing Liquid

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Milad Sadegh Yazdi ◽  
Mohammad Bakhshi-Jooybari ◽  
Hamid Gorji ◽  
Mohsen Shakeri ◽  
Maziar Khademi
Keyword(s):  
Deep Drawing ◽  
Thickness Distribution ◽  
Radial Pressure ◽  
Chamber Pressure ◽  
Drawing Ratio ◽  
Forming Force ◽  
Flowing Liquid ◽  
Hydrodynamic Deep Drawing ◽  
Study Results ◽  
Formed Part

Among the sheet hydroforming processes, hydrodynamic deep drawing (HDD) process has been used to form complex shapes and can produce parts with high drawing ratio. Studies showed that radial pressure created on the edge of the sheet can decrease the drawing force and increase drawing ratio. Thus, increasing of radial pressure to an amount greater than chamber pressure, and independent control of these pressures, is the basic idea in this study. In this research, the effect of radial and chamber pressures on formability of St13 and pure copper sheets in the process of hydrodynamic deep drawing assisted by radial pressure (HDDRP) with inward flowing liquid is investigated. Giving that a significant portion of the maximum thinning of the formed part occurs in the beginning of the process, the pressure supply system used in the experimental tests was designed in a way, which provides simultaneous control of the radial and chamber pressures throughout the process. Thickness distribution, forming force, and tensile stresses are the parameters that were evaluated in this study. Results indicated that using a higher radial pressure than the chamber pressure and controlling their values in the initial stages of the process enhances the thickness distribution of the formed part in all regions. A comparison between the thickness distribution and maximum forming force of the formed parts by the HDDRP and HDDRP with inward flowing liquid methods showed that by applying the later method, parts with more uniform thickness distribution and less maximum thinning and forming force can be achieved.

scholarly journals Investigation of a Modified Hydrodynamic Deep Drawing Assisted by Radial Pressure with Inward Flowing Liquid Process

2018 ◽  
Vol 190 ◽  
pp. 09003
Author(s):  
Maziar Khademi ◽  
Milad Sadegh yazdi ◽  
Mohammad Bakhshi-Jooybari ◽  
Hamid Gorji
Keyword(s):  
Deep Drawing ◽  
Thickness Distribution ◽  
Radial Pressure ◽  
Drawing Ratio ◽  
Cavity Pressure ◽  
Flowing Liquid ◽  
Hydrodynamic Deep Drawing ◽  
Simultaneous Control ◽  
Die Set ◽  
Cylindrical Parts

Hydrodynamic Deep Drawing (HDDRP), the combination of hydroforming and conventional deep drawing, accommodates the advantages of the two processes. A technique, called HDDRP with inward flowing liquid, has been introduced based on the idea of insertion of radial pressure around the blank rim. The radial pressure created on the blank edge, can increase the drawing ratio. Thus, increasing the radial pressure to an amount greater than the cavity pressure, and independent control of these pressures is the basic idea of this research for forming cylindrical parts. To perform the experiments, two independent pumps were used to provide the two pressures independently. The pressure supply system and the die set were designed in a way that provides simultaneous control of the pressures throughout the process. Then, the effects of radial pressure paths on thickness distribution of cylindrical St13 cups were investigated. In addition, a comparison between HDDRP and HDDRP with inward flowing liquid processes has been performed experimentally. Results indicated that using a higher radial pressure than the cavity pressure and controlling their values at any moment of the process enhances the thickness distribution of the formed part in all regions.

Investigation into Influence of Pre-Forming Depth on Multi-Stage Hydrodynamic Deep Drawing of Thin-Wall Cups with Stepped Geometries

2012 ◽  
Vol 457-458 ◽  
pp. 1219-1222 ◽  
Author(s):  
Yu Zhu ◽  
Min Wan ◽  
Ying Ke Zhou ◽  
Qing Hai Liu ◽  
Nan Song Zheng ◽  
...  
Keyword(s):  
Deep Drawing ◽  
Failure Modes ◽  
Thickness Distribution ◽  
Steel Part ◽  
Drawing Ratio ◽  
Thin Wall ◽  
Forming Process ◽  
Hydrodynamic Deep Drawing ◽  
Multi Stage ◽  
Thin Walled

Hydrodynamic deep drawing (HDD) is an effective method for manufacturing complicated and thin-walled parts. Aiming at the forming process of the stainless steel part with 0.4 mm thick and complex stepped geometries, the technology scheme of multi-stage HDD assisted by conventional deep drawing (CDD) is proposed in consideration of wrinkling and destabilization in the unsupported region of the conical wall, and finite element models are built. As a key process parameter, pre-forming depth on the quality of the parts is explored with assistance of numerical simulations and verification experiments. Furthermore, the failure modes, including wrinkling and fracture during forming process are discussed; meanwhile, the optimum pre-forming depth is realized. The results indicate that the technological method is proven to be feasible for integral forming of thin-walled parts with a large drawing ratio and stepped geometries; moreover, the parts with uniform thickness distribution and high quality are successfully formed by adopting optimum pre-forming depth.

Process analysis of hydrodynamic deep drawing of cone cups assisted by radial pressure

2015 ◽  
Vol 231 (10) ◽  
pp. 1793-1802 ◽  
Author(s):  
Alireza Jalil ◽  
Mohammad Hoseinpour Gollo ◽  
SM Hossein Seyedkashi
Keyword(s):  
Deep Drawing ◽  
Critical Pressure ◽  
Process Analysis ◽  
Fluid Pressure ◽  
Radial Pressure ◽  
Strain Hardening Exponent ◽  
Geometrical Parameters ◽  
Drawing Ratio ◽  
Hydrodynamic Deep Drawing ◽  
Rupture Pressure

Forming of flat sheets into shell conical parts is a complex manufacturing process. Hydrodynamic deep drawing process assisted by radial pressure is a new hydroforming technology in which fluid pressure is applied to the peripheral edge of the sheet in addition to the sheet surface. This technique results in higher drawing ratio and dimensional accuracy, better surface quality, and ability of forming more complex geometries. In this research, a new theoretical model is developed to predict the critical rupture pressure in production of cone cups. In this analysis, Barlat–Lian yield criterion is utilized and tensile instability is considered based on the maximum load applied on the sheet. The proposed model is then validated by a series of experiments. The theoretical predictions are in good agreement with the experimental results. The effects of geometrical parameters and material properties on critical rupture pressure are also studied. The critical pressure is increased with increase in the height ratio, strain hardening exponent, and anisotropy. Higher punch nose radius expands the safe zone. It is shown that the critical pressure decreases for drawing ratios higher than 4.

Optimization of pressure paths in hydrodynamic deep drawing assisted by radial pressure with inward flowing liquid using a hybrid method

2018 ◽  
Vol 97 (5-8) ◽  
pp. 2587-2601 ◽  
Author(s):  
Milad Sadegh-yazdi ◽  
Mohammad Bakhshi-Jooybari ◽  
Mohsen Shakeri ◽  
Hamid Gorji ◽  
Maziar Khademi
Keyword(s):  
Hybrid Method ◽  
Deep Drawing ◽  
Radial Pressure ◽  
Flowing Liquid ◽  
Hydrodynamic Deep Drawing

scholarly journals Investigation of Wrinkling in Hydrodynamic Deep Drawing Assisted by Radial Pressure with Inward Flowing Liquid

2017 ◽  
Vol 183 ◽  
pp. 65-70 ◽  
Author(s):  
Maziar Khademi ◽  
Abdolhamid Gorji ◽  
Mohammad Bakhshi ◽  
Milad Sadegh Yazdi
Keyword(s):  
Deep Drawing ◽  
Radial Pressure ◽  
Flowing Liquid ◽  
Hydrodynamic Deep Drawing

Theoretical, numerical and experimental investigation of hydro-mechanical deep drawing of steel/polymer/steel sandwich sheets

2018 ◽  
Vol 233 (5) ◽  
pp. 1529-1546 ◽  
Author(s):  
Majid Fazlollahi ◽  
Mohammad Reza Morovvati ◽  
Bijan Mollaei Dariani
Keyword(s):  
Deep Drawing ◽  
Fluid Pressure ◽  
Chamber Pressure ◽  
Drawing Ratio ◽  
Drawing Process ◽  
Forming Force ◽  
Limit Drawing Ratio ◽  
Deep Drawing Process ◽  
Sandwich Sheet ◽  
Sandwich Sheets

Fabricating flat sandwich sheets into components with a required shape and dimensions is a challenging job in the metal forming field. In this article, hydro-mechanical deep drawing was used for sandwich sheet forming. The aim of the work is to achieve higher drawing ratio of these sheets. Theoretical, numerical and experimental analysis of the hydro-mechanical deep drawing of sandwich sheets was carried out. Separated layers theory method is used for theoretical analysis of the process. Then, the numerical simulation of the process was developed by finite element method. The effect of core layer thickness on the forming force of the sandwich sheet and effective parameters of the process such as strain and forming force was investigated. Experimental works were conducted on the steel/polymer/steel sandwich sheets by a hydro-mechanical deep drawing die. A good agreement was observed between theoretical, numerical and experimental results. The safe zone of fluid pressure for achieving a part without rupture was obtained. It was shown that the limit drawing ratio is increased by increasing the pressure but after a particular point, the limit drawing ratio is decreased by increasing the chamber pressure. It was also observed that maximum drawing ratio for achieving a part without rupture in the hydro-mechanical deep drawing process is higher than conventional deep drawing process.

Investigation into hydromechanical reverse redrawing assisted by separate radial pressure—process development and theoretical verification

1997 ◽  
Vol 211 (6) ◽  
pp. 451-462 ◽  
Author(s):  
J B Kim ◽  
D W Lee ◽  
D Y Yang ◽  
C S Park
Keyword(s):  
Deep Drawing ◽  
Process Development ◽  
Radial Pressure ◽  
Fe Analysis ◽  
Navier Stokes ◽  
Chamber Pressure ◽  
Drawing Ratio ◽  
Rigid Plastic ◽  
Navier Stokes Equation ◽  
Forming Condition

High-quality cups with a deep drawing ratio of more than four cannot be simply drawn by conventional drawing and redrawing. A special technology is required to form cups of a high deep drawing ratio. In the present study, after the conventional mechanical deep drawing process, subsequent hydromechanical reverse redrawing with controlled radial pressure has been developed. In order to increase the deep drawing ratio by more than four, the radial pressure is controlled independently of the chamber pressure and thus an optimum forming condition can be determined by varying the radial pressure. The process has been verified by a rigid-plastic finite element (FE) analysis considering all the external force boundary conditions induced by the hydrostatic pressure. The pressure distribution on the sheet is calculated numerically from the simplified Navier-Stokes equation. Through the experiment and the FE analysis, it has been shown that hydromechanical reverse redrawing assisted by separate radial pressure, developed in the present study, helps to increase the drawability of cylindrical cups, and thus it is useful when forming long cups.

Investigation into hydrodynamic deep drawing assisted by radial pressure

2004 ◽  
Vol 148 (1) ◽  
pp. 119-131 ◽  
Author(s):  
Lihui Lang ◽  
Joachim Danckert ◽  
Karl Brian Nielsen
Keyword(s):  
Deep Drawing ◽  
Radial Pressure ◽  
Hydrodynamic Deep Drawing

Effect of Geometries of Die/Blank Holder and Punch Radii in Angular Deep-Drawing Dies on DP Steel Formability

2015 ◽  
Vol 813-814 ◽  
pp. 269-273 ◽  
Author(s):  
P. Venkateshwar Reddy ◽  
S. Hari Prasad ◽  
Perumalla Janaki Ramulu ◽  
Sirish Battacharya ◽  
Daya Sindhu Guptha
Keyword(s):  
Deep Drawing ◽  
Thickness Distribution ◽  
Frictional Coefficient ◽  
Drawing Ratio ◽  
Drawing Process ◽  
Dp Steel ◽  
Punch Force ◽  
Blank Holder ◽  
Deep Drawing Process ◽  
Drawing Dies

In recent days deep-drawing is one of the most important methods used for sheet metal forming. The geometries of die/blank holder and punch are one of the parameters for deep-drawing. This paper presents an attempt to determine the effect of different geometries of die/blank holder, punch radii and blank holding force on deep drawing process for the formability of DP Steel of 1mm sheet. The numerical simulations are performed for deep drawing of cylindrical cups at a constant frictional coefficient of 0.12 and different blank holding forces of 10, 15 and 20kN are used. For numerical simulation PAM STAMP 2G a commercial FEM code in which Hollomon’s power law and Hills 1948 yield’s criterion is used. The die/blank holder profile used with an angles of α=0°, 12.5°, 15° and die/punch profile with a radii of R= 6 and 8mm were simulated to determine the influence of punch force and thickness distribution on the limit drawing ratio. The aim of this study is to investigate the effect of tool geometries on drawability of the deep-drawing process.

Sign in / Sign up

Export Citation Format

Share Document