Experimental modeling of fluid pressure in hydrostatic forming for cylindrical product

2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040158
Author(s):  
Nguyen Thi Thu ◽  
Nguyen Dac Trung
Keyword(s):  
Fluid Pressure ◽  
Regression Function ◽  
Die Design ◽  
Design Calculation ◽  
Forming Process ◽  
Blank Holder ◽  
Forming Technology ◽  
Input Parameters ◽  
Function Relationship ◽  
And Control

Forming fluid pressure is an important technological parameter that determines whether a product can be accurately formed according to the size and profile of the die in hydrostatic forming technology. The expected value of this parameter is often very high because it acts as the punch in forming complex products from sheet metal. However, it is difficult to achieve high values because the forming fluid pressure depends on the ability to hold high pressure of equipment system and input parameters including the blank holder pressure, the depth of die, the thickness of workpiece. Moreover, it is also necessary to have a mathematical model for this parameter to facilitate the calculation and control of the forming process. In order to solve the above problems, this paper will indicate a simple way to avoid the pressure drop during forming process, and establish a regression function relationship between the forming fluid pressure for typical cylindrical product and input parameters above by experimental research method. The results contribute to die design, calculation and control of process parameters to facilitate shaping thin shell products in actual hydrostatic forming technology.

scholarly journals Experimental Modeling of Pressure in the Hydrostatic Formation of a Cylindrical Cup with Different Materials

2021 ◽  
Vol 11 (13) ◽  
pp. 5814
Author(s):  
Trung-Kien Le ◽  
Thi-Thu Nguyen ◽  
Ngoc-Tam Bui
Keyword(s):  
Fluid Pressure ◽  
Regression Method ◽  
Mathematical Equation ◽  
Forming Process ◽  
Forming Technology ◽  
Input Parameters ◽  
Sheet Products ◽  
Cylindrical Cup ◽  
The Relationship

Forming complex sheet products using hydrostatic forming technology is currently a focus of the majority of forming processes. However, in order to increase stability during the forming process, it is necessary to identify and analyze the dependency of the forming pressure and the quality of a product on input parameters. For the purpose of modeling the forming pressure, this paper presents empirical research on the product of a cylindrical cup made of various materials, including carbon steel (DC04), copper (CDA260), and stainless steel (SUS 304) with different thicknesses (0.8 mm, 1.0 mm, and 1.2 mm), under a defined range of binder pressures. The regression method is selected to formulate an equation that shows the relationship between the input parameters, including the materials (ultimate strength and yield stress), workpiece thickness, binder pressure and the output parameter, and the formation of fluid pressure. The mathematical equation allows us to determine the extent of the effect of each input on the forming pressure. The experimental results can be used for the easier planning and forecasting of the process and product quality in hydrostatic forming.

Applying 2k Factorial Design to Study on Parameters Affecting Springback of Forming of Advanced High Strength Steel Sheets (AHSS)

2017 ◽  
Vol 872 ◽  
pp. 83-88
Author(s):  
Ramil Kesvarakul ◽  
Chamaporn Chianrabutra ◽  
Watcharapong Sirigool
Keyword(s):  
Elastic Recovery ◽  
Weight Ratio ◽  
High Strength ◽  
Die Design ◽  
Statistical Experimental Design ◽  
Blank Holder Force ◽  
Forming Process ◽  
Blank Holder ◽  
Punch Radius ◽  
Springback Angle

Advanced high strength steels (AHSS) are widely used in the automotive industry due to their appropriate strength to weight ratio. This alloy has unique hardening behavior and variable unloading elastic modulus; however, the unavoidable obstacle of AHSS sheet metal forming is springback. The springback is a result of elastic recovery and residual stress. The aim of this study is to determine the proper process parameters enabling the reduction of the springback defects in AHSS forming process. This work was divided into two parts, regarding to the effects of numerical parameters and process parameter on forming AHSS. In this paper, a U-shape forming was used to examine the springback behaviors, such as springback angle, sidewall curl, and thickness, through an experiment. To achieve this purpose, 2k factorial statistical experimental design has been employed to investigate the parameters affecting the springback of forming in AHSS to find out the main effect in the springback reduction focusing on using as a guideline for die design. It showed that the blank holder force is the most influential parameter. The second is the punch radius. However, the blank holder force and punch radius is not simple to adjust in die design, the die radius becomes the important parameter to be used to reduce the springback angle.

Strain Control in an Intelligent Die Based Upon Local Force Control and Blank Holder Forces

2009 ◽  
Author(s):  
William J. Emblom ◽  
Klaus J. Weinmann ◽  
John E. Beard
Keyword(s):  
Closed Loop ◽  
Open Loop ◽  
Die Design ◽  
Closed Loop Control ◽  
Blank Holder Force ◽  
Punch Force ◽  
Blank Holder ◽  
Loop Control ◽  
And Control ◽  
Bead Penetration

An experimental evaluation of the strains in an oval stamp forming die is presented. The die design included a flexible blank holder and active draw beads. The die was instrumented with local punch force and wrinkle sensors and control systems were developed in order to follow local punch force and wrinkle trajectories. Strains were measured after pan forming for both open and closed-loop tests. The relation between blank holder force, draw bead penetration, and strains were explored in the critical strain region of the formed pan. Closed-loop control of the local punch forces at the die ends was established using blank holder forces. The strains for tests with various lubrication conditions and draw bead penetrations were compared. It was observed that there is a tendency for the strains in critical locations to converge or remain constant for the closed-loop control tests while the strains tended to increase with blank holder force for open-loop tests. It was concluded that by controlling local punch forces, strain is indirectly controlled.

Prediction and Control of Hot Pressing Rebound of Fan Blade Based on Thermal Mechanical Coupling Simulation

2014 ◽  
Vol 941-944 ◽  
pp. 2284-2287
Author(s):  
Ping Yang
Keyword(s):  
Control Measures ◽  
Forming Process ◽  
Mechanical Coupling ◽  
Forming Technology ◽  
Distribution Rule ◽  
Depth Analysis ◽  
Prediction And Control ◽  
Fan Blade ◽  
Shape Characteristics ◽  
And Control

The article designed the forming process according to the shape characteristics of one type of fan blade. It put forward forming technology solutions combined with practical manufacturing capability. Based on many factors such as heat coupling numerical simulation and process optimization were proceeded in DEFORM-3D platform, in-depth analysis of the distribution rule of law, warping, the stress and the strain in forming process, put forward to control measures for the law of rebound deformation, gain reasonable technology standards, and experimental verification, and therefore solve the key technical difficulties of production process, for relevant industry leaves parts production provides a practical and efficient, economical and reliable forming technology.

Hot Draw Mechanical Preforming of an Automotive Door Inner Panel

2008 ◽  
Author(s):  
S. George Luckey ◽  
Peter A. Friedman
Keyword(s):  
Elevated Temperature ◽  
Automotive Industry ◽  
Superplastic Forming ◽  
Gas Pressure ◽  
Die Design ◽  
Second Step ◽  
Forming Process ◽  
Forming Technology ◽  
The Press ◽  
Critical Aspects

A novel sheet metal forming technology based on aspects of both warm forming and superplastic forming has recently been developed. The new forming process, referred to as hot draw mechanical preforming (HDMP), uses two sequential steps to form a panel within a single tool at elevated temperature. In the first step, the cushion system acts on a binder and upper die to draw the blank over a punch which serves to draw in metal from the perimeter of the blank. In the second step gas pressure is applied to finish the panel details. This two step process of drawing in metal followed by gas forming can result in a significant expansion of the forming envelope for conventional AA5xxx series aluminum sheet alloys commonly used within the automotive industry. Similar to SPF, the HDMP process is performed within a single forming press equipped with heated platens and using gas pressure to shape the component during elevated temperature forming. However, the HDMP process utilizes a blankholder to control the flow of material into the forming cavity during the drawing stage and therefore requires the addition of an integrated cushion system in the bed of the press. HDMP dies are of interest in automotive applications because they maintain the low-investment attributes of SPF tooling while also significantly reducing the forming time as compared to conventional SPF. This work details the CAE based design of an HDMP die to form a one-piece aluminum door inner that can not be formed with conventionally forming processes. Critical aspects addressed in the development of the die include manufacturing targets, part design for manufacturing, and die design for operation at elevated temperature.

Investigation on Free-Wheel Hub for Starter Rotary Forming Process and Die Design Based on Numerical Simulation

2012 ◽  
Vol 557-559 ◽  
pp. 2155-2158
Author(s):  
Ping Wang ◽  
Liang Li
Keyword(s):  
Numerical Simulation ◽  
Hydraulic Press ◽  
Die Design ◽  
Quality Requirement ◽  
Forming Process ◽  
Forming Technology ◽  
Die Structure ◽  
Similar Part ◽  
3D Software ◽  
Deform 3D

Free-wheel hub plays an important role in automobile starter system, so there is higher quality requirement on geometry and precision. In order to improve the efficiency and comprehensive functions of the part, according to the features of the lower part with involute small module internal helical spline, the rotary forming technology was put forward, and the forming process was simulated by the DEFORM-3D software. In the die design, the use of rotary punch made the process of rotary forming achieved in common hydraulic press, and can serve as an important reference to the design of forming process and die structure of similar part.

scholarly journals Die Design of Flexible Multi-Point Forming Process

2019 ◽  
Vol 14 (2) ◽  
pp. 22-29
Author(s):  
Tahseen Fadhel Abaas ◽  
Karem Mohsen Younis ◽  
Khalida Kadhim Mansor
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Setting Time ◽  
Die Design ◽  
Work Piece ◽  
Shape Error ◽  
Forming Process ◽  
Blank Holder ◽  
Flexible Manufacture ◽  
Minimum Force

Multi-point forming (MPF) is an advanced flexible manufacture technology, and the technology results from the idea that the whole die is separated into small punches that can be adjusted height. This idea is applied to the traditional rigid blank-holder, so flexible blank-holder (FBH) idea can be obtained. In this work, the performance of a multi-point die is investigated with pins in square matrix and suitable blank holder. Each pin in the punch holder can be a significant moved according to the die high and at different load that applied with spring with respect to spring stiffness. The results shows the reduction in setting time with respect to traditional single point incremental forming process that lead to (90%). and also show during the forming process, the deformation of the interpolator can induce a shape error in the formed work-piece and the blank holder can reduce/eliminate dimples that sometimes arise in the work-piece. The minimum force applied using multi-point die is 28.556KN, while the load when complete the forming process is 30.8KN that caused displacement of die to 32.8mm.

Finite Element Simulation of Deep Drawing Processes for Shell Bar RR Impact RH/LH

2018 ◽  
Vol 875 ◽  
pp. 24-29
Author(s):  
Aekkapon Sunanta ◽  
Surasak Suranuntchai
Keyword(s):  
Finite Element ◽  
Deep Drawing ◽  
Yield Function ◽  
Production Quality ◽  
Die Design ◽  
Blank Holder Force ◽  
Forming Process ◽  
Blank Holder ◽  
Restraining Force ◽  
Shell Bar

Finite Element Method (FEM) is one of the most useful techniques to analyze problems in metal forming process because of this technique can reduce cost and time in die design and trial step [1]. This research is aimed to predict the optimal parameters in order to eliminate cracks and wrinkles on automotive deep drawing product “Shell Bar RR Impact RH/LH”. The material was made from high strength steel JSC440W sheet with thickness 1.8 mm. The parameters that had been investigated were blank holder force (BHF) and drawbead restraining force (DBRF). In order to simplify the process, punch and die in the simulation were assumed to be a rigid body, which neglected the small effect of elastic deformation. The material properties assumed to be anisotropic, behaved according to the constitutive equation of power law and deformed elastic-viscoplastic, which followed Barlat 3 components yield function. Most of the defects such as cracks and wrinkles were found during the processes on the parts. In the past, the practical productions were performed by trial and error, which involved high production cost, long lead time and wasted materials. From the results, when decreased blank holder force to 30 tons, cracks on the part were removed but wrinkles had a tendency to increase in part area because of this part is the asymmetrical shape. Finally, applying about drawbead restraining force at 154.49 and 99.75 N/mm could improve product quality. In conclusion, by using the simulation technique, the production quality and performance had been improved.

On the thickness distribution and the maximum thinning ratio in hydrostatic forming for sheet metal

2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040144
Author(s):  
Nguyen Thi Thu ◽  
Nguyen Dac Trung
Keyword(s):  
Sheet Metal ◽  
Thickness Distribution ◽  
Design Calculation ◽  
Relative Depth ◽  
Technological Parameters ◽  
Industrial Manufacturing ◽  
Input Parameters ◽  
Forming Characteristics ◽  
And Control ◽  
Forming Methods

In manufacturing, thickness distribution and maximum thinning greatly affect product quality in sheet metal forming. They depend on many input parameters, such as technological parameters, geometric shape of die, workpiece’s materials and forming methods. Hydrostatic forming technology is particularly suitable for forming thin-shell products with complex shapes. However, due to the forming characteristics, the thinning phenomenon in this technology is much more intense than in other forming methods. Therefore, this study aims to determine the thickness distribution and the relationship between the maximum thinning ratio and input parameters including blank holder pressure, relative depth of the die and relative thickness of the workpiece in this technology. The chosen product shape is cylinder and the chosen method is the orthogonal second-order design. The results are expressed in graphs and functions and they can be applied in product design, calculation and control of input parameters in industrial manufacturing.

Upscaling of foam forming technology for pilot scale

TAPPI Journal ◽  
2019 ◽  
Vol 18 (8) ◽  
Author(s):  
JANI LEHMONEN ◽  
TIMO RANTANEN ◽  
KARITA KINNUNEN-RAUDASKOSKI
Keyword(s):  
Production Efficiency ◽  
Strength Loss ◽  
Pilot Scale ◽  
Foam Density ◽  
Forming Process ◽  
Production Scale ◽  
Forming Technology ◽  
Wet Pressing ◽  
Foam Forming ◽  
Board Industry

The need for production cost savings and changes in the global paper and board industry during recent years have been constants. Changes in the global paper and board industry during past years have increased the need for more cost-efficient processes and production technologies. It is known that in paper and board production, foam typically leads to problems in the process rather than improvements in production efficiency. Foam forming technology, where foam is used as a carrier phase and a flowing medium, exploits the properties of dispersive foam. In this study, the possibility of applying foam forming technology to paper applications was investigated using a pilot scale paper forming environment modified for foam forming from conventional water forming. According to the results, the shape of jet-to-wire ratios was the same in both forming methods, but in the case of foam forming, the achieved scale of jet-to-wire ratio and MD/CD-ratio were wider and not behaving sensitively to shear changes in the forming section as a water forming process would. This kind of behavior would be beneficial when upscaling foam technology to the production scale. The dryness results after the forming section indicated the improvement in dewatering, especially when foam density was at the lowest level (i.e., air content was at the highest level). In addition, the dryness results after the pressing section indicated a faster increase in the dryness level as a function of foam density, with all density levels compared to the corresponding water formed sheets. According to the study, the bonding level of water- and foam-laid structures were at the same level when the highest wet pressing value was applied. The results of the study show that the strength loss often associated with foam forming can be compensated for successfully through wet pressing.

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