scholarly journals Experimental Study of Ultrasonic Vibration Effects on Punch Radial in Sheet Hydroforming Process

2021 ◽  
Author(s):  
Reza Ghasemi ◽  
Majid Elyasi ◽  
Hamid Baseri ◽  
Mohammad Javad Mirnia
Keyword(s):  
Ultrasonic Vibration ◽  
Deep Drawing ◽  
Metal Forming ◽  
Thickness Distribution ◽  
Maximum Height ◽  
Sheet Hydroforming ◽  
Working Zone ◽  
Hydroforming Process ◽  
Vibration Assistance ◽  
Safe Working

Abstract Nowadays, one of the metal forming processes that are widely used in industries is sheet hydroforming. Because of high complexity and sensitivity, this process needs precise calculations in the die and method to control metal flow correctly and prevent defects. Therefore recently, new processes were combined to this process to increase precision and effectiveness. For example, ultrasonic vibration assistance forming. Using hydroforming and ultrasonic vibration as new methods were studied in several research types separately, and each of them redounded to different analyses and improvements in the process. Even synchronic use of these two methods was studied in some metal forming processes such as tube hydroforming, but it has not been studied in sheet hydroforming. Therefore the aim of this research is the experimental study of St14 sheet hydroforming ultrasonic vibration assistance. For this purpose, ultrasonic vibration (with 20 KHz frequency and 4μm amplitude) was applied to a hydromechanical deep drawing die into punch radial in the hydroforming process. Then process parameters consisting of LDR, maximum height, forming force, safe working zone, and thickness distribution were determined and compared in four case states conventional deep drawing(CDD), hydroforming deep drawing(HDD), ultrasonic vibration assistance deep drawing(UDD) and ultrasonic vibration assistance hydroforming deep drawing(UHDD). Results indicated that applying ultrasonic vibration into the sheet hydroforming process increases LDR and the maximum height of the cup, decreases forming force and develops a safe working zone. Also was very effective in thickness distribution and decrease of sheet thinning in critical sections.

Experimental Study of Drawing Load Curves in Forming Conical Parts by Hydroforming and Conventional Deep Drawing Processes

2011 ◽  
Vol 291-294 ◽  
pp. 556-560 ◽  
Author(s):  
Salman Norouzi ◽  
Amir Reza Yaghoubi ◽  
Mohammad Bakhshi-Jooybari ◽  
Abdolhamid Gorji
Keyword(s):  
Experimental Study ◽  
Sheet Metal Forming ◽  
Deep Drawing ◽  
Metal Forming ◽  
Pure Copper ◽  
Experimental Program ◽  
Drawing Process ◽  
Deep Drawing Process ◽  
Load Variation ◽  
Hydroforming Process

Since conical parts have wide applications in the industry and forming these parts is one of the most complex and difficult fields in sheet metal forming processes, the study on different methods in forming these parts can be useful. Hydroforming and conventional multistage deep drawing are two deep drawing processes which have been used to form conical parts. Hydroforming deep drawing is one of the special deep drawing processes which have been introduced in order to overcome some inherent problems in the conventional deep drawing with rigid tools. In the present work, an experimental program has been carried out to compare the drawing load variation and maximum drawing load in forming pure copper conical-cylindrical cups with the thickness of 2.5 mm by hydroforming and conventional multistage deep drawing processes. The results of the study demonstrate that drawing load variation is more uniform in the forming of conical parts by hydroforming deep drawing process. The maximum drawing load for drawing copper blank occurs at a higher amount in hydroforming process.

The Effect of Polyurethane Hardness on the New Die-Set of Sheet Hydroforming Process Parameters

2012 ◽  
Vol 152-154 ◽  
pp. 1623-1627
Author(s):  
Morteza Hosseinzadeh
Keyword(s):  
Process Parameters ◽  
Thickness Distribution ◽  
Effective Parameters ◽  
Blank Holder Force ◽  
Blank Holder ◽  
Sheet Hydroforming ◽  
Die Set ◽  
Hydroforming Process

In recent years, several sheet hydroforming methods have been introduced by researchers. Despite the advantages of these methods, they have some limitations. The author [1] already proposed a novel sheet hydroforming method that is a combination of the standard and hydromechanical sheet hydroforming processes. The proposed method has the advantages of both processes and eliminates their limitations. In this method, a polyurethane diaphragm was used as a part of die-set to control the blank holder force. In this paper, the effect of polyurethane hardness on the effective parameters of the combined sheet hydroforming die-set such as forming pressure, thickness distribution of formed cup and maximum thinning zone of formed cup was investigated experimentally. It was shown that a softer polyurethane needs to a higher oil pressure to prevent wrinkling in the flange of the part. And tearing occurs at higher level of forming pressure. Also it was shown that by softer polyurethane, better thickness distribution was obtained.

Thickness Distribution in Conical Parts Formed by Hydroforming and Conventional Multistage Deep Drawing Processes

2011 ◽  
Vol 189-193 ◽  
pp. 2884-2887
Author(s):  
Abdolhamid Gorji ◽  
Amir Reza Yaghoubi ◽  
Mohammad Bakhshi-Jooybari ◽  
Salman Norouzi
Keyword(s):  
Deep Drawing ◽  
Metal Forming ◽  
Thickness Distribution ◽  
Pure Copper ◽  
Experimental Program ◽  
Drawing Process ◽  
Blank Holder ◽  
Sheet Surface ◽  
Two Stages ◽  
Explosive Forming

Forming conical parts is one of the difficult fields in sheet metal forming processes. Because of low contact area of the sheet with the punch in the initial stages of forming, too much tension applied to the sheet that it causes bursting. Furthermore, since the major part of the sheet surface between the blank holder and punch tip is free, wrinkles appears on the wall of the drawn parts. These parts are normally formed in industry by processes such as spinning, explosive forming or multistage deep drawing. Hydroforming deep drawing is one of the special deep drawing processes which have been introduced in order to overcome some inherent problems in the conventional deep drawing with rigid tools. In the present work, an experimental program has been carried out to form and compare the forming pure copper conical-cylindrical cups by hydroforming and conventional multistage deep drawing processes. The conical parts in conventional deep drawing process formed in two stages. The results of the study demonstrate that thickness distribution are more uniform in the parts formed by hydroforming compared to conventional multi stages deep drawing processes.

Research on Box Drawing Coefficient of Friction Based on Dynaform

2012 ◽  
Vol 628 ◽  
pp. 223-228
Author(s):  
Zhi Gao Luo ◽  
Xu Dong Li ◽  
Jing Jing Zhang ◽  
Jun Li Zhao
Keyword(s):  
Friction Coefficient ◽  
Sheet Metal ◽  
Deep Drawing ◽  
Metal Forming ◽  
Thickness Distribution ◽  
Forming Limit ◽  
Drawing Process ◽  
Analysis Software ◽  
Element Analysis ◽  
Wall Thickness Distribution

The box body drawing process is prone to breakage defect. Using finite element analysis software Dynaform5.7, the box part in deep drawing process was simulated. The friction coefficient was observed to change between sheet metal and die. Analysis of sheet metal forming limit and wall thickness distribution，therefore came out with the following conclusion：box deep drawing is affected by the lubrication , when the friction coefficient is lower than 0.17, Lubrication can effectively prevent the box shaped parts from cracks. At the same time, the research still is developing a new drawing.

scholarly journals Effect of Tool Geometry Parameters on the Formability of a Camera Cover in the Deep Drawing Process

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3993
Author(s):  
Thanh Trung Do ◽  
Pham Son Minh ◽  
Nhan Le
Keyword(s):  
Deep Drawing ◽  
Thickness Distribution ◽  
Metal Flow ◽  
Sheet Thickness ◽  
Side Wall ◽  
Tool Geometry ◽  
Drawing Process ◽  
Nose Radius ◽  
Deep Drawing Process

The formability of the drawn part in the deep drawing process depends not only on the material properties, but also on the equipment used, metal flow control and tool parameters. The most common defects can be the thickening, stretching and splitting. However, the optimization of tools including the die and punch parameters leads to a reduction of the defects and improves the quality of the products. In this paper, the formability of the camera cover by aluminum alloy A1050 in the deep drawing process was examined relating to the tool geometry parameters based on numerical and experimental analyses. The results showed that the thickness was the smallest and the stress was the highest at one of the bottom corners where the biaxial stretching was the predominant mode of deformation. The problems of the thickening at the flange area, the stretching at the side wall and the splitting at the bottom corners could be prevented when the tool parameters were optimized that related to the thickness and stress. It was clear that the optimal thickness distribution of the camera cover was obtained by the design of tools with the best values—with the die edge radius 10 times, the pocket radius on the bottom of the die 5 times, and the punch nose radius 2.5 times the sheet thickness. Additionally, the quality of the camera cover was improved with a maximum thinning of 25% experimentally, and it was within the suggested maximum allowable thickness reduction of 45% for various industrial applications after optimizing the tool geometry parameters in the deep drawing process.

Optimization of Tube Hydroforming Process Using Probabilistic Constraints on Failure Modes

2011 ◽  
Vol 62 ◽  
pp. 21-35 ◽  
Author(s):  
Anis Ben Abdessalem ◽  
A. El Hami
Keyword(s):  
Failure Modes ◽  
High Reliability ◽  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Forming Limit Diagram ◽  
Plastic Instability ◽  
Probabilistic Constraints ◽  
Forming Limit ◽  
Reliability Based Design ◽  
Hydroforming Process

In metal forming processes, different parameters (Material constants, geometric dimensions, loads …) exhibits unavoidable scatter that lead the process unreliable and unstable. In this paper, we interest particularly in tube hydroforming process (THP). This process consists to apply an inner pressure combined to an axial displacement to manufacture the part. During the manufacturing phase, inappropriate choice of the loading paths can lead to failure. Deterministic approaches are unable to optimize the process with taking into account to the uncertainty. In this work, we introduce the Reliability-Based Design Optimization (RBDO) to optimize the process under probabilistic considerations to ensure a high reliability level and stability during the manufacturing phase and avoid the occurrence of such plastic instability. Taking account of the uncertainty offer to the process a high stability associated with a low probability of failure. The definition of the objective function and the probabilistic constraints takes advantages from the Forming Limit Diagram (FLD) and the Forming Limit Stress Diagram (FLSD) used as a failure criterion to detect the occurrence of wrinkling, severe thinning, and necking. A THP is then introduced as an example to illustrate the proposed approach. The results show the robustness and efficiency of RBDO to improve thickness distribution and minimize the risk of potential failure modes.

Multi-Step Forward Finite Element Method for the Numerical Simulation of Sheet Metal Forming

2011 ◽  
Vol 474-476 ◽  
pp. 251-254
Author(s):  
Jian Jun Wu ◽  
Wei Liu ◽  
Yu Jing Zhao
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Deep Drawing ◽  
Metal Forming ◽  
Mapping Method ◽  
Constitutive Relationship ◽  
Element Method

The multi-step forward finite element method is presented for the numerical simulation of multi-step sheet metal forming. The traditional constitutive relationship is modified according to the multi-step forming processes, and double spreading plane based mapping method is used to obtain the initial solutions of the intermediate configurations. To verify the multi-step forward FEM, the two-step simulation of a stepped box deep-drawing part is carried out as it is in the experiment. The comparison with the results of the incremental FEM and test shows that the multi-step forward FEM is efficient for the numerical simulation of multi-step sheet metal forming processes.

In-Process Visualisation for Deformation Monitoring and Analysis of Sheet Metal Forming Processes

2013 ◽  
Vol 677 ◽  
pp. 384-387 ◽  
Author(s):  
Wai Kei Ricky Kot ◽  
Luen Chow Chan
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Deep Drawing ◽  
Metal Forming ◽  
Deformation Process ◽  
Deformation Monitoring ◽  
Displacement Sensor ◽  
Laser Displacement Sensor ◽  
Profile Data ◽  
Profile Change

In this paper, a visualisation system will be discussed that can be used to capture the deformation profile of the sheet blank during sheet metal forming processes, such as deep drawing and shape forming. The visualisation system utilizes a 2D laser displacement sensor for deformation profile acquisition. The sensor is embedded in the die and the laser propagates through the die to detect the profile change of the specimen concealed in the die during operation. The captured profile data will be collected, manipulated and transferred to a monitor for display via a controller. This visualisation of the deformation profile will provide engineers and researchers with an intuitive means of analysing and diagnosing the deformation process during sheet metal forming.

A Critical Review of Tube and Sheet Metal Hydroforming Technology

1996 ◽  
Author(s):  
Jian An ◽  
A. H. Soni
Keyword(s):  
Sheet Metal ◽  
Thickness Distribution ◽  
Fluid Pressure ◽  
Point Of View ◽  
Parameter Design ◽  
Back Side ◽  
Part Quality ◽  
Element Simulation ◽  
Part Surface ◽  
Hydroforming Process

Abstract The hydroforming technology, which is rapidly gaining popularity in the sheet metal and tube forming industry is reviewed. The features and the characteristics of the hydroforming process are described. The uniformly distributed fluid pressure covers the back side of the sheet as a die generates many advantages in the technical point of view as improving the part surface quality, reducing the forming severity and smoothing the thickness distribution. The benefits of using hydroforming technology are examined and analyzed in a technical level. The better part quality, less cost of tooling, materials saving and part weight reduction can be achieved using the hydroforming technology. The design methodologies for the hydroforming process parameters are reviewed and discussed in a certain detail. Computer-aided-engineering such as finite element simulation is suggested for such process parameter design.

Optimization of Deep Drawing Processes Using Statistical Design of Experiments

1996 ◽  
Author(s):  
Dietrich Bauer ◽  
Regine Krebs
Keyword(s):  
Mathematical Model ◽  
Analysis Of Variance ◽  
Orthogonal Array ◽  
Deep Drawing ◽  
Metal Forming ◽  
Drawing Process ◽  
Drawing Force ◽  
Forming Process ◽  
Deep Drawing Process ◽  
Metal Forming Process

Abstract For a deep drawing process some important controllable variables (factors) upon the maximum drawing force are analyzed to find a setting adjustment for these process factors that provides a very low force for the metal forming process. For this investigation an orthogonal array L18 with three-fold replication is used. To find the optimum of the process, the experimental results are analyzed in accordance with the robust-design-method according to Taguchi (Liesegang et. al., 1990). For this purpose, so-called Signal-to-Noise-ratios are calculated. The analysis of variance for this S/N-ratios leads to a mathematical model for the deep drawing process. This model allows to find the pressumed optimal settings of the investigated factors. In the following, a confirmation experiment is carried out by using these optimal settings. The maximum drawing force of the confirmation experiment does not correspond with the confidence interval, which was calculated by analysis of variance techniques. So the predicted optimum of the process does not lead to a metal forming process with very low deep drawing force. The comparison with a full factorial plan shows that there are interactions between the investigated factors. These interactions could not be discovered by the used orthogonal array. Thus the established mathematical model does not describe the relation between the factors and deep drawing force in accordance with the practical deep drawing conditions.

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