Adaptive Simulations of T-Shape Tube Hydroforming Processes

2007 ◽  
Vol 340-341 ◽  
pp. 627-632 ◽  
Author(s):  
Yeong-Maw Hwang ◽  
Bing Hong Chen ◽  
Wen Chan Chang
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Adaptive Algorithm ◽  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Loading Path ◽  
Finite Element Code ◽  
Simulation Results ◽  
Formed Product ◽  
The Relationship

A successful THF process depends largely on the loading paths for controlling the relationship between the internal pressure, axial feeding and the counter punch. In this study, an adaptive algorithm combined with a finite element code LS-DYNA 3D is proposed to control the simulation of T-shape hydroforming with a counter punch. The effects of the friction coefficients at the interface between the tube and die on the loading path and thickness distribution of the formed product are discussed. Experiments of protrusion hydroforming are also conducted. The final shape and thickness distribution of the formed product are compared with the simulation results to verify the validity of this modeling.

Optimization using finite element analysis, neural network, and experiment in tube hydroforming of aluminium T joints

2007 ◽  
Vol 221 (8) ◽  
pp. 1299-1305 ◽  
Author(s):  
F Mohammadi ◽  
H Kashanizade ◽  
M Mosavi Mashadi
Keyword(s):  
Neural Network ◽  
Finite Element ◽  
Internal Pressure ◽  
Objective Function ◽  
Tube Hydroforming ◽  
Optimization Methods ◽  
Loading Path ◽  
Complex Method ◽  
T Joints ◽  
Axial Feeding

In tube hydroforming (THF) of T joints, loading conditions (internal pressure and axial feeding) should be determined in such a way that the tube does not wrinkle or burst and is fully calibrated. In the current study THF of an aluminium T joint is simulated with the finite element method (FEM) using a commercial code. An explicit method is used to overcome convergence problems that are encountered in an implicit method. Internal pressure and axial feeding are two variables in the optimization problem and the loading path is optimized. The objective function is the clamping force, and the constraints of wrinkling, minimum thickness, and calibration should be achieved. The objective and constraint functions are obtained by training a neural network and the objective function is minimized using several optimization methods including hill-climbing search, simulated annealing, and complex method. The axial feeding and internal pressure obtained by optimization methods are used to conduct an experiment. Thickness distribution, calibration pressure, and axial feeding in experiment and FEM are compared and it is shown that there is a good agreement between them.

Investigation on the Effect of Pulsating Pressure on Tube-Hydroforming Process

2011 ◽  
Vol 473 ◽  
pp. 618-623
Author(s):  
Khalil Khalili ◽  
Seyed Yousef Ahmadi-Brooghani ◽  
Amir Ashrafi
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Element Model ◽  
Fe Model ◽  
Axial Feeding ◽  
Hydroforming Process ◽  
The Finite Element Model ◽  
Good Agreement

Tube hydroforming process is one of the metal forming processes which uses internal pressure and axial feeding simultaneously to form a tube into the die cavity shape. This process has some advantages such as weight reduction, more strength and better integration of produced parts. In this study, T-shape tube hydroforming was analyzed by experimental and finite element methods. In Experimental method the pulsating pressure technique without counterpunch was used; so that the internal pressure was increased up to a maximum, the axial feeding was then stopped. Consequently, the pressure decreased to a minimum. The sequence was repeated until the part formed to its final shape. The finite element model was also established to compare the experimental results with the FE model. It is shown that the pulsating pressure improves the process in terms of maximum protrusion height obtained. Counterpunch was eliminated as being unnecessary. The results of simulation including thickness distribution and protrusion height were compared to the part produced experimentally. The result of modeling is in good agreement with the experiment. The paper describes the methodology and gives the results of both experiment and modeling.

scholarly journals Thickness Improvement and Calibration Pressure Reduction of Stepped Tubular Components Using Axial Hydro-pressing Method

2021 ◽  
Author(s):  
Cong Han ◽  
Yongpeng Zhuang ◽  
Jing Li
Keyword(s):  
Wall Thickness ◽  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Pressure Rise ◽  
Loading Path ◽  
Pressing Method ◽  
Feeding Pressure ◽  
Cooperation Relationship ◽  
The Relationship ◽  
Tubular Components

Abstract A new tube axial hydro-pressing method was proposed to solve the problems of high forming pressure and severely uneven wall thickness distribution of traditional tube hydroforming methods to form stepped tubular components. The forming pressure of the traditional hydroforming and the tube axial hydro-pressing method is studied theoretically, the mechanical model of the fillet area is established, and the forming pressure calculation formula is given. Based on this, an investigation of the tube axial hydro-pressing method is carried out by numerical simulation and experimental methods, and compared with the traditional tube hydroforming method. The key to the tube axial hydro-pressing method is to precisely control the relationship between the protrusion height and the axial feed, which is achieved by precisely controlling the feeding pressure and the axial displacement. Therefore, the constant pressure device in the experiment was used to eliminate the influence of the pressure rise caused by the volume compression on its cooperation relationship, to achieve accurate control of the loading path, eliminate wrinkles and flash defects. A qualified workpiece is successfully manufactured when the internal pressure is 18.0 MPa and the feed on each side is 15.0 mm. The forming pressure is reduced by 88.0%, and the feed is increased by 6.5%, which reduces the wall thickness reduction by 9.0%. The wall thickness difference of the workpiece can be controlled within 7.0%. The tube axial hydro-pressing method is suitable for forming stepped tubular components, which can achieve more replenishment at lower pressures, thereby effectively improving the uniformity of wall thickness and significantly reducing the forming pressure.

Tube Hydroforming of Magnesium Alloys at Elevated Temperatures

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Yeong-Maw Hwang ◽  
Yan-Huang Su ◽  
Bing-Jian Chen
Keyword(s):  
Finite Element ◽  
Elevated Temperatures ◽  
Flow Line ◽  
Thickness Distribution ◽  
Testing Machine ◽  
Tube Hydroforming ◽  
Axial Feeding ◽  
Forming Temperature ◽  
Formed Product ◽  
Deform 3D

In this paper, a hydraulic forming machine with the functions of axial feeding, counter punch, and internal pressurization is designed and developed. This self-designed forming machine has a capacity of 50 tons for axial feeding and counter punch, 70 MPa for internal pressurization, and 300°C for forming temperature. Using this testing machine, experiments of T-shape protrusion of magnesium alloy AZ61 tubes at elevated temperatures are carried out. A commercial finite element code DEFORM 3D is used to simulate the plastic deformation of the tube within the die during the T-shape protrusion process. Different kinds of loading paths for the pressurization profile and the strokes of the axial feeding and the counterpunch are scheduled for analyses and experiments of protrusion processes at 150°C and 250°C. The numerical thickness distributions and the flow line configurations of the formed product are compared with the experimental results to validate this finite element modeling. The thickness distribution of the formed product or the flowability of AZ61 tubes at 150°C and 250°C is discussed. The effects of the forming rate on tube flowability at 250°C are also investigated. Through the observation of the flow line configurations of the tube material, adequate backward speeds of the counter punch relative to the axial feeding for preventing the material from accumulating at the die entrance region are verified. Finally, a sound product with a protrusion height of 49 mm is obtained.

Design and Control of Forming Processes Using Optimization Techniques

1999 ◽  
Author(s):  
O. Ghouati ◽  
H. Lenoir ◽  
J. C. Gelin ◽  
M. Baida
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Thickness Distribution ◽  
Optimization Technique ◽  
Optimization Techniques ◽  
Finite Element Code ◽  
Optimal Process ◽  
Shell Elements ◽  
Numerical Examples ◽  
And Control

Abstract The paper deals with the design and control of forming processes. The finite element code used is based on isoparametric shell elements with three or four nodes, the workpiece being considered as a sheet metal. An optimization technique is used in order to achieve the design or the control of the process by determining the optimal process parameters. The criterion used in that purpose can be based on thickness distribution as well as the respect of the final shape desired for the product. Numerical examples are presented as illustration.

scholarly journals Movable Die and Loading Path Design in Tube Hydroforming of Irregular Bellows

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1518
Author(s):  
Yeong-Maw Hwang ◽  
Yau-Jiun Tsai
Keyword(s):  
Tube Hydroforming ◽  
Simulation Software ◽  
Die Design ◽  
Loading Path ◽  
Feeding Types ◽  
Element Simulation ◽  
Hydroforming Process ◽  
Formed Product ◽  
Loading Path Design ◽  
Deform 3D

Manufacturing of irregular bellows with small corner radii and sharp angles is a challenge in tube hydroforming processes. Design of movable dies with an appropriate loading path is an alternative solution to obtain products with required geometrical and dimensional specifications. In this paper, a tube hydroforming process using a novel movable die design is developed to decrease the internal pressure and the maximal thinning ratio in the formed product. Two kinds of feeding types are proposed to make the maximal thinning ratio in the formed bellows as small as possible. A finite element simulation software “DEFORM 3D” is used to analyze the plastic deformation of the tube within the die cavity using the proposed movable die design. Forming windows for sound products using different feeding types are also investigated. Finally, tube hydroforming experiments of irregular bellows are conducted and experimental thickness distributions of the products are compared with the simulation results to validate the analytical modeling with the proposed movable die concept.

Research on Wrinkling Behavior in Tube Hydroforming with Axial Feeding

2014 ◽  
Vol 622-623 ◽  
pp. 739-746
Author(s):  
Zhu Lin Hu ◽  
Lian Fa Yang ◽  
Yu Lin He
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Metal Forming ◽  
Shape Change ◽  
Tube Hydroforming ◽  
Loading Path ◽  
Axial Feeding ◽  
Loading Paths ◽  
Element Simulation

Tube hydroforming (THF) is one of metal forming technologies which has been widely used to manufacture complex hollow workpeices. In THF, a variety of failures may occur and one of them is wrinkling. But recent researches show that wrinkling may be used as a preforming process to improve the formability of tubes. In this paper, a new geometry-based wrinkling indicator is proposed to evaluate the wrinkling level in THF and the wrinkle evolution diagram (WED) based on the shape change of the wrinkles is presented to display the four-stage evolution of the useful wrinkles. The wrinkling levels in THF with axial feeding under various loading paths are predicted respectively via finite element simulation, the influence of loading paths on the wrinkling behavior is investigated, and the evolving stages of the useful wrinkles is revealed via the proposed WED. The results indicate that the proposed wrinkle indicator can distinctly evaluate the wrinkling level, the wrinkling level under pulsating loading path is higher than that under polygonal linear one and four-stage evolution of the useful wrinkles could be evidently demonstrated via the WED. Notation

Numerical and Experimental Study of the Effect Pressure Path in Tube Hydroforming Process

2011 ◽  
Vol 473 ◽  
pp. 579-586
Author(s):  
Majid Elyasi ◽  
Hassan Khanlari ◽  
Mohammad Bakhshi-Jooybari
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Stainless Steel ◽  
Experimental Approach ◽  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Initial Pressure ◽  
Low Carbon ◽  
Element Simulation ◽  
Hydroforming Process

In this paper, the effect of pressure path on thickness distribution and product geometry in the tube hydroforming process is studied by finite element simulation and experimental approach. In simulations and experiments, low carbon stainless steel (SS316L) seamless tubes were used. The obtained results indicated that with increasing of the initial pressure, the bulge value of the part increases and the wrinkling value decreases. In addition, if the initial pressure is highly decreased, then bursting may occur.

A Method of Improving Limiting Drawing Ratio：Differential Temperature Deep Drawing Based on Superplasticity

2011 ◽  
Vol 239-242 ◽  
pp. 392-397
Author(s):  
Xue Feng Xu ◽  
Ning Li ◽  
Gao Chao Wang ◽  
Hong Bo Dong
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Deep Drawing ◽  
Thickness Distribution ◽  
Coupled Analysis ◽  
Flowing Water ◽  
Finite Element Code ◽  
Uniform Thickness ◽  
Forming Process ◽  
Good Agreement

A thermal-mechanical coupled analysis of superplastic differential temperature deep drawing (SDTDD) with the MARC finite element code is performed in this paper. Initial drawing blank of an AA5083 bracket was calculated and adjusted according to the simulation result. During the SDTDD simulation, the power-law constitutive model of AA5083 was established as function of temperature and implanted in software MARC through new complied subroutine. Under the guide of the numerical simulation, the die was fabricated and the AA5083 bracket was successfully manufactured via superplastic differential temperature deep drawing. In forming practice, the temperature of female die was kept at 525°C, i.e. the optimal superplastic temperature of AA5083, and the punch was cooled by the flowing water throughout the forming process. The drawing velocity of punch was 0.1mm/s. Results revealed that the formed bracket had a sound uniform thickness distribution. Good agreement was obtained between the formed thickness profiles and the predicted ones.

Two Dimensional Plane Strain Modeling of Tube Hydroforming

2000 ◽  
Author(s):  
G. T. Kridli ◽  
L. Bao ◽  
P. K. Mallick
Keyword(s):  
Finite Element ◽  
Plane Strain ◽  
Material Properties ◽  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Strain Hardening Exponent ◽  
Hydraulic Pressure ◽  
Two Dimensional ◽  
Dimensional Plane ◽  
Hydroforming Process

Abstract The tube hydroforming process has been used in industry for several years to produce components such as exhaust manifolds. Recent advances in forming machines and machine control systems have allowed for the introduction and the implementation of the process to produce several automotive components, which were originally produced by the stamping process. Components such as side rails, engine cradles, space frames, and several others can be economically produced by tube hydroforming. The process involves forming a straight or a pre-bent tube into a die cavity using internal hydraulic pressure, which may be coupled with controlled axial feeding of the tube. One of the remaining challenges facing product and process engineers in designing hydroformed parts is the lack of an extensive knowledge base of the process. This includes a full understanding of the process mechanics and the effects of the material properties on the quality of the hydroformed product. This paper reports on the results of two dimensional plane strain finite element models of the tube hydroforming process, which were conducted using the commercial finite element code ABAQUS/Standard. The objective of the study is to examine the effects of material properties, die geometry, and frictional characteristics on the selection of the hydroforming process parameters. The paper discusses the effects of the strain-hardening exponent, friction coefficient at the die-workpiece interface, initial tube wall thickness, and die corner radii on the thickness distribution of the hydroformed tube.

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