On the Friction Effect on the Characteristics of Hydroformed Tube in a Square Section Die: Analytical, Numerical and Experimental Approaches

A focus on the effect of friction condition on tube hydroforming during corner filling in a square section die is proposed. Three approaches have been developed: an analytical model from the literature has been programmed, finite element simulations have been conducted and experiments have been carried out. Effect of friction coefficient on the thickness distribution in the square section of the hydroformed tube is studied. Critical thinning is found to take place in the transition zone between the straight wall and the corner radius and this minimal thickness seems to be the more appropriate parameter for the evaluation of the friction coefficient.

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Study of Localized Thinning of Copper Tube Hydroforming in Square Section Die: Effect of Friction Conditions

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.651-653.65 ◽

2015 ◽

Vol 651-653 ◽

pp. 65-70 ◽

Cited By ~ 3

Author(s):

Abir Abdelkefi ◽

Nathalie Boudeau ◽

Pierrick Malecot ◽

Noamen Guermazi ◽

Gérard Michel

Keyword(s):

Finite Element ◽

Friction Coefficient ◽

Analytical Model ◽

Thickness Distribution ◽

Tube Hydroforming ◽

Analytical Models ◽

Specific Test ◽

Good Evaluation ◽

Shaped Tube ◽

Tube Expansion

The friction conditions are responsible of the thickness distribution in a part realized by tube hydroforming. Then it is essential to have a good evaluation of the friction coefficient for running predictive finite element simulations. The tube expansion in a square die is one of tests proposed for the friction evaluation. In the literature, several analytical models have been developed for this specific test. The present paper concentrates on one of this model and results obtained from the analytical analysis, FE simulations and experiments are compared. The repartition of the thickness over the shaped tube and its evolution during the process are studied. The tendencies are in agreement but some complementary evaluations are proposed for using the proposed approach for the evaluation of the friction coefficient with the analytical model.

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Numerical investigation of plastic flow and residual stresses generated in hydroformed tubes

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/1464420721989746 ◽

2021 ◽

pp. 146442072198974

Author(s):

A Ktari ◽

A Abdelkefi ◽

N Guermazi ◽

P Malecot ◽

N Boudeau

Keyword(s):

Finite Element ◽

Residual Stresses ◽

Finite Element Model ◽

Plastic Flow ◽

Tube Hydroforming ◽

Three Dimensional ◽

Element Model ◽

Tube Cross Section ◽

Straight Wall ◽

Hydroforming Process

During tube hydroforming process, the friction conditions between the tube and the die have a great importance on the material plastic flow and the distribution of residual stresses of the final component. Indeed, a three-dimensional finite element model of a tube hydroforming process in the case of square section die has been performed, using dynamic and static approaches, to study the effect of the friction conditions on both plastic flow and residual stresses induced by the process. First, a comparative study between numerical and experimental results has been carried out to validate the finite element model. After that, various coefficients of friction were considered to study their effect on the thinning phenomenon and the residual stresses distribution. Different points have been retained from this study. The thinning is located in the transition zone cited between the straight wall and the corner zones of hydroformed tube due to the die–tube contact conditions changes during the process. In addition, it is clear that both die–tube friction conditions and the tube bending effects, which occurs respectively in the tube straight wall and corner zones, are the principal causes of the obtained residual stresses distribution along the tube cross-section.

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Adaptive Simulations of T-Shape Tube Hydroforming Processes

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.340-341.627 ◽

2007 ◽

Vol 340-341 ◽

pp. 627-632 ◽

Cited By ~ 1

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.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.473.579 ◽

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.

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Two Dimensional Plane Strain Modeling of Tube Hydroforming

10.1115/imece2000-1862 ◽

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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Investigation of Load Path Effect on Thickness Distribution and Product Geometry in the Bulge Hydroforming Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.110-116.1477 ◽

2011 ◽

Vol 110-116 ◽

pp. 1477-1482 ◽

Cited By ~ 1

Author(s):

Majid Elyasi ◽

Hassan Khanlari ◽

Mohammad Bakhshi-Jooybari

Keyword(s):

Finite Element ◽

Stainless Steel ◽

Finite Element Simulation ◽

Experimental Approach ◽

Thickness Distribution ◽

Tube Hydroforming ◽

Low Carbon ◽

Load Path ◽

Element Simulation ◽

Hydroforming Process

In this paper, the effect of load path on thickness distribution and product geometry in the tube hydroforming process is studied by finite element simulation and experimental approach. The pressure path was obtained by using finite element simulation and its validation with experiments. In simulations and experiments, low carbon stainless steel (SS316L) seamless tubes were used. The obtained results indicated that if pressure reaches to maximum faster, bulge value and thinning of the part will be more and wrinkling value will be less.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.473.618 ◽

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.

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Tube Hydroforming of Magnesium Alloys at Elevated Temperatures

Journal of Engineering Materials and Technology ◽

10.1115/1.4001833 ◽

2010 ◽

Vol 132 (3) ◽

Cited By ~ 10

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.

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Numerical Inverse Method for Friction Coefficient Estimation in Tube Hydroforming

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.473.548 ◽

2011 ◽

Vol 473 ◽

pp. 548-555 ◽

Cited By ~ 2

Author(s):

Antonio Fiorentino ◽

Roberto Marzi ◽

Elisabetta Ceretti ◽

Claudio Giardini

Keyword(s):

Friction Coefficient ◽

Inverse Method ◽

Thickness Distribution ◽

Influencing Factor ◽

Tube Hydroforming ◽

Process Conditions ◽

Final Thickness ◽

Novel Approach ◽

Definition Of ◽

The Right

Friction plays an important role in forming processes, in fact it influences the material flow and therefore it affects the process and part characteristics. In particular, friction is a very influencing factor in Tube Hydroforming (THF), where high die-part contact pressure and area make the material sliding very difficult. As a consequence, the material hardly flows to the expansion zones and the part formability can be compromised. To obtain sound parts, FEM models allow to study the process and optimize its parameters, but they require the right definition of the friction at tube-die interface. For these reasons, friction represents a key-point in THF processes and its knowledge and prediction are very important even if, nowadays, a comprehensive friction test for THF is not available in literature. With this paper, the Authors want to propose a novel approach to estimate friction for THF processes. In particular it will be described a numerical inverse method that allows to estimate the Coulombian friction coefficient combining experimental test and FE simulation results. The method is based on the effects of friction on the tube final thickness distribution when it is pressurized and compressed by two punches under different lubrication conditions without expansion. In particular, it will be shown how the use of few and fast FE simulations allows to estimate an analytical function that takes into account the process conditions and that can be used in combination with experimental results in order to estimate the friction coefficient in THF processes.

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