A Critical Review of Tube and Sheet Metal Hydroforming Technology

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.

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

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 ◽

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.

Theoretical and Experimental Analysis of Failure for the Hemisphere Punch Hydroforming Processes

Journal of Manufacturing Science and Engineering ◽

10.1115/1.2831049 ◽

1996 ◽

Vol 118 (3) ◽

pp. 434-438 ◽

Cited By ~ 12

Author(s):

Tze-Chi Hsu ◽

Shian-Jiann Hsieh

Keyword(s):

Experimental Data ◽

Limit Theorem ◽

Sheet Metal ◽

Lower Bounds ◽

Yield Criterion ◽

Fluid Pressure ◽

Upper And Lower Bounds ◽

Premature Failure ◽

Hydroforming Process ◽

Theoretical Results

A limit theorem of plasticity has been developed to investigate the hemisphere punch hydroforming process. The limit theorem of plasticity is used to predict the upper and lower bounds of the permissible fluid pressure. Loci representing the critical fluid pressures which result in the rupture and wrinkling are presented. The property of the sheet metal is governed by Hill’s quadratic yield criterion with a power-law hardening for anisotropic material. The premature failure is avoidable if the fluid pressure path is restricted to travel only within the suggested bounds. The theoretical results which include the failure prediction and wrinkling distribution are verified by conducting a serial of hydroforming experiments. The experimental data agrees well with the computed results and demonstrates the technological usefulness of the results.

Numerical – Experimental Correlation of Sheet Hydroformed Component

10.4028/www.scientific.net/kem.651-653.1140 ◽

2015 ◽

Vol 651-653 ◽

pp. 1140-1145

Author(s):

Alessandro Spagnolo ◽

Teresa Primo ◽

Gabriele Papadia ◽

Antonio del Prete

Keyword(s):

Finite Element ◽

Process Parameters ◽

Complex Geometry ◽

Thickness Distribution ◽

Fluid Pressure ◽

Experimental Tests ◽

Element Analysis ◽

Influence Of Process Parameters ◽

Experimental Correlation ◽

Sheet hydroforming has gained increasing interest in the automotive and aerospace industries because of its many advantages such as higher forming potentiality, good quality of the formed parts which may have complex geometry. The main advantage is that the uniform pressure can be transferred to any part of the formed blank at the same time. This paper reports numerical and experimental correlation for symmetrical hydroformed component. Experimental tests have been carried out through the hydroforming cell tooling, designed by the authors thanks to a research project, characterized by a variable upper blankholder load of eight different hydraulic actuators. The experimental tests have been carried out following a factorial plane of two factors, with two different levels for each factor and three replicates for each test with a total of 12 tests. In particular two process parameters have been considered: blank holder force, die fluid pressure. Each factor has been varied between an High (H) and Low level (L). The order in which have been conducted the tests has been established through the use of the Minitab software, in order to ensure the data normality and the absence of auto-correlation between the tests. An ANOVA analysis has been performed, in addition, with the aim of evaluating the influence of process parameters on the thickness distribution of the component, its formability and feasibility. Finally, finite element analysis (FEA) was used to understand the formability of a material during the hydroforming process. In this paper, the commercial finite element code LS-Dyna was used to run the simulations. A good numerical – experimental correlation has been obtained.

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 ◽

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.

Analysis of Multiple Stage Hydroforming of Sheet Metal With Intermediate Annealing

Volume 6: 18th Computers in Engineering Conference ◽

10.1115/detc98/cie-5514 ◽

1998 ◽

Author(s):

Varadaraju A. Gandikota ◽

Viswanathan Madhavan ◽

Steven J. Hooper

Keyword(s):

Sheet Metal ◽

Fluid Pressure ◽

Sheet Thickness ◽

Aircraft Engine ◽

Heat Treatments ◽

Intermediate Annealing ◽

Sheet Metal Parts ◽

Element Simulation ◽

Thickness Variations ◽

Explicit Dynamic

Abstract This paper presents the development of a finite element simulation of multistage hydroforming of sheet metal parts with annealing between forming stages, implemented using the commercial explicit dynamic code LS-DYNA. In each of the hydroforming stages, the sheet is formed to the shape of the die used in that stage by the application of fluid pressure on the top surface of the sheet. At the end of each stage, the stresses in the part are relieved and changes in material properties due to various heat treatments are accommodated while maintaining the deformed geometry of the part, including sheet thickness variations. In this manner the forming of an aircraft engine nacelle inlet lip in three stages with annealing between the stages has been simulated. In addition, single stage hydroforming to the final shape and three stage forming without intermediate annealing have been simulated. The results are used to compare the effectiveness of intermediate die shapes to the effectiveness of intermediate heat treatments in extending sheet metal formability. It is found that intermediate heat treatments enhance the ability of intermediate die shapes to promote uniform deformation of the sheet.

Buckling of Tube for Tube Hydroforging

Volume 2A: Advanced Manufacturing ◽

10.1115/imece2019-10630 ◽

2019 ◽

Author(s):

Chetan P. Nikhare

Keyword(s):

Axial Force ◽

Thickness Distribution ◽

Fluid Pressure ◽

Tube Hydroforming ◽

Expansion Ratio ◽

Rigid Bodies ◽

Maximum Expansion ◽

Tube Forming ◽

Strain Pattern ◽

Abstract Tube forming is one of the most common manufacturing processes to shape the tubes. Within tube forming operations the general practice is to expand and reduce the tube end cross-section and bend the tube by means of a solid mandrel. Mostly the mandrel is rigid bodies. To reduce the friction between the tube and the tool, tube hydroforming process was evolved in which the fluid was highly pressurized to expand the tube shape to the desired shape. By reducing the friction more uniform thickness could be achieved and thus increase in formability. In this paper, the tube was formed in two steps with low fluid pressure and axial force. The tube will be allowed to a useful maximum buckle by applying the axial force and/or a ramp internal pressure which then hydroforged with constant pressure for the maximum expansion ratio. The buckling mechanics of tube with respect to the fluid pressure and the axial force was studied. Further, the pressure requirement for hydroforging was investigated with respect to the length of the tube. The strain pattern and thickness distribution were studied in the buckling/bulging and hydroforging step.

Punch Radius Influence on “Large Size” Hydroformed Components

10.4028/www.scientific.net/kem.504-506.937 ◽

2012 ◽

Vol 504-506 ◽

pp. 937-942

Author(s):

Gabriele Papadia ◽

Antonio del Prete ◽

Alessandro Spagnolo

Keyword(s):

Sheet Metal ◽

Process Parameters ◽

Process Design ◽

Numerical Study ◽

Fluid Pressure ◽

Large Size ◽

Blank Sheet ◽

Punch Radius ◽

Hydroforming Process ◽

Compressed Fluid

Sheet metal hydroforming has gained increasing interest during last years, especially as application in the manufacturing of some components for: automotive, aerospace and electrical appliances for niche productions. Different studies have been also done to determine the optimal forming parameters making an extensive use of FEA. In the hydroforming process a blank sheet metal is formed through the action of a fluid and a punch. It forces the sheet into a die, which contains a compressed fluid. Many studies have been focused on the analysis of process and geometric parameters influence about the hydroforming process of a single product with main dimensions till to 100 mm. In this paper the authors describe the results of an experimental activity developed on two different large sized products obtained through sheet metal hydroforming. Different geometric and process parameters have been taken into account during the testing phase to study, in particular, the punch radius influence on the process feasibility. An ANOVA analysis has been implemented to study the influence of geometrical and process parameters on the maximum hydroforming depth. Through this work it has been possible to verify that in the hydroforming process of large size products geometry and, in particular, punch radius, are some of the main factors that influences the feasibility of the products. Different considerations can be made about the effects of the blankholder force and the fluid pressure on the maximum hydroforming depth. As further developments, the authors would perform a numerical study in order to enlarge the knowledge of the process design space to other possible values of the punch radius.

Comparison of some Final Part Geometrical Characteristics of Cylindrical Cups Manufactured by Deep-Drawing and Two-Point Incremental Sheet Forming

10.4028/www.scientific.net/kem.410-411.355 ◽

2009 ◽

Vol 410-411 ◽

pp. 355-363 ◽

Cited By ~ 2

Author(s):

Babak Taleb Araghi ◽

Markus Bambach ◽

Gerhard Hirt

Keyword(s):

Sheet Metal ◽

Deep Drawing ◽

Thickness Distribution ◽

Sheet Forming ◽

Incremental Sheet Forming ◽

Surface Strain ◽

Forming Process ◽

Sheet Metal Parts ◽

Part Surface ◽

Metal Forming Process

Asymmetric incremental sheet forming (AISF) is a new sheet metal forming process in which sheet metal parts are produced by CNC-controlled movements of a simple ball-headed forming tool. Despite its flexibility and successful application in many cases, AISF has not yet been established in an industrial context due to some still existing process limits such as severe thinning, which strongly depends on the inclination of the part surface, as well as a limited geometric accuracy due to springback. Furthermore, there is little knowledge available about the properties of parts produced by AISF, especially in comparison to deep-drawn parts. The aim of the present paper is to compare cylindrical cups manufactured by deep-drawing and AISF regarding the resulting strain and thickness distribution. For AISF, different forming strategies were applied. Comparisons of the wall thickness and surface strain distributions show similar results for the cup produced by deep-drawing and the best cup produced by AISF, but the surface strains and the sheet thinning in the parts formed by AISF were larger than in the deep-drawn part.

Optimization of Tube Hydroforming Process Using Probabilistic Constraints on Failure Modes

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.62.21 ◽

2011 ◽

Vol 62 ◽

pp. 21-35 ◽

Cited By ~ 2

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 ◽

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.