Application of two dimensional (2D) FEA for the tube hydroforming process

2002 ◽  
Vol 42 (11) ◽  
pp. 1285-1295 ◽  
Author(s):  
Muammer Koç ◽  
Taylan Altan
Keyword(s):  
Tube Hydroforming ◽  
Two Dimensional ◽  
Hydroforming Process

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.

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.

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

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.

Experimental Researches upon Changes of a Pipe's Roughness after Hydroformation

2013 ◽  
Vol 371 ◽  
pp. 111-115
Author(s):  
Bogdan Constantin Vaceanu ◽  
Gheorghe Nagit ◽  
Vasile Huian
Keyword(s):  
Surface Roughness ◽  
Tube Hydroforming ◽  
Work Piece ◽  
Copper Pipe ◽  
Work Area ◽  
The Coefficient Of Friction ◽  
Hydroforming Process ◽  
Aluminum Pipe ◽  
Experimental Researches

Surface roughness was studied in the tube hydroforming process, considering the quality of the material and the coefficient of friction between the work piece and die. Other researchers have studied the surface roughness to the front of an aluminum pipe [. The aim of this work was to analyze changes in a copper pipe roughness occurred after hydroforming process with fluid. Effects of changing roughness were studied, following the deformation of the material in the work area and roughness changes occurring in the material flow. After achieving hydroforming process, the surface roughness was measured by electron microscopy SEM in different areas of the hydro formed tube. After hydroforming process, an increase of surface roughness in connection areas of the mold to the curvature and the transverse direction of the pipe.

Corner Fill Modeling of Tube Hydroforming

2000 ◽  
Author(s):  
J. Y. Chen ◽  
Z. C. Xia ◽  
S. C. Tang
Keyword(s):  
Numerical Experiment ◽  
Internal Pressure ◽  
Process Design ◽  
Tube Hydroforming ◽  
Design Guidelines ◽  
Structural Components ◽  
Round Tube ◽  
Fundamental Understanding ◽  
Hydroforming Process ◽  
Square Box

Abstract Hydroforming process provides important advantages for automotive structural components over conventional stamp-and-weld parts, but it also brings unique challenges in process design. This paper attempts to obtain fundamental understanding of the process through corner fill modeling. A round tube is pressurized to expand into a square box with tight radius in the numerical experiment. Several parameters are identified and investigated during the process, namely, the internal pressure, end feed, and the lubricant. Their effects on the deformation profiles are presented, and their importance in process design is discussed. The established design guidelines from the study can be a valuable tool for hydroforming process engineers and part designers.

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