Tube Buckling: An Advantage to Tube Shaping

2018 ◽  
Author(s):  
Chetan P. Nikhare
Keyword(s):  
Tube Hydroforming ◽  
Rigid Bodies ◽  
Outer Diameter ◽  
Forming Process ◽  
Tube Forming ◽  
Strength Coefficient ◽  
Tube Shape ◽  
Tube Flaring ◽  
Hydroforming Process ◽  
Proper Consideration

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. One of the process within tube end forming process is flaring which is the focus of this paper. In tube flaring process the conical shape rigid tool flares the end of the tube. While flaring the tube, the tube buckles if proper consideration would not have been taken. In this paper, various influencing parameters such as outer diameter to tube thickness ratio, length or the tube, the strength coefficient of the tube and conical angle of the tool were analyzed. It was noted that the most important factor affect the buckling of the tube is its strength coefficient. Considering this parameter the buckling was carried out in a set die and a tube shape was formed. The advantages of this process over similar processes were discussed.

Buckling of Tube for Tube Hydroforging

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 ◽  
Hydroforming Process

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.

Numerical analysis in a beverage can utilizing tube hydroforming process

2019 ◽  
Vol 28 (6) ◽  
pp. 77-83
Author(s):  
Jorge Carlos León Anaya ◽  
José Antonio Juanico Loran ◽  
Juan Carlos Cisneros Ortega
Keyword(s):  
Mechanical Properties ◽  
Numerical Analysis ◽  
Metal Forming ◽  
Tube Hydroforming ◽  
Forming Process ◽  
Aluminum Tube ◽  
Plastic Deformation Process ◽  
Metal Forming Process ◽  
Hydroforming Process

Numerical analysis for Tube Hydroforming (THF) was developed in this work to predict the behavior of extruded aluminum tube in a forming die for beverage can applications. THF is a metal forming process dependent of three parameters: friction between the tube and the die, internal pressure, and material properties of the tube. Strain hardening is a governing phenomenon that occurs in the plastic deformation process of metals. Hollomon’s equation offers a mathematical description of the metal behavior in the plastic zone. For a proper simulation, experimental determination of the mechanical properties of aluminum 6061-T5 were conducted and test specimens where obtained directly from the aluminum tube. Experimental data were necessary because no sufficient data of the mechanical properties of the tube were available in the literature. Numerical simulations of THF were performed, and the results were compared with analytical results for validation purposes with less than 10% of error.

Reliability Analysis of the Tube Hydroforming Process Based on Forming Limit Diagram

2005 ◽  
Vol 128 (3) ◽  
pp. 402-407 ◽  
Author(s):  
Bing Li ◽  
Don R. Metzger ◽  
Tim J. Nye
Keyword(s):  
Automotive Industry ◽  
Metal Forming ◽  
Tube Hydroforming ◽  
Forming Limit Diagram ◽  
Probability Of Failure ◽  
Alternative Methods ◽  
Forming Limit ◽  
Forming Process ◽  
Hydroforming Process ◽  
Free Bulging

Tube hydroforming is an attractive manufacturing process in the automotive industry because it has several advantages over alternative methods. In order to determine the reliability of the process, a new method to assess the probability of failure is proposed in this paper. The method is based on the reliability theory and the forming limit diagram, which has been extensively used in metal forming as the criteria of formability. From the forming limit band in the forming limit diagram, the reliability of the forming process can be evaluated. A tube hydroforming process of free bulging is then introduced as an example to illustrate the approach. The results show this technique to be an innovative approach to avoid failure during tube hydroforming.

TUBE HYDROFORMING PROCESS DESIGNE OF TORSION BEAM TYPE REAR SUSPENSION CONSIDERING DURABILITY

2008 ◽  
Vol 22 (31n32) ◽  
pp. 6199-6205 ◽  
Author(s):  
KYUNG-TAEK LEE ◽  
HONG-JUEN BACK ◽  
HEE-TAEK LIM ◽  
IN-SUK OH ◽  
HEON-YOUNG KIM
Keyword(s):  
Dynamic Performance ◽  
Tube Hydroforming ◽  
The Finite Element Method ◽  
Forming Process ◽  
Cross Sectional ◽  
Torsion Beam ◽  
Rear Suspension ◽  
Suspension Systems ◽  
Hydroforming Process ◽  
Beam Type

Manufacturing processes for automobile suspension components have generally considered the formability but not the durability of the suspension system, even though the latter is very important in the dynamic performance of the vehicle. Suspension systems should be designed with both formability and durability in mind. This paper describes the design of an optimal forming process to control the cross-sectional properties of the torsion beam in rear suspension systems for increased roll durability. Stamping and hydroforming simulations were performed using the finite element method to determine the optimum tube hydroforming process for producing a torsion beam with the best roll durability performance.

scholarly journals Hydroforming Process for an Ultrasmall Bending Radius Elbow

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Shangwen Ruan ◽  
Lihui Lang ◽  
Yulong Ge
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Welding Process ◽  
Forming Process ◽  
Sealing Performance ◽  
Lap Welding ◽  
Hydroforming Process ◽  
Bending Radius

Bent pipes are widely used in automotive, aviation, and aerospace industries for delivering fluids. Parts having small relative bending radiuses are called elbows. However, fabricating a thin-walled elbow part using the simple bending process poses many challenges. One possible way to manufacture elbows is with the stamping-welding process. The major drawbacks of this method include the decline in sealing performance and the addition in weight attributed to the lap welding process. Tube hydroforming (THF) is considered as a feasible solution to these problems. However, the forming process could be quite complex, and multistep forming is necessary. This study investigates the effects of preliminary processes on elbow forming such as bending, partition forming, and heat treatment and presents a high-performance optimized process design to achieve an ultrasmall radius elbow. The effects of multistep forming on the thickness distribution and the heat treatment on the microstructure have been evaluated. The results obtained from simulations show a reasonable agreement with those from the experiments.

scholarly journals Stability Analysis of Steel Welded Tubes Forming Process Using Numerical Simulations

2021 ◽  
Vol 15 (2) ◽  
pp. 298-304
Author(s):  
Marko Delić ◽  
Vesna Mandić ◽  
Marko Popović
Keyword(s):  
Influencing Factors ◽  
Numerical Experiments ◽  
Hard Metal ◽  
Outer Diameter ◽  
Forming Process ◽  
Tube Forming ◽  
Welded Tube ◽  
Optimal Values ◽  
Geometrical Factors ◽  
The Stability

In this paper, the research results of the stability of steel welded tubes forming process are presented. The aim of this research is to determine influence of geometrical and tribological parameters on stability of the process and to determine optimal values of influential process parameters. A research plan with variation of influential parameters was made, on the basis of which experimental and numerical experiments were performed. Tube forming was performed in one operation in a two-part tool made of hard metal by a combination of widening and narrowing. The geometrical factors observed during experiments are length, outer diameter and thicknesses of steel welded tube as a billet. Friction conditions in contact between tool and tubular workpiece are considered in two cases, the first one when standard machine oil is used as a lubricant and the second one when tube billet surface is phosphated. Based on results of experiments, influencing factors on stability of tube forming process were analysed and optimal production technology was recommended, including optimal values of influencing factors. Results obtained by experimental research were confirmed through numerical experiments based on finite element method.

Scalability of conventional tube hydroforming processes from macro to micro/meso

2017 ◽  
Vol 232 (12) ◽  
pp. 2164-2177 ◽  
Author(s):  
James Lowrie ◽  
Gracious Ngaile
Keyword(s):  
Tube Hydroforming ◽  
Small Scale ◽  
Forming Process ◽  
Element Analysis ◽  
Aspect Ratios ◽  
Small Complex ◽  
Metal Forming Process ◽  
Hydroforming Process ◽  
Increasing Demand ◽  
Complex Parts

Due to the increasing demand for small, complex parts, researchers are putting a great deal of effort into applying the metal forming process to the micro and meso world. However, the tube hydroforming process is yet to be fully realized on this small scale because of the difficulties which arise in scaling the conventional tooling to the microscale. This article discusses the difficulties that arise as a result of simply shrinking the traditional hydroforming tools to the microscale. A simple mathematical model is then proposed as a way to help designers determine the limits of the conventional punch with a tapered nose commonly used in tube hydroforming. The model is then validated by performing a finite element analysis of the punch, and the results of the model are discussed in relation to the scaling concepts posed at the beginning of this article. It is determined that as the punch shrinks down, the stresses on the punch rise significantly as a result of changing aspect ratios of the workpiece and the inability to accurately machine very small holes through the punch body. A nonconventional tube hydroforming method may therefore be required to perform micro-tube hydroforming operations, especially on harder materials.

Real-Time Friction Error Compensation in Tube Hydroforming Process Control

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Gracious Ngaile ◽  
Chen Yang ◽  
Obadiah Kilonzo
Keyword(s):  
Process Control ◽  
Real Time ◽  
Error Compensation ◽  
Tube Hydroforming ◽  
Loading Path ◽  
Forming Process ◽  
Loading Paths ◽  
Proposed Model ◽  
Metal Forming Process ◽  
Hydroforming Process

Tube hydroforming (THF) is a metal-forming process that uses a pressurized fluid in place of a hard tool to plastically deform a given tube into a desired shape. In addition to the internal pressure, the tube material is fed axially toward the die cavity. One of the challenges in THF is the nonlinear and varying friction conditions at the tube-tool interface, which make it difficult to establish accurate loading paths (pressure versus feed) for THF. A THF process control model that can compensate for the loading path deviation due to frictional errors in tube hydroforming is proposed. In the proposed model, an algorithm and a software platform have been developed such that the sensed forming load from a THF machine is mapped to a database containing a set of loading paths that correspond to different friction conditions for a specific part. A real-time friction error compensation is then carried out by readjusting the loading path as the THF process progresses. This scheme reduces part failures that would normally occur due to variability in friction conditions. The implementation and experimental verification of the proposed model is discussed.

Real Time Friction Error Compensation in Tube Hydroforming Process Control

2011 ◽  
Author(s):  
Gracious Ngaile ◽  
Obadiah Kilonzo ◽  
Chen Yang
Keyword(s):  
Process Control ◽  
Real Time ◽  
Error Compensation ◽  
Tube Hydroforming ◽  
Loading Path ◽  
Forming Process ◽  
Loading Paths ◽  
Proposed Model ◽  
Metal Forming Process ◽  
Hydroforming Process

Tube Hydroforming (THF) is a metal-forming process that uses a pressurized fluid in place of a hard tool to plastically deform a given tube into a desired shape. In addition to the internal pressure, the tube material is fed axially toward the die cavity. One of the challenges in THF is the nonlinear and varying friction conditions at the tube-tool interface, which make it difficult to establish accurate loading paths (pressure vs feed) for THF. A THF process control model that can compensate for the loading path deviation due to frictional errors in tube hydroforming is proposed. In the proposed model, an algorithm and a software platform have been developed such that the sensed forming load from a THF machine is mapped to a database containing a set of loading paths that correspond to different friction conditions for a specific part. A real-time friction error compensation is then carried out by readjusting the loading path as the THF process progresses. This scheme reduces part failures that would normally occur due to variability in friction conditions. The implementation and experimental verification of the proposed model is discussed.

Reliability Analysis of the Tube Hydroforming Process Based on Forming Limit Diagram

2003 ◽  
Author(s):  
Bing Li ◽  
Don R. Metzger ◽  
T. J. Nye
Keyword(s):  
Tube Hydroforming ◽  
Forming Limit Diagram ◽  
Alternative Methods ◽  
Forming Limit ◽  
Process Conditions ◽  
Forming Process ◽  
Element Simulation ◽  
Hydroforming Process ◽  
Free Bulging ◽  
The Relationship

Tube hydroforming has become an increasingly attractive manufacturing process in automotive industry due to it having several advantages over alternative methods. The forming limit diagram has been extensively used in metal forming as the criteria of formability. A method to assess the probability of failure of the process based on reliability theory and the forming limit diagram is proposed in this paper. The tube hydroforming process is affected by many parameters such as geometry, material properties, and process conditions. Finite element simulation was used to predict the relationship between the strain and these parameters, and a numerical method was applied to get the statistical distribution of the strain. Based on the forming limit band in the forming limit diagram, the reliability of the forming process can be evaluated. A tube hydroforming process of free bulging is then introduced as an example to illustrate the approach. The results show this reliability evaluation technique to be an innovative approach for product designers and process engineers to avoid failure during tube hydroforming.

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