The effects of loading path on process parameters in the free tube forming process

2021 ◽  
pp. 095440542110106
Author(s):  
Seyed Saeid Mosavi ◽  
Siamak Mazdak ◽  
Mohammad Reza Sheykholeslami ◽  
Vajihe Sadat Sajadi ◽  
Peyman Yousefi
Keyword(s):  
Movement Time ◽  
Thickness Distribution ◽  
Experimental Tests ◽  
Loading Path ◽  
Forming Process ◽  
Thickness Change ◽  
Geometrical Quality ◽  
Bending Radius ◽  
Movement Mechanism ◽  
Applied Forces

The free bending method is the simplest method among the tube bending processes without the use of a die. Despite the simplicity of the process, there is no proper control over the geometrical tolerance of the product. The loading path or in other words the bearing movement mechanism is one of the effective factors on product geometry. In this paper, a finite element simulation has been carried out to investigate two different bearing movement time-paths (synchronous and asynchronous mechanisms); then, the results have been verified with experimental tests. The thickness distribution in different directions, ovality, bending radius, and applied forces on the bearing and the tube for both bearing movement mechanisms are the main results of this paper. The amplitude of thickness change in both mechanisms was equal. But there is a uniform trend in variation of thickness distribution in synchronous mechanisms. So, better geometrical quality of products is expected in this mechanism. On the other hand, because of uniform force distribution with tube movement in the bearing and tube, the stability of the asynchronous mechanism is higher than the synchronous mechanism.

3D Loading Path-Generating Method for FEM Simulation of Incremental Sheet Metal Forming Process

2010 ◽  
Vol 97-101 ◽  
pp. 2810-2815 ◽  
Author(s):  
Yan Xu ◽  
Shuang Gao Li ◽  
Lin Gao
Keyword(s):  
Sheet Metal ◽  
Incremental Forming ◽  
Thickness Distribution ◽  
Fem Simulation ◽  
Loading Path ◽  
Forming Process ◽  
Forming Simulation ◽  
Generating Method ◽  
Incremental Sheet Metal Forming ◽  
3D Loading

Incremental forming of sheet metal is difficult to be simulated for its complicated 3D loading path. In this work, an acceptable approach to generate 3D loading path, called “virtual guiding model method” is accomplished. The method, which has the similar idea with the conventional copy mill, is based on FEM and the basic principle of kinematics. With the help of the method, multi-stage incremental forming of a drawing typed square cup was simulated in the FEM software-PAMSTAMP and experimented. Through measuring the thickness distribution the vertical edge of the cup, the most difference between them is less than 0.05mm, which is satisfied with engineering request, and the results shows that the 3D loading path generating method is one of the most effective way to realize the incremental forming simulation.

Investigation on Wrinkling Deformation in Multi-Pass Incremental Sheet Forming Process

2016 ◽  
Vol 725 ◽  
pp. 578-585 ◽  
Author(s):  
Zhao Bing Liu ◽  
Paul Anthony Meehan
Keyword(s):  
Thickness Distribution ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Final Part ◽  
Optimized Design ◽  
Forming Process ◽  
Element Analysis ◽  
Form Complex

Incremental Sheet Forming (ISF) is a promising rapid prototyping technology used to form complex three-dimensional shapes. For forming a part with severely sloped regions, design of multi-stage deformation passes (intermediate shapes or preforms) before the final part, is widely adopted as a desirable and practical way to control the material flow in order to obtain a more uniform thickness distribution and avoid forming failure. However, a problem sometimes encountered in multi-pass forming is wrinkling deformation between two adjacent deformation passes. This may lead to forming process instability and even fracture. The overall quality of the final part may also deteriorate even if the part is formed successfully. In this paper, the wrinkling phenomenon in multi-pass incremental sheet forming is investigated by means of finite element analysis (FEA) and experimental tests to analyse the wrinkling formation mechanism. This research gives an insight into the optimized design of deformation passes in order to eliminate the unwanted wrinkling deformation in multi-pass incremental forming process.

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.

Prediction of Wrinkling and Bursting in Hydroforming of Tubes in Box-Shaped Die Using FEM

2011 ◽  
Vol 486 ◽  
pp. 213-216
Author(s):  
Amir Masoud Mirhosseini ◽  
Mohsen Loh Mousavi ◽  
Ghasem Amirian
Keyword(s):  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Experimental Tests ◽  
Loading Path ◽  
Technical Knowledge ◽  
Optimal Range ◽  
Axial Feeding ◽  
Shaped Part ◽  
Dynamic Software ◽  
Explicit Dynamic

In recent years, tube hydroforming has been considered by automobile and airplane industries, because it decreases weight and increases solidity of parts. For this reason, technical knowledge for manufacturing with better quality and accuracy has been developing. However, there are some probable defects in forming by hydroforming technique, which are bursting and wrinkling caused by improper loading paths. Therefore, it is very important to apply a proper path pressure proportional to axial feeding. In this research, firstly, tube hydroforming in a box-shaped die has been simulated by means of 3-D FEM in explicit dynamic software ABAQUSE 6.9-1. For prediction of these occurrences, different paths of pressure have been analyzed and then by comparison with obtained results from the simulation performed such as thickness distribution and final form of the tube, the range of pressure and axial feeding have been predicted. Accordingly, optimal range and loading path for hydroforming of box-shaped part without failure is determined. Considering the working conditions related to the same experimental tests and comparing these conditions with simulated results, efficiency and accuracy of the proposed method have been also investigated.

Sensitivity Analysis of Process Parameters in the Drawing and Ironing Processes

2013 ◽  
Vol 554-557 ◽  
pp. 2256-2265 ◽  
Author(s):  
Vasco M. Simões ◽  
Jeremy Coër ◽  
Hervé Laurent ◽  
M.C. Oliveira ◽  
J. Luís Alves ◽  
...  
Keyword(s):  
Process Parameters ◽  
Deep Drawing ◽  
Thickness Distribution ◽  
Experimental Tests ◽  
Contact Forces ◽  
Outer Diameter ◽  
Forming Process ◽  
Punch Force ◽  
Inner Radius ◽  
Cylindrical Cup

Deep drawing is one of the most important operations used in sheet metal forming. Within this, forming of cylindrical cup is one of the most widely studied deep drawing processes since it allows analysing the effect of different process parameters in phenomena such as earing, springback and ironing. In fact, during the deep drawing of a cylindrical cup the blank thickness gradually increases as the blank outer diameter is reduced to the die inner diameter, resulting in a thickness increase from a point near the bottom radius until the maximum value at the top of the cup. Therefore, if the gap between the punch and the die is not sufficiently large to allow the blank material to flow, ironing of the cup wall will occur. The ironing process typically imposes high contact forces, normal to the surface of the punch and the die, which can lead to the occurrence of galling, particularly for aluminium alloys. In this work an experimental device, adopted in previous studies, was used to analyse the influence of the lubricant conditions in the deep drawing of a cylindrical cup. The study considers an AA5754-O aluminium alloy blank with a diameter of 60 mm, which is fully deep drawn with a 33 mm diameter punch. Due to the forming conditions, the cup is deep drawn and ironing of the cup wall also occurs. The experimental tests were performed considering different amounts of lubricant in the blank surfaces in the contact with the die and with the blank-holder in order to better understand the influence of these tools on the process. The experimental study was complemented with numerical simulations, exploring the conditions induced by the ironing operation, quite challenging for the numerical simulation of the process using the finite element method. Besides the influence of the contact with friction conditions in the forming process (i.e. punch force evolution, thickness distribution along the cup wall and contact pressure), the influence of the die shoulder and inner radius were also analysed.

scholarly journals Formability study and metallurgical properties analysis of FSWed AA 6061 blank by the SPIF process

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Payam Tayebi ◽  
Ali Fazli ◽  
Parviz Asadi ◽  
Mahdi Soltanpour
Keyword(s):  
Base Metal ◽  
Strain Distribution ◽  
Thickness Distribution ◽  
Experimental Studies ◽  
Welding Process ◽  
Forming Limit ◽  
Forming Process ◽  
Friction Stir ◽  
Numerical Process ◽  
Tailor Welded Blank

AbstractIn this study, in order to obtain the maximum possible formability in tailor-welded blank AA6061 sheets connected by the friction stir welding (FSW) procedure, the incremental sheet forming process has been utilized. The results are presented both numerically and experimentally. To obtain the forming limit angle, the base and FSWed sheets were formed in different angles with conical geometry, and ultimately, the forming limit angle for the base metal and FSWed sheet is estimated to be 60° and 57.5°, respectively. To explore the effects of welding and forming procedures on AA6061 sheets, experimental studies such as mechanical properties, microstructure and fracture analysis are carried out on the samples. Also, the thickness distribution of the samples is studied to investigate the effect of the welding process on the thickness distribution. Then, the numerical process was simulated by the ABAQUS commercial software to study the causes of the FSWed samples failure through analyzing the thickness distribution parameter, and major and minor strains and the strain distribution. Causes of failure in FSWed samples include increased minor strain, strain distribution and thickness distribution in welded areas, especially in the proximity of the base metal area.

scholarly journals Concept for controlled adjustment of residual stress states in semi-finished products by gradation extrusion

2021 ◽  
Author(s):  
René Selbmann ◽  
Markus Baumann ◽  
Mateus Dobecki ◽  
Markus Bergmann ◽  
Verena Kräusel ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Experimental Tests ◽  
Residual Stress Distribution ◽  
Forming Process ◽  
Compressive Stresses ◽  
Energy Consuming ◽  
Stress States ◽  
Set Up ◽  
Time And Energy

AbstractThe residual stress distribution in extruded components and wires after a conventional forming process is frequently unfavourable for subsequent processes, such as bending operations. High tensile residual stresses typically occur near the surface of the wire and thus limit further processability of the material. Additional heat treatment operations or shot peening are often inserted to influence the residual stress distribution in the material after conventional manufacturing. This is time and energy consuming. The research presented in this paper contains an approach to influence the residual stress distribution by modifying the forming process for wire-like applications. The aim of this process is to lower the resulting tensile stress levels near the surface or even to generate compressive stresses. To achieve these residual compressive stresses, special forming elements are integrated in the dies. These modifications in the forming zone have a significant influence on process properties, such as degree of deformation and deformation direction, but typically have no influence on the diameter of the product geometry. In the present paper, the theoretical approach is described, as well as the model set-up, the FE-simulation and the results of the experimental tests. The characterization of the residual stress states in the specimen was carried out by X-ray diffraction using the sin2Ψ method.

scholarly journals The Effect of Process Parameters in Helical Rolling of Balls on the Quality of Products and the Forming Process

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2125 ◽  
Author(s):  
Janusz Tomczak ◽  
Zbigniew Pater ◽  
Tomasz Bulzak
Keyword(s):  
Metal Flow ◽  
Experimental Tests ◽  
Rolling Process ◽  
Helical Rolling ◽  
Forming Process ◽  
University Of Technology ◽  
Quality Of Products ◽  
Skew Rolling

This paper presents selected numerical and experimental results of a skew rolling process for producing balls using helical tools. The study investigates the effect of the billet’s initial temperature on the quality of produced balls and the rolling process itself. In addition, the effect of billet diameter on the quality of produced balls is investigated. Experimental tests were performed using a helical rolling mill available at the Lublin University of Technology. The experiments consisted of rolling 40 mm diameter balls with the use of two helical tools. To determine optimal rolling parameters ensuring the highest quality of produced balls, numerical modelling was performed using the finite element method in the Forge software. The numerical analysis involved the determination of metal flow kinematics, temperature and damage criterion distributions, as well as the measurement of variations in the force parameters. The results demonstrate that the highest quality balls are produced from billet preheated to approximately 1000 °C.

Optimization of Sheet Metal Process Parameters of a Shield Case Piece Using Computer Simulation

2006 ◽  
Vol 510-511 ◽  
pp. 330-333
Author(s):  
M.C. Curiel ◽  
Ho Sung Aum ◽  
Joaquín Lira-Olivares
Keyword(s):  
Sheet Metal ◽  
Thickness Distribution ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Physical Processes ◽  
Forming Process ◽  
Element Analysis ◽  
One Step ◽  
Range Of Values ◽  
Principal Strains

Numerical simulations based on Finite Element Analysis (FEA) are widely used to predict and evaluate the forming parameters before performing the physical processes. In the sheet metal industry, there are basically two types of FE programs: the inverse (one-step) programs and the incremental programs. In the present paper, the forming process of the shield case piece (LTA260W1-L05) was optimized by performing simulations with both types of software. The main analyzed parameter was the blankholding force while the rest of the parameters were kept constant. The criteria used to determine the optimum value was based on the Forming Limit Diagram (FLD), fracture and wrinkling of the material, thickness distribution, and the principal strains obtained. It was found that the holding force during the forming process deeply affects the results, and a range of values was established in which the process is assumed to give a good quality piece.

scholarly journals Simulation of incremental forming processes of a pyramidal ring made of two materials

2018 ◽  
Vol 19 (3) ◽  
pp. 313
Author(s):  
Masood Ghassabi ◽  
Milad Salimi ◽  
Mohammad Haghpanahi
Keyword(s):  
Feed Rate ◽  
Rotational Speed ◽  
Incremental Forming ◽  
Thickness Distribution ◽  
Single Point ◽  
Dimensional Accuracy ◽  
Cnc Machine ◽  
Forming Force ◽  
Forming Process ◽  
Dimensional Precision

Incremental forming is one of the most well-known forming processes for complex and asymmetric parts. This method uses a CNC machine, simple forming tool, and a die. This study focused on effects of some parameters such as the material, feed rate, pitch, rotational speed and movement strategy of tool on the dimensional precision, forming force, thickness distribution and fracture in the welding area. The results showed that single point incremental forming (SPIF) led to a better thickness distribution with lower tool force, whereas two-point incremental forming led to better dimensional accuracy. Rotational speed does not have any significant impact on the forming process while decreasing the feed rate partially reduced the forming force. According to the results, although dimensional precision in double point incremental forming is better than SPIF, when it comes to the thickness distribution, forming force, and economic issues, SPIF is in favor. The results also showed that by connecting two materials, different parameters for the two materials could be investigated simultaneously in one simulation process.

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