Investigation of Die Corner Filling in Hydroforming of Cylindrical Stepped Tubes Using Finite Element Simulation and Experiment

2009 ◽  
Vol 410-411 ◽  
pp. 335-343
Author(s):  
Mohammad Bakhshi-Jooybari ◽  
Majid Elyasi ◽  
A. Gorji ◽  
G. Mohammad-Alinejad ◽  
S.J. Hosseinipour ◽  
...  

Seamless tubular components, such as stepped tubes, conical tubes and box shape tubes, are mainly produced in tube hydroforming process. In forming the components in this process, complete filling the die corners is very difficult. In this paper, the mechanism of improvement of die corner filling in a proposed tube hydroforming die was investigated. The FEM simulation results showed that the material flow and stress distribution could theoretically clarify the die corner filling in the proposed die. Also, the comparison of the die corner filling between the new die and a conventional die was explained. In order to verify the simulation results, some experiments were performed.

2007 ◽  
Vol 344 ◽  
pp. 461-467 ◽  
Author(s):  
M. Loh-Mousavi ◽  
Kenichiro Mori ◽  
K. Hayashi ◽  
M. Bakhshi

The filling of the die corner in hydroforming of a tube with a box die was improved by controlling wrinkling under oscillation of internal pressure. In this process, a small wrinkle occurs near the die corner in the former stage, and then the wrinkle is eliminated in the latter stage because the flat bulge appears in the former stage due to the oscillation of internal pressure. A hydroforming process of steel tubes with a box die was performed in both three dimensional finite element simulation and experiment. The filling of the die corner for the mean linear pressure was not sufficient due to large wrinkles appearing in the former stage, whereas bursting occurs for the peak linear pressure due to round bulging. On the other hand, the uniformity of wall thickness of the formed tube was improved by the pulsating pressure.


Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1518
Author(s):  
Yeong-Maw Hwang ◽  
Yau-Jiun Tsai

Manufacturing of irregular bellows with small corner radii and sharp angles is a challenge in tube hydroforming processes. Design of movable dies with an appropriate loading path is an alternative solution to obtain products with required geometrical and dimensional specifications. In this paper, a tube hydroforming process using a novel movable die design is developed to decrease the internal pressure and the maximal thinning ratio in the formed product. Two kinds of feeding types are proposed to make the maximal thinning ratio in the formed bellows as small as possible. A finite element simulation software “DEFORM 3D” is used to analyze the plastic deformation of the tube within the die cavity using the proposed movable die design. Forming windows for sound products using different feeding types are also investigated. Finally, tube hydroforming experiments of irregular bellows are conducted and experimental thickness distributions of the products are compared with the simulation results to validate the analytical modeling with the proposed movable die concept.


2011 ◽  
Vol 101-102 ◽  
pp. 962-965 ◽  
Author(s):  
Wen Liu ◽  
Ji Qiang Li ◽  
Bin Bin Chen ◽  
Zhi Xin Jia

Based on the analysis of now available evaluation indexes to estimate the formability of T-shaped tube hydroforming, an aggregative indicator is proposed. The effect of load path on the formability of T-shaped tube is discussed by FEM simulation, and validity of the evaluation index and simulations are proved by experiment. Results show that with the broken line load path of 0-35-35-60, the value of aggregative indicator is the greatest and the formability is the best. The optional parameters are testified by experiment and the results are in agreement with the FEM simulation results.


2011 ◽  
Vol 473 ◽  
pp. 579-586
Author(s):  
Majid Elyasi ◽  
Hassan Khanlari ◽  
Mohammad Bakhshi-Jooybari

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.


2013 ◽  
Vol 770 ◽  
pp. 281-284
Author(s):  
Zhen Yin ◽  
Hua Li ◽  
Zi Yang Cao ◽  
Yu Can Fu

Aiming at the deficiency of existing focused ultrasonic technology, a new high-power Spherical Shell Focused Ultrasonic Transducer (SSFUT) was designed. The SSFUT is composed of a sandwich piezoelectric ultrasonic transducer and a bending vibration spherical shell. Simulation on acoustic field of SSFUT was carried out. the acoustic field pressure distribution nephogram and the axial acoustic pressure curve of the SSFUT were obtained. The consistency of finite element simulation results and experimental results was verified by testing. The research provides a theoretical basis for implementation and application of the new focused ultrasonic technology.


Author(s):  
K.S. Sekar ◽  
K. Sudhagar ◽  
S.N. Murugesan

The capabilities of presses are sometimes limited due to larger cutting force requirement for some sheet metal operations. Reducing the tonnage requirements for such operations will sometimes make the presses capable of doing such operations. FEM simulation can be a reliable tool in predicting the amount of tonnage required for the metal stamping operation. An attempt is taken in this study to analyse the behaviour of the hole piercing operation in an automobile chain part using DEFORM 3D software. The main focus is on the prediction of tonnage requirement with different shear methods on the piercing. Simulations were conducted with flat, single sheared, double sheared, reverse double sheared, convex sheared and concave sheared punches and analyzed for variations in the press load. The phenomena of piercing are also observed through the simulation based on AISI 1060 steel component used for automobile chain as inner plate. Simulation results showed that the shear angles provided on piercing punches will reduce the punch load significantly.


2011 ◽  
Vol 110-116 ◽  
pp. 1477-1482 ◽  
Author(s):  
Majid Elyasi ◽  
Hassan Khanlari ◽  
Mohammad Bakhshi-Jooybari

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.


2006 ◽  
Vol 129 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Bing Li ◽  
T. J. Nye ◽  
Don R. Metzger

The tube-hydroforming process has undergone extremely rapid development. To ensure a reliable hydroforming process at the design stage, applying robust design methodologies becomes crucial to the success of the resulting process. The reliability of the tube-hydroforming process based on the tube wall thickness thinning ratio is studied in this paper. In order to improve the reliability of the process, the Taguchi method, which is capable of evaluating the effects of process variables on both the mean and variance of process output, is used to determine the optimal forming parameters for minimizing the variation and average value of the thinning ratio. Finite element simulation is used to analyze the virtual experiments according to the experimental arrays. A cross-extrusion hydroformed tube is employed as an example to illustrate the effectiveness of this approach.


2013 ◽  
Vol 347-350 ◽  
pp. 1153-1157
Author(s):  
Hai Ying Zhang ◽  
Ling Bai ◽  
Guo Jun Zhang ◽  
Rui Mao ◽  
Wen Liu

Based on the analysis of now available evaluation indexes to estimate the formability of Variable cross-section Y-shaped tube hydroforming, an aggregative indicator is proposed. The effect of load path on the formability of Variable cross-section Y-shaped tube is discussed by FEM simulation, and validity of the evaluation index and simulations are proved by experiment. Results show that with the broken line load path of 0-30-30-40, the value of aggregative indicator is the greatest and the formability is the best. The optional parameters are testified by experiment and the results are in agreement with the FEM simulation results.


2014 ◽  
Vol 675-677 ◽  
pp. 1664-1669
Author(s):  
Yan Zhe Zhao ◽  
Jie Sun ◽  
Ke Yu Wang

Liquid nitrogen cryotherapy is an effective treatment method for skin disease. However, due to the manual operation in the therapeutic process, the treatment effect is difficult to reach. Aimed this problem, the process of freezing in liquid nitrogen was explored. Firstly, the experiment of liquid nitrogen cryotherapy on pork with skin tissue is conducted to investigate the temperatures variation with time. Secondly, three-dimensional numerical simulation of liquid nitrogen cryotherapy was performed. According to the difference in the results of the simulation and experiment, the causes of differences are analyzed and related parameters are optimized. At last, the optimized parameters make the simulation results closer to the experimental results, and provide a reference for the simulation of human skin.


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