Determination of Loading Path for Warm Tube Hydroforming of Diamond Shaped Parts

2011 ◽  
Author(s):  
Wei Chen ◽  
L. C. Chan ◽  
T. C. Lee
Keyword(s):  
Numerical Simulation ◽  
Tube Hydroforming ◽  
Fem Simulation ◽  
Loading Path ◽  
Loading Paths ◽  
Different Types ◽  
Series Of Experiments ◽  
Simulation Results ◽  
Good Agreement

This paper aims to present an optimization process for three different types of loading paths studied in the numerical simulation of tube hydroforming of diamond-shaped sheet products. These three different types of loading paths werestudied in a numerical simulation of tube hydroforming of diamond-shaped products. The loading paths by which the best final shapes were obtained in the simulation were adopted in actual processing operation. A series of experiments were conducted within the temperature range of 270±10°C. Constitutive behavior was assumed to be elasto-plastic, and the material parameters used in the simulation were obtained from corresponding literature. The designed loading ratios were incorporated into the model to obtain the corresponding hydroforming results. The simulation results are used in the experimental verification and the products were compared with the simulation results. The experimental results showed a good agreement with the predicted numerical results, indicating that FEM simulation is an effective tool in optimizing processing procedures.

Forming Margin Diagram for Tube Hydroforming with Radial Crushing under Linear Loading Path

2012 ◽  
Vol 538-541 ◽  
pp. 1106-1110 ◽  
Author(s):  
Zhi Hua Tao ◽  
Lian Fa Yang
Keyword(s):  
Fe Simulation ◽  
Tube Hydroforming ◽  
Loading Path ◽  
Fe Model ◽  
Forming Process ◽  
Loading Paths ◽  
Contour Lines ◽  
Working Status ◽  
Simulation Results ◽  
Linear Loading

Tube hydroforming with radial crushing (THFRC) process is one of tube hydroforming methods that is suitable for overlong structure parts forming process avoiding wrinkling and bursting failure. In this paper, the Forming Margin Diagram (FMD) for THFRC process was presented to optimize loading paths. Initially, parameters of Finite Element (FE) simulation in this study were represented, which contained FE model and linear loading paths. Afterwards, boundaries of the FMD were delimited based on real working status. Moreover, curves of corner radius, bursting failure and thickness uniform rate were determined by FE simulation results to establish the FMD, and the curves and zones on the FMD were analyzed simultaneously. Furthermore, features of contour lines were discussed, and the usage of the FMD was introduced.

Numerical Simulation on Thixo-Forging of Magnesium Matrix Composite

2011 ◽  
Vol 189-193 ◽  
pp. 2535-2538 ◽  
Author(s):  
Hong Yan ◽  
Wen Xian Huang
Keyword(s):  
Numerical Simulation ◽  
Matrix Composite ◽  
Metal Flow ◽  
Magnesium Matrix Composite ◽  
Magnesium Matrix ◽  
Simulation Based ◽  
Prior Literature ◽  
Simulation Results ◽  
Computer Numerical Simulation ◽  
Good Agreement

The thixo-forging of magnesium matrix composite was analyzed with computer numerical simulation based on rigid viscoplastic finite element method. The constitutive model of SiCp/AZ61 composite was established in our prior literature. Behavior of metal flow and temperature field were obtained. The differences between traditional forging and thixo-forging processes were analyzed. Results indicated that thixo-forging was better in filling cavity than forging. Simulation results were good agreement with experimental ones.

scholarly journals Numerical Simulations of V-Shaped Plates Subjected to Blast Loadings: A Validation Study

2016 ◽  
Vol 10 (11) ◽  
pp. 203
Author(s):  
Mohd Zaid Othman ◽  
Qasim H. Shah ◽  
Muhammad Akram Muhammad Khan ◽  
Tan Kean Sheng ◽  
M. A. Yahaya ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Variable Mass ◽  
Blast Loading ◽  
Experimental Results ◽  
Average Difference ◽  
Simulation Results ◽  
Blast Loadings ◽  
Carrier Vehicle ◽  
Good Agreement

A series of numerical simulations utilizing LS-DYNA was performed to determine the mid-point deformations of V-shaped plates due to blast loading. The numerical simulation results were then compared with experimental results from published literature. The V-shaped plate is made of DOMEX 700 and is used underneath an armour personal carrier vehicle as an anti-tank mine to mitigate the effects of explosion from landmines in a battlefield. The performed numerical simulations of blast loading of V-shaped plates consisted of various angles i.e. 60°, 90°, 120°, 150° and 180°; variable mass of explosives located at the central mid-point of the V-shaped vertex with various stand-off distances. It could be seen that the numerical simulations produced good agreement with the experimental results where the average difference was about 26.6%.

Effect of the Load Path on Formability of T-Shaped Tube Hydroforming

2011 ◽  
Vol 101-102 ◽  
pp. 962-965 ◽  
Author(s):  
Wen Liu ◽  
Ji Qiang Li ◽  
Bin Bin Chen ◽  
Zhi Xin Jia
Keyword(s):  
Tube Hydroforming ◽  
Fem Simulation ◽  
Evaluation Index ◽  
Load Path ◽  
Line Load ◽  
Evaluation Indexes ◽  
Shaped Tube ◽  
Simulation Results

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.

scholarly journals Initial Value Determination of Chua System with Hidden Attractors and Its DSP Implementation

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Xianming Wu ◽  
Weijie Tan ◽  
Huihai Wang
Keyword(s):  
Numerical Simulation ◽  
Digital Signal Processor ◽  
Digital Signal ◽  
Hidden Attractors ◽  
Initial Value ◽  
Circuit Realization ◽  
Dsp Implementation ◽  
Simulation Results ◽  
Value Determination

In this paper, a method for determining the initial value of the hidden attractors in the Chua system is studied. The initial value of the hidden attractors can be calculated quickly and accurately by the proposed method, and the hidden attractors can be found by numerical simulation. Then, the initial values of the hidden attractors are set accurately by digital signal processor (DSP), so as to the circuit realization of the chaotic system with hidden attractors is performed. The results show that the numerical simulation results of Matlab are consistent with the experimental results of DSP.

Scattering Tomography and Its Application to Sooting Diffusion Flames

1994 ◽  
Vol 116 (1) ◽  
pp. 144-151 ◽  
Author(s):  
M. P. Mengu¨c¸ ◽  
P. Dutta
Keyword(s):  
Diffusion Flames ◽  
Tomographic Reconstruction ◽  
Scattering Coefficient ◽  
Reconstruction Technique ◽  
Transmission Tomography ◽  
Ion Laser ◽  
Series Of Experiments ◽  
Argon Ion ◽  
Good Agreement

A new analytical tomographic reconstruction technique was developed for the determination of the extinction and scattering coefficient distributions in axisymmetric media. This method, called “scattering tomography,” was tested for several particle concentration profiles corresponding to those for diffusion flames. After that, a series of experiments were performed on sooting acetylene flames using an argon-ion laser nephelometer. The experimental results were reduced using both the transmission and scattering tomography techniques to obtain the extinction coefficient profiles. It was shown that in the center of the flame, the results from these two approaches were in good agreement. Scattering tomography can be used to determine both the absorption and scattering coefficient distributions in the medium. In addition to that, it is preferable over the transmission tomography if the medium is optically very thin and particles are predominantly scattering.

Adaptive Simulations of T-Shape Tube Hydroforming Processes

2007 ◽  
Vol 340-341 ◽  
pp. 627-632 ◽  
Author(s):  
Yeong-Maw Hwang ◽  
Bing Hong Chen ◽  
Wen Chan Chang
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Adaptive Algorithm ◽  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Loading Path ◽  
Finite Element Code ◽  
Simulation Results ◽  
Formed Product ◽  
The Relationship

A successful THF process depends largely on the loading paths for controlling the relationship between the internal pressure, axial feeding and the counter punch. In this study, an adaptive algorithm combined with a finite element code LS-DYNA 3D is proposed to control the simulation of T-shape hydroforming with a counter punch. The effects of the friction coefficients at the interface between the tube and die on the loading path and thickness distribution of the formed product are discussed. Experiments of protrusion hydroforming are also conducted. The final shape and thickness distribution of the formed product are compared with the simulation results to verify the validity of this modeling.

Research on Wrinkling Behavior in Tube Hydroforming with Axial Feeding

2014 ◽  
Vol 622-623 ◽  
pp. 739-746
Author(s):  
Zhu Lin Hu ◽  
Lian Fa Yang ◽  
Yu Lin He
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Metal Forming ◽  
Shape Change ◽  
Tube Hydroforming ◽  
Loading Path ◽  
Axial Feeding ◽  
Loading Paths ◽  
Element Simulation

Tube hydroforming (THF) is one of metal forming technologies which has been widely used to manufacture complex hollow workpeices. In THF, a variety of failures may occur and one of them is wrinkling. But recent researches show that wrinkling may be used as a preforming process to improve the formability of tubes. In this paper, a new geometry-based wrinkling indicator is proposed to evaluate the wrinkling level in THF and the wrinkle evolution diagram (WED) based on the shape change of the wrinkles is presented to display the four-stage evolution of the useful wrinkles. The wrinkling levels in THF with axial feeding under various loading paths are predicted respectively via finite element simulation, the influence of loading paths on the wrinkling behavior is investigated, and the evolving stages of the useful wrinkles is revealed via the proposed WED. The results indicate that the proposed wrinkle indicator can distinctly evaluate the wrinkling level, the wrinkling level under pulsating loading path is higher than that under polygonal linear one and four-stage evolution of the useful wrinkles could be evidently demonstrated via the WED. Notation

Comparison of Offset and Wiping Z-Die Designs for Precision Z-Bent Part Fabrication

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Sutasn Thipprakmas ◽  
Pakkawat Komolruji ◽  
Wiriyakorn Phanitwong
Keyword(s):  
Fem Simulation ◽  
The Finite Element Method ◽  
Spring Back ◽  
Bend Radius ◽  
Dimensional Precision ◽  
Bending Process ◽  
Simulation Results ◽  
Bend Angles ◽  
Selection Of ◽  
Good Agreement

In recent years, the requirements for high dimensional precision on Z-bent shaped parts have become increasingly stringent. To attain these requirements, the suitable selection of the Z-die bending type has to be considered much more strictly. In this research, two types of Z-bending processes, offset Z-die bending and wiping Z-die bending, were investigated using the finite element method (FEM) to identify the spring-back characteristics and dimensions of Z-bent shaped parts. In the case of offset Z-die bending, the spring-back characteristics on both bend angles were similar. In contrast, in the case of wiping Z-bending, the spring-back characteristics on both bend angles were different. In addition, the dimensions of the Z-bent shaped parts were investigated. It was found, in the case of wiping Z-bending, that web thinning was generated and the outer bend radius was out of tolerance. To validate the FEM simulation results, experiments were carried out. The FEM simulation results showed good agreement with the experimental results in terms of the bend angles and the overall geometry of the Z-bent shaped parts. To achieve precise Z-bent shaped parts, the suitable selection of Z-die bending type in the Z-die bending process is very important.

Effects of Materials on Formation of Double-Layered Liners Shaped Charges

2009 ◽  
Vol 79-82 ◽  
pp. 1277-1280
Author(s):  
Yu Zheng ◽  
Xiao Ming Wang ◽  
Wen Bin Li ◽  
Wen Jin Yao
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Numerical Simulations ◽  
Double Layer ◽  
Two Dimensional ◽  
Materials Properties ◽  
X Ray ◽  
Dimensional Finite Element ◽  
Simulation Results ◽  
Good Agreement

In order to study the effects of liner materials on the formation of Shaped Charges with Double Layer Liners (SCDLL) into tandem Explosively Formed Projectile (EFP), the formation mechanism of DLSCL was studied. Utilizing two-dimensional finite element dynamic code AUTODYN, the numerical simulations on the mechanical phenomenon of SCDLL forming into tandem EFP were carried out. X-ray pictures were obtained after Experiments on SCDLL. Comparisons between experimental results and numerical simulation results have good agreement. It can be concluded from the results that the materials properties and configurations of both liners are crucial to the formation of tandem EFP.

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