Influence Law of Initial Reverse Bulging on Sheet Hydroforming Process

2017 ◽  
Vol 746 ◽  
pp. 99-107 ◽  
Author(s):  
Li Hui Lang ◽  
Quan Da Zhang
Keyword(s):  
Numerical Simulation ◽  
Wall Thickness ◽  
Reasonable Agreement ◽  
Experimental Results ◽  
Forming Limit ◽  
Technological Parameters ◽  
Sheet Hydroforming ◽  
Hydroforming Process

In order to investigating the effect of the combination of two technological parameters such as the initial bulging height and the initial bulging pressure on the sheet , the sheet hydroforming process was studied. Firstly, by using the method of numerical simulation, the sheet hydroforming process with and without the initial bulging were discussed; Secondly, the effect of both the initial bulging height and the initial bulging pressure which were based on the hydroforming with the initial bulging on the forming of the part was studied; Thirdly, the result of the simulation was verified in the experiment. It was found that when the initial bulging height is 3.75mm and the initial bulging pressure is 2MPa, the maximum thinning ratio of the sheet is 4.803% at the end of the sheet hydroforming process. According to the hydroforming process without the initial bulging factors, the maximum thinning ratio is 5.123%. It can be found that the initial bulging factors play a key role in the sheet hydroforming process. The maximum thinning ratio of the wall thickness can be decreased effectively by the appropriate initial bulging height and bulging pressure, and the forming limit can also be improved at the same time. The results of numerical simulation have a reasonable agreement with the experimental results.

Effect of the Thickness of Dies for the Solidification Balance of Permanent Mould Casting AZ91D Magnesium Alloy

2009 ◽  
Vol 610-613 ◽  
pp. 750-753
Author(s):  
Jian Hua Zhao ◽  
Si Yuan Long ◽  
Hui Xu ◽  
Li Yan
Keyword(s):  
Numerical Simulation ◽  
Magnesium Alloy ◽  
Wall Thickness ◽  
Hot Spot ◽  
Experimental Results ◽  
Single Cycle ◽  
Chilling Effect ◽  
Az91d Magnesium Alloy ◽  
Mould Casting ◽  
Cooling Ability

The hot spot forming tendency during solidification of AZ91D magnesium alloy in permanent mould casting with the dies of different wall thickness via numerical simulation with Anycasting software was studied in the present paper. The experimental results showed that in a single cycle casting the increase in the thickness enhanced the cooling ability of the mould and promoted balanced solidification in a certain degree, while in multi-cycle casting, the thickened die-wall gradually lose its localized chilling effect. In contrast, the die with a decreased wall thickness in a certain range was easier to achieve the desired solidification balance.

Study on Formability of TRIP Steel in Incremental Sheet Forming

2013 ◽  
Vol 634-638 ◽  
pp. 2881-2884 ◽  
Author(s):  
Jin Wang ◽  
Li Hua Li ◽  
Bao Ping Wang ◽  
Hu Sen Jiang
Keyword(s):  
Numerical Simulation ◽  
Production Process ◽  
Wall Thickness ◽  
Trip Steel ◽  
Forming Limit Diagram ◽  
Intersection Point ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Forming Limit ◽  
Initial Angle

The formability of a TRIP590 steel with 0.67mm thick in incremental sheet forming (ISF) was investigated. A variable angle cone, which opening diameter and generatrix radius are 100mm, and initial angle is 35 °, was formed until the specimen cracked. The depth at the intersection point of the actual wall thickness and theoretical wall thickness of the cone was measured, and the forming limit angle of the TRIP590 steel was got and about 66.5 °. Additionally, an arc groove and a cross arc groove were formed. Through measuring changes of the grids printed on the surface of the tested sheet, the forming limit diagram of the TRIP590 steel in ISF was obtained. The forming limit angle and diagram obtained can be used in designing the production process and numerical simulation of forming the TRIP steel.

Study on Explosion in Spherical Vessel Vented into Dump Vessel

2011 ◽  
Vol 396-398 ◽  
pp. 988-992 ◽  
Author(s):  
Yuan Yu ◽  
Jun Cheng Jiang ◽  
Qing Wu Zhang
Keyword(s):  
Numerical Simulation ◽  
Reasonable Agreement ◽  
Experimental Results ◽  
Maximum Pressure ◽  
Cfd Model ◽  
Gas Explosion ◽  
Spherical Vessel ◽  
Vessel Volume

The gas explosion in spherical vessel vented into a dump vessel (“dump vessel vented”) was studied by experimental and numerical simulation. The CFD model used provided a reasonable agreement with the experimental results. The maximum pressure of the explosion vessel is more than the direct venting. But when ratio of dump vessel volume (vd) to explosion vessel volume (ve) is more than or equal to 5, the maximum pressure in the explosion vessel approximately equal to the maximum pressure of simple vented.

The Numerical Simulation of Air Bulge Forming of Profiled Can

2010 ◽  
Vol 97-101 ◽  
pp. 2774-2778
Author(s):  
Jie Jin ◽  
Xin He
Keyword(s):  
Numerical Simulation ◽  
Parameter Estimation ◽  
Friction Coefficient ◽  
Process Parameters ◽  
Wall Thickness ◽  
Process Parameter ◽  
The Other ◽  
Technological Parameters ◽  
Forming Process ◽  
Inner Pressure

Air bulge forming is a forming process where an inner pressure deforms the material to the shape of a die cavity. The main concerns about such a process of profiled cans are to avoid wall thickness reduction, wrinkling and bursting. The success of this process strongly depends on the choice of process parameters, i.e. the properties of material, thickness and inner pressure. By transforming the problem into a deformation controlled rather than a force controlled process, the results from the process parameter estimation become more reliable but on the other hand less intuitive. In this context, the influence of materials, friction coefficient, transitional fillet radius, thickness and bulging load are studied and some suited technological parameters and forming rules are obtained. The most important point is that the simulation and results of experiments are probably consistent.

Numerical and Experimental Study on Sheet Hydroforming of 2A12 Aluminum Alloy

2016 ◽  
Vol 716 ◽  
pp. 981-987
Author(s):  
Chu Wang ◽  
Min Wan ◽  
Wen Nan Yuan
Keyword(s):  
Aluminum Alloy ◽  
Wall Thickness ◽  
Initial Pressure ◽  
Pressure Curve ◽  
Cavity Pressure ◽  
Sheet Hydroforming ◽  
Fundamental Parameters ◽  
Sheet Formability ◽  
Hydroforming Process

In this paper, the sheet hydroforming process of 2A12 aluminum alloy with uniform die cavity pressure on to the blank is proposed and investigated both primarily through the finite element method (FEM) and experiments. The influence of the die cavity pressure curve on the quality of the products was explored and the measures to promote the sheet formability were discussed. The results from the studied case indicate that the profile of the cavity pressure was one of the fundamental parameters directly related to the product's quality and precision. Excessive or insufficient initial pressure is not conducive for the reduction of wall thickness thinning and guarantee of wall thickness uniformity. And the wall thickness thinning is reduced and the thickness evenness is improved by increasing the maximum cavity pressure within a proper range. Moreover, an optimum cavity pressure curve generated by the numerical and experimental methods was properly applied in forming the aluminum alloy part without rupture and with slight wrinkle in the flange area. The study demonstrates that the results of simulations based on the identified parameters were in reasonable agreement with those from experiments.

Finite element simulations and experimental verifications for forming limit curve determination of two-layer aluminum/brass sheets considering the incremental forming process

2021 ◽  
pp. 146442072110452
Author(s):  
A. Jalali ◽  
R. Hashemi ◽  
M. Rajabi ◽  
P. Tayebi
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Incremental Forming ◽  
Bottom Layer ◽  
Finite Element Simulations ◽  
Experimental Results ◽  
Forming Limit ◽  
Forming Process ◽  
Simulation Results ◽  
Aluminum 1050

In this paper, forming limit diagram (FLD) of aluminum/brass two-layer sheets through an incremental forming process (ISF) was studied numerically and experimentally. At first, the two-layer aluminum 1050/brass (65% copper) sheets were fabricated using the roll bonding process. Also, the finite element simulations of the incremental forming process with ABAQUS software were utilized to predict the FLD. For this purpose, the criterion of the second derivative of the equivalent plastic strain was used to predict fracture. Finally, the numerical simulation results were compared with the experimental results. For instance, comparing experimental and numerical FLD0 values for the formed samples with forming angle 62.5-degree showed a 7% difference. However, the difference was negligible, and numerical simulation results could be used with an appropriate reliability coefficient. The effect of sheet arrangement towards tools was then investigated. It finds out from the experimental results that the formability of the Brass/Al (brass was up layer and aluminum was bottom layer) was more than the Al/Brass (aluminum is up layer and brass is bottom layer). In the following, the ISF parameters such as forming limit angle, step-down, and thickness distribution were investigated.

Sheet Hydroforming Process Numerical Model Improvement Through Experimental Results Analysis

2010 ◽  
Author(s):  
Papadia Gabriele ◽  
Del Prete Antonio ◽  
Anglani Alfredo ◽  
F. Barlat ◽  
Y. H. Moon ◽  
...  
Keyword(s):  
Numerical Model ◽  
Experimental Results ◽  
Sheet Hydroforming ◽  
Hydroforming Process ◽  
Model Improvement

Numerical and Experimental Investigation into the Aluminum Alloy Irregular Box Sheet Hydroforming Process

2012 ◽  
Vol 602-604 ◽  
pp. 1846-1849
Author(s):  
Yong Ming Wang ◽  
Li Hui Lang ◽  
Ya Su Xie
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
Loading Path ◽  
Cavity Pressure ◽  
Pressure Loading ◽  
Flat Bottom ◽  
Sheet Hydroforming ◽  
Hydroforming Process ◽  
Simulation And Experiment ◽  
Blank Shape

Sheet hydroforming process of one irregular box with unequal height and flat bottom was investigated by numerical simulation and experiment. The effect of blank shape and pressure loading path on the forming result was discussed. The key process parameter was optimized. The results have shown that the round blank is the best shape blank. The part can be formed with the appropriate blank shape and die cavity pressure.

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.

Simulation of a Free Standing Riser Model and Validation With Experimental Results

2014 ◽  
Author(s):  
Marcio Yamamoto ◽  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Tomo Fujiwara ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Previous Experiment ◽  
Numerical Results ◽  
Experimental Results ◽  
Previous Article ◽  
Scale Model ◽  
Analysis Software ◽  
Free Standing ◽  
Reduced Scale

In this article, we present the numerical analysis of a Free Standing Riser. The numerical simulation was carried out using a commercial riser analysis software suit. The numerical model’s dimensions were the same of a 1/70 reduced scale model deployed in a previous experiment. The numerical results were compared with experimental results presented in a previous article [1]. Discussion about the model and limitations of the numerical analysis is included.

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