Dynamically Regulate and Control Complicated Auto Panel Uniform Forming

2011 ◽  
Vol 239-242 ◽  
pp. 1543-1551
Author(s):  
Mao Yu Zhao ◽  
Qian Wang Chen ◽  
Ke Min Xue ◽  
Ping Li

A complicated auto panel forming is nonuniform plastic course and it is critical for dynamic reasonable the process parameters to avoid and decrease non-crackle, non-wrinkle, thickness uniformity forming defects. So, the forming of auto panel right beam is simulated by finite element software while the blank holder force and depth, die radius, punch radius of draw bead are independent variables, acquiring forming quality object (the data about the crack, winkle and the thinning)by orthogonal experiment. And the weight of multi-object is calculated by analytic hierarchy process, the grey relational generating and the grey rational grade of multi-objective are all calculated by the grey theory system while forming course is subdivision.Then, the dynamic optimization process parameters of blank holder force and draw bead restrain force are attained. Furthermore, employing the dynamic regulation-control optimization data to numerically simulate the auto panel forming. The conclusion demonstrates that the forming quality is obviously increased by the optimized process parameters.

2016 ◽  
Vol 851 ◽  
pp. 163-167
Author(s):  
Dong Yan Lin ◽  
Yi Li

The hydroforming process of the aluminum alloy panel was simulated by the software DYNAFORM. The effects of process parameters (blank holder force, depth of panel and height of draw bead) on springback of the aluminum alloy were investigated. The max springback of the panel was analyzed by weighted scoring method. Then the process parameters were synthetically optimized for the max positive and negative springback. The results showed that the height of draw bead affects obviously the comprehensive springback of the panel. The optimization of the process parameters obtained by the orthogonal experiment can effectively reduce the max springback of the panel.


Author(s):  
Lei Li ◽  
Haihong Huang ◽  
Fu Zhao ◽  
Xiang Zou ◽  
Qi Lu ◽  
...  

Studies have indicated that reducing the process energy demand is as important as improving the energy conversion efficiency to make manufacturing equipment more energy efficient. However, little work has been done to understand the energy demand characteristics of the widely employed drawing process. In this paper, the energy demand of the cylindrical drawing process under a range of operating parameters was measured and analyzed. Since any energy saving efforts should not have negative effects on the product quality, the forming quality of the drawn part indicated by the maximum thinning and thickening ratios and variation of thickness was also considered. To identify the main contributors to energy demand and forming quality, two sets of experiments were designed based on the Taguchi method. The first set of experiments include three parameters (i.e., punch velocity, blank holder force, and drawn depth) at three levels, while the second set of experiments only include two factors (i.e., punch velocity and blank holder force) at three levels due to their impacts on the forming quality. Analysis of variance (ANOVA) and analysis of means (ANOM) were then used to analyze the experimental results. Finally, grey relational analysis (GRA) was used to reveal the correlation between the forming quality and the process energy. Results show that the mean thickness variation has the strongest relational grading with the process energy, which suggests that the process energy can be used as an effective indicator to predict mean thickness variation of the drawn part. The identified characteristics of the process energy and the forming quality can be used to select process parameters for reduced energy demands of drawing processes.


Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 166
Author(s):  
Jiansheng Xia ◽  
Jun Zhao ◽  
Shasha Dou

There are many typical symmetric large plastic deformation problems in aluminum alloy stamping. Warm stamping technology can improve the formability of materials and obtain parts with high-dimensional accuracy. Friction behavior in the stamping process is significant for the forming quality. An accurate friction coefficient is helpful in improving the prediction accuracy of forming defects. It is hard to obtain a unified and precise friction model through simple experiments due to the complicated contact conditions. To explore the effect of friction behavior on the forming quality, warm friction experiments of the AA6061 aluminum alloy and P20 steel with different process parameters were carried out using a high-temperature friction tester CFT-I (Equipment Type), including temperatures, the interface load, and sliding speeds. The variation curves of the friction coefficient with various parameters were obtained and analyzed. The results show that the friction coefficient increases with temperature and decreases with the sliding speed and load. Then, the influences of process parameters on the surface morphology of the samples after friction were observed by an optical microscope; adhesive wear occurred when the temperature increased, and the surface scratch increased and deepened with the increase in the load. Finally, the friction coefficient models of the speed and load were established by analyzing the data with Original software. Compared with the experimental and the finite element analysis results of the symmetrical part, the errors of the velocity friction model in thickness and springback angle are less than 4% and 5%, respectively. The mistakes of the load friction model are less than 6% and 7%, respectively. The accuracy of the two friction models is higher than that of the constant friction coefficient. Therefore, those coefficient models can effectively improve the simulation accuracy of finite element software.


2012 ◽  
Vol 455-456 ◽  
pp. 1122-1127
Author(s):  
Xiang Wu Jia ◽  
Shu Gen Hu

Taking example for U-shape sheet metal, the paper studies the forming and springback process with Dynaform, how much the springback influenced by several factors is studied, including die figure, stamping velocity, the stroke, the blank holder force and friction. Then a useful conclusion can be reached: Using die figure to optimize the technological parameters remarkably reduce the springback value, it provides a new method to control and solve the springback issue.


2013 ◽  
Vol 631-632 ◽  
pp. 649-659
Author(s):  
Mao Yu Zhao ◽  
Qian Wang Chen

A suitable match of annealing process parameters is critical for obtaining the fine microstructure of material. Low carbon low alloy steel (20CrMnTi) was heated for various durations near Ac temperature to achieve fine pearlite and ferrite grains. Annealing temperature and time were used as independent variables, and material property data were acquired by orthogonal experiment under intercritical annealing followed by subcritical annealing process (IASAP). The weights of plasticity (hardness, yield strength, section shrinkage, and elongation) of annealing material were calculated by analytic hierarchy process, and then the process parameters were optimized by using the grey theory system. The results observed by SEM images show that the optimized material microstructure consists of refining and distributing uniformly ferrite-pearlite grains, and smaller lamellar cementites. Morphologies on tension fracture surface of the optimized material indicates that the numbers of dimple fracture show more finer toughness obviously comparing with other annealing materials. Moreover, the yield strength value of the optimized material decreases apparently measured by tensile test. Thus, the new optimized strategy is accurate and feasible.


2021 ◽  
Author(s):  
Huiting Wang ◽  
Jianfei Kong ◽  
Hongbo Pan ◽  
Jinxiu Fang ◽  
Xiaohui Shen

Abstract This study focus on the effects of the key process parameters during a modified hydrodynamic deep drawing utilizing a combined floating and static die cavity (HDDC). A two-stage hydraulic loading path is recommended in the novel process, and each stage of the hydraulic loading path is a linear loading path with an inflection point. The method to evaluate the wrinkle and forming dimension precision of the formed parts is introduced at first. Then the influence of the key parameters of the two-stage hydraulic loading path as well as the blank holder force on the dimension accuracy and surface quality of the formed parts was studied in detail. The results showed that the influence of the liquid pressure during the second stage is more significant than that in the first stage in hydrodynamic deep drawing utilizing a combined floating and static die cavity. The initial pressure of the second stage and the maximum pressure arriving moment during this stage have a significant impact on the dimensional accuracy of the formed parts, and the smaller initial pressure or the later the maximum pressure of the second stage arrives, the higher the accuracy of the formed part is. Similarly, the influence of the blank holder force in the second stage on the forming accuracy is more significant than that in the first stage.


2011 ◽  
Vol 291-294 ◽  
pp. 335-338
Author(s):  
Ying Tong

According to the shape character of some one automobile inner panel of front fender the forming steps characterized by some process combined was brought forward. Based on FEM software the drawing process was simulated by a blank-holder force scheme 100000N, 200000N, 300000N. As the simulation results, in order to eliminate the fractures in diagonal reinforcements, it is infeasible only to decrease blank-holder force, but enlarging the die round corner is necessary. As fractures have been eliminated, in order to eliminate wrinkles, the blank-holder force needs to be increased. Otherwise the wrinkle region can be confined into useless area which needs to be cut off. Finally none forming defects occur as blank-holder force 300000N and die round corner 5mm.


2012 ◽  
Vol 579 ◽  
pp. 32-41
Author(s):  
Tung Sheng Yang ◽  
Jen Chuan Yeh ◽  
Sheng Yi Chang

This study applies the finite element method (FEM) in con-junction with an abductive network to predict springback’s angle during the U-shaped bending process with counter force. To verify the prediction of FEM simulation for springback, the experimental data are compared with the results of current simulation. Bending force, effective stress distribution and springback are investigated for different process parameters, such as profile radius of die, blank holder force and counter force of U-shaped bending process, by finite element analysis. The abductive network is then utilized to synthesize the data sets obtained from numerical simulations. Finally, prediction model is established for predicting springback’s angle under a suitable range of process parameters.


1993 ◽  
Vol 115 (1) ◽  
pp. 110-117 ◽  
Author(s):  
S. A. Majlessi ◽  
D. Lee

The deep drawing process of square and rectangular shells were investigated under different process conditions, and using two different drawing quality steels. The main objective was to identify the significance of some of the process parameters on the outcome of the drawing operation. The process parameters examined were shape and size of blank, the blank-holder force and frictional condition between blank and tooling. The results of this investigation were presented in terms of punch load, through thickness and in-plane strain distributions, formations of flange wrinkles and fracture, and the largest possible blank size that can be drawn successfully. Some of these experimental results were used to verify the validity of a simplified analytical model which was described in the first part of this paper.


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