scholarly journals Research of the wrinkling elimination of stainless steel SUS304 by viscous pressure

2019 ◽  
Vol 39 (2) ◽  
pp. 141-147
Author(s):  
Tiejun Gao ◽  
Xiaojun Liu ◽  
Hepeng Zhang ◽  
Kun Yu
Keyword(s):  
Stainless Steel ◽  
Sheet Metal ◽  
Evaluation Method ◽  
Elimination Rate ◽  
Viscous Medium ◽  
Forming Process ◽  
Forming Precision ◽  
Viscous Pressure ◽  
Buckling Test ◽  
Viscous Pressure Forming

Wrinkling is one of the most important factors influencing a forming precision of sheet metal, which brings difficulties to the forming process of sheet metal. In order to eliminate the wrinkling during the forming process, an accurate prediction is necessary. In this paper, the wrinkling elimination process was investigated based on the principle of the Yoshida Buckling Test (YBT) and viscous pressure forming. The experimental device was designed, and evaluation method of the wrinkling elimination rate was presented by the stainless steel SUS304. On this basis, the wrinkling elimination experiment was carried out, the influences of both the viscous medium molecular weight and the tensile state of wrinkle under the viscous pressure on the wrinkling elimination were obtained.

Effect of Loading Location of Viscous Medium on Sheet Deformation in Viscous Pressure Bulge (VPB) Test

2010 ◽  
Vol 154-155 ◽  
pp. 775-780
Author(s):  
Jian Guang Liu ◽  
Zhong Jin Wang ◽  
Qing Yuan Meng ◽  
Yu Long Zheng
Keyword(s):  
High Pressure ◽  
Sheet Metal ◽  
Deformation Behavior ◽  
Central Zone ◽  
Viscous Medium ◽  
Dome Height ◽  
Loading Mode ◽  
Viscous Pressure ◽  
Viscous Pressure Forming ◽  
Sheet Deformation

Viscous pressure forming (VPF) uses a highly viscous but flowable material as pressure-carrying medium (PCM). Due to the relative low flowability of viscous medium compared with fluid, nonuniform pressure distribution in viscous medium can be used to control and regulate the deformation sequence of the workpiece through controlling the loading mode of viscous medium. In the present study, viscous pressure bulge (VPB) tests with three kinds of loading location of viscous medium (central zone, corner zone and the whole deformation zone) are conducted and the influences of loading location of viscous medium on sheet deformation behavior are investigated via numerical simulations and experiments. It is found that changing the loading location of viscous medium can greatly affect the deformation behavior of sheet metal. When the viscous medium is injected from the die corner zone, a local high pressure formed at the corner zone of sheet metal and a higher limiting dome height and strains are obtained.

Research on Formability of Aluminum Alloy 2024 Sheet by Viscous Pressure Forming

2013 ◽  
Vol 634-638 ◽  
pp. 2872-2876 ◽  
Author(s):  
Tie Jun Gao ◽  
Yao Wang ◽  
Jian Guang Liu ◽  
Zhong Jin Wang
Keyword(s):  
Aluminum Alloy ◽  
Pressure Field ◽  
Thickness Distribution ◽  
Viscous Medium ◽  
High Rate ◽  
Forming Process ◽  
Aluminum Alloy 2024 ◽  
Viscous Pressure ◽  
Flexible Die ◽  
Viscous Pressure Forming

Viscous pressure forming(VPF) using a semi-solid, flowable, highly viscous and certain rate sensitive macromolecule polymer as the forming flexible-die is a good forming method for high strength, low plasticity, complex sheet metal parts. In this paper, the bulging process of aluminum alloy 2024 sheet is carried out by combining methods of experiments with numerical simulation. Influences of viscous medium properties on the geometry of bulging specimens, thickness distribution and the pressure field of viscous medium are analyzed, and the limit bulging heights of aluminum alloy 2024 sheets are obtained. The research results show that choosing viscous medium with high rate sensitivity in the forming process can increase the non-uniformity of viscous pressure field, improve the viscous pressure bulging property of aluminum alloy 2024 sheet, and ameliorate the distribution uniformity of wall thickness of bulging specimens.

Blank holder force (BHF) control in viscous pressure forming (VPF) of sheet metal

2000 ◽  
Vol 98 (1) ◽  
pp. 7-16 ◽  
Author(s):  
Leonid B Shulkin ◽  
Ronald A Posteraro ◽  
Mustafa A Ahmetoglu ◽  
Gary L Kinzel ◽  
Taylan Altan
Keyword(s):  
Sheet Metal ◽  
Blank Holder Force ◽  
Blank Holder ◽  
Viscous Pressure ◽  
Viscous Pressure Forming

Application of Viscous Pressure Forming in Aeronautics and Astronautics

2014 ◽  
Vol 989-994 ◽  
pp. 3306-3309
Author(s):  
Ji Guang Li ◽  
Jie Gang Zhang ◽  
Jing Ping Liu ◽  
Rui Feng Zhao ◽  
Yang Li ◽  
...  
Keyword(s):  
Basic Principle ◽  
High Strength ◽  
Thin Wall ◽  
Forming Process ◽  
Variable Diameter ◽  
Thin Walled ◽  
Viscous Pressure ◽  
Viscous Pressure Forming ◽  
Thin Wall Part ◽  
Super Alloy

Viscous pressure forming (VPF) is a new developed sheet soft-punch forming process in 1900s. The basic principle and characteristics of VPF are described. The applications of VPF technologies of nickel-based super-alloy corrugated thin-walled part, asymmetrical thin-wall part with variable diameter, super-alloy thin-walled part with variable diameters, corrugated thin-walled part with larger diameter and small section are presented. The results show that VPF is suitable for the forming of parts with high strength, low plasticity, super thin-wall and complex shaped.

Research on Formability of Aluminum Alloy Automotive Panels by Using Viscous Pressure Forming

2014 ◽  
Vol 939 ◽  
pp. 355-360
Author(s):  
Yi Li ◽  
Zhong Jin Wang ◽  
Dong Yan Lin ◽  
Yan Ping Li
Keyword(s):  
Aluminum Alloy ◽  
Viscous Medium ◽  
Rigid Punch ◽  
Sheet Blank ◽  
Automotive Panels ◽  
Viscous Pressure ◽  
Viscous Pressure Forming

The viscous pressure forming (VPF) was applied to form an automotive aluminum alloy panel in this paper. The formability of the panel was investigated. Further, the springback characteristics of the panel were analyzed. The results show that the viscous medium is helpful to improve the flow of the sheet blank. The positive and negative springback occur for the panel formed by VPF. It is different from the panel formed by rigid punch forming, in which only the positive springback occurs. Furthermore, the springback value of the panel formed by VPF is smaller than the latter.

scholarly journals A Novel Approach to Predict Wrinkling of Aluminum Alloy During Warm/Hot Sheet Hydroforming Based on an Improved Yoshida Buckling Test

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1165 ◽  
Author(s):  
Gaoshen Cai ◽  
Jubo Fu ◽  
Dongxing Zhang ◽  
Jinlin Yang ◽  
Yongfeng Yuan ◽  
...  
Keyword(s):  
Normal Stress ◽  
Sheet Metal ◽  
Fluid Pressure ◽  
Prediction Method ◽  
Forming Process ◽  
Tensile Direction ◽  
Sheet Hydroforming ◽  
Novel Approach ◽  
Metal Forming Process ◽  
Buckling Test

In order to predict the wrinkling of sheet metal under the influence of fluid pressure and temperature during warm/hot hydroforming, a numerical simulation model for sheet wrinkling prediction was established, taking into account through-thickness normal stress induced by fluid pressure. From simulations using linear and quadratic elements, respectively, it was found that the latter gave results that were much closer to experimental data. A novel experimental method based on an improved Yoshida Buckling Test (YBT) was proposed for testing the wrinkling properties of sheets under the through-thickness normal stress. A wrinkling coefficient suitable for predicting wrinkling was also presented. Based on the numerical simulations, an experimental validation of wrinkling performance was conducted. Ridge-height curves measured along the main diagonal tensile direction of the sheet were presented and showed that the wrinkling prediction criterion provided good discrimination. Furthermore, the wrinkling properties of several different materials were simulated to evaluate the accuracy of the prediction method, and the results revealed that the improved YBT gave good predictions for wrinkling in the conventional sheet metal forming process, while the prediction results for wrinkling in warm/hot sheet hydroforming were also accurate with the fluid pressure of zero.

Theoretical Prediction of Sheet Metal Wrinkling Based on the Potential Function Analysis

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Yixi Zhao ◽  
Xumin Wan ◽  
Leitao Gao ◽  
Qingshuai Kong ◽  
Zhongqi Yu
Keyword(s):  
Prediction Model ◽  
Potential Function ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Function Analysis ◽  
Energy Criterion ◽  
Forming Process ◽  
Flange Wrinkling ◽  
Buckling Test

The wrinkling research in sheet metal forming process has always been one of the most common hot topics. There are many methods to predict the sheet metal wrinkling while it is still difficult to accurately predict the initiation of wrinkling. The variational study of the potential function can be used to analyze the sheet metal wrinkling and acquire the stable energy criterion. In this paper, the sheet metal wrinkling mechanisms are explained in detail, and a wrinkling prediction model is proposed based on derivation and the potential function analysis during sheet metal forming processes. Meanwhile, the finite element (FE) simulation and experimental results of Yoshida buckling test (YBT) are used to verify the accuracy of the theoretical wrinkling prediction model. And the wrinkling prediction model has also applied to analyze the conventional spinning forming process, and the critical moment of flange wrinkling had been accurately predicted.

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