scholarly journals Friction Characteristics Analysis of Symmetric Aluminum Alloy Parts in Warm Forming Process

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 166
Author(s):  
Jiansheng Xia ◽  
Jun Zhao ◽  
Shasha Dou
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Process Parameters ◽  
Friction Model ◽  
Forming Process ◽  
Friction Behavior ◽  
Forming Quality ◽  
Finite Element Software ◽  
Forming Defects

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.

scholarly journals Determination of Hot Stamping Friction Coefficient of 7075 Aluminum

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1111
Author(s):  
Xiangji Li ◽  
Xu Yan ◽  
Zhiqiang Zhang ◽  
Mingwen Ren ◽  
Hongjie Jia
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Thickness Distribution ◽  
Hot Stamping ◽  
Displacement Curve ◽  
Friction Behavior ◽  
Forming Quality ◽  
Forming Defects ◽  
Force Displacement ◽  
Lubrication Conditions

Aluminum alloy hot stamping technology can improve the formability of materials and obtain parts with high dimensional accuracy. Friction behavior in the hot stamping process is very important for forming quality. Accurate friction coefficient is helpful to improve the prediction accuracy of forming defects. It is hard to obtain the friction coefficient by simple experiments due to the complicated thermal–mechanical coupling and contact conditions during the hot stamping of aluminum alloys. In order to explore the effect of friction behavior on forming quality, hot stamping experiments of 7075 aluminum alloy U-shaped parts with different lubricants were carried out. The influence of different lubricants on the force–displacement curve, material inflow, surface appearance, and thickness distribution of the formed part was analyzed. The results showed that a good lubrication effect could be obtained with the molybdenum disulfide lubricant. The friction coefficient under different lubrication conditions was obtained by using the inverse problem optimization method. Compared with the experimental results, the determined friction coefficients could accurately predict the force–displacement curves and the thickness distributions of formed parts under different lubrication conditions.

Numerical Investigation of Size Effect on Dry Friction Behavior in Micro Upsetting Process

2014 ◽  
Vol 997 ◽  
pp. 321-324
Author(s):  
Wei Zheng ◽  
Guang Chun Wang ◽  
Bing Tao Tang ◽  
Xiao Juan Lin ◽  
Yan Zhi Sun
Keyword(s):  
Friction Coefficient ◽  
Size Effect ◽  
Dry Friction ◽  
Normal Pressure ◽  
Friction Model ◽  
Strain Hardening Exponent ◽  
Forming Process ◽  
Friction Behavior ◽  
Initial Yield Stress ◽  
Coulomb’S Friction

After modifying the Wahime/Bay friction model, a new friction model suitable for micro-forming process without lubrication is established. In this model, it is shows that the friction coefficient is a function of strain hardening exponent, the normal pressure and the initial yield stress of material. Based on the experimental data, the micro-upsetting process is simulated using the proposed friction model. The simulation results are used to investigate the size effect on the dry friction behavior. It is found that the Coulomb’s friction coefficient is dropping with miniaturization of specimens when the amount of reduction is not too large.

Numerical Simulation of Temperature and Effective Strain Distribution of Aluminum Alloy in the Whole Rough Rolling Process

2014 ◽  
Vol 602-605 ◽  
pp. 326-329
Author(s):  
Bo Zhang ◽  
Xiao Ping Liang ◽  
Jun Feng Fu
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Process Parameters ◽  
Strain Distribution ◽  
Orthogonal Experiment ◽  
Effective Strain ◽  
Contact Heat ◽  
Finite Element Software ◽  
Rough Rolling

A two-dimensional finite element mathematical model of rough rolling in "1+4" hot continuous rolling of 5052 aluminum alloy was developed by using finite element software Deform, The temperature and effective strain distribution of the strip in different process parameters has been investigated in by simulating the mathematical model in different simulation conditions. The process parameters such as rolling speed, initial temperature, contact heat transfer coefficient between work roll and strip have been considered. The simulation conditions were built by the means of orthogonal experiment. The process parameters, which can make the temperature and effective strain of the strip in a relatively uniformity distribution, were achieved by analyzing the simulation results under different simulation conditions. To judge the uniformity of the temperature and effective strain distribution of the strip quantitative in different simulation conditions, standard deviation has been used as a criterion.

scholarly journals Through-Process Finite Element Modeling for Warm Flanging Process of Large-Diameter Aluminum Alloy Shell of Gas Insulated (Metal-Enclosed) Switchgear

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1784
Author(s):  
Da-Wei Zhang ◽  
Tian-Lin Shi ◽  
Sheng-Dun Zhao
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Temperature Field ◽  
Large Diameter ◽  
Outer Diameter ◽  
Fe Model ◽  
Fe Modeling ◽  
Forming Process ◽  
Forming Characteristics ◽  
Forming Defects

The large diameter metal shell component (LDMSC) is an important part of gas insulated (metal-enclosed) switchgear (GIS). The LDMSC with multi branches is filled with gas under certain pressure. The plastic forming process is an efficient approach to manufacturing the high reliability LDMSC. The warm flanging process has been widely used to form LDMSC using aluminum alloy. The forming process is characterized by local heating, and the distribution of temperature is strongly inhomogeneous. Although the wall thickness of the shell is 10 mm to 20 mm, the ratio of outer diameter to thickness is more than 40. These present some difficulties in the flanging process and result in some forming defects. Detailed forming characteristics are hard to obtain by analytical and experimental methods. Thus, the through-process finite element (FE) modeling considering heating, forming, unloading, and cooling is one of the key problems to research the manufacturing process of LDMSC. In this study, the through-process FE modeling of the warm flanging process of LDMSC using aluminum alloy was carried out based on the FORGE. The thermo-mechanical coupled finite element method was adopted in the modeling, and the deformation of the workpiece and the die stress were considered together in the modeling. A full three-dimensional (3D) geometry was modeled due to inhomogeneous distribution in all directions for the temperature field. The simulation data of local flame heating could be transferred seamlessly to the simulations of the deforming process, the unloading process, and the cooling process in the through-process FE model. The model was validated by comparison with geometric shapes and forming defects obtained from the experiment. The developed FE model could describe the inhomogeneous temperature field along circumferential, radial, and axial directions for the formed branch as well as the deformation characteristic and the unloading behavior during the warm flanging process. By using the FE model, the forming defects during the flanging process and their controlling characteristics were explored, the evolution of the temperature field through the whole process was studied, and deformation and springback characteristics were analyzed. The results of this study provide a basis for investigating deformation mechanisms, optimizing processes, and determining parameters in the warm flanging process of a large-diameter aluminum alloy shell component.

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
Keyword(s):  
Process Parameters ◽  
Orthogonal Experiment ◽  
Grey Theory ◽  
Blank Holder Force ◽  
Dynamic Regulation ◽  
Blank Holder ◽  
Forming Quality ◽  
Finite Element Software ◽  
Forming Defects ◽  
Auto Panel

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.

Simulation Study and Optimization of Process Parameters in Precision Forming of the Nut Plate

2012 ◽  
Vol 602-604 ◽  
pp. 1878-1882
Author(s):  
Xiang Bei Wang ◽  
Duo Nian Yu ◽  
Hong Yan Chang
Keyword(s):  
Finite Element ◽  
Field Distribution ◽  
Process Parameters ◽  
Strain Field ◽  
Constitutive Relationship ◽  
Stress And Strain ◽  
Forming Process ◽  
Forming Quality ◽  
Metal Material ◽  
Damage And Fracture

For researching the stress and strain field distribution and the effect of process parameters on forming quality in the precision forming process of mid-thick nut plate, this paper builds the nut plate 3d parts of precise forming finite element entity model in ABAQUS software, and then uses Johnson-cook model to describe the material constitutive relationship and metal material damage and fracture. The ALE adaptive technology has been used to control material large deformation in finite-element analysis of elastic-plastic. Based on this model, this paper analyzes the stress and strain field distribution,average pressure stress distribution and metal material plastic flow rates distribution, and the influence of the process parameters on the forming quality in the forming process.

An improved nonlinear model considering relative velocity for the friction behavior between untwisted glass-fiber tow and roller

2021 ◽  
pp. 004051752110308
Author(s):  
Yang Liu ◽  
Zhong Xiang ◽  
Xiangqin Zhou ◽  
Zhenyu Wu ◽  
Xudong Hu
Keyword(s):  
Friction Coefficient ◽  
Glass Fiber ◽  
Relative Velocity ◽  
Friction Model ◽  
Woven Fabric ◽  
Test Results ◽  
Application Process ◽  
Friction Behavior ◽  
Improved Model

Friction between the tow and tool surface normally happens during the tow production, fabric weaving, and application process and has an important influence on the quality of the woven fabric. Based on this fact, this paper studied the influence of tension and relative velocity on the three kinds of untwisted-glass-fiber tow-on-roller friction with a Capstan-based test setup. Furthermore, an improved nonlinear friction model taking both tension and velocity into account was proposed. According to statistical test results, firstly, the friction coefficient was found to be positively correlated with tension and relative velocity. Secondly, tension and velocity were complementary on the tow-on-roller friction behavior, with neither being superior to the other. Thirdly, an improved model was found to present well the nonlinear characteristics between friction coefficient and tension and velocity, and predicational results of the model were found to agree well with the observations from Capstan tests.

Analysis on Temperature Field of Work-Piece during Cross Wedge Rolling

2011 ◽  
Vol 230-232 ◽  
pp. 352-356
Author(s):  
Wen Ke Liu ◽  
Kang Sheng Zhang ◽  
Zheng Huan Hu
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Metal Flow ◽  
Work Piece ◽  
Contact Deformation ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Rigid Plastic ◽  
Finite Element Software ◽  
Deform 3D

Based on the rigid-plastic deformation finite element method and the heat transfer theories, the forming process of cross wedge rolling was simulated with the finite element software DEFORM-3D. The temperature field of the rolled piece during the forming process was analyzed. The results show that the temperature gradient in the outer of the work-piece is sometimes very large and temperature near the contact deformation zone is the lowest while temperature near the center of the rolled-piece keeps relatively stable and even rises slightly. Research results provide a basis for further study on metal flow and accurate shaping of work-piece during cross wedge rolling.

scholarly journals Design of Hydraulic Bulging Die for Automobile Torsion Beam and Optimization of Forming Process Parameters

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Kefan Yang ◽  
Youmin Wang ◽  
Kexun Fu
Keyword(s):  
Friction Coefficient ◽  
Process Parameters ◽  
Orthogonal Experiment ◽  
Die Design ◽  
Molding Pressure ◽  
Hydraulic Pressure ◽  
Forming Process ◽  
Torsion Beam ◽  
Supporting Pressure ◽  
Hydraulic Bulging

The hydraulic bulging technology of tubes can provide hollow parts with special-shaped cross sections. Its manufacturing process can effectively improve material utilization and product accuracy and reduce the number and cost of molds. However, the hydraulic bulging process of parts is very complicated. The size of the tube blank, the design of the loading route, and the forming process parameters will have an effect on the molding quality. Closed tubular torsion automobile beam is considered as the research object to study hydraulic bulging die design and optimize forming process parameters. CATIA software is used to design torsion beam product structure and hydraulic bulging die. AMESim software is employed to design hydraulic synchronous control system for cylinders on both sides of the hydraulic bulging die. Mathematical control model is established and verified in Simulink software. DYNAFORM software is applied to conduct numerical simulation of hydraulic expansion. The supporting pressure, molding pressure, friction coefficient, and feeding quantity are taken as orthogonal experiment level factors. Maximum thinning and maximum thickening rates are taken as hydraulic pressure expansion evaluation indexes to complete the orthogonal experiments. Main molding process parameters are analyzed via orthogonal experiment results and optimized by employing the Taguchi method. Optimal hydraulic bulging parameters are obtained as follows: supporting pressure of 20 MPa, molding pressure of 150 MPa, feeding quantity of 25 mm, and friction coefficient of 0.075. Simulation analysis results indicate that the maximum thinning rate is equal to 9.013%, while the maximum thickening rate is equal to 16.523%. Finally, the design of hydraulic bulging die for torsion beam was completed, and its forming process parameters were optimized.

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