scholarly journals Prediction of Wrinkling of a Beverage Can Subjected to the Redrawing Process by J2 Deformation Theory

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1168
Author(s):  
Jin Jae Kim ◽  
Phu Van Nguyen ◽  
Young Suk Kim
Keyword(s):  
Deformation Theory ◽  
Effective Strain ◽  
Stress Path ◽  
Yield Locus ◽  
Design Parameters ◽  
Forming Process ◽  
Profile Angle ◽  
Classical Plasticity ◽  
The Difference ◽  
Aluminum Cans

Wrinkling of beverage cans is one of the problems faced by can manufacturers and aluminum suppliers. The bottom of an aluminum can is wrinkled by compression during the forming process. In this study, to predict the occurrence of wrinkles during the redrawing process of AA3104 (t = 0.265 mm), which is the material used to fabricate aluminum cans, the classical plasticity J2 deformation theory (J2D) and flow theory (J2F) were considered. J2F considers only the deformation perpendicular to the yield locus, whereas J2D considers the deformation perpendicular to the yield locus and that tangential to the yield locus. Wrinkles are predicted using finite element (FE) analyses based on J2D and J2F, and the results are compared. J2F could not predict the number and amplitude of wrinkles. By contrast, the wrinkles predicted using J2D exhibited good agreement with sample data obtained for a real can. To find the difference between the results obtained using J2F and J2D, evolutions of stress path in a wrinkled element are compared. It was confirmed that compressive stress is more dominant in the J2D case than in the J2F case. Moreover, the measured effective strain of the element is small, under 0.04. In conclusion, J2D is more suitable for predicting the wrinkling behavior of aluminum cans than J2F. In addition, ANOVA and ANOM analysis are performed to evaluate the influence of the design parameters, namely friction coefficient, thickness, and outer profile angle, and the parameters are optimized to reduce wrinkles by combining the Taguchi method with FE simulation based on the J2D theory.

Workspace, dexterity and dimensional optimization of microhexapod

2015 ◽  
Vol 35 (4) ◽  
pp. 341-347 ◽  
Author(s):  
E. Rouhani ◽  
M. J. Nategh
Keyword(s):  
Degrees Of Freedom ◽  
Optimization Problem ◽  
Screw Theory ◽  
Design Parameters ◽  
Dimensional Synthesis ◽  
Content Type ◽  
Workspace Analysis ◽  
The Difference ◽  
Flexure Joints ◽  
6 Degrees Of Freedom

Purpose – The purpose of this paper is to study the workspace and dexterity of a microhexapod which is a 6-degrees of freedom (DOF) parallel compliant manipulator, and also to investigate its dimensional synthesis to maximize the workspace and the global dexterity index at the same time. Microassembly is so essential in the current industry for manufacturing complicated structures. Most of the micromanipulators suffer from their restricted workspace because of using flexure joints compared to the conventional ones. In addition, the controllability of micromanipulators inside the whole workspace is very vital. Thus, it is very important to select the design parameters in a way that not only maximize the workspace but also its global dexterity index. Design/methodology/approach – Microassembly is so essential in the current industry for manufacturing complicated structures. Most of the micromanipulators suffer from their restricted workspace because of using flexure joints compared to the conventional ones. In addition, the controllability of micromanipulators inside the whole workspace is very vital. Thus, it is very important to select the design parameters in a way that not only maximize the workspace but also its global dexterity index. Findings – It has been shown that the proposed procedure for the workspace calculation can considerably speed the required calculations. The optimization results show that a converged-diverged configuration of pods and an increase in the difference between the moving and the stationary platforms’ radii cause the global dexterity index to increase and the workspace to decrease. Originality/value – The proposed algorithm for the workspace analysis is very important, especially when it is an objective function of an optimization problem based on the search method. In addition, using screw theory can simply construct the homogeneous Jacobian matrix. The proposed methodology can be used for any other micromanipulator.

Closed-Form Correlation of Buildings Energy Use With Key Design Parameters Calibrated Using a Genetic Algorithm

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Raed I. Bourisli ◽  
Adnan A. AlAnzi
Keyword(s):  
Genetic Algorithm ◽  
Closed Form ◽  
Energy Use ◽  
Building Design ◽  
Office Buildings ◽  
Design Parameters ◽  
Wide Range ◽  
Variable Function ◽  
Real Coded Genetic Algorithm ◽  
The Difference

This work aims at developing a closed-form correlation between key building design variables and its energy use. The results can be utilized during the initial design stages to assess the different building shapes and designs according to their expected energy use. Prototypical, 20-floor office buildings were used. The relative compactness, footprint area, projection factor, and window-to-wall ratio were changed and the resulting buildings performances were simulated. In total, 729 different office buildings were developed and simulated in order to provide the training cases for optimizing the correlation’s coefficients. Simulations were done using the VisualDOE TM software with a Typical Meteorological Year data file, Kuwait City, Kuwait. A real-coded genetic algorithm (GA) was used to optimize the coefficients of a proposed function that relates the energy use of a building to its four key parameters. The figure of merit was the difference in the ratio of the annual energy use of a building normalized by that of a reference building. The objective was to minimize the difference between the simulated results and the four-variable function trying to predict them. Results show that the real-coded GA was able to come up with a function that estimates the thermal performance of a proposed design with an accuracy of around 96%, based on the number of buildings tested. The goodness of fit, roughly represented by R2, ranged from 0.950 to 0.994. In terms of the effects of the various parameters, the area was found to have the smallest role among the design parameters. It was also found that the accuracy of the function suffers the most when high window-to-wall ratios are combined with low projection factors. In such cases, the energy use develops a potential optimum compactness. The proposed function (and methodology) will be a great tool for designers to inexpensively explore a wide range of alternatives and assess them in terms of their energy use efficiency. It will also be of great use to municipality officials and building codes authors.

Effect of Thickness on Mechanically Tunable Magnetic Anisotropy of FeGa Thin Films Deposited on Flexible Substrates

2015 ◽  
Vol 815 ◽  
pp. 227-232 ◽  
Author(s):  
Ying Yu ◽  
Shu Hong Xie ◽  
Qing Feng Zhan
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Effective Strain ◽  
Anisotropy Field ◽  
Saturation Field ◽  
Effective Anisotropy ◽  
Magnetostriction Constant ◽  
The Difference ◽  
Different Strains

A practical way to manipulate the magnetic anisotropy of magnetostrictive FeGa thin films grown on flexible polyethylene terephthalate (PET) substrates is introduced in this study. The effect of film thickness on magnetic properties and magnetostriction constant of polycrystalline FeGa thin films was investigated. The anisotropy field Hk of flexible FeGa films, i.e., the saturation field determined by fitting the hysteresis curves measured along the hard axis, was enhanced with increasing the tensile strain applied along the easy axis of the thin films, but this enhancement via strain became unconspicuous with increasing the thickness of FeGa films. In order to study the magnetic sensitivity of thin films responding to the external stress, we applied different strains on these films and measure the corresponding anisotropy field. Moreover, the effective magnetostriction constant of FeGa films was calculated from the changes of both anisotropy field and external strain based on the Villari effect. A Neel’s phenomenological model was developed to illustrate that the effective anisotropy field of FeGa thin films was contributed from both the constant volume term and the inverse thickness dependent surface term. Therefore, the magnetic properties for the volume and surface of FeGa thin films were different, which has been verified in this work by using vibrating sample magnetometer (VSM) and magneto-optic Kerr effect (MOKE) system. The anisotropy field contributed by the surface of FeGa film and obtained by MOKE is smaller than that contributed by the film volume and measured by VSM. We ascribed the difference in Hk to the relaxation of the effective strain applied on the films with increasing the thickness of films.

The Research on the Mechanical Property of CBF/PP Composite Board

2010 ◽  
Vol 150-151 ◽  
pp. 1063-1067
Author(s):  
Fei Fei Zhu ◽  
Zhi Li Zhong ◽  
Zong Fu Guo
Keyword(s):  
Mechanical Property ◽  
Polypropylene Fiber ◽  
Basalt Fiber ◽  
Variance Analysis ◽  
Forming Process ◽  
Composite Board ◽  
Actual Application ◽  
Wide Range ◽  
Significant Difference ◽  
The Difference

The three composite boards which were made of continuous basalt fiber (CBF) and polypropylene fiber (PP) in different fiber ratios were researched on this paper. The manufacturing forming process included blending, carding, web formation, laminating and compression molding orderly. The tension and bending properties were investigated experimentally, and then dual variance analysis was used to show the significant difference of the mechanical property in the transverse and longitudinal orientation as well the appreciable impact of different fiber ratios to the mechanical property. The results show that the difference of the tension and blending strength in the same direction, among composite boards in different fiber proportions, is about 1~10Mpa; the difference in the same fiber proportion, between transverse and longitudinal, vary within a wide range from 10Mpa to 30Mpa. The results of variance analysis have also proved the conclusion, the difference between transverse and longitudinal is more significant than the difference among different fiber proportions. In the similar study, the significance hadn’t been seen sufficiently, so this paper provides reference to the actual application of the composite board.

scholarly journals Deformation Characteristics and Microstructure Analysis of Aluminum Alloy Component with Complex Shape by Cold Orbital Forming

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 808
Author(s):  
Wei Feng ◽  
Chaoyi Jin ◽  
Jiadong Deng ◽  
Wuhao Zhuang
Keyword(s):  
Aluminum Alloy ◽  
Complex Shape ◽  
Fe Simulation ◽  
Effective Strain ◽  
Electron Back Scatter Diffraction ◽  
Main Body ◽  
Deformation Characteristics ◽  
Alloy Component ◽  
Forming Process ◽  
Orbital Forming

This work aimed to study the deformation characteristics and microstructure of AA6063 aluminum alloy component with complex shape manufactured by cold orbital forming processing. The material flowing behavior was analyzed by Finite Element (FE) simulation and forming experiments were carried out using bar blank with different lengths. The microstructure of the boss zone cut from the formed samples was observed using scanning electron microscopy (SEM) and electron back-scatter diffraction (EBSD). FE simulation and experiment results both showed the aluminum base can be formed using cold orbital forming process. The distributions of the effective strain of the component with different blank lengths were almost the same, and the effective strain was bigger at the boss and the flash as the forming finished. The material flow is complex, especially in the boss, and the folding defect was observed at the root of the boss. The distribution of Mg2Si strengthening precipitate is more homogeneous in the matrix, has a different shape, and shows directivity at different position of boss zone. The grains are elongated, and the extent is different at different positions of the boss zone after cold orbital forming, and the crystal orientation discrepancy is smaller in the component main body and bigger in the boss zone. Subsequent forming process and blank optimization need to be further researched to improve forming quality.

Study on FGH95 Superalloy Prepared by Spray Forming

2011 ◽  
Vol 337 ◽  
pp. 434-438
Author(s):  
Yi Xu ◽  
Shu Qin
Keyword(s):  
Technological Parameter ◽  
Nonmetallic Inclusions ◽  
Preparation Method ◽  
Spray Forming ◽  
Forming Process ◽  
Cylindrical Billet ◽  
Phase Size ◽  
The Difference ◽  
Cooling Velocity ◽  
Fgh95 Superalloy

FGH95 superalloy cylindrical billet was prepared by spray forming, The yield is 73.6%, porosity is 0.6%, the oxygen content is only 20ppm. Spray forming preparation method and technological parameter were illustrated. The microstructure on the different positions of billet were observed. The results show that the difference of γ′ phase size, feature and distribution depend on different cooling velocity and local temperature difference during the spray forming process. SEM of nonmetallic inclusions were observed, and XPS of nonmetallic inclusions, nozzle and adhesive were analysed, the results show that the nonmetallic inclusions were from nozzle and adhesive.

scholarly journals Rock Mass Behavior under Tunnel Widening in Asymmetric and Symmetric Modes Considering Different Shapes and Parametric Conditions

Geosciences ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 518
Author(s):  
Babar Khan ◽  
Syed Muhammad Jamil ◽  
Jung Joo Kim ◽  
Turab H. Jafri ◽  
Jonguk Kim
Keyword(s):  
Rock Mass ◽  
In Situ Stress ◽  
Design Parameters ◽  
Tunnel Widening ◽  
Tunnel Support ◽  
Mass Behavior ◽  
Rock Types ◽  
The Difference ◽  
Support Conditions

To accommodate traffic volume on roads due to ever-increasing population growth, the widening of highways and motorways is in high demand. Nevertheless, the widening of tunnels on these road networks is quite complex due to the presence of numerous rock types, in situ stress, and different widening modes. To overcome these complexities, eight different tunnel shapes were simulated under varying support conditions for asymmetric and symmetric widening. It was found that the tunnels with a round shape, such as horseshoe and semicircular with flatbed, are more effective for asymmetric widening, whereas the provision of a rounded invert in these shapes can reverse the widening option to symmetric. Furthermore, an insignificant effect of the difference in asymmetric and symmetric widening of regular tunnel shapes, such as box, rectangular, and semi-elliptical, was found. A full factorial design statistical analysis confirmed the decrease in tunnel deformation by using various tunnel support systems and showed a significant deformation difference according to monitoring locations at the tunnel periphery. The deformation difference in the case of both tunnel widening modes was also analyzed according to different design parameters. This study provides a comprehensive understanding of rock mass behavior when the widening of any underground opening is carried out.

Optimizing Roll Forming Processes with the Aid of a New Numerical Algorithm

2012 ◽  
Vol 504-506 ◽  
pp. 857-862 ◽  
Author(s):  
Ahmad Abrass ◽  
Thomas Kessler ◽  
Peter Groche
Keyword(s):  
Numerical Algorithm ◽  
Numerical Algorithms ◽  
Roll Forming ◽  
Design Parameters ◽  
Fe Model ◽  
Forming Process ◽  
Cross Sectional ◽  
Cross Sectional Profile ◽  
Sectional Profile ◽  
Roll Forming Process

For the manufacturing of large quantities of profile-shaped products, the roll forming process represents one of the most effective metal forming technologies. During this process, the sheet metal will be formed into a desired cross-sectional profile using successive pairs of forming rolls. This process is well known as a very complex process in industry because of the multiplicity of the process and design parameters. For that reason, the optimization of roll forming processes using numerical methods like the finite element method is very complex and time-consuming. In this paper, a numerical method will be introduced to accelerate the simulation and to optimize the roll forming process. The newly developed algorithm will be illustrated and validated by analyzing the roll forming process. The details of the FE-model and the numerical algorithm will be described. Furthermore, the results of the numerical simulation with and without the application of the numerical algorithms will be compared. Finally, the process will be optimized using the newly developed method.

Development of Tool Path Correction Algorithm in Incremental Sheet Forming

2014 ◽  
Vol 622-623 ◽  
pp. 382-389 ◽  
Author(s):  
Antonio Fiorentino ◽  
G.C. Feriti ◽  
Elisabetta Ceretti ◽  
C . Giardini ◽  
C.M.G. Bort ◽  
...  
Keyword(s):  
Tool Path ◽  
Error Distribution ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Correction Algorithm ◽  
Forming Process ◽  
Part Geometry ◽  
Toolpath Planning ◽  
The Difference ◽  
Tool Path Correction

The problem of obtaining sound parts by Incremental Sheet Forming is still a relevant issue, despite the numerous efforts spent in improving the toolpath planning of the deforming punch in order to compensate for the dimensional and geometrical part errors related to springback and punch movement. Usually, the toolpath generation strategy takes into account the variation of the toolpath itself for obtaining the desired final part with reduced geometrical errors. In the present paper, a correction algorithm is used to iteratively correct the part geometry on the basis of the measured parts and on the calculation of the error defined as the difference between the actual and the nominal part geometries. In practice, the part geometry is used to generate a first trial toolpath, and the form error distribution of the resulting part is used for modifying the nominal part geometry and, then, generating a new, improved toolpath. This procedure gets iterated until the error distribution becomes less than a specified value, corresponding to the desired part tolerance. The correction algorithm was implemented in software and used with the results of FEM simulations. In particular, with few iterations it was possible to reduce the geometrical error to less than 0.4 mm in the Incremental Sheet Forming process of an Al asymmetric part, with a resulting accuracy good enough for both prototyping and production processes.

scholarly journals Development of a novel high straining backward extrusion process

2018 ◽  
Vol 190 ◽  
pp. 06001 ◽  
Author(s):  
Qiang Wang ◽  
Zhimin Zhang ◽  
Xubin Li ◽  
Huifang Zhang
Keyword(s):  
Flow Direction ◽  
Effective Strain ◽  
Fibrous Tissue ◽  
Axial Direction ◽  
Extrusion Process ◽  
Backward Extrusion ◽  
New Process ◽  
Processed Sample ◽  
The Difference ◽  
Low Performance

In this study, a new method of backward extrusion is proposed. In this new process, a punch with a movable mandrel was designed. A hollow billet was firstly backward extruded and subsequently upset with the use of the punch after the mandrel returned. The extrusion and upsetting processes were successively executed in order for a higher effective strain to be imposed and a fibrous tissue flow direction to be controlled. In order for the capability of this process to be investigated, experimental and finite element (FE) methods were used. The effective strain of the final part prepared by both the conventional and the new process were compared along the bottom radial and wall axial direction respectively. In the results, it is shown that the plastic strain applied through the processed sample was approximately higher in twice the value of the sample processed via conventional backward extrusion. Consequently, this may improve the mechanical properties and anisotropy of the final products. The difference of the UTS and the TYS between radial and tangential at the bottom was less than 3%.This new process has proven to be promising for parts with a central hole at the bottom production in order for the parts low performance to be improved.

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