Construction of a Prediction Model for an Acceptable T-Shape Tube Product in Magnesium Alloy Hydro-Forming

Author(s):  
S. Y. Lin ◽  
C. M. Chang ◽  
R. F. Shyu

The finite element method in conjunction with abductive neural network is applied to predict an acceptable T-shape product of which the minimum wall thickness and the protrusion height being fulfilled the industrial demand in the magnesium alloy hydro-forming. AZ31 magnesium alloy circular tube is used as the billet material for hydro-forming with hydraulic pressure as the main forming power combined with the mechanically auxiliary force from the punch to fabricate a qualified T-shape tubing product. Finite element software is adopted to investigate the forming characteristics of T-shape tube forming, by changing process parameters such as punch velocity, hydraulic pressure, fillet radius of the die and tool-workpiece interface friction etc. to investigate the material flow of tube forming, and the variations of wall thickness and protrusion height. And the neural network method in turn is applied to synthesize the data sets obtained from the numerical simulations and a prediction model for an acceptable T-shape tube product in magnesium alloy hydro-forming is thus constructed. From the prediction model, a suitable range of the process parameters variation for producing those qualified T-shape tubes that may be accepted in industrial applications can thus be identified.

2013 ◽  
Vol 465-466 ◽  
pp. 704-708
Author(s):  
Shen Yung Lin ◽  
Hong Yi Liao

This work presents the tube forming characteristics of a trailing arm which the whole forming processes are arranged through pre-bending twice and hydro-forming once. This work utilizes the finite element method to simulate the hydro-forming process of the trailing arm by changing the process parameters, such as velocity of left and right punches and internal hydraulic pressure, etc. The effects of process parameters on the distribution states of the tube wall-thickness, distribution of equivalent stresses and strains, and formability of the forming arm are thus investigated. Taguchi method, orthogonal array and factor response are then applied together to determine the optimal process parameter combinations corresponding to two single-quality objects, minimum tube wall-thickness and maximum equivalent stress, with nominal-the-best and smaller-the-better, respectively. It shows that the velocity of the right punch for the billet material axial feeding supplement should be larger than that of the left punch preventing the uneven bursting of the tube-wall on right-end. The analysis of variance also shows that left punch velocity is a major contribution parameter for tube wall-thickness while that primarily affects the equivalent stress is the internal pressure.


2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Wei Liang ◽  
Qiongying Lv ◽  
Lin Guan ◽  
Zhigang Xing

The paper studies the complicated problem in the spinning process of the shell with longitudinal and latitudinal inner ribs. The finite element software ABAQUS is used to establish the finite element model of the cylindrical shell with the longitudinal and latitudinal inner ribs. The numerical simulation of the spinning process is carried out. The stress distribution and strain distribution of the inner and outer surfaces during the spin-forming process are determined, and the orthogonal test method is used to determine the optimization process test parameters. The influence of the main process parameters on the wall thickness difference of the inner rib shell is obtained by the range analysis: wall thickness reduction rate > rotary wheel feed speed > rotor working angle (arranging according to their influences). And then the corresponding process parameters recommended by the spinning test are given. The measurement problem of inner ribs is solved by building of the robot shape measurement system which helps detect the three-dimensional shape of the inner ribs, and the precision of the spun sample was detected by the point cloud deviation comparison.


2007 ◽  
Vol 364-366 ◽  
pp. 973-979
Author(s):  
Shen Yung Lin ◽  
C.M. Chang ◽  
C.K. Chang

Due to the light weight and electromagnetic interference shielding capabilities in magnesium alloy material, it is widely utilized in 3C electronic components and automobile parts. However, its formability is very poor due to the phenomenon of negative strain hardening rate appearing as the deformation in large strain range, so it is usually formed as die casting or casting styles leads to much scrap, and manufacturing cost is thus increased. The objective of this study is to investigate the effect of process parameters on T-shape tube hydro-forming characteristics for magnesium alloy and it may offer the data resulting from the analysis to predict an acceptable product of tube fitting for magnesium alloy forming in industry. AZ31 magnesium alloy tube is used as the billet material for hydro-forming with hydraulic pressure as the main forming power combined with the mechanical auxiliary force from the punch to fabricate the T-shape tubing products. Finite element code DEFORM-3D is adopted to investigate the forming states of T-shape tube forming, by changing process parameters; such as punch velocity, hydraulic pressure, fillet radius of the die and tool-workpiece interface friction etc. to investigate the material flow of tube fitting, wall thickness variations, and stress and strain distributions. By qualifying the forming processes whether if it is completed or not, and synthesizing the overall analysis and judgment, we establish an admissible level of process parameter range for complete tube manufacture. The results show that suitable mechanical force can help material flow, prevent large strain deformation falling into the area of negative strain hardening rate, enhance magnesium alloy to become easy in forming and make tube fitting to be formed successfully.


Author(s):  
John Martin

The pilger process is a cold-worked mechanical process that combines the elements of extrusion, rolling, and upsetting for the formation of thin-walled tubes. This complex manufacturing process relies on the results of trial and error testing programs, experimental parameter sensitivity studies, and prototypical applications to advance the technology. This finite element modelling effort describes the methods, models, and assumptions used to assess the process parameters used to manufacture thin-walled tubing. The modelling technique breaks down the manufacturing process into smaller computer generated models representing fundamental process functions. Each of these models is linked with the overall process simulation. Simplified assumptions are identified and supporting justifications provided. This work represents proof of principle modelling techniques, using large deformation, large strain, finite element software. These modelling techniques can be extended to more extensive parameter studies evaluating the effects of pilger process parameter changes on final tube stress and strain states and their relationship to defect formation/propagation. Sensitivity studies on input variables and the process parameters associated with one pass of the pilger process are also included. The modelling techniques have been extended to parameter studies evaluating the effects of pilger process parameter changes on tube stress and strain states and their relationship to defect formation. Eventually a complex qualified 3-D model will provide more accurate results for process evaluation purposes. However, the trends and results reported are judged adequate for examining process trends and parameter variability.


2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Haibo Xie ◽  
Zhanjiang Wang ◽  
Na Qin ◽  
Wenhao Du ◽  
Linmao Qian

Abstract An integrated finite element and artificial neural network method is used to analyze the impact of scratch process parameters on some variables related to elastoplastic deformation of titanium alloy. The elastoplastic constitutive parameters applied for scratch simulations are obtained from the nanoindentation experiments and finite element analysis. The validity of the finite element model of scratch is confirmed by comparing the friction forces from simulations to those from experiments. The input parameters of the artificial neural network are three scratch process parameters: tip normal force, tip radius, and shear friction coefficient. The outputs are four variables related to material deformation measured during scratch: scratch depth, elastic recovery height, plowing height, and plowing friction coefficient. The network is trained with pairs of input and output datasets generated by scratch simulations. The prediction results of the neural network are in agreement with the finite element results. The model provides assistance for the prediction and analysis of complex relationships between scratch process parameters and variables related to material deformation, and between the plowing friction coefficient and the relevant parameters. The results show the independence of scratch depth and the shear friction coefficient, and the positive relationships between the shear friction coefficient and plowing friction coefficient.


Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 891 ◽  
Author(s):  
Guangsong Ma ◽  
Guanglin He ◽  
Yukuan Liu ◽  
Yachao Guo

To study the influence of the structural parameters of the ammunition liner of small-caliber ammunition on the forming characteristics of the projectile, an integrated circumferential multiple explosively formed projectile (MEFP) warhead with an integrated shell and the liner was initially designed, and the wall thickness of the liner is variable. LS-DYNA finite-element software is used to simulate the integral circumferential MEFP of the preliminary design, based on the numerical simulation results, the influence of the thickness at the center of the liner, and the curvature radius of the liner on the shape and velocity of the formed projectile. The numerical simulation results show that when the thickness of the center of the liner is constant and the curvature radius increases gradually, the velocity of the formed projectile decreases and the length: Diameter ratio of formed projectile decreases gradually. When the curvature radius of the liner remains unchanged, the velocity of the formed projectile decreases with the increase of the thickness of the center of the liner, and the shape of the formed projectile does not change significantly. The results show that when the design of integrating the shell and the liner was adopted for the integral circumferential MEFP warhead, the shape of the formed projectile is greatly affected by the curvature radius of the liner (curvature radius of inner and outer walls of the liner), but less by the thickness of the center of the liner. The velocity of the formed projectile is affected by the curvature radius of the inner and outer walls of the liner and the thickness of the center of the liner. Moreover, the influence of the thickness of the center of the liner on the velocity of the formed projectile is greater than that of the curvature radius of the outer wall of the liner.


2012 ◽  
Vol 271-272 ◽  
pp. 452-456
Author(s):  
Shu Feng Sun ◽  
Ping Ping Wang ◽  
Xin Wu ◽  
Sen Lin

Machining process parameters are main factors influencing machining quality and efficiency. Finite element models of tool and part are set up using finite element software Deform-3D. Variety laws of cutting force and temperature under different process parameters are simulated. The results are analyzed. Cutting force grows obviously with the growth of cutting speed (vc). However, cutting force fluctuates and decreases with the growth of cutting depth (ap) indicating the phenomenon of work hardening. Cutting force fluctuates and grows with the growth of feed rate ( f ). But the influence of feed rate ( f ) to cutting force is smaller than that of cutting speed (vc). The growths of the above mentioned three process parameters all cause the rise of temperature. Machining simulation research provides the optimum process parameters for CNC programming.


2013 ◽  
Vol 459 ◽  
pp. 455-461 ◽  
Author(s):  
Hisaki Watari ◽  
Hidemitsu Hamano ◽  
Shi Ichi Nishida ◽  
Hayato Asou

In recent several years, although production of magnesium has risen dramatically, production of magnesium alloy sheet remains still at a very low level in practical use. The major barrier to greatly increased magnesium alloy use has been in still primarily high manufacturing cost as well as poor work ability of wrought magnesium sheet alloys. One of the author has investigated in cold roll forming of magnesium alloy, however detailed forming characteristics of the wrought magnesium alloy sheets has not been clarified. The aim of the study is to confirm possibilities of practical use of wrought magnesium alloy by using told roll forming process. A three dimensional elasto-plastic analysis by finite element method (FEM) has been conducted to examine the shapes of cross section, spring back characteristics, bending strains and longitudinal membrane strain of magnesium alloy sheet and cold rolled steel sheet during forming.


2019 ◽  
Vol 956 ◽  
pp. 253-259 ◽  
Author(s):  
Zhong Ren ◽  
Xing Yuan Huang

In this study, the effect of wall thickness on the extrudate swell of plastic microtubules was investigated by using the finite element numerical method. For the traditional extrusion and gas-assisted extrusion, under the same process parameters, the extrudate swell ratios of plastic microtubules with the different wall thicknesses were all obtained. Moreover, to analyze the difference between the traditional extrusion and gas-assisted extrusion, the physical fields distributions, such as flow velocities, pressure and the stresses distributions of plastic microtubules with the different wall thicknesses under two kinds different extrusions were also obtained and compared. Numerical results show that, for the traditional extrusion, the extrudate swell ratio decreases with the increasing of the wall thickness, but for the gas-assisted extrusion, the swell ratios are equal to 0 and not changed. In addition, from the viewpoints of physical fields distributions, for the traditional extrusion, with the increasing of the wall thickness, the velocities, pressure and stresses of melt are all decreased, which result in the reducing of the extrudate swell phenomenon. However, for the gas-assisted extrusion, the X velocity, pressure, and stresses are all equal to 0, which results in the elimination the extrudate swell phenomenon of plastic microtubules.


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