ORIGINAL_ARTICLE
Mathematical Analysis of Shearing Viscoelastic Beam
Subjected to Continuous Moving Load
In this paper, the dynamic response of a viscoelastic beam subjected to a moving distributed load has been studied. The viscoelastic properties of the beam have been considered as linear standard model in shear and incompressible in bulk. The stress components have been separated to the shear and dilatation components and as a result the governing equations in viscoelastic form has been obtained using direct method. These equations have been solved by the eigenfunction expansion method. In this research, according to the introduced dimensionless coefficients, a parametric study has been presented and the effects of the load velocity and viscoelastic materials have been investigated. The obtained results show the maximum decay corresponds to the cases that the first natural period equals totimes that the relaxation time.
http://jsme.iaukhsh.ac.ir/article_515396_9085dbda2fa91ea951803748f3cc1bfa.pdf
2010-06-22
1
10
Viscoelastic beam
Moving load
Mathematical analysis
Linear standard model
Mohammad
Tehrani
1
M.Sc. Graduated, Shahrood University of Technology
AUTHOR
H.R.
Eipakchi
eipakchi@shahroodut.ac.ir
2
Assistant Professor, Shahrood University of Technology
LEAD_AUTHOR
[1] HUANG C. C., Forced motions of viscoelastic cylindrical, Journal of Sound and Vibration,39(3), 1975, pp. 273-286.
1
[2] HUANG C. C., Forced motions of viscoelastic thick cylindrical shell, Journal of Sound and Vibration, 45(4), 1976, pp. 529-537.
2
[3] HUANG C. C., Moving loads on viscoelastic cylindrical shells, Journal of Sound and Vibration, 60(3), 1978, pp. 351-358.
3
[4] Fung R.F., Hang J. and Echen W., Dynamic stability of a viscoelastic beam subjected to harmonic and parametric excitations simultaneously, Journal of Sound and Vibration, 198, 1996, pp. 1–16.
4
[5] Karnaukhov V. G., Kirichok I. F., Vibrations and dissipative heating of a viscoelastic beam under a moving load , Journal of Sound and Vibration ,41(1), 2005, pp. 49 – 55.
5
[6] Kocatürk T., Şimşek M., Vibration of viscoelastic beams subjected to an eccentric compressive force and a concentrated moving harmonic force, Journal of Sound and Vibration, 291, 2006, pp. 302–322,
6
[7] Kocatürk T., Şimşek M., Dynamic analysis of eccentrically prestressed viscoelastic Timoshenko beams under a moving harmonic load , Computers and Structures , 84, 2006, pp. 2113–2127.
7
[8] Şimşek M., Kocatürk T., Nonlinear dynamic analysis of an eccentrically prestressed damped beam under a concentrated moving harmonic load, Journal of Sound and Vibration, 320, 2009, pp. 235–253.
8
[9] Mofid M., Tehranchi A., Ostadhossein A., On the viscoelastic beam subjected to moving mass, Advances in Engineering Software, 41, 2010, pp. 240-243.
9
[10] Fryba L., Vibration of solids and structures under moving loads., The Netherlands Noordhoff International, 1972.
10
[11] Riande E., Calleja R.D., Prolongo M.G., Masegosa R.M., Salom C., Polymer viscoelasticity stress and strain in practice, Marcel Dekker INC, 2000.
11
ORIGINAL_ARTICLE
Numerical Investigations on the Effect of Pulsating Pressure on Improvement of Formability in Hydroforming of Bent Tube by FEM
In this paper, hydroforming process of bent tubes in T-shaped die is studied for pulsating and linear pressure paths by the finite element method. Forming Limit Diagrams (FLDs) and thickness distribution curves are used to investigate the effect of pulsating pressure on hydroforming process. In addition, the obtained numerical results are compared with experimental results of hydroforming of straight tubes with T-shape protrusions. Itis shown that for tubes with similar bend radius and diameter of bent tube, the formability increases by linear pressure which means pulsating pressure is not so effective. But in the bent tubes whith bend radius larger than tube diameter, pulsating pressure improves formability in hydroforming process. Also, it is found that in hydroforming the pulsating pressure can not increase formability in any bent tube case. In some cases the linear pressure path is more effective for formability.
http://jsme.iaukhsh.ac.ir/article_515397_f6b6ed7a718ce50a2df881b04bd9aaf0.pdf
2010-06-22
11
20
Hydroforming
Bent tube
Finite Element Method
pulsating pressure
Formability
Amir
Khorsandi
1
Lecturer, Mechanical Engineering Department, Islamic Azad University, Khomeinishahr Branch
AUTHOR
Mohsen
Loh-Mousavi
loh-mousavi@iaukhsh.ac.ir
2
Assistant Professor , Mechanical Engineering Department, Islamic Azad University, Khomeinishahr Branch
LEAD_AUTHOR
[1] Mac Donald B.J., Hashmi M., Near-Net-Shape Manufacture of Engineering Components using Bulge-Forming Process , J. Mater. Process. Technol., Vol. 120, 2002, pp. 341-347.
1
[2] www.opton.co.jp.
2
[3] Mori K., Patwari A.U., Maki, S. , Improvement of formability by Oscillation of Internal pressure in pulsating hydroforming of Tube, Annals of the CIRP, 53-1 (2004), pp. 215-218.
3
[4] Loh-Mousavi M., Bakhshi-Jooybari M., Mori K., Hyashi K., Improvement of formability in T-shape hydroforming of tubes by pulsating pressure, Key Engineering Materials , Vol. 222, 2008, pp. 1139-1146.
4
[5] Strano M., Jirathearanat S., Altan T. ,Adaptive FEM Simulation for Tube Hydroforming:a Geometry-Based Approach for Wrinkle Detection, The Ohio State University, Columbus, USA, 2001.
5
[6] TranaK. , Finite element simulation of the tube hydroforming process – bending, performing and hydroforming , Journal of Materials Processing Technology, 127, 2002, pp. 401–408.
6
[7] Loh-Mousavi M. ,Bakhshi-jooybari M., Mori K., Maeno T. , Farzin M., Hosseinipoor S.J. , 3-D Finite element simulation of pulsating free bulge hydroforming of tubes, Iranian Journal of Science & Technology, Vol. 32, No. B6, 2008, pp 611-618.
7
[8] Kim J., Kim S.W., Song W. J., Kang B. S., Analytical and numerical approach to prediction of forming limit in tube hydroforming , Int. J. of Mechanical Sciences, Vol. 47, 2005, pp. 1023-1037.
8
[9] Singh H., Fundamentals of hydroforming, Society of Manufacturing Engineers, 2003.
9
ORIGINAL_ARTICLE
Inverse Identification of Circular Cavity in a 2D Object via Boundary Temperature Measurements Using Artificial Neural Network
In geometric inverse problems, it is assumed that some parts of domain boundaries are not accessible and geometric shape and dimensions of these parts cannot be measured directly. The aim of inverse geometry problems is to approximate the unknown boundary shape by conducting some experimental measurements on accessible surfaces. In the present paper, the artificial neural network is used to solve these kinds of problems in conduction heat transfer in 2D objects. In order to train the neural network, some direct problems are solved by using the finite element method. In order to evaluate the applicability of the proposed method, different cases with different number of measuring points and different error levels are examined. The results show that the ANN can effectively be used in solving inverse geometry problems in heat conduction.
http://jsme.iaukhsh.ac.ir/article_515420_3f3a3eeddb1d1e7724bf09c1eb364684.pdf
2010-06-22
21
30
Shape identification
Inverse heat transfer
Neural network
Finite Element Method
Mohammad Amin
Ahmadfard
1
M.Sc. Student, Islamic Azad University, Shiraz Branch
AUTHOR
Mohammad Javad
Kazemzadeh-parsi
mjk@iaushiraz.net
2
Assistant Porfessor, Islamic Azad University, Shiraz Branch.
LEAD_AUTHOR
Ali Reza
Tahavvor
3
Assistant Porfessor, Islamic Azad University, Shiraz Branch
AUTHOR
[1] Ferreira M.D.C., Venturini W.S., Inverse analysis for two-dimensional structures using the boundary element method, Advances in Engineering Software, 41, 2010, pp. 1061-1072.
1
[2] Mera N.S., Elliott L., Ingham D.B., , Numerical solution of a boundary detection problem using genetic algorithms, Engineering Analysis with Boundary Elements, 28, 2004, pp. 405-411.
2
[3] Mehrjoo M., Khaji N., Moharramiand H., Bahreininejad A., Damage detection of truss bridge joints using Artificial Neural Networks, Expert Systems with Applications, 35, 2008, pp. 1122-1131.
3
[4] Park G., Park S., and Kim J. , Estimating the existence probability of cavities using integrated geophysics and a neural network approach, Computers & Geosciences, 36, 2010,pp. 1161-1167.
4
[5] Liu S.W., Huang j.h., Sung J.C., Lee. C., , Detection of cracks using neural networks and computational mechanics, Computer Methods in Applied Mechanics and Engineering, 191, 2002, pp. 2831-2845.
5
[6] Gupta S., Ray A., Keller E., Symbolic time series analysis of ultrasonic data for early detection of fatigue damage , Mechanical Systems and Signal Processing, 21, 2007, pp. 866-884.
6
[7] Hsieh C. K.,Kassab. A. J., A general method for the solution of inverse heat conduction problems with partially unknown system geometries, International Journal of Heat and Mass Transfer, 29, 1986, pp. 47-58.
7
[8] Darabi A., Maldague X., , Neural network based defect detection and depth estimation in TNDE, NDT ,35, 2002, pp. 165-175
8
[9] Mera N. S. , Elliott L. , Ingham D. B., , the use of neural network approximation models to speed up the optimization process in electrical impedance tomography, Computer Methods in Applied Mechanics and Engineering, 197, 2007, pp. 103-114
9
[10] Mera N. S., Elliott L. , Ingham D. B., Detection of subsurface cavities in IR-CAT by a real coded genetic algorithm, Applied Soft Computing, 2, 2002, pp. 129-139
10
[11] Rus G., Gallego R., Optimization algorithms for identification inverse problems with the boundary element method, Engineering Analysis with Boundary Elements, 26, 2002, pp. 315-327.
11
[12] Chamekh A., BelHadjSalah H. , Hambli R. , Gahbiche A. , Inverse identification using the bulge test and artificial neural networks, Journal of Materials Processing Technology, 177, 2006, pp. 307-310.
12
[13] Hagan M., Demuth H. B., Beale M. , Neural Network Design, PWS. pub. Co., Dec. 1995, pp. 66-79.
13
ORIGINAL_ARTICLE
An Experimental Study on Effects of Hot Plate Welding Parameters
on Toughness Energy and Tensile Strength in Weld Line
of Thermoplastic Parts
Integral production of the thermoplastic parts with complicated geometric shapes by the processes such as injection molding and extrusion is not economical. It is better to divide the final shape into more simple parts and after production join them by an appropriate welding process. This research aims to study the tensile strength and toughness energy of high- density polyethylene parts which have been welded in different temperatures, pressures and times using hot plate method. The standard samples are separated from the welded samples by using the laser cutting device according to the tension standard ASTM D638-1 and then tested by the tension device. The results show that the tensile strength of welded parts is less than, and the toughness energy is more than not welded parts. Also, the tensile strength and the toughness energy increase with increasing the time and maintenance temperature. However, increasing the pressure causes the molten material between the two parts come out and overflow into the part edges. This results in decreasing the tensile strength and the toughness energy of the weld line.
http://jsme.iaukhsh.ac.ir/article_515421_9f10cd96963fe62d2e9ad796b7786a3e.pdf
2010-06-22
31
40
Hot plate welding
Thermoplastics
High-density polyethylene
Tensile strength
Toughness energy
Amir
Hooshmandpoor
1
M.Sc., Manufacturing Department, Graduated School Faculty, Islamic Azad University, Dezful Branch
AUTHOR
abdol Mohammad
Rezavand
rezavand@iaud.ac.ir
2
Assistant Professor, Manufacturing Department, Graduated School Faculty, Islamic Azad University, Dezful Branch
LEAD_AUTHOR
Mehdi
Nazari Marveyan
3
Lecturer, Mechanical Engineering, Emam Hossein University, Tehran.
AUTHOR
[1] Astoks V., Toward weld strength data base for hot tool welding of Thermoplastics, Society of Plastics Engineering, 2000, pp. 1058-1063.
1
[2] Troughton Michael, Handbook of Plastic Joining, United States of America, 2008,
2
[3] Lin T.T. , Benatar., A Effect of hot plate welding parameters on the weld strength of polypropylene, ANTEC, 12, Society of Plastics Engineering conference proceedings, 1993, pp. 961-966.
3
[4] Potente H. , Tappe P., Scale- up laws in heated tool butt welding of HDPE , Polymer Engineering and Science,Vol. 29, 1989, pp.876-881.
4
[5] Stokes V.K., Joining methods for plastics and plastics composites: an overview, Polymer Engineering and Science, Vol. 29, 1989, pp. 546-551.
5
[6] Yousefpour Ali, Hojjati Mehdi ,Pierre Immarigeon - Jean., Fusion bonding/welding of thermoplastic composites., SAGE Journal of Thermoplastics Composites Materials, Vol. 17, 2004 , pp. 303-341.
6
[7] Bucknell, C., Hot plate welding of plastics: factor affecting weld strength, Polymer Engineering and Science, Vol. 20, 1980,pp.653-660.
7
[8] Potente H., Improved efficiency by high temperature heated tool welding, Welding in the World, Vol. 17, 1979, pp. 456-461.
8
[9] John P., Heated plate welding of HDPE pipes at low ambient temperature, Welding in the world, Vol. 20, 1982, pp.1251-1258.
9
[10] Lyashenko V., The butt fusion welding of thermoplastics tubes in winter conditions, welding Production, Vol. 12, 1975, pp. 325-332.
10
[11] Poopat Bovornchok, Yuan Chung, Benatar Avraham, Optimization of Contact Hot Plate Welding of HDPE, Society of Plastics Engineering, 1999, pp. 1386-1390.
11
[12] Yuan Chun, Poopat Bovornchokg and Benatar Avraham, Hot plate welding of polypropylene and talc reinforced polypropylene composites, Society of Plastics Engineering, 1999, pp 1396-1402.
12
[13] Oliver MJ, Duarte FM, Tchalamov and Cunho Am, Hot plate welding of Glass Reinforced Polypropylenem, Society of Plastics Engineering, 2001, pp. 396-340.
13
[14] Kagan VAL. Optimized Mechanical Performance of and Molded Butt Joints- Part II – Weld and Knit Lines Integrity., SAGE Journal of Reinforced plastic and Composits, Vol. 22, 2003, pp. 867-879.
14
[15] Mokhtarzadeh Abbass, Benatar Avraham, Expepiments in Hot Plate Welding of Polypropylene Nanocomposites, Society of Plastics Engineering, 2004, pp. 1168-1172.
15
]16[ باقری، ر.، مبانی خواص مکانیکی پلاستیکها، جهاد دانشگاهی دانشگاه صنعتی اصفهان، 1384 ، صص
16
115 - 120.
17
ORIGINAL_ARTICLE
Study the Effects of Nano Fluid as a Coolant in Milling Process for Improving Machining Parameters
The aim of this research work is to evaluate the effects of coolant including nano- powder material for the cooling purpose in milling process and comparing the results with the conventional coolant. Generation heat and weak heat transfer reduces the tool life and also deteriorate surface roughness during milling operation. To overcome this problem, it is necessary to use coolant for cooling as well as lubrication purposes. Due to limited heat removal rate from the work piece through the conventional coolant, some nano powder material is added to coolant, to improve the heat transfer coefficient. The added nano powder also increases machinability, decreases production time and improve surface roughness. In this paper nano fluid of copper with 99 percent purity added to Z1 coolant for machining of St37 work piece in milling machine. In this research, some factors such as rotational speed, feed and depth of cut in the three states of machining, with different coolant including Z1 and nano fluid and dry condition were investigated and finally temperature of machined work piece and its surface quality were evaluated. By comparing the obtained results it is evident that the heat removal rate and surface quality in the case of nano fluid are improved and furthermore the tool life as well as machining efficiency increases.
http://jsme.iaukhsh.ac.ir/article_515422_e0f72b4f732e7be5da57b6c443f552e0.pdf
2010-06-22
41
46
Copper nanofluid
Coolant fluid
Surface finish
Milling process
Tool Life
Ahmad
Afsari
afs@iaushiraz.net
1
Assistant Porfessor,Islamic Azad university, Shiraz Branch
LEAD_AUTHOR
AmirHossein
Zarei
2
M.Sc. Student, Islamic Azad university, Shiraz Branch
AUTHOR
[1] Calistes R., controlling gradation of surface strains and nano structuring by large-strain machining, Journal of scripta material, 60, 2009 , pp.17-20.
1
[2] Beskok A., Karniadakis G., Micro flow and nano flow fundamental and simulation, Elsevier,2003.
2
[3] Wang X., Xu X., Choi U.S., Thermal conductivity of nanoparticle-fluid mixture, Journal of Thermophys Heat Transfer, Vol. 13, No.4, 1999, pp. 474-480.
3
[4] Vela Martinez L., Analysis of compliance between the cutting tool and the work piece on the stability of a turning process, Journal of machine tools manufacture, Vol. 48,Issue 9, 2008, pp.1054-1062.
4
[5] Xuan Y., Li Q., Heat transfer enhancement of nano fluids, International Journal of Heat Fluid flow, Vol. 21, 2000, pp. 58-64.
5
[6] Choi U.S., Enhancing thermal conductivity of fluids with nano particles, Development and Application of Non-Newtonian Flows, ASME, FED-Vol. 231/MD-Vol. 66,1995, pp. 99-105.
6
[7] توکلی روداب م.، افسری ا.، روستا پور ا.ر.، بررسی سیستم خنک کاری ماشین تراش با بکار گیری نانو سیال و مقایسه آن با امولسیون سیالات متداول، پایان نامه کارشناسی ارشد رشته مهندسی مکانیک گرایش ساخت و تولید، دانشگاه آزاد اسلامی شیراز، 1388.
7
ORIGINAL_ARTICLE
Analytical and Numerical Investigation of Four-roll Bending
Four-roll bending process is usually used for manufacturing of seamed thick-walled and thin-walled cylinders. Due to complexity of this process, the analytical solution of plate bending in this process has not been developed completely. The existence of friction and multi-step processing makes it more difficult. Investigation of four-roll bending process using analytical and numerical methods is the main aim of current research. At first, using plate deformation theories, an analytical solution for four-roll bending process is extracted. By decomposing the deformation to elastic and elasto-plastic, the required bending moment is calculated. Considering the distribution of bending moment along the plate, the radius of bending is calculated considering spring back effects. The four-roll bending process is simulated by the finite element method. The simulation results show that the level of strain is less than the critical value and hence there are no damaged parts in the plate during process. Besides, bending radius of the plate after spring back is calculated and compared with the analytical values. Finally, for validation of analytical and numerical results, some experiments were conducted on aluminum. Results of this research show that both analytical and numerical methods are proper techniques for predicting plate behavior during four-roll bending.
http://jsme.iaukhsh.ac.ir/article_515423_76da7707710c7243a627125aae5fbf0d.pdf
2010-06-22
47
58
Four-roll bending
Plastic deformation of plates
Spring Back
Bending radius
M.
Ashrafi
ashrafi@iaukhsh.ac.ir
1
Lecturer, Mechanical Engineering Department, Islamic Azad University, Khomeinishahr Branch.
LEAD_AUTHOR
V.
Poorgharibshahi
2
- Lecturer, Islamic Azad University, Tiran Branch
AUTHOR
[1] Gandhi A.H., Raval H.K., Analytical and empirical modeling of top roller position for three-roller cylindrical bending of plates and its experimental verification, Journal of Materials Processing Technology, Vol. 197, (1-3), 2008, pp. 268-278.
1
[2] Gu X., Franzke M., Bambach M., Hirt G., Experimental and numerical investigation of grid sheet bending behavior in four-roll bending, CIRP Annals - Manufacturing Technology, Vol. 59, (1), 2010, pp 303-306.
2
[3] Feng Z., Champliaud H., Three-stage process for improving roll bending quality, Simulation Modelling Practice and Theory, Vol. 19, (2), 2011, pp. 887-898.
3
[4] Hua M., Sansome D.H., Baines K., Mathematical modeling of the internal bending moment at the top roll contact in multi-pass four-roll thin-plate bending, Journal of Materials Processing Technology, Vol. 52, 1995, pp. 425-459.
4
[5] Hua M. , Cole I.M., Baines K., A formulation for determining the single-pass mechanics of the continuous four-roll thin plate bending process, Journal of Materials Processing Technology, Vol. 67, 1997, pp. 189-194.
5
[6] Hua M., Baines K., Cole I.M., Continuous four-roll plate bending: a production process for the manufacture of single seamed tubes of large and medium diameters, International Journal of Machine Tools and Manufacture, Vol. 39, Issue 6, 1999, pp. 905-935.
6
[7] Lee S. M., Shivpuri R., Investigation of two square-to-round multipass rolling sequences by the slab-finite-element method, Int. J. Mach. Tools Mf., Vol. 32, 1992, pp. 315-327.
7
[8] Zeng J., Liu Zh., Champliaud H., FEM dynamic simulation and analysis of the roll-bending process for forming a conical tube, Journal of Materials Processing Technology, Vol. 198, Issue 1-3, 2008, pp. 330-343.
8
[9] Brunet M., Mguil S., Pol P., Modeling of a roll-forming process with a combined 2D and 3D FEM code, Journal of Materials Processing Technology, Vol. 80, 1998, pp. 213-219
9
[10] Li Zh., Yang H., Li H., Xu J., An accurate 3D-FE based radius prediction model for in-plane roll-bending of strip considering spread effects, Computational Materials Science, Vol. 50, Issue 2, 2010, pp. 666-677.
10
[11] Weinmann K.J., Rosenberger A.H., Sanchez L.R., Turkovich B.F., The Bauschinger Effect of Sheet Metal Under Cyclic Reverse Pure Bending, CIRP Annals - Manufacturing Technology, Vol. 37, Issue 1, 1988, pp. 289-293
11
[12] Hemmerich E., Rolfe B., Hodgson P.D., Weiss M., The effect of pre-strain on the material behaviour and the Bauschinger effect in the bending of hot rolled and aged steel, Materials Science and Engineering: A, Vol. 528, Issue 9, 2011, pp. 3302-3309.
12
ORIGINAL_ARTICLE
Optimization of Axisymmetric Extrusion Die Profiles
In this research, optimization process of axisymmetric extrusion dies is proposed. Plastic zone is analyzed using finite element method in the Eulerian system with flow formulation. The die profiles are defined by Bezier curves with six control points. Two effective functions are considered in this research; standard deviation of the strain rate and the rate of energy consumption during extrusion process. A coupled numerical approach of finite element analysis in Eulerian system and the non-gradient Nelder-Mead method is utilized to determine optimum die profiles. Results show that optimized die has higher uniformity in strain rate distribution and less strain values with respect to the non-optimum conical die. In the case of minimizing energy consumption rate, results show that for the die with constant and variable lengths and low friction, the die profile tends to the stream line. In die with variable length and high friction, friction has more effective role in optimization and the die length tends towards lower lengths during optimization.
http://jsme.iaukhsh.ac.ir/article_515424_292a43a17eff7cb1a2d90c0b54d128e9.pdf
2010-06-22
59
70
Extrusion
Finite Element Method
Optimization
Bezier curves
Constant strain rate
Hassan
Nahvi
nahvi@iaukhsh.ac.ir
1
Associate Professor, Mechanical Engineering Department, Islamic Azad University, Khomeinishahr Branch
LEAD_AUTHOR
Mahdi
Hassanzadeh
2
Lecturer, Mechanic Department, Islamic Azad University, Kordkuy Branch.
AUTHOR
[1] Mihelic A. Stok B., Tool design optimization in extrusion processes, Computers & Structures, Vol. 68, 1998, pp. 283-293.
1
[2] Lee S.K., Ko D.C. Kim B.M., Optimal die profile design for uniform microstructure in hot extrusion product, International Journal of Machine Tool Manufacturing, Vol. 40, 2000, pp 1457–1478.
2
[3] Kim N. H., Kang C. G., Kim B.M., Die design optimization for axisymmetric hot extrusion of metal matrix composites, International Journal of Mechanical Sciences, Vol. 42, 2000, pp. 1507-1520.
3
[4] Ulysse P., Extrusion die design for flow balance using FE and optimization methods, International Journal of Mechanical Sciences, Vol. 44, 2002, pp. 319–341.
4
[5] Juchen X., Xinyun W., Lin Z., Guoan H Optimization of die profile for improving die life in the hot extrusion process, Journal of Materials Processing Technology, Vol. 142, 2003, pp. 659–664.
5
[6] Yan H., Xia J, An approach to the optimal design of technological parameters in the profile extrusion process, Science and Technology of Advanced Materials, Vol. 7, 2006, pp. 127–131.
6
[7] Xianghong W., Guoqun Z., Yiguo L, Xinwu M., Numerical simulation and die structure optimization of an aluminum rectangular hollow pipe extrusion process, Materials Science and Engineering A 435–436, 2006, pp. 266-274.
7
[8] Gordona W. A., Van Tyneb C.J., Moon Y. H., Axisymmetric extrusion through adaptive dies- Part 3: Minimum pressure streamlined die shapes, International Journal of Mechanical Sciences, Vol. 49, 2007, pp. 104-115.
8
[9] Bakhshi-Jooybari M., Saboori M., Noorani-Azad M., Hosseinipour S. J., Combined upper bound and slab method, finite element and experimental study of optimal die profile in extrusion, Materials and Design, Vol. 28, 2007, pp. 1812-1818.
9
[10] Dixit P. M., Dixit U. S., Modeling of Metal Forming and Machining Processes, Springer, London, 2008.
10
[11] Altan T., Oh S.I., Gegel H.L., Metal Forming Ð Fundamentals and Applications, American Society of Metals, Cleveland, OH, 1983.
11
[12] Saxena A., Sahay B., Computer Aided Engineering Design, Springer, 2005.
12
[13] Himmelblau D.M., Applied Nonlinear Programming, McGraw-Hill, New York, 1972.
13
[14] Hosford W. F., Caddell R. M., Metal Forming: Mechanics and Metallurgy Cambridge University Press, 2007.
14
ORIGINAL_ARTICLE
Optimization of Flash, Billet Dimensions and Friction Factor in
Closed Die Cold Forging Process
Three important parameters in designing a closed die for forging process are ratio of width to flash thickness, ratio of height to billet diameter and the friction factor. In this paper the influences of these parameters on the required force for the forging and percentage of die filling were investigated. It was found that by controlling the flash dimension, the material loss is reduced and the percentage of die filling is increased. Also, an experimental model was simulated and analyzed by finite element method. To validate the numerical results obtained by this research, value of gained force from finite element method was compared with the obtained experimental results. In order to coordinate and connect between the mentioned parameters and obtain a performance function, a two layer neural network was used. Finally, by using neural network and genetic algorithm, the optimum sets of parameters which minimized the force and maximized the percentage of die filling were found. These values were compared with the experimental results of other researchers. The genetic algorithm has good correlation with the experimental method as well as it has presented acceptable estimation for effective parameters in the forging process.
http://jsme.iaukhsh.ac.ir/article_515428_05f8c40319fe81e0129277545e4ca990.pdf
2010-06-22
71
80
forging
Billet
Flash
Closed die
FEM Method
Neural network
Genetic Algorithm
Mehdi
Zohoor
mzohoor@kntu.ac.ir
1
Assistant Professor, Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran
LEAD_AUTHOR
Hossein
Shahverdi
2
- Assistant Professor, Mechanical and Aerospace Engineering Department, Science and Research Branch, Islamic Azad University, Tehran, Iran
AUTHOR
Amin
Tafakori
3
M.Sc. Graduate Student, Faculty of Mechanical and Aerospace Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
AUTHOR
اردیبهشت ۱۳۸۵.
1
[2] Sheridan S. A., Forging Design HandBook, American Society For Metals, MetaPark, Ohio, 1972.
2
[3]Ranatunga V. R., Gunasekera J. S.,Use of UBET For Design Of Flash Gap in Closed Die Forging, Journal of Materials Processing Technology, Vol. 111, 2001, pp. 107-112.
3
[4] Tavangar R., Taheri A. K. Prediction of Optimum Flash Dimention in Axisymmetric Closed Die Forging, Second. Mech. Int. Conf., Shiraz University, May 1996.
4
[5]Saniee F., Jaafari M., Analytical, numerical and experimental analyses of the close die forging, Journal of Materials Processing Technology, 2002, pp. 334-340.
5
[6] www.matweb.com
6
[7]Rumelhart D. E., Hinton G. E., Williams R.J., Learning internal representation by error propagation, Parallel Distributed Processing, Vol. 1, 1986, pp. 318–362 .
7
[8] Holland J. H., Genetic Algoritm Scientific American” ,ASM Intl, July 1992, pp 44-50.
8
[10] Gen M., Cheng R., Genetic Algoritm and Engineering Design, ASM Intl, 1997.
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