2024-03-29T14:02:29Z
https://www.ije.ir/?_action=export&rf=summon&issue=11563
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
An Investigation into the Deep Drawing of Fiber-Metal Laminates based on Glass Fiber Reinforced Polypropylene
Mehran
Kadkhodayan
ali
rajabi
Abstract Fiber-metal laminates (FMLs) are new type of composite materials which could improve defects of traditional composites in ductility, formability, impact and damage tolerance. Drawing behavior of a thermoplastic based FML was investigated consisting of glass-fiber reinforced polypropylene composite laminate and aluminum AA1200-O as the core and skin layers, respectively. The effects of process variables consisting of blank-holder force, temperature, blank diameter and blank thickness were studied on the forming behavior of the FML. To reduce the number of experiments and investigate process variables on maximum drawing force and wrinkling of specimens, design of experiments was used. The experimental results were indicated that the general effects of blank-holder force on the failure mode in FMLs and the effects of blank diameter and blank thickness of a FML in deep drawing was similar to custom metals. Furthermore results were demonstrated that a high interaction between the temperature and the blank-holder force was required to remove the wrinkling. To validate the results of experiments, engineering constants of GFRP were obtained using Timoshenko’s beam theory and numerical simulations were performed by the finite element software, ABAQUS.
Deep drawing
Fiber
metal laminate
Design of experiments
Finite Element
2014
03
01
349
358
https://www.ije.ir/article_72261_9c313825cee5fb77c2a24843f05ebe64.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Reduction of Odometry Error in a two Wheeled Differential Drive Robot (TECHNICAL NOTE)
R.
Saravanan
T.
Ravikumar
Pose estimation is one of the vital issues in mobile robot navigation. Odometry data can be fused with absolute position measurements to provide better and more reliable pose estimation. This paper deals with the determination of better relative localization of a two wheeled differential drive robot by means of odometry by considering the influence of parameters namely weight, velocity, wheel perimeter and tyre width. Experiments have been conducted based on central composite rotatable design matrix. A mathematical model has been developed for the robot using Response Surface Methodology (RSM) with the help of MINITAB software. An optimum condition for minimum odometry error was obtained by using Excel (XL) Solver.
Mobile Robot
Odometry
Relative Localization
Response Surface Methodology
Excel Solver
2014
03
01
359
366
https://www.ije.ir/article_72262_3cde50287bdb4b819245100bfa843f17.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Crack Detection In Functionally Graded Beams Using Conjugate Gradient Method
Malihe
Eftekhari
Mojtaba
Eftekhari
Mohammad
Hosseini
In this paper the conjugate gradient (CG) method is employed for identifying the parameters of crack in a functionally graded beam from natural frequency measurement. The crack is modeled as a massless rotational spring with sectional flexibility. By using the Euler-Bernoulli beam theory on two separate beams respectively and applying the compatibility requirements of the crack, the characteristic equation can be obtained as a function of natural frequency and location and depth of crack. In direct problem, the natural frequency is computed using analytical analysis. Moreover, the location and depth of crack are determined by measuring the three natural frequencies of beam in inverse problem. In this study, the CG method is utilized in inverse problem to determine the location and depth of crack. The obtained results show the efficiency of CG algorithm in terms of accuracy and the convergence speed.
functionally graded beam
Crack detection
Conjugate Gradient Method
2014
03
01
367
374
https://www.ije.ir/article_72263_a0ac2c13fdbf5354004d342bd32ac8e6.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Effect of Length-scale Parameter on Pull-in Voltage and Natural Frequency of a Micro-plate
Ghader
rezazadeh
Kaveh
Rashvand
Hadi
Madinei
This paper deals with the effect of the intrinsic material length-scale parameter on the stability and natural frequency of a rectangular micro-plate for two different cases; fully clamped and fully simply supported. A variational formulation based on Hamilton’s principle and the modified couple stress theory is used to obtain the nonlinear governing equation of a micro-plate incorporating the stretching effect. In the static case, the nonlinear governing equation is solved using the step-by-step linearization method (SSLM) and in the dynamic case, is integrated using fourth-ordered Runge-Kutta method. The static and dynamic pull-in parameters, limiting the stability regions of capacitive MEMS devices, are calculated and compared to those obtained by the classical theory. The numerical results reveal that the intrinsic size dependence of materials is more significant for smaller thicknesses and in this case, the stretching effect can be neglected.
Material length
Scale Parameter
Modified couple stress theory
Rectangular micro
Plate
Stability
2014
03
01
375
384
https://www.ije.ir/article_72264_f527b57359d1be36ad47220a29d712e3.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Semi-analytical Approach for Free Vibration Analysis of Variable Cross-Section Beams Resting on Elastic Foundation and under Axial Force
Alborz
Mirzabeigy
in this paper, free vibration of an Euler-Bernoulli beam with variable cross-section resting on elastic foundation and under axial tensile force is considered. Beam’s constant height and exponentially varying width yields variable cross-section. The problem is handled for three different boundary conditions: clamped-clamped, simply supported-simply supported and clamp-free beams. First, the equation of motion that governs the free vibration is derived and then dimensionless frequencies are determined by using differential transform method (DTM). DTM is a semi-analytical approach based on Taylor expansion series that is powerful tool in solution ordinary and partial differential equations. The effects of axial force, elastic foundation coefficient and non-uniformity parameter on dimensionless frequencies are investigated. Wherever possible, comparisons are made with the studies in open literature. Results show, the DTM yields rapid convergence without any frequency missing although convergence rate depend on boundary conditions. Also, dimensionless frequencies are sensitive to axial force rather than other parameters.
Variable Cross
Section Beam
Elastic Foundation
axial force
Differential transform method
2014
03
01
385
394
https://www.ije.ir/article_72265_c3a457f7e547dab5fd44316738d5a7f4.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Optimal Design of Sandwich Panels Using Multi-Objective Genetic Algorithm and Finite Element Method
Abolfazl
Khalkhali
N.
Narimanzadeh
Sharif
Khakshournia
Saeed
Amiri
Low weight and high load capacity are remarkable advantages of sandwich panels with corrugated core, which make them more considerable by engineering structure designers. It’s important to consider the limitations such as yielding and buckling as design constraints for optimal design of these panels. In this paper, multi-objective optimization of sandwich panels with corrugated core is carried out by minimizing two supposed objective functions, the structure’s weight and deflection. The finite element model of structure is created using the commercial software ANSYS, which is employed to calculate the deflection of panel in different problem conditions. A NSGA-II code prepared in MATLAB, is used to perform the optimization process in a gradual evolution trend, which leads to obtain the Pareto front consisting a set of design vectors and optimal objective function vectors. Two conventional methods are then used to select the trade-off optimal point among the Pareto non-dominant optimal set.
Sandwich panels
multi
objective optimization
Finite Elements Method
2014
03
01
395
402
https://www.ije.ir/article_72266_adb3b989a7941894512bf7c6927b94ed.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Effect of Compression Ratio on Emission of CI Engine using Neat Karanja Oil and Karanja Oil Methyl Ester Blends
saroj
acharya
Pragya
Patnaik
The standard design parameters of a compression ignition engine fail to give specified performance with strait vegetable oil (SVO) from different origins. This study is performed to find the effect of compression ratio on emission characteristics such as carbon monoxide (CO), carbon dioxide (CO2), hydrocarbon (HC), nitrogen oxides (NOx) and smoke opacity with all the tested fuels in a single cylinder, four stroke VCR engine fueled with neat Karanja oil blends (10% and 20%) with diesel (on volume basis) and Karanja oil methyl ester (KOME) blends (20%, 40% and 60%) and the results are compared with diesel. Experiment has been conducted at compression ratios of 16:1, 17:1, 18:1. At higher CR minimum value CO is recorded 0.04% for 20% blend of KOME (B20), while it show maximum CO2 recorded 4.45%. Lowest HC and NOx emission recorded 22 ppm and 552 ppm respectively for 40% blend of KOME (B40). Emissions are marginally higher for K10 and K20 than diesel. Overall observation shows that B40 shows lowest emissions than other blends of KOME at higher compression ratio.
Karanja oil
Karanja oil methyl ester
Variable compression ratio engine
Emission
2014
03
01
403
410
https://www.ije.ir/article_72267_f35ff92f8b62be5d75a767f7a39bf5aa.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
An Experimental Study on the Thermal Conductivity of Carbon Nanotubes/Oil (TECHNICAL NOTE)
Milad
Tajik Jamal-Abad
Ali morad
Rashidi
Maryam
Gohari
[if gte mso 9]> In the present work, the thermal conductivity coefficients of nanoparticle-oil suspensions for two types of carbon nanotubes, single-walled (SWNTs) and multi-walled (MWNTs) carbon nanotubes at 0.1, 0.2 and 0.3 wt.% were measured by a modified transient hot wire method (KD2-pro thermal property meter). Results showed that the thermal conductivity of suspension containing single-walled carbon nanotubes is higher than that of suspension containing multi-walled carbon nanotubes. It was also observed that the thermal conductivity coefficients of both nanofluids increase with increasing temperature.
CNTs
Nanofluid
Thermal conductivity
2014
03
01
411
416
https://www.ije.ir/article_72268_79357a8ef898c060e1e872a7f39cd250.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Improvement of Surface Finish when EDM AISI 2312 Hot Worked Steel using Taguchi Approach and Genetic Algorithm
masoud
azadi moghaddam
farhad
kolahan
Nowadays, Electrical Discharge Machining (EDM) has become one of the most extensively used non-traditional material removal process. Its unique feature of using thermal energy to machine hard to machine electrically conductive materials is its distinctive advantage in the manufacturing of moulds, dies and aerospace components. Howevere, EDM is a costly process and hence proper selection of its process parameters is essential to reduce production cost and improve product quality. In this study the effect of input EDM parameters on 2312 hot worked steel, widely used in mold manufacturing, is modeled and optimized. The proposed approach is based on statistical analysis on the experimental data. The input parameters are peak current (I), pulse on time (Ton), pulse off time (Toff), duty factor (h) and voltage (V). Surface roughness is the most important performance characteristic in EDM. The experimental data are gathered using Taguchi L36 design matrix. In order to establish the relations between input and output parameters, various regression functions have been fitted on the experimental data. In the last section of this research, genetic algorithm has been employed for optimization of process parameters. Using the proposed optimization procedure, proper levels of input parameters for any desirable output can be identified. A verification test is also performed to verify the accuracy of optimization procedure in determining the optimal levels of machining parameters. The results indicate that the proposed modeling technique and genetic algorithm are quite efficient in modeling and optimization of EDM process parameters.
Taguchi technique
Signal to noise analysis (S/N)
Electrical discharge machining (EDM)
optimization
Genetic algorithm (GA)
analysis of variance (ANOVA)
2014
03
01
417
424
https://www.ije.ir/article_72269_034e143e51d36216c1cbc7c5aa160945.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Development of a Predictive Finite Element Model For Investigation of Phases Behavior After Cold Rolling Process
Sareh
Esmaeili
soheila
sojodi
One of the surface defects that arise in sheet metal working is when the part removes from the die. Since there are no external forces to make this defect, the origin of such fail is known as residual stress. Residual stress can develop in sheet metal forming due to non uniform deformation. In this paper, the workpiece is carbon steel with different volume fractions and arrangement of ferrite and pearlite. Due to different stress-strain curve of each phase, after cold rolling, one phase deforms elastically, whereas the other undergoes on elastic-plastic deformation. On unloading to zero applied stress, this effect can produce residual stress. Therefore, in order to reduce the surface defects in sheet metal forming, an intelligent predictive code using a validated elastic plastic finite element method is generated for a plain strain deformation of cold rolling process. Results obtained show that in regular arrangement of ferrite and pearlite, workpiece microstructure has great influence on the residual stress distribution and by decreasing the width of each strip; the fluctuation of residual stress is reduced. The purpose of this study is developing the state of the art instructions for arrangement of phases after hot rolling process which the total residual stress produced after cold rolling and sheet metal working will be minimized.
Rolling
Two phase alloy
Surface defect
Elastic
Plastic
FEM
2014
03
01
425
430
https://www.ije.ir/article_72270_affcb2c758690de0d90668ad2d3e40c3.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Length Scale Effect on Vibration Analysis of Functionally Graded Kirchhoff and Mindlin Micro-Plates
Emad
Jomehzadeh
Hamid Reza
Noori
In this paper, the modified couple stress theory is used to study vibration analysis of functionally graded rectangular micro-plates. Considering classical and first order plate theories, the couple governing equations of motion are obtained by using the Hamilton’s principle. Considering an assumed mode method, the accurate size dependent natural frequencies are established for simply supported functionally graded rectangular micro-plates. To show the accuracy of the formulations, present results in specific cases are compared with available results in literature and a good agreement is seen. It is found that the natural frequency parameter of micro-plates will decrease as thickness-length ratio increases especially for lower length scale values. The effects of length scale, functionally graded parameter and plate theories on natural frequencies of functionally graded micro-plates are discussed in details.
vibration
Micro
Plate
Functionally graded
Modified couple stress theory
2014
03
01
431
440
https://www.ije.ir/article_72271_fbc947e8fda494def736f71c9630ff88.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
A Study on Combination of von Mises and Tresca Yield Loci In Non-Associated Viscoplasticity
Farzad
Moayyedian
Mehran
Kadkhodayan
In this study a non-associated viscoplastic flow rule (NAVFR) with combining von Mises and Tresca loci in place of yield and plastic potential functions and vice verse is presented. With the aid of fully implicit time stepping scheme and discussing the other studies on plastic potential flow rules and also experimental results it is shown that the proposed NAVFR can be adopted to forecast the experimental events more accurate than the conventional associated viscoplastic flow rules (AVFR).
rate
Dependant Non
associated Viscoplastic Flow Rule
Fully Implicit Time Stepping Scheme
Internally Pressurized Thick Walled Cylinder
2014
03
01
441
448
https://www.ije.ir/article_72272_ef45bdd5984e9c027b6ef90c7e73d0cb.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Hydrogen and Ethanol as Potential Alternative Fuels Compared to Gasoline under Improved Exhaust Gas Recirculation
Arash
Nemati
Samad
Jafarmadar
S.
Khalil Arya
Mohsen
Mardi Kolur
In the present study, a computational fluid dynamics (CFD) method have been utilized to investigate the effects of exhaust gas recirculation (EGR) and initial charge pressure by means of using a supercharger on the emissions and performance of a SI engine. This engine is fueled separately by gasoline and two potential alternative fuels, hydrogen and ethanol. The results of simulation are compared to the experimental data. There is a good agreement among the results. The calculations are carried out for EGR ratios between 0% and 20% and four cases of initial pressure have been mentioned: Pin= 1, 1.2, 1.4, 1.6 bar. The effect of EGR on NOx emission of hydrogen is more than others while its effect on IMEP of hydrogen is less than others. From the viewpoints of emission and power, 10% of EGR seems to be the most desirable amount. The most noticeable effect of supercharging is on gasoline unlike hydrogen that seems to be affected the least. The comparison of results shows that hydrogen due to its high heating value and burning without producing any carbon-based compounds such as HC, CO and CO2 is an ideal alternative fuel compared to the other fuels.
SI engine
hydrogen
Alternative fuels
EGR
supercharging
Emission
2014
03
01
449
456
https://www.ije.ir/article_72273_6f1282b4c04d3b588d91e024ecfb2a6e.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Performance Study of a Solar Integrated Central Heating System of a Residential Building Using Trnsys- an Hourly Simulation Model (RESEARCH NOTE)
Mohammad
Ahmadzadehtalatapeh
In this investigation, the performance of an existing heating system of a residential building incorporated with an array of solar thermal collectors was studied. For this purpose, transient systems simulation program model was assembled to estimate the hour-by-hour performance of the existing and the system equipped with the solar thermal collectors in terms of the provided space air conditions and energy consumption. In the modified heating system, the capability of the three standard types of solar collectors, namely, unglazed, glazed painted absorber, and evacuated tube liquid flat-plate solar collectors in providing required heating energy into the space was examined to determine the most appropriate configuration. Based on the simulation results, the systems incorporated with the solar thermal collectors are capable of providing the desired indoor air conditions for four and five months of the year. However, the energy performance of the systems indicates that the existing system incorporated with the glazed painted absorber solar collectors (Plant B) has the priority in terms of the energy savings, while could provide the desired indoor air conditions for five out of the eight months of the study and it is recommended to be implemented in the existing heating system.
Energy Saving
Heating system
Space air condition
solar collector
TRNSYS
2014
03
01
457
466
https://www.ije.ir/article_72274_1e7d9c6a6772eeefd5aa338364c3f003.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
A New Intelligent Approach to Patient-cooperative Control of Rehabilitation Robots
Mozafar
Saadat
Naghmeh
Garmsiri
This paper presents a new intelligent method to control rehabilitation robots by mainly considering reactions of patient instead of doing a repetitive preprogrammed movement. It generates a general reference trajectory based on different reactions of patient during therapy. Three main reactions has been identified and included in reference trajectory: small variations, force shocks in a single moment and variable level of participation. This reference trajectory can facilitate every kind of patient-cooperative controller of rehabilitation with an evaluation factor. A simple planar 2-DOF exoskeleton is used as rehabilitation robot for leg therapy. The low level controller used here is Brain Emotional Learning Based Intelligent Controller (BELBIC) which is participating to develop an admittance control scheme. Performance of this controller has compared to PID with simulations and better results have observed specially in control signal and speed of reaction when controller encounters a force shock.
Admittance Control
BELBIC
Rehabilitation Robot
2014
03
01
467
474
https://www.ije.ir/article_72275_127ea5b19d9f95d65d5d14469e3de3af.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Analytical Solution of Stress Field in Adhesively Bonded Composite Single-Lap Joints Under Mechanical Loadings
Seyed Abdolmajid
Yousefsani
Masoud
Tahani
Ehsan
Selahi
In this paper, considering an adhesively bonded composite single-lap joint, a novel approach is presented to predict the peel and shear stress distributions of the adhesive layer for an ASTM standard test sample. In current method, the equilibrium equations are derived using the energy method and based on the Timoshenko’s beam theory. Two solution procedures then are discussed, one of which represents a solution approach based on the direct variational method allied with use of the Ritz approximation; while the second one is based on a linear estimating function. Unlike previous methods, in which the variation of stress through the thickness of adhesive is neglected or is assumed to be linear and they cannot be used to analyze the joints with thick adhesive layers; considering the effects of adhesive thickness makes it possible to employ present method to analyze the joints with thick adhesive layers as well as thin ones.
adhesive bonding
Composite Joint
Interlaminar Peel and Shear Stress
Analytical Solution
energy method
2014
03
01
475
486
https://www.ije.ir/article_72276_cb9ce3a50528a4e3bcdc3b0c4c802aea.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Stability Analysis in Parametrically Excited Electrostatic Torsional Micro-actuators
Ghader
Rezazadeh
Behrokh
Abbasnejad
rasoul
shabani
This paper addresses the static and dynamic stabilities of a parametrically excited torsional micro-actuator. The system is composed of a rectangular micro-mirror symmetrically suspended between two electrodes and acted upon by a steady (dc ) while simultaneously superimposed to an (ac ) voltage. First, the stability of the system subjected to a quasi-statically applied (dc ) voltage is investigated, where the pull-in instability, equilibrium positions, and bifurcation points of the system are determined. Then by superimposing an (ac) voltage and extracting a Mathieu type governing equation the effects of (ac ) component on the stability of the system is investigated. By varying excitation parameters (steady (dc) voltage and time-dependent amplitude of (ac ) excitation), transition curves and the stability margins of the micro-mirror are demonstrated. Theoretically obtained margins are checked by means of numerical simulations. The results show that superimposing the harmonic (ac ) component could have a stabilizing effect and allow an increase of the steady (dc ) component beyond the pull-in value. The obtained results could be used in design of micro-actuators.
MEMS
Micro
mirror
Electrostatic actuation
Parametric oscillation
Perturbation Method
2014
03
01
487
498
https://www.ije.ir/article_72277_f69deced9911d5db798b6df58dc603d4.pdf
International Journal of Engineering
IJE
1025-2495
1025-2495
2014
27
3
Vibration Analysis of a Nonlinear System with a Nonlinear Absorber under the Primary and Super-harmonic Resonances (TECHNICAL NOTE)
Leila
saberi
Hassan
Nahvi
Abstract In vibratory systems, linear and nonlinear vibration absorbers can be used to suppress the primary and super-harmonic resonance responses. In this paper, the behavior of a nonlinear system with a nonlinear absorber, under the primary and super-harmonic resonances is investigated. The stiffnesses of the main system and the absorber are cubically nonlinear and the dampers are linear. Multiple time scales method is used to obtain approximate solution of the nonlinear equations of motion. Results show that at primary resonance, a linear absorber can suppress the peak amplitude of the system better than a non-linear one. But under super-harmonic resonance, the vibration amplitude can be more effectively reduced by adding a nonlinear absorber to the vibrating system.
Nonlinear vibrations
Primary Resonance
Super
harmonic resonance
Non
Linear Absorber
Multiple time scales
2014
03
01
499
508
https://www.ije.ir/article_72278_1d72e3cc879bd2dcc2fd6569256b0b66.pdf