AN EXTENDED CONTINUUM MECHANICS FORMULATION ENHANCED BY DIRECT COUPLING WITH MOLECULAR DYNAMICS
S. E.
HABIBI
Dept. of Mechanical Engineering, Persian Gulf University, Bushehr, I. R. of Iran
author
M.
FARID
School of Mechanical Engineering, College of Engineering, Shiraz University, Shiraz, I. R. of Iran
author
M. H. KADIVAR
KADIVAR
School of Mechanical Engineering, College of Engineering, Shiraz University, Shiraz, I. R. of Iran
author
M. MAHZOON
MAHZOON
School of Mechanical Engineering, College of Engineering, Shiraz University, Shiraz, I. R. of Iran
author
text
article
2015
eng
Based on the notion of micro-structure in linear elasticity presented by Mindlin, a newextended continuum mechanics (ECM) formulation is derived which can be utilized to model thematerial behavior at atomic scale. An attempt has been made to present a formulation capable ofproducing the molecular dynamics (MD) simulation results with less computational effort. To thisend, some new kinematical variables are defined and some constitutive relations are obtained fromMD. To validate the proposed ECM formulation, it is applied to a properly defined sampleproblem and the response is compared with the MD simulation result and the classical continuummechanics (CCM) solution.
Iranian Journal of Science and Technology Transactions of Mechanical Engineering
Shiraz University
2228-6187
39
v.
M1
no.
2015
1
14
https://ijstm.shirazu.ac.ir/article_2944_51886de0fd589371dd0668f31e21b535.pdf
dx.doi.org/10.22099/ijstm.2015.2944
FREE VIBRATION OF FUNCTIONALLY GRADED SIZE DEPENDENT NANOPLATES BASED ON SECOND ORDER SHEAR DEFORMATION THEORY USING NONLOCAL ELASTICITY THEORY
M. R.
NAMI
School of Mechanical Engineering, Shiraz University, Shiraz, I. R. of Iran
author
M.
JANGHORBAN
School of Mechanical Engineering, Shiraz University, Shiraz, I. R. of Iran
author
text
article
2015
eng
In this article, an analytical solution is developed to study the free vibration analysis offunctionally graded rectangular nanoplates. The governing equations of motion are derived basedon second order shear deformation theory using nonlocal elasticity theory. It is assumed that thematerial properties of nanoplate vary through the thickness according to the power lawdistribution. Our numerical results are compared with the results of isotropic nanoplates andfunctionally graded macro plates. The effects of various parameters such as nonlocal parameterand power law indexes are also investigated.
Iranian Journal of Science and Technology Transactions of Mechanical Engineering
Shiraz University
2228-6187
39
v.
M1
no.
2015
15
28
https://ijstm.shirazu.ac.ir/article_2945_1f9c90be3d465cc01702ac765150cfba.pdf
dx.doi.org/10.22099/ijstm.2015.2945
OFFLINE AND ONLINE INVESTIGATION OF DROP IMPACT DAMAGE ON GFRP COMPOSITE USING NON-DESTRUCTIVE DATA BY ARTIFICIAL NEURAL NETWORK
P.
RAMASAMY
Dept. of Mechanical Engineering,Sri Balaji Chockalingam Enginering College, Arni, Tamilnadu, India-632317
author
S.
SAMPATHKUMAR
Dept. of Mechanical Engineering, College of Engineering, Guindy, Anna University, Chennai-600 025, Tamilnadu,
India
author
text
article
2015
eng
The objective of this experimental work was to assess the drop impact damage onWoven Glass Fibre Reinforced Polymer composite laminate through online method and offlinemethod. Online monitoring of drop impact damage was carried out by Acoustic Emission (AE)technique and AE signals during the drop impact test were captured. From the analysis of AEsignals, it was observed that as the impact energy increases the AE parameters such as counts,counts to peak, signal strength and root mean square (RMS) values also increase. Offlineassessment of impact damage on composite laminate was also observed by ultrasonic techniqueand it was inferred that ultrasonic parameters, namely amplitude and attenuation ratio weredecreased with increase in impact energy of test. But attenuation coefficient had an indirectrelationship with impact energy. During online/offline monitoring of composite laminate theAE/UT parameters which were obtained from real time monitoring are used to predict ImpactDamage Tolerance (IDT) using a separate trained artificial neural network model. Based on theIDT value of composite, the component should be continued in-service or replaced.
Iranian Journal of Science and Technology Transactions of Mechanical Engineering
Shiraz University
2228-6187
39
v.
M1
no.
2015
29
38
https://ijstm.shirazu.ac.ir/article_2946_5fbca434100955aed3f12becc4d1aa43.pdf
dx.doi.org/10.22099/ijstm.2015.2946
2&3-DIMENSIONAL OPTIMIZATION OF CONNECTING ROD WITH GENETIC AND MODIFIED CUCKOO OPTIMIZATION ALGORITHMS
S. A.
MOEZI
Young Researchers and Elite Club, Shiraz Branch, Islamic Azad University, Shiraz, I. R. of Iran
author
E.
ZAKERI
Young Researchers and Elite Club, Shiraz Branch, Islamic Azad University, Shiraz, I. R. of Iran
author
Y.
BAZARGAN-LARI
Dept. of Mechanical Engineering, Shiraz Branch, Islamic Azad University, Shiraz, I. R. of Iran
author
A.
ZARE
Dept. of Mechanical Engineering, Shiraz Branch, Islamic Azad University, Shiraz, I. R. of Iran
author
text
article
2015
eng
In this paper, a connecting rod was modeled and analyzed by finite element method. Byusing genetic algorithm (GA) and modified cuckoo optimization algorithm (MCOA), the materialproperties and some geometrical specifications were optimized. Cost function was a combination ofweight and stress. The connecting rod was under a load of 21.8 kN which obtained 360o crank angleat 5700 rev/min. The reduction percentages of weight in 2-D analysis were 45.47% and 50.34%based on GA and MCOA, respectively. The reduction percentages of stress were also 1.26% and2.20% based on GA and MCOA, respectively. The values of reduction percentages in 3-D analysisshowed the same trends.The results showed that applying each of the algorithms was efficient. Meanwhile, the resultsof MCOA were better than GA, because of the smaller number of iterations and the initialpopulation, which resulted in increasing the rate of convergence (i.e. decreasing computationaltime) and accuracy of answers. It can be mentioned that MCOA is an efficient and reliablealgorithm and can be used as a benchmark for future works.
Iranian Journal of Science and Technology Transactions of Mechanical Engineering
Shiraz University
2228-6187
39
v.
M1
no.
2015
39
49
https://ijstm.shirazu.ac.ir/article_2947_1b5dc7d0070f3a1961efe09b1c809735.pdf
dx.doi.org/10.22099/ijstm.2015.2947
IMPROVING THE EFFECTIVENESS OF A PHOTOVOLTAIC WATER PUMPING SYSTEM BY USING BOOSTER REFLECTOR AND COOLING ARRAY SURFACE BY A FILM OF WATER
H.
TABAEI
Dept. of Mechanical Engineering, College of Engineering, Shahid Bahonar University of Kerman, Kerman, I. R. of Iran
&
Energy & Environmental Engineering Research Center, Shahid Bahonar University of Kerman, Kerman, I. R. of Iran
author
M.
AMERI
Dept. of Mechanical Engineering, College of Engineering, Shahid Bahonar University of Kerman, Kerman, I. R. of Iran
&
Energy & Environmental Engineering Research Center, Shahid Bahonar University of Kerman, Kerman, I. R. of Iran
author
text
article
2015
eng
The increase of cell temperature with increased irradiance is probably the mostsignificant disadvantage of using Photovoltaic modules equipped with booster reflectors. The aimof this study is to investigate the possibility of improving the performance of a photovoltaic waterpumping system by using a booster reflector and to keep the temperature of PV panels at a lowlevel by cooling PV panels with a film of water. The water required for covering the cells is fed bythe pump itself. By applying the modifications on the photovoltaic water pump system, significantimprovement in the output power from PV panels, and therefore in the pump flow rate, isdisplayed in the experimental results.
Iranian Journal of Science and Technology Transactions of Mechanical Engineering
Shiraz University
2228-6187
39
v.
M1
no.
2015
51
60
https://ijstm.shirazu.ac.ir/article_2948_f2d8048a057dede63dc3d983d2e0e3d6.pdf
dx.doi.org/10.22099/ijstm.2015.2948
INFLUENCE OF INJECTION TIMING AND COMPRESSION RATIO ON PERFORMANCE, EMISSION AND COMBUSTION CHARACTERISTICS OF JATROPHA METHYL ESTER OPERATED DI DIESEL ENGINE
R.
SENTHIL
Dept. of Mechanical Engineering, University College of Engineering Villupuram, Tamilnadu, India
author
R.
SILAMBARASAN
Dept. of Mechanical Engineering, University College of Engineering Villupuram, Tamilnadu, India
author
text
article
2015
eng
Diesel fuel has a limited resource and concerns over environmental pollution areleading to the use of ‘bio-origin fuels’ as they are renewable and environmentally benign. Jatrophamethyl ester, an esterified biofuel, has an excellent cetane number and a reasonable calorific value.It closely resembles the behaviour of diesel. However, being a fuel of different origin, the standarddesign limits of a diesel engine is not suitable for Jatropha methyl ester. Therefore, in this work,operational parameters are studied to find out the optimum performance of Jatropha methyl esterrun diesel engine. The parameters varied are the compression ratio (CR) and injection timing (IT)along with load in a diesel engine. This work targets finding the effects of the engine operatingparameters on the performance of the engine with regard to specific fuel consumption (SFC) andbrake thermal efficiency (BTHE) with Jatropha methyl ester(J20) as fuel. Further exhaustemissions of the engine for the above conditions are also studied.Thus J20 can be effectively usedin a diesel engine without any modification. At compression ratio of 19.5 along with injectiontiming of 30obTDC (before top dead centre) will give better performance and lower emissionwhich is very close to diesel. Comparison of performance and emission was done for differentvalues of compression ratio along with injection timing to find the best possible combination foroperating engine with J20. It is found that the combined increase of compression ratio andinjection timing increases the BTE and reduces SFC while having lower emissions. Diesel (20%)saved, will greatly meet the demand of fuel in railways.
Iranian Journal of Science and Technology Transactions of Mechanical Engineering
Shiraz University
2228-6187
39
v.
M1
no.
2015
61
76
https://ijstm.shirazu.ac.ir/article_2949_2d9e2de713377822c359f2d7e6ad2804.pdf
dx.doi.org/10.22099/ijstm.2015.2949
AN EXPERIMENTAL AND NUMERICAL STUDY OF DUCTILE FRACTURE OF COPPER/STAINLESS STEEL CLAD SHEET IN DEEP DRAWING PROCESS
M.
MASHAYEKHI
Dept. of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, I. R. of Iran
author
F.
DEHGHANI
Dept. of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, I. R. of Iran
author
N.
TORABIAN
Dept. of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, I. R. of Iran
author
M.
SALIMI
Dept. of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, I. R. of Iran
author
text
article
2015
eng
This work is an attempt towards employing ductile damage criterion and finite elementsimulations for prediction of fracture initiation and evolution in deep drawing of copper/stainlesssteel clad sheets. The material mechanical properties and ductile damage parameters weredetermined through standard and notched tensile tests. The effect of some important processparameters on damage evolution were examined through numerical modeling and the acceptablerange of variations for each parameter were introduced in order to prevent tearing of the blankduring the process. The numerical predictions of deformation and fracture behavior were in a goodagreement with experimental observations.
Iranian Journal of Science and Technology Transactions of Mechanical Engineering
Shiraz University
2228-6187
39
v.
M1
no.
2015
77
87
https://ijstm.shirazu.ac.ir/article_2950_217a834f98430002d003423836acd511.pdf
dx.doi.org/10.22099/ijstm.2015.2950
DESIGN OF THE DIE PROFILE FOR THE INCREMENTAL RADIAL FORGING PROCESS
M.
AFRASIAB
School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, I. R. of Iran
author
H.
AFRASIAB
Mechanical Engineering Department, Babol University of Technology, Babol, I. R. of Iran
author
M.R.
MOVAHHEDY
Center of Excellence in Design, Robotics, and Automation, Department of Mechanical Engineering, Sharif
University of Technology, Azadi Ave., Tehran, I. R. of Iran
author
G.
FARAJI
School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, I. R. of Iran
author
text
article
2015
eng
In this paper, based on the slab method of analysis, a novel and general approach isdeveloped for studying the radial forging process with curved profile dies. The presented approachis not only more general with respect to previous studies, but it is also easier to understand and useand can be efficiently used for optimization of the die profile depending on the forging geometryand conditions. The obtained general equations reduce to those obtained in previous studies for thespecial case of linear dies. The process is also simulated by the finite element method to furtherenhance the results of the study. The obtained results provide useful information for the optimaldesign of the radial forging die.
Iranian Journal of Science and Technology Transactions of Mechanical Engineering
Shiraz University
2228-6187
39
v.
M1
no.
2015
89
100
https://ijstm.shirazu.ac.ir/article_2951_fbe6098b8e29ca589fa947194c09a557.pdf
dx.doi.org/10.22099/ijstm.2015.2951
DESIGN OPTIMIZATION OF BOX TYPE GIRDER OF AN OVERHEAD CRANE
M.
ABID
Interdisciplinary Research Centre, COMSATS Institute of Information Technology, Wah Cantt, Pakistan
&
Faculty of Mechanical Engineering, GIK Institute of Engineering Sciences and Technology Topi, Pakistan
author
M. H.
AKMAL
Faculty of Mechanical Engineering, GIK Institute of Engineering Sciences and Technology Topi, Pakistan
author
H. A.
WAJID
Department of Mathematics, COMSATS Institute of Information Technology, Lahore, Pakistan
&
Department of Electrical Engineering, Faculty of Engineering, Islamic University of Medina, Al-Medina Al-
Munawarah, K.S.A.
author
text
article
2015
eng
Double bridge girder overhead cranes are used for heavy duty applications in theindustry. In this paper a detailed parametric design optimization of the main girder of box type isperformed for a 150Ton capacity and 32m long span crane, after its basic design using availabledesign rules. Design optimization is performed using detailed 3D finite element analysis bychanging the number, shape and location of horizontal stiffeners along the length of the girder andnumber and location of stiffeners along the vertical direction to control any possible buckling, withminimum possible weight and for safe stress and deflection. Optimization is performed in twosteps. In the first step, keeping plates thickness constant different types and number of stiffenersare added and optimized geometry is found. In the second step, the best geometry of the first stepis further optimized for maximum allowable bending stress by changing thickness, height andwidth of the box girder with minimum possible weight. Effect of added stiffeners is highlighted incontrolling its buckling.
Iranian Journal of Science and Technology Transactions of Mechanical Engineering
Shiraz University
2228-6187
39
v.
M1
no.
2015
101
112
https://ijstm.shirazu.ac.ir/article_2952_e938282753e548e3b6b540509e04a33a.pdf
dx.doi.org/10.22099/ijstm.2015.2952
SELF-TUNING OF AN INTERVAL TYPE-2 FUZZY PID CONTROLLER FOR A HEAT EXCHANGER SYSTEM
H.
BEIRAMI
Dept. of Instrumentation and Automation Engineering, Shiraz University, Shiraz, I. R. of Iran
author
M. M.
ZERAFAT
Faculty of Advanced Technologies, Nano Chemical Engineering Dept., Shiraz University, Shiraz, I. R. of Iran
author
text
article
2015
eng
A novel technique is investigated for PID controller adaptation in order to control thetemperature of a liquid-phase reactor tank by using a heat exchanger system. As for nonlinearity,time delay problems and model uncertainties introduced by the heat exchanger, an interval type-2fuzzy system (IT2FS) is implemented to enhance and improve the total control performance.Moreover, the fuzzy inference rules which enable the adaptive adjustment of PID parameters areestablished based on error and error variations. Target tracking, oscillation control and errorevaluation for the proposed controller are compared with previously performed control strategieson the mentioned heat exchanger system. The results show that the adaptive technique for PIDgain based on IT2FS has lower error and strengthened capacity for external oscillation control andalso an acceptable tracking capability.
Iranian Journal of Science and Technology Transactions of Mechanical Engineering
Shiraz University
2228-6187
39
v.
M1
no.
2015
113
129
https://ijstm.shirazu.ac.ir/article_2953_17fb10e0e3517ce4484a166270449436.pdf
dx.doi.org/10.22099/ijstm.2015.2953
VCNC CONTOUR FOLLOWING TASKS USING ROBUST QFT CONTROLLER
J.
JAHANPOUR
Dept. of Mechanical Engineering, Mashhad Branch, Islamic Azad University, Mashhad, I. R. of Iran
author
M.
HONARI-TORSHIZI
Dept. of Mechanical Engineering, Mashhad Branch, Islamic Azad University, Mashhad, I. R. of Iran
author
M. R.
GHARIB
Dept. of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, I. R. of Iran
author
text
article
2015
eng
In this paper, the Quantitative Feedback Theory (QFT) is proposed to design acontroller for feed drive of Virtual Computer Numerical Control (VCNC) systems. The designedrobust QFT controller is also compared to two commonly used controller design methods, i.e.Fuzzy Control (FC) and Sliding Mode Control (SMC), for contour tracking problem. The positioncommands required for contour following task are evaluated by the Non-Uniform Rational BSpline(NURBS) curve interpolator with the S-shape feedrate profile for two contours, i.e. "heart"and "omega" as the case studies. After modeling the feed drive of the VCNC system, the robustQFT controller and also FC and SMC controllers are designed to achieve the allowable tolerancecontour error. The simulation results for the "heart" and "omega" contour following tasks with theaforementioned controllers were analyzed and discussed. It is found that the designed QFTcontroller not only achieves the tight contour error but also yields better satisfactory performance,especially at the corners of the tool path, compared to the other controllers used in contourfollowing applications in VCNC systems.
Iranian Journal of Science and Technology Transactions of Mechanical Engineering
Shiraz University
2228-6187
39
v.
M1
no.
2015
131
145
https://ijstm.shirazu.ac.ir/article_2954_34ff59e25e131d3c6a2f80da3a33946e.pdf
dx.doi.org/10.22099/ijstm.2015.2954
EXPERIMENTAL STUDY OF THE EFFECTS OF AIR-INJECTION, INJECTION TIMING AND COOLED EGR ON THE COMBUSTION, EMISSIONS AND PERFORMANCE OF A NATURE ASPIRATED DIRECT INJECTION DIESEL ENGINE
M.
MANSOURY
Dept. of Mechanical Engineering, University of Urmia,Urmia, West Azerbaijan, I. R. of Iran
author
S.
JAFARMADAR
Dept. of Mechanical Engineering, University of Urmia,Urmia, West Azerbaijan, I. R. of Iran
author
N.
KOUSHESHI
Dept. of Mechanical Engineering, University of Urmia,Urmia, West Azerbaijan, I. R. of Iran
author
text
article
2015
eng
In this literature, a combined method has been employed to simultaneously reducesmoke (Soot) and oxide of nitrogen (Nox) and maintain the performance parameters of dieselengine. This includes creating an air jet by designing an air-cell inside the piston body, advancedinjection timing and using cold exhaust gas recirculation. The tested engine was an MT4.244engine that worked as natural aspiration. The air-cell causes reduction in both Soot and NOxemissions. Furthermore, applying cold EGR had a noticeable effect on NOx emission reduction.Advancing injection timing, the performance parameters of the engine could be improved. Thetests were done in 25%, 50%, 75% and 100% load conditions, for the engine speed of 2000 rpm.The results showed that by simultaneous reduction of Soot and NOx emissions, performanceparameters can be kept in a suitable range. The greatest reductions in NOx and Soot emissionshave been observed in 100% load. There have been no considerable changes in BSFC (BrakeSpecific Fuel Consumption and power) while injection timing advances have been applied for5° CA and 5% EGR.
Iranian Journal of Science and Technology Transactions of Mechanical Engineering
Shiraz University
2228-6187
39
v.
M1
no.
2015
147
152
https://ijstm.shirazu.ac.ir/article_2955_9ee97d18232330078da9a9ee52ba7a8e.pdf
dx.doi.org/10.22099/ijstm.2015.2955