IFC
text
article
2017
per
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
0
0
http://mme.modares.ac.ir/article_17258_5d6bebe47305eb1ab70b02bf0f3c51a4.pdf
Predicting Nonlinear Behavior of Adipose Tissue Extracellular Matrix Based on Structural Model
behzad
seyfi
Department of Biomedical Engineering, Amirkabir University of TEchnology
author
Nasser
Fatouraee
دانشگاه صنعتی امیرکبیر
author
Abbas
Samani
دانشگاه وسترن انتاریو
author
text
article
2017
per
Adipose tissue is a loose connective tissue distributed in two main anatomic depots including subcutaneous and visceral. Since in many pathological condition and diseases associated with adipose tissue alteration, the microcomponents of adipose tissue undergoes considerable changes from mechanical characteristics point of view, it is quite vital to present an accurate structural technique for modelling tissue microstructure. Accordingly, this paper presents a structural model based on adipose tissue main components and interaction between them. Adipocytes was considered as a fluidic spheres and extracellular matrix modeled as solid media. The interaction between these two different phases simulated by solving wellknown fluidstructure interaction (FSI) problem. In order to obtain the constitutive parameters for ECM, finite element simulation results fitted to experimental uniaxial compression test data. To make a comparison between the performances of different constitutive models, three conventional hyperelastic models were used for describing the mechanical behavior of ECM. The agreement between experimental data and simulation results confirm that the presented technique has a high potential for modeling adipose tissue microstructure both in normal and pathological condition. Considering the accuracy and mathematical complexity, results show that Yeoh hyperelastic model has a better performance than two others. In all three model, results reveals that the stiffness of adipose tissue ECM is ~ (23) times higher than that of the adipose tissue.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
1
8
http://mme.modares.ac.ir/article_17019_7a7a78929c4aa0e6bc926978756786ed.pdf
Simulation and impedance control of the grasping of a spherical object with soft contact surfaces
Seyed Hamidreza
Heidary
Biomechatronics and Cognitive Engineering Research Laboratory, School of Mechanical Engineering, Iran University of Science and Technolgy
author
Borhan
Beigzadeh
استادیار، آزمایشگاه تحقیقاتی بیومکاترونیک و مهندسی شناختی، مهندسی مکانیک، دانشگاه علم و صنعت ایران
author
Mohammad
Riahi
مدیر گروه ساخت و تولید دانشکده مهندسی مکانیک دانشگاه علم و صنعت
author
text
article
2017
per
Soft tips, in human fingers, plays a great role in object grasping; specially, when we talk about isotropic and elastic matters. By other word, stability of a typical grasping is really dependent on contact conditions. Well, rolling is the type of constraint approached by this feature and focused in this paper. Grasping an elastic sphereformed ball by a pair of softtip parallel fingers is presented. For starters, by modeling objects as a massspring system, dynamic and kinematic systems of equations are derived. Then, a positionbased impedance control is developed for the supposed system. To implement and validate the suggested controller, a pair of softtip fingers, holding an elastic ball, simulated in ADAMS; this software begets a control block in the Simulink software as a plant of the control system. As a consequence, the process of grasping under the effect of controller can be simulated in real time. The result of the simulation shows the ability of controller in appropriate tracking fingers till making contacts with ball and more importantly, by graphs, stability of grasping is guaranteed.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
9
19
http://mme.modares.ac.ir/article_17007_579a7fdf56a4251a7484cfd82238e7f2.pdf
Optimization of friction stir welding parameters of dissimilar AA5052 and AA6061T6 joint for achieving optimum microstructure and mechanical properties
Alireza
Fallahi Arezoudar
دانشیار گروه آموزشی ساخت و تولید، دانشکده مهندسی مکانیک، دانشگاه صنعتی امیرکبیر، تهران، ایران
author
Akbar
Hosseini
مربی گروه آموزشی ساخت و تولید، دانشکده مهندسی مکانیک، دانشگاه صنعتی امیرکبیر، تهران، ایران
author
text
article
2017
per
Friction stir welding is a solid state process in which no fusion occurring on it. This method of welding is uses for metals that have low weldability or their fusion welds haven’t good quality. The effect of friction stir welding parameters, including rotational speed, linear speed, shoulder diameter and pin diameter on AA5052 to AA6061 dissimilar joints was studied in this paper. These parameters were optimized Using Taguchi method of Design of Experiments. then thermal simulation of process was done with ABAQUS software in which the temperature distribution results were in good agreement with the simulation results. The results of specimens tensile tests were confirmed by metallography and microhardness tests result. With increasing the linear speed and reducing the rotational speed, heat input reduced and grain size of all weld areas is decreased. The retreating side of all instances had a smaller grain size than advancing side. This is because of the thermal properties of 6061 alloy (higher conductivity and lower heat capacity), which leads to lower peak temperature and higher thermal diffusivity on that. The optimal parameters including rotational speed of 1400 rpm, linear speed of 80 mm/min, shoulder diameter of 15 mm and a pin diameter of 3.5 mm, was achieved. The maximum tensile strength of 228.3 Mpa achieved in rotation speed of 1400 RPM, linear speed of 80 mm/min, shoulder diameter of 15 mm and pin diameter of 3.5 mm.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
20
30
http://mme.modares.ac.ir/article_17008_b4a33093222fbe96b2e8bc16ddb854d1.pdf
Vibration Characteristics of FluidConveying Pipes in presence of a Dynamic Vibration Absorber
Mousa
Rezaee
Professor  University of Tabriz
author
Vahid
Arab Maleki
دانشجوی دکتری / دانشگاه تبریز
author
text
article
2017
per
The fluid induced vibration in fluid conveying pipes can cause fatigue and failure in the system. Therefore, controlling these unwanted vibrations and suppressing the vibrations of the fluid conveying pipe is important. In this paper by considering the passive vibration absorber for the fluid conveying pipe, the influence of the vibration absorber parameters on the dynamic behavior of the system is investigated. The governing equations of motion are obtained via the Newton’s second law, and analytical solutions for the characteristic equation and mode shapes of the system are obtained through the power series method. After verifying the obtained results, the effect of the vibration absorber parameters and the fluid flow velocity on the vibration behavior of the fluid conveying pipe have been investigated. Results show that by increasing the absorber mass, the effect of absorber on decreasing the oscillations amplitude is diminished. At different fluid velocities, the oscillation amplitude of the system can be reduced considerably by specifying proper values of the absorber parameters. At velocities near the critical velocity, where the oscillation amplitude reaches a maximum value, using a suitable vibration absorber may reduce the maximum oscillations amplitude of the system by 98%. The method presented in current study can be easily generalized to design passive vibration absorber for fluid conveying pipes with different boundary conditions.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
31
38
http://mme.modares.ac.ir/article_17020_4d07fbfe58d4a748d97ea4b0ce93d3e7.pdf
Discovering an empirically new relation and obtain the flow pattern map for dimpled tubes in twophase flow for refrigerant R600a
ali
vahabi
کارشناس ارشد
author
Maziar
Shafaee
University of Tehran
author
alireza
sarmadian
کارشناس
author
hooman
mashoof
کارشناس
author
text
article
2017
per
In present work, heat transfer and flow pattern map of dimpled and horizontal tubes were studied during phases of boiling and condensation of mandatory convection of hydrocarbon R600a. Empirical relationship will be expressed based on empirical data obtained by such experiments and fit the experimental results and Matlab software to show flow pattern map for such refrigerant with proper accuracy. The cycle consists of a pump, two preheaters, two testing parts, two condensers, flow meter and reversing valve. In this study, experimental evaporator is a copper tube with internal diameter of 8.7 mm and length of 1200 mm. the heat required for fluid evaporation is supplied by thermal element twisted around it. Such tube has been designed in forms of dimpled and straight models to evaluate effect of placement of dimples inside tubes. The test was conducted by refrigerant mass flow between 155 and 470 kg/m^2 s and vapor quality between 0.05 and 0.78. Moreover, flow patterns and their transitions for refrigerant R600a during flow boiling inside a helically dimpled tube and a smooth tube were visually observed and analyzed. Annular, intermittent, and stratifiedwavy flow were recognized for plain tube whereas there was no stratifiedwavy flow in flow pattern visualization of dimpled tube. Investigation clearly shows that the dimples in evaporation significantly impact the two phase flow pattern. Inside the helically dimpled tube the intermittent/annular transitions occurs at lower vapor quality value than for the smooth tube.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
39
48
http://mme.modares.ac.ir/article_17067_0c7f51d7967b62de134a893bd0783d61.pdf
Effects of convergence of the superhydrophobic walls on the performance of microchannels as heat sinks
Hamidreza
Ermagan
Faculty of Mechanical Engineering, Semnan University, Semnan, Iran.
author
Roohollah
Rafee
دانشیار هیات علمی دانشکده مکانیک دانشگاه سمنان
author
text
article
2017
per
In the present study, thermal performance of a microchannel heat sink with superhydrophobic walls is studied for different ratios of the wall convergence. To this end, threedimensional NavierStokes equations and energy equation subject to the slip boundary conditions, viz. velocity slip and temperature jump, are numerically solved using the finite volume method. Then, the variations of thermal resistance of the heat sink with the number of channels, width and heighttapered ratios, are studied for a fixed pumping power. The results show that by utilizing the superhydrophobic walls, the optimum widthtapered ratio of the channel is higher than that of the hydrophilic walls. The accentuated effect of the number of channels on thermal performance in the presence of liquidsolid interfacial slip weakens the effect of converging the width of the channel. It is also revealed that the optimum number of channels also increases to give prominence to the effect of interfacial slip by diminishing the smallest dimension of the channel. Finally, it is shown that for a pumping power of 0.05 W, using a heat sink with converging microchannels and superhydrophobic walls, reduces the overall thermal resistance by 28 percent, compared to that with conventional microchannels. In fact, the increase in fluid flow rate resulting from the use of converging microchannels with superhydrophobic walls outweighs the undesirable effect of temperature jump on heat transfer, in a sense that the heat sink performance augments considerably.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
49
58
http://mme.modares.ac.ir/article_17058_c0cf5f5154cf3806eee21f129a171795.pdf
Numerical simulation of twophase flow within an effervescent atomizer using volume of fluid model
Zahra
Alizadeh Kaklar
دانشجوی دکتری
author
mohamadreza
ansari

author
text
article
2017
per
In the present study twophase flow within the effervescent atomizer has been simulated by the volume of fluid interface tracing model using 0.08%, 0.32%, 1.24%, and 4.9% gastoliquid mass ratios and 0.38 L/min liquid flow rate. The purpose of this simulation is to study twophase flow regimes within the effervescent atomizer and their effect on the atomization quality. This study also considers the gasliquid interface instabilities in different twophase flow regimes inside the atomizer. The compressibility of gas phase which is rear in literature survey included in gastoliquid mass ratios of 1.24% and 4.9%, due to the high gas phase velocity in constant liquid flow rate and high gastoliquid mass ratios. The effect of gravitational force is considered in all simulations. The results of the simulation indicate that by increasing the gastoliquid mass ratio, the twophase flow regime inside the discharge passage transfers from bubbly flow regime with long bubbles to annular flow regime. In addition to decreasing the liquid film thickness coming out from discharge orifice (during transform of the flow regime from bubbly flow to annular flow), the liquid interface instabilities increase in the annular flow regime and besides, where segregated ligaments from the liquid interface become shorter, thinner and more unstable. This type of regime is the most efficient flow behavior for the effervescent atomizer.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
59
67
http://mme.modares.ac.ir/article_17022_80da3885695e4ce4bb0f9b38d61b64c9.pdf
Threedimensional modeling of a dewpoint evaporative cooler using a modified boundary condition and considering effects of channels’ entrance regions
Hamoon
Jafarian
دانشجوی دکتری
author
Hoseyn
Sayyaadi
دانشیار دانشگاه خواجه نصیرالدین طوسی
author
Farschad
Torabi
عضو هیئت علمی
author
text
article
2017
per
This paper presented a numerical modeling of dewpoint counterflow indirect evaporative coolers as a potential alternative to the conventional cooling systems. Unlike the conventional method of assuming constant surface heat (mass) flux or constant surface temperature boundary condition on the separating wall, the present article calculated real boundary conditions. Real boundary conditions were obtained by simultaneous solving of momentum, energy and mass transfer equations of the two flows coupled on the wall. Calculating real boundary conditions lead to a real distribution of humidity ratio and temperature on the separating wall where at each point, the summation of heat fluxes from air streams in adjacent channels is equal to the latent heat of evaporation at that point. Moreover, the model accuracy was increased through considering hydrodynamic and thermal developing flows of two air streams. The model predicted supply air temperature under different conditions, and the results were compared against experimental data as well as previous numerical models. It was shown that the maximum deviation of the supply air temperature was under ±3.3%. Then, a parametric analysis was conducted, which studies the effects of the inlet air velocity, channel gap, channel length and returned air ratio on the supply air temperature, dewpoint effectiveness, cooling capacity and pressure drop. The results indicated that increasing channel length and returned air ratio, and reducing channel gap and inlet air velocity improved the dewpoint effectiveness but increased the initial cost and pressure drop and decreased the cooling capacity.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
68
78
http://mme.modares.ac.ir/article_17059_1b1f14f3537eed77af01ffd24f7e5bde.pdf
The Novel Control Method for Voice Coil Actuator Fatigue Testing Machine
Javad
Safehian
دانشجوی دکتری تخصصی مکانیک طراحی کاربردی دانشگاه فردوسی مشهد
عضو هیئت علمی گروه مکانیک/ دانشگاه آزاد اسلامی واحد نیشابور
مسئول باشگاه پژوهشگران و نخبگان دانشگاه آزاد اسلامی واحد نیشابور
author
Ali Akbar
Akbari
عضو هیئت علمی دانشکدهی مکانیک/ دانشگاه فردوسی مشهد
author
Seyed Kamal
Hosseini Sani
عضو هیئت علمی دانشکدهی برقکنترل، دانشگاه فردوسی مشهد
ریاست بخش برق پژوهشکدهی هواخورشید دانشگاه فردوسی مشهد
author
text
article
2017
per
Developed novel adaptive controller is suitable for timevarying linear system subject to harmonic reference signal with variable average and amplitude. This controller is experienced successfully at high frequencies on voice coil actuator (VCA) fatigue testing machine which has variable timevarying dynamic. In this applicable approach, assuming having linear system around operation point and slow rate timevariation, tracking control of harmonic reference signal is replaced with regulation control of average and amplitude of harmonic reference signal. In the proposed method, a SingleInput SingleOutput (SISO) system estimated by a fourthorder model, is considered as the simplest decoupled MultiInput MultiOutput (MIMO). This causes reduction in the amount of computations and no need to complicated hardware. Consequently, the proposed method provides a realtime control for implementation of random harmonic loading with rapid changes in average and amplitude. To complete control objectives, primary control by the PI controller, dynamic saturation blocks and linearization blocks, are employed. Soft start of loading due to PI controller, provides enough time for system identification of adaptive controller and guarantee avoidance of impact on specimen and credibility of fatigue test. In addition, the using of linearization blocks for trajectory planning of command signal and using of dynamic saturation blocks, restrain the overshoot of loading and prevent excitation of unmodelled dynamics. Finally, different materials under different frequency loading are successfully tested.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
79
90
http://mme.modares.ac.ir/article_17054_051793b69d0bdde681e9338bddcedda3.pdf
AE based damage investigation in composite laminates under lowvelocity impact tests
Mohammad
Ghayoomi Mohammadi
student AmirKabir University of Technology
author
Ali
Mahdian Ahi
Master of science/ AmirKabir University of Technology
author
Jalal
Yousefi
Phd student/ AmirKabir University of Technology
author
Mehdi
Ahmadi Najafabadi
دانشیار دانشگاه صنعتی امیرکبیر، دانشکده مکانیک
author
text
article
2017
per
One of the main issues associated with application of laminated composites in industrial applications is their brittletype behavior under impact loading. The low velocity impact may lead to crucial internal damages without being detectable by visual inspection and can signiﬁcantly reduce the strength of laminated composites. The main purpose of this research is to characterize the damage mechanisms in laminated composites under low velocity impact tests. For this purpose, a quasistatic test was first utilized out to achieve initial information about impact tests. Low velocity impact tests were then employed for unidirectional glass/epoxy composite specimens, and Acoustic Emission (AE) signals were acquired during impact events. Next, AE signals were examined using wavelet approach to discriminate released energy related to each distinct damage mechanism. Besides, a method was obtained to estimate threshold impact energy from the quasistatic test, beyond which damage meaningfully extends. As a final point, the AE based approach using wavelet transform methodology was suggested to forecast the total damage area. Finally, it was figured out that this AE method can be a reliable approach in damage evaluation under impact loads in composite structures.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
91
100
http://mme.modares.ac.ir/article_17055_f203c478ce77c7db9fa8eff5246db8a9.pdf
Numerical simulation the effect of existing sulfur in the concentrate particles on flame temperature and pollutants in the flash furnace copper smelting
neda
rajabi
Mechanic, Engineering, Ferdowsi, Mashhad, Iran
author
mohammad
moghiman
مکانیک، مهندسی، فردوسی، مشهد، ایران
author
text
article
2017
per
In this study numerical simulation of the flash furnace copper smelting, was carried out to investigate the pollutants formation in combustion of sulfide concentrates and ancillary fuels. This simulation was done with use of Eulerian framework for continuous phase flow field and Lagrangian approach for discrete phase particles. For modeling of combustion flow and applying turbulence effects on the rate of chemical reactions used the composition of Probability Density Function (PDF) and RNG, kε model. Due to the thermodynamically condition of flash smelting furnace, the combustion of sulfur which is exist in Concentrate particles occurs explosively and with high radiation. Calculation The effect of radiative heat transfer was done by the discrete ordinate method (DOM). The numerical simulation results show, under combustion conditions with extra air and in partly high temperatures (>1273K) the only noteworthy sulfurous species are SO2 and in colder points SO2 is transformed to SO3. In the points which enough oxygen is not available, the concentration of SO, and S2 unburned are increased. The results also show, the maximum temperature is decreased with increase of existing sulfur in the concentrate particles and the minimum temperature is increased, because the radiation intensity is increased so the furnace temperature is more uniformly. This behavior has a significant influence on reduction thermal NOx emission.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
101
108
http://mme.modares.ac.ir/article_17057_f31d01f9bb315bc69526fb9a8ac36f8f.pdf
Experimental study of projectiles with flat, conical and hemispherical nose shapes on low velocity impact on GLARE 3
Mohammad
Ekrami
کارشناسی ارشد مکانیک جامدات، گروه مهندسی مکانیک، واحد یادگار امام خمینی (ره) شهرری، دانشگاه آزاد اسلامی، تهران
author
Hamed
Ahmadi
استادیار مکانیک جامدات، دانشکده مهندسی مکانیک، دانشگاه تربیت مدرس، تهران
author
Mohammad
Bayat
عضو هیئت علمی دانشگاه آزاد اسلامی
author
Hadi
Sabouri
استادیار مکانیک جامدات، گروه مهندسی مکانیک، دانشکده فنی، دانشگاه خوارزمی، تهران
author
text
article
2017
per
In this paper, drop weight impact tests using projectiles with different nose shapes on GLARE 3 are examined experimentally. GLARE targets are made of two aluminum sheets and six composite layers by hand layup method. The composite layers are constructed using unidirectional Eglass fiber and cy219 resin with adding hy5161 as a hardener. The projectiles are manufactured in flat, hemispherical and conical 90̊ nose shapes and hardened. The projectiles collide to targets with initial impact energies of 40, 55 and 70 Joule. In this study, the effects of nose shape at the maximum impact force, the penetration, the energy absorption, and damage zone are examined. The results show that conical projectile in all three impact energies and hemispherical projectile at 55 and 70 Joule fully penetrate targets. Under impacts of the flat projectile, a shear plug is formed on the upper face of targets and a plastic deformation is created on the bottom face of targets in impact energies of 40 and 55 Joule. For hemispherical projectile at 40 Joule and for flat one at 70 Joule, the tensile stresses in the aluminum sheet located at the bottom face of target result in longitudinal crack. Moreover, results show that the maximum and minimum contact force and energy absorption are occurred in the projectile with flat and conical nose shapes, respectively.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
109
118
http://mme.modares.ac.ir/article_17056_6a209d64abfbda8f1098f7db78821272.pdf
Identification of the heat conduction coefficients of a functionally graded material with inverse application of the boundary elements method and using imperialist competitive algorithm
seyed asadollah
shaker
yazd university
author
mahmud
khodadad
هیات علمی دانشگاه یزد
author
hosein
ashrafi
professor assistant, kashan university
author
text
article
2017
per
Identification of the thermal conductivity of a functionally graded material (FGM) is considered as an inverse heat conduction problem. In this investigation, the measurements of the temperatures on the portion of the 2D body where heat flux is specified as the boundary condition and/or the heat flux on the portion of the boundary where temperature is specified as the boundary condition are used as additional data needed to identify the thermal conductivity of the FGM domain in an inverse procedure. The thermal conductivity is approximated as a quadratic function of only one direction, and therefore three constant coefficients should be estimated simultaneously. The solution of the direct heat conduction problem for FGM domain is obtained using the boundary elements method (BEM). The imperialist competitive algorithm (ICA) which is an evolutionary and metaheuristic global optimization is used to identify the constants in the thermal conductivity function of the quadratic FGM. An inverse computer code is developed which employs the boundary temperature and heat flux measurements data obtained by solving the direct boundary elements code with known thermal conductivity. To show the feasibility and effectiveness of the developed inverse code, a number of example problems are solved and results are verified.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
119
130
http://mme.modares.ac.ir/article_17066_d6b0624caa8675b16c55fb4c54955bb0.pdf
Theoretical and Experimental Investigation of Heat Generation in Bone Drilling: Determination of the Share of Heat Input to the Bone Using Machining Theory and Inverse Conduction Heat Transfer
Ehsan
Shakouri
Islamic Azad Universitytnb
author
Mehdi
Maerefat
دانشگاه تربیت مدرس
author
text
article
2017
per
Bone fracture occurs as a result of accident, old age and disease. Generally bone fracture treatment consists of stabilizing the fractured bone in the right position. In complex fractures, stabilizing internal and external tools and equipment is used to stabilize the fractured bone in position. Bone drilling is required in order to connect fixating devices. The forces required for chip formation increase the temperature during bone drilling. The phenomenon of thermal necrosis of the bone occurs if the temperature exceeds 47°C. Thermal necrosis inhibit bone fixation and causes the wrong bone healing. In this study has been trying to calculate the heat of drilling process using the machining theory and estimate the share of heat input to the bone by the Weiner theory. Drilling tests conducted on samples of bovine bones and temperature changes in the location of the hole are measured and using inverse conduction heat transfer method, the heat input is calculated and compared with the theoretical heat. Results showed that the experimental and theoretical heats at different processing conditions are close to each other and revealed that the machining and Weiner theories are able to predict the heat input to the bone and temperature changes in the position of the hole.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
131
140
http://mme.modares.ac.ir/article_17076_d1d69fd288947549c73621f7c4bf1cd6.pdf
Vibration Analysis of a Laminated Deep Curved Beams Subjected to a Moving Load by Considering the Rotary Inertia and Shear Force
Hoda
Sarparast
تربیت مدرس
author
Siamak
Esmaeilzade Khadem
author
text
article
2017
per
The vibration analysis of curved composite structures under the moving vehicles, is rarely investigated in litreture. Therefore, this paper is studied the dynamic response of a simply supported laminated deep curved beam under a moving load based on Timoshenko beam theory.It is assumed that the curvature of the beam and the amplitude and the speed of the moving load areconstant.The governing equations of motion for the system is extracted by Hamilton principles. A numerical and analytical methods are applied to obtain the dynamic response of the system.Also, the critical speed of the moving load and the fundamental frequency of the beam are obtained. The effects of the moving load characteristics, geometrical and material parameters such as the moving load speed, the radius of curvature and the modulus of elasticity in principal direction on the dynamic responses, fundamental frequency and critical speed of the system are investigated. The results show that the minimum and maximum deflection of the beam are occurred for layup [90/0/90/0] and [45/45/45/45]respectively. Furethermore, the increasing of the speed movingload leads to the decreasing thedynamic deflection. It is also shown that the increasing of the radius of the curved beams leads to the decreasingof the frequency and critical speed moving load.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
141
151
http://mme.modares.ac.ir/article_17077_167540379b26bc0c77a12e0f291afbac.pdf
Propellant Management Device (PMD) Design Optimization of Hydrazine Fuel Tank
Hassan
Naseh
پژوهشگاه هوافضا
author
Ali
Alipour
فارغ التحصیل کارشناسی ارشد مهندسی فضایی دانشگاه آزاد
author
text
article
2017
per
The purpose of this article is to design the optimum method of Propellant Management Device (PMD) of hydrazine fuel tank which used in zerogravity conditions. To this end, numerical methods are used to analysis of the tank and the fuel behavior inside the tank with PMD to optimize system design parameters. Hence, Ansys version 17 software used to finalize modelling, analysis, meshing and consideration of fuel behavior in PMD by utilizing the Volume Of Fluid (VOF) method. Also Solid Works software version 2016 is used to primary PMD and tank modeling. Then, numerical simulation is performed to consider PMD's performance and to illustrate the capillary phenomenon for continues fuel transferring in zerogravity conditions. The design variables in tank and PMD optimization respectively are: minimizing the tank weight to safety factor ratio; dimensional specifications of tank and PMD (height, diameter, length and width dimensions). The objectives of PMD optimization are to achieve maximum volumetric and mass flow rate values. On the other hands, to achieve the most desirable amount of fuel to PMD, that at the end of the time of simulation used by flow rates curves. Numerical analysis results that are obtained include: optimal system parameters related to the specifications of the tank with minimum weight and maximum safety factor and also optimal system parameters related to specifications of PMD with maximum performance of mass and volume flow rates in zero gravity. In conclusion, by comparing the existing systems with the optimal system parameters results will be verified.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
152
160
http://mme.modares.ac.ir/article_17078_1c90b91192408a09f7f567e1e722b864.pdf
Continuous adjointbased shape optimization for low reynolds number oscillating airfoils in turbulent flow on unstructured grids
Mohammad
Ghaffari
دانشگاه فردوسی مشهد
author
Ali
Tavakoli Sabour
سازمان پژوهشی باقرالعلوم
author
Mahmoud
Passandideh Fard
دانشگاه فردوسی مشهد
author
text
article
2017
per
The growing and diverse applications of low Reynolds number operating vehicles impose the need for their accurate study. Optimization is an important part of computational science that can improve the performance and increase the efficiency of the initial geometry. most of the research studies on aerodynamic optimization were focused on high Reynolds number airfoils. But for aerodynamic devices that have small dimensions, like MAVs, usually the flow speed is low and thus the unsteady effects caused by boundary layer separation cannot be neglected. In this article, oscillating airfoil with pitching motion in turbulent and low Reynolds flow has been optimized with the continuous adjoint method. Drag to lift ratio was chosen to be the objective function and free form deformation parameters is adopted for the surface geometry perturbations. Since aerodynamic optimization generally consists of two parts, first solving the flow equation and then computing the gradient of the objective function, in this article in order to evaluate the accuracy of the optimization process both has been validated. The results show that the adjoint equation converges well and with specifying the suitable constraints, the designed shape approaches to the most optimized level without the loss of performance.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
161
170
http://mme.modares.ac.ir/article_17079_bed328c9bcd5c885eddfe92a8d41ceff.pdf
Discrete dislocation plasticity investigation of creep deformation in nickelbased single crystal superalloys
Siamak
Soleymani Shishvan
ِDepartment of Structural Engineering, Faculty of Civil Engneering, University of Tabriz, Tabriz, Iran
author
text
article
2017
per
High temperature creep in nickelbased superalloys is investigated by discrete dislocation plasticity (DDP). A twodimensional unite cell model representing microstructure of superalloy and comprising γ^' particles in γ matrix phase is considered under uniaxial constant stress loading. While plastic deformation of γ phase occurs by a combination of dislocation glide and dislocation climb coupled to the diffusion of vacancies, elastic γ^' particles undergo deformation due to the stressdriven interfacial diffusion at the γ/γ^' interfaces in addition to bulk elastic deformation. It is noted that diffusion of vacancies is explicitly considered where local concentration of vacancies determines climb of dislocations. This model predicts the onset of tertiary creep in superalloys as extensively observed in experiments for commercially important nickelbased superalloys at moderate stress and temperature levels. Possible associated mechanisms are accordingly discussed. Moreover, effects of parameters such as volume fraction of γ^' particles are studied and discussed. Superalloys with three values for volume fraction of γ^' particles are investigated and obtained results indicate that the volume fraction of γ^' particles plays an important role in the creep behaviour of superalloys. Results of this study can be used in a continuum constitutive rule to investigate structural components under operational conditions.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
171
179
http://mme.modares.ac.ir/article_17068_b0fab7b7e42ed2fec839ebb88bfa57dc.pdf
Investigation of mechanical properties and microstructure for Al/Cu/SiC composite produced by Cross Accumulative Roll Bonding process
Davood
Rahmatabadi
کارشناس ارشد مهندسی مکانیک/ دانشگاه علم و صنعت ایران
author
Moslem
Tayyebi
کارشناس ارشد مهندسی مواد/ دانشگاه صنعتی سهند تبریز
author
Ramin
Hashemi
Assistant professor / Iran University of Technology
author
Beitallah
Eghbali
استاد دانشکده مهندسی مواد/ دانشگاه صنعتی سهند تبریز
author
text
article
2017
per
In this investigation, for the first time, used from Cross Accumulative Roll Bonding to produced Al/Cu/SiC composite. Microstructure and mechanical properties of produced composite were evaluated by using of optic microscopy, scanning electron microscopy, uniaxial tensile test, microhardness, respectively. Results of microstructure showed that after eight pass, has a perfectly uniform distribution of reinforcing and strong bond between particles. Tensile strength fell at the first and then continuously increased. Also trend of tensile strength and elongation was similar. Microhardness value for aluminum and copper layers of produced composite 1469% and 163% enhanced compare to annealed samples, respectively. Investigation of tensile fracture surface after eight pass showed that the mechanism of fracture in shear ductile for Al matrix.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
180
184
http://mme.modares.ac.ir/article_17080_dec06e78c2e5fbfed6c3d4229c374458.pdf
Numerical investigation of back flow arrester effect on altitude test simulator starting performance
Nematollah
Fouladi
کارشناس پژوهشی/پژوهشگاه فضایی ایران
author
text
article
2017
per
During transient phase of motor burning in an altitude test simulator, the low momentum exhaust combustion gases could not establish supersonic flow in the exhaust diffuser. This leads to a reverse flow of the exhaust gases into the vacuum chamber through the annular gap between nozzle and diffuser walls. This spoils the vacuum in the chamber and it is potentially dangerous for measurement instruments inside the vacuum chamber. In this research; at the first, the physics of the flow at initial transient phase of motor burning is investigated numerically and the backflow phenomenon is illustrated. Then, the influences of backflow arrester (BFA) in variations of vacuum chamber pressure and temperature are studied at the transient starting phase. It has been found that applying BFA to decrease the backflow to the vacuum chamber has no significant effect on starting time of the diffuser but it has strong effect on peak pressure and temperature reduction of the vacuum chamber. It is although found that attaining to the steady condition in vacuum chamber is delayed with this instrument. However, using oneway backflow arrester of reasonable size, both the starting time of diffuser and the peak temperature of the vacuum chamber experience a strong reduction. Although, the vacuum chamber steady condition is accelerated with this alternative. Therefore, this device is more suitable than conventional BFA for transient starting phase of the altitude test simulators.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
185
196
http://mme.modares.ac.ir/article_17060_d992745fea4c8ee30d7214906c1577ab.pdf
A Study on the Nonlinear Vibrations of Electrostatically Actuated Micro Beams with Anelastic StressStrain Behavior
Amir
Veysi Gorgabad
دانشجوی دکتری، دانشکده مهندسی مکانیک، دانشگاه ارومیه، ارومیه، ایران
author
Ghader
Rezazadeh
استاد مهندسی مکانیک، دانشکده مهندسی مکانیک، دانشگاه ارومیه، ارومیه، ایران
author
Rasoul
Shabani
استاد مهندسی مکانیک، دانشکده مهندسی مکانیک، دانشگاه ارومیه، ارومیه، ایران
author
text
article
2017
per
In this paper the nonlinear dynamic of an electrostatically actuated microbeam with viscoelasticanelastic behavior considering size effect is studied. The microbeam is deflected using a bias DC voltage and then driven to vibrate around its deflected position by a harmonic AC load. Regarding the stressstrain behavior of anelastic materials, the constitutive equation of microbeams is derived based on the modified couple stress theory (MCST). Assuming electrostatic and midplane stretching forces as the main sources of the nonlinearity and taking advantage of the Galerkin projection method, the partial differential equation is transformed to a set of nonlinear ordinary differential equation (ODE). Multiple scales method is used to obtain an approximate analytical solution for nonlinear resonant curves. The effect of different mechanical behaviors of materials including elasticity, viscoelasticity and anelasticity, length scale parameter, anelastic relaxation time and relaxation intensity on the nonlinear vibration analysis are studied. The results demonstrate that there is very large dependence of resonance curves on the different mechanical behavior of materials. It is seen that there are special conditions which the elastic and anelastic models predict similar results while the predicted results from anelastic and viscoelastic models are different from each other. It is found that the relaxation intensity and anelastic relxation time can change the resonant curves significantly.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
197
206
http://mme.modares.ac.ir/article_17061_87fc7bf5aca3074c116850f852fa1631.pdf
A HyperViscoelastic Model for an Individual Stem Cell Subjected to Cyclic Loading for Mechanical Modulation toward Differentiating to Fibrochondrocytes
Bahman
Vahidi
Assistant professor/University of Tehran
author
Esmaeel
Rahimpour
MSc student/University of Tehran
author
Zahra
Mollahoseini
MSc student/University of Tehran
author
text
article
2017
per
Stem cells due to their ability of selfrenewing and the potential of differentiating to different cell lineages are the ideal choices in regenerative tissue engineering. Under cyclic loading, these cells could differentiate to those kind of cells that experience similar conditions inside the body, like osteocytes and chondrocytes. In this research, the purpose is to investigate the effect of the 10 percent cyclic strain with the frequency of 1 Hertz on the mechanical response of a single mesenchymal stem cell cultured in a fibrin hydrogel block, using the finite element method and considering the role of integrins and implementing the Simo’s hyperviscoelastic model for the cytoskeleton as long as the uniaxial loading leads the cell to differentiate toward Fibrochondrocyte. The results of presented model show that the averages of the circumferential, radial and shear stresses are 240, 260 and 140 Pascal, respectively and corresponding forces are 24, 45 and 15 PicoNewton. The results imply that stresses and forces generated inside the cytoskeleton are large enough to elicit a different response from the cell. This research results can be very effective for better designing of biological experiments.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
207
216
http://mme.modares.ac.ir/article_17103_07b2f03a35a668516b1dc84e8e2b356f.pdf
Reliability analysis of mechanical systems using directional simulation and an efficient importance sampling technique
Mohammad Reza
Moarefzadeh
استادیار دانشگاه امام حسین (ع)
author
text
article
2017
per
Reliability analysis of mechanical systems, in some special circumstances, may suffer technical difficulties which need desirable solutions. One such a case may exist when working in a space of highly correlated random variables and/or the space of random variables with extremely different variances. If in these spaces; which are socalled "extremely nonproportional spaces"; the relevant limit state function is also highly nonlinear, simulation methods are normally preferred for reliability analysis. Directional simulation is one of these methods which is fully wellknown. This method, however, may be not efficient if it is crudely applied in these spaces. In such conditions, directional simulation often needs a massive computational effort in order to achieve good and reasonable results. In this paper reliability analysis of a blade of a hydrokinetic turbine (as an important mechanical system) is performed whose random variables' variances are extremely different and thus create a nonproportional space for directional simulation. To make the analysis more efficient, use of an importance sampling technique with a set of novel relationships is proposed in this paper. These relationships make the required calculations not only possible, they facilitate the computations to be very fast and efficient compared to those normally used in conjunction with traditional importance sampling methods.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
217
224
http://mme.modares.ac.ir/article_17098_2a18b311950de559cb3e59926792f515.pdf
Numerical Analysis of compressible flow using ECUSP2011 (LDE) method in Edgebased data structure in different meshes
Vahid
Esfahanian
استاد/مرکز تحقیقات خودرو، سوخت و محیط زیست دانشگاه تهران
author
Behnoud
Jodeiri Habibi
کارشناسی ارشد دانشگاه تهران
author
Maziar
Shafaee
University of Tehran
author
text
article
2017
per
One of the methods for solving NavierStokes equations in order to analyse aerodynamic flows is using finite volume method. Since aerodynamic flows are mostly in the range of compressible flows, here one of the density based algorithm (CUSP) have been studied to connecting equations. So here by adding LD (Low diffusion) part to the CUSP method a new method LDE (Low diffusion ECUSP) have been created which containing new improved discretizations and it has been extended for a unstructured two dimensional mesh. Because of using edgebased data structure it gives the ability to solve the unstructured and structured meshes. Also the discretization of time section is done explicitly by RungeKutta method. It has acceptable stability range in compare with the amount of calculation utilized. Then, the results of new improved method (LDE) have been studied for a unstructured 2d mesh and compared with old method which it has been improved for unstructured mesh. The results show that the convergence time and the number of iterations to reach desired error are reduced. Also error percentage of numerical results like pressure coefficient is reduced. Moreover, dissipation of this new method does better than first method in terms of capturing shock location in a proper way.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
225
235
http://mme.modares.ac.ir/article_17096_6da1afd9a52699cb09a6d47a05db0fca.pdf
Analytical and Numerical Analysis of Chaos in Attitude Dynamics of a Satellite in an Elliptic Orbit
Seyed Hossein
Sadati
Assistant Professor
author
Mohammad Reza
Chegini
دانشجوی دکترا
author
Hassan
Salarieh
هیئت علمی
author
text
article
2017
per
In this paper, we investigate chaos in attitude dynamics of a rigid satellite in an elliptic orbit analytically and numerically. The goal in the analytical part is to prove the existence of chaos and then to find a relation for the width of chaotic layers based on the parameters of the system. The numerical part is aimed at validating the analytical method using the Poincare maps and the plots obtained on the sensitivity to initial conditions. For this end, first, the Hamiltonian for the unperturbed system is derived. This Hamiltonian has three degrees of freedom due to the threeaxis free rotation of the satellite. However, the unperturbed attitude dynamics has two firstintegrals of motion, namely, the energy and the angular momentum. Next, we use the SerretAndoyer transformation and reduce the unperturbed system Hamiltonian to onedegree of freedom. Then, the gravity gradient perturbation due to moving in an elliptic orbit is approximated in SerretAndoyer variables and time. Due to this approximation and simplification, the system Hamiltonian transforms to a onedegreeoffreedom nonautonomous one. After that, Melnikov’s method is used to prove the existence of chaos around the heteroclinic orbits of the system. Finally, a relation for calculating the width of chaotic layers around the heteroclinic orbits in the Poincare map of the SerretAndoyer variables is analytically derived. Results show that the analytical method gives a good approximation of the width of chaotic layers. Moreover, the results show that the analytical method is accurate even for orbits with large eccentricities.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
236
244
http://mme.modares.ac.ir/article_17082_2aa00a189834bfc272b81e0de0d477b2.pdf
The effect of geometrical imperfection on the axial buckling of unstiffened and stiffened composite cylinders with and without cutout
Ali
Talezadehlari
دانشجوی دکتری دانشگاه تربیت مدرس
author
Gholam Hossein
Rahimi
Tarbiat Modarres Univ
author
text
article
2017
per
Although many researchers investigated the effect of geometrical imperfection on the buckling load of unstiffened shells, the stiffened shells were not studied yet. In this paper, the effects of geometrical imperfection the buckling load of unstiffened and stiffened composite shell with and without cutout are investigated. For this goal, several specimens are manufactured and tested. The mechanical properties of fibers and resin matrix and volume fraction of fibers in the shell and the stiffeners are determined based on the standard tests. Finally, the mechanical properties of each component are calculated by micromechanical relations. These properties are used for finite element modeling by ABAQUS package. Linear eigen value analysis and nonlinear RIKS method which can consider the geometrical imperfection are used. FE results are validated in comparison with experimental tests. Using FE model, the effects of imperfection amplitude on the buckling behavior of unstiffened and stiffened shell with and without cutout are studied. The results show that geometrical imperfections have more effect on the buckling load of unstiffened shells in comparison with stiffened ones. Nevertheless, ignoring these imperfections and using eigen value analysis overestimate the buckling load. This fact is more evidence for shells without an opening. In perforated shells, the cutout itself represents an imperfection that is much more significant than geometric imperfections.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
245
256
http://mme.modares.ac.ir/article_17083_4b68568c1a67a44db14362d3f66db1c8.pdf
Performance enhancement of tubeintube heat exchanger utilized in mechanical vapor compression system along with its semiempirical Nusselt number
Seyed Mostafa
khodashenas
دانشجو دانشگاه خواجه نصیرالدین طوسی
author
Mahsa
Hajialibabaie
دانشجو دانشگاه خواجه نصیرالدین طوسی
author
Ali
Keshavarz Valian
دانشیار دانشگاه خواجه نصیر الدین طوسی
author
text
article
2017
per
Vapor compression is an effective method of desalination in a small scale system. Such system has two hot outlet flows. These flows are used to preheat the feedwater. In this research, tubeintube heat exchanger with different number of inner tubes was designed and constructed as preheater. This heat exchanger contains many inner tubes where each tube is a separate inner flow line for hot flow. Heat exchanger was tested with one, two and three inner tubes. Volumetric flow rates varried from 30 to 120 lit/hr in annulus and 20 to 90 lit/hr for inner tubes respectively. The results showed that by changing number of inner tubes from 1 to 3, heat transfer increased 29%. However, 38.4% decrease in equivalent hydraulic diameter led to 22% drop in average nusselt number. Afterward, a dimensionless coefficient of performance enhancement, defined as the ratio of heat transfer rate variation and the required pumping power, used to determine number of inner tubes. The results implied that heat exchanger performance improved by increasing the number of inner tubes from 1 to 2. But there is no significant improvement when number of inner tubes changes from 2 to 3. Finally, a semiemperical equation is presented for determination of Nusselt number in a heat exchanger with two inner tubes. This study indicated that this type of heat exchanger has the best performance for the system within the tested range.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
257
264
http://mme.modares.ac.ir/article_17106_c77c7174950c8d24a6bec82ae4d53e2e.pdf
Reliabilitybased topology optimization of continuous structure using particle swarm algorithm
Hamed
Mohammadzadeh
Mechanical Engineering Department, Ferdowsi University of Mashhad
author
Mohammad Hossein
Abolbashari
دانشگاه فردوسی مشهد
author
text
article
2017
per
Reliability and optimization are two key elements for structural design. The reliabilitybased topology optimization (RBTO) is a powerful and promising methodology for finding the optimum topologies with the uncertainties. In this paper, the particle swarm algorithm (PSO) using performance measure approach (PMA) is proposed in the RBTO procedure. Conventionally, the approximate limit state function along with the most probable point (MPP) search algorithms is used for calculation the reliability index. On the other hand, the choice of penalty function for having a convergent search plays a critical role. In addition one does not need to use approximate limit state function and calculating the derivatives of limit state function with respect to random variables. Furthermore, the convergence problem of the MPP search algorithms for complicated limit state functions does not exist. This paper presents RBTO using bidirectional evolutionary structural optimization (BESO) with an improved filter scheme. The topologies obtained by RBTO are compared with that of obtained by deterministic topology optimization (DTO). Results of the RBTO using PSO show that PSO can be effectively applied to RBTO and its use is quite simple.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
265
272
http://mme.modares.ac.ir/article_17109_61ff99ca423aa6e391a774b4ebabaf56.pdf
Numerical Modelling of Flood Waves Propagation in Sewer Networks using one and TwoDimensional Modified HLLC Method
Hossein
Mahdizadeh
Faculty member of Birjand University
author
Hadi
Cheharbidi
M.Sc graduate in CivilEng from Graduate University of Advanced Technology, Kerman, Iran
author
Sadegh
Moodi
M.Sc graduated in CivilEng from University of Sistan and Baluchestan, Zahedan, Iran
author
text
article
2017
per
Modelling of flood waves within surface and subsurface network is quite complicated. This complexity is mainly with respect to different flow regimes propagation into the sewer network which interacts with each other at connections between underground networks. The main purpose of the present paper is modelling and hydrodynamic prediction of these types of bore interactions using the shallow water equations. The shallow water equations are then solved using a secondorder accurate HLLC Riemann which is able to model the wave propagation over wet and dry states based upon a combination of particular Riemann wave speeds. Friction terms are treated in a separate way within the associated source terms. First, the numerical solver is employed to model the shock and rarefaction waves over the wet and dry states and the achieved numerical results are compared with the exact solution. Then, the effect of friction terms for the onedimensional dam failure propagation over wet and dry bed is considered and the computed results are compared with the STARCD which is a NavierStokes solver. Finally, twodimensional flood wave propagation is modelled within a rectangular sewage section and the obtained results are validated with the threedimensional STARCD results. The numerical results demonstrate that the defined numerical solver in both one and twodimensional provides very good agreement with the exact solution and NavierStokes solver.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
273
282
http://mme.modares.ac.ir/article_17110_8c5906aad52a76e252f960372a00fcaf.pdf
Evaluating modulated gradient model in computing subgrid scale tensors
Elyas
Kermani
دانشگاه فردوسی مشهد
author
Ehsan
Roohi
عضو هیات علمی / دانشگاه فردوسی مشهد
author
text
article
2017
per
Accurate modeling of the subgrid scales (SGS) is crucial in determining the accuracy of the large eddy simulations (LES) in turbulent flow analysis. In recent years, new branches of the subgrid scales models called gradientbased models were developed in computing the subgrid scales stresses and heat fluxes and used in large eddy simulations. In this work, the modulated gradient model (MGM) equations were implemented in the OpenFOAM package, and pimpleFoam solver was modified to improve the solution accuracy. The modulated gradient model is based on the Taylorseries expansion of the subgrid scales stress and employs the local equilibrium hypothesis to evaluate the subgrid scales kinetic energy. To assess the accuracy of the modulated gradient model as well as the improved pimpleFoam solver, turbulent channel flow at a frictional Reynolds number of 395 was simulated via the OpenFOAM package and results were compared with the direct numerical simulation (DNS) data as well as the numerical solution of the Smagorinsky, Dynamic Smagorinsky, Deardorff models. The results show that modulated gradient model evaluates first and second order turbulence parameters with a highlevel of accuracy.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
283
294
http://mme.modares.ac.ir/article_17107_e1b1dda97fb5e1d69c679baad51cf41d.pdf
Investigation of the incremental tube forming process and the influence of the vital process parameters on the quality of final product
Ali
Basti
Assistant Professor/ University of Guilan
author
Hamed
khanipoor
آزاد
author
text
article
2017
per
Manufacturing structures with light weight and high strength in the industry is growing. Therefore, use of bent profiles and tubes in structures is increasing. In this paper, method of the incremental tube forming for bending tube is investigated. In this method using combination of spining and bending tube simultaneously improves the bending process for highstrength metals. The analytical model for incremental tube forming process is provided. The model is used for understanding the physics of the process and determine the amount of the required bending moment. In addition, numerical modeling of the incremental tube forming process for to forecast failures caused by bending is performed. The numerical modeling has been used to evaluate the effective parameters on the incremental tube forming process, such as feeding the second step, the rotational speed of spinning tool, feeding tube axis in the whole process and the effect of attack angle the spinning rolls and the results show The numerical model can be used to examine defects related to the speed of the process and Before producing the appropriate parameters to produce higher quality final product selected.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
295
306
http://mme.modares.ac.ir/article_17102_61949ba1558b9587e64eab6c18f443ea.pdf
Effect of edge preparation on residual stress of welding in dissimilar joints
mehran
charkhi
دانشجوی کارشناسی ارشد/ دانشکده مهندسی مکانیک/ دانشگاه تربیت مدرس
author
Davood
Akbari
استادیار دانشکده مهندسی مکانیک  دانشگاه تربیت مدرس
author
text
article
2017
per
In this paper, thermomechanical behavior of the welding process was analyzed to determine the effect of edge preparation on the residual stress magnitude and distribution in dissimilar joints. By using a verified finite element model, an efficient user subroutine was developed to consider the effects of phase transformation. In order to verify the model, experimental data for similar and dissimilar joints, obtained by deep hole drilling method, were utilized. Good agreement was observed between the finite element and experimental data. The results indicated that the developed computational method is an effective tool to predict the residual stress of dissimilar weld joints. The present finite element model was developed in a buttwelded pipe to consider the effect of pipe wallthickness, groove shape and root opening distance. It was observed that the pipe wallthickness has important influences on the distribution and magnitude of residual stress. Moreover, By increasing the pipe thickness in the dissimilar buttwelded pipes, tensile axial residual stresses on the inner surface of the dissimilar joint decreased on the stainless steel side, but only a small variation was observed on the carbon steel side. compressive axial residual stresses on the inner surface and the tensile axial residual stresses on the outer surface increased by increasing the pipe wall thickness especially on the carbon steel side. Increasing of the weld groove shape and root opening distance lead to higher compressive axial stresses on the inner surface and higher tensile axial stresses on the outer surface, only on the carbon steel side.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
307
315
http://mme.modares.ac.ir/article_17097_15faa5b3ee5e06ca134365bb7d2e7075.pdf
Investigation of experimental and numerical simulation of residual stresses distribution of rolling mill rolls in ultrasonic peening technology
Alireza
Abbasi
دانشگاه کاشان
author
Saeid
Amini
دانشیار دانشکده مهندسی مکانیک، دانشگاه کاشان
author
Ghanbarali
Shikhzade
دانشگاه کاشان
author
text
article
2017
per
In this study, a nondistractive method of xray diffraction (XRD) was used to determine residual stress of rolling mill rolls made of graphite steel (GSH48). This method utilizes the variations of distance between crystal planes as strain. The determination of residual stress was performed samples in different depths before and after conducting ultrasonic peening technology. In UPT process, impacts were exerted on the workpiece ball tool, resulting in the improvement of some mechanical properties such as residual stress by creating work hardening and compression. After the simulation and manufacturing of ultrasonic vibratory tool and then the installation of that on lathe machine, UPT operations were conducted on the prepared samples. Measuring residual stress from surface to 0.5 mm depth was performed before and after the UPT process. After the numerical simulation of the UPT, the distribution of experimental residual stress and numerical simulation was compared that the results suggested the increase of compressive residual stress about 0.4 mm from the surface after the UPT process. The rise of compressive residual stress in the rolling mill rolls leads to the increase of their strength and fatigue life and as a result, their working efficiency is boosted. After the UPT process, the grain size of the surface was calculated from the model of the xray diffraction using ViliamsonHall relation that grain size was obtained 60.2 nm. The refinement of surface structure arises because of displacement arrangement again due to vibration with high frequency and severe plastic deformation after the UPT process.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
316
324
http://mme.modares.ac.ir/article_17105_5f5bda69f886b9c748cbec187dc99679.pdf
Practical implementation of a PID  Model Reference Adaptive Controller (MRAC) for a 2DOF Camera Gimbal
Mahdi
Haj Mohammadi Hossein Abadi
دانشگاه اصفهان
author
Hamed
Shahbazi
دانشگاه اصفهانگروه مهندسی مکانیک
author
Hossein
Karimpour
دانشگاه اصفهان
author
Kamal
Jamshidi
دانشگاه اصفهان
author
text
article
2017
per
Using model reference adaptive control, we are looking for automatic setting of controller parameters such that the system response under different inertial conditions follows a single reference model. A camera stabilizer or gimbal consists of a movable stand for camera that enables a smooth picture capture. One of the inconveniencies of the commercial gimbals is that they are specific to carry their own cameras. If a new camera is installed on them, the gimbal cannot maintain its primary function properly. This problem occurs because of the different mass, inertia and centroid position of cameras. One of the important aspects in this particular application is the realtime implementation of control laws developed on software environments such as MATLAB on the real system. In this paper, a twodegrees of freedom gimbal has been designed and fabricated with paying attention to use hardwares ith fast response time. Then a PID Model Reference Adaptive Control has been implemented on this hardware. Finally, the efficiency and robustness of this model reference adaptive controller was investigated both numerically and practically against various sources of disturbances .
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
325
332
http://mme.modares.ac.ir/article_17185_a14d7957ca96bf48752164e64032fda4.pdf
Optimization and advanced exergy evaluation of a ClausiusRankine cycle to be used in solar power systems
Nozar
Akbari
عضوهیات علمی
author
Soheil
Sheikhi
مربی
author
text
article
2017
per
Regarding the growing cost of energy, shortage of resources, and environmental issues, the importance of reducing energy consumption and optimization of related industries has been revealed more than anytime. Solar energy is one of the suitable solutions to acquire clean and cheap energy. The first step is to design the cycle using Aspen HYSYS simulator. After that exergy analysis is carried out on the proposed system. Results show that LPT2, LPT3 and HEX2 have the highest exergy destruction and should be considered for revision. Results of exergy analysis are then examined more deeply with the help of advanced exergy analysis. In this section exergy destruction is divided into four parts, endogenous/exogenous and avoidable/unavoidable to investigate the precise reason of the components’ exergy destruction. Results show that the three components which had the most exergy destruction, are the real reason behind exogenous exergy destruction of the system so by optimizing these components we can also decrease the total exergy destruction of the system too. At last by choosing the right variables and total produced work as the primary function, the optimization is done using the Aspen HYSYS optimizer and the optimized parameters are compared to the basic parameters which resulted in more power production and less exergy destruction and production cost.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
333
342
http://mme.modares.ac.ir/article_17104_f19ad30b2cd1af3225589d1e1d3631d7.pdf
Numerical investigation of symmetry and asymmetry rigid wedge slamming using OpenFOAM code
Mobin
Masoomi
Noshirvani University of Technology
author
Mahdi
Yousefifard
Assistant Professor of Mechanical Engineering
Noshirvani Institute of Technology
author
Abas
Ramiar
Noshirvani University of Technology
author
text
article
2017
per
In this article, rigid wedge water entry problem under different conditions are evaluated using numerical scheme. It continues to be one of the fundamental issues raised in the hydrodynamics studies and known as a reference for the study of slamming phenomena. The exact calculation of the pressure caused by the slamming phenomenon can be used to analyze the appropriate structural analysis of the ships. In the current study, important variables such as speed and fluid pressure is investigated using computational fluid dynamics method based on the open source OpenFOAM code by numerical solution of the governing equations of tow phase fluid. In order to verify the simulation results obtained from this research, he values of the maximum pressure and t he location and exact time of its occurrence and also pressure coefficient distribution at the impact region have been compared by experimental results of other studies. These investigations have been utilized at different impact velocities and angles. By comparing the numerical results and experimental values, an error was found in the range of 2 to 9%. In addition, variables affecting the pressure applied to the wedge such as water entry velocity and different deadrise angles have been studied.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
343
352
http://mme.modares.ac.ir/article_17108_688e2a50d4bbfef3b100f26f5a09557e.pdf
Designing virtual vibration absorber with adaptable stiffness for vibrations control under harmonic excitation with noise in timevarying frequency
Soheil
Salighe
دانشجوی کارشناسی ارشد / دانشگاه شیراز
author
Hossein
Mohammadi
هیات علمی / دانشگاه شیراز
author
text
article
2017
per
In the present article, a real massspring system under external excitation with timevarying frequency is studied. The external excitation causes additional oscillations in the real massspring system response which disrupt the path tracking procedure. Adaptive control law, which is considered for annihilating the additional oscillations, is equal to a virtual vibration absorber which its stiffness regardless of the real system and external excitation uncertainties, can be updated based on the linear absorber theory until the natural frequency of the absorber reaches the excitation frequency. The variation of the frequency is based on the step and ramp function which relatively are equal to the sudden and transient change from the initial value to the final value of the frequency. Besides, the effects of the noise with various amplitudes existed in the transient variation of the frequency on updating the virtual absorber stiffness is developed. Simulation results are presented to demonstrate that the determined adaptation law guarantees the adaptation of virtual absorber stiffness considering excitation frequency variation based on both step function and ramp function and eliminates additional vibrations of the real system.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
353
362
http://mme.modares.ac.ir/article_17182_ceefc4bcdd620934405358c6612a1238.pdf
Damage detection in Glass Fiber Reinforced Plastic (GFRP) using neural network based on denoising with different mother wavelets
Majid
Khazaee
دانشگاه صنعتی امیرکبیر
author
Ali
Salehzadeh Nobari
دانشگاه صنعتی امیرکبیر، دانشکده مهندسی هوافضا
author
Meghdad
Khazaee
دانشگاه تربیت مدرس
author
text
article
2017
per
In this paper, a vibrationbased damage detection approach for multilayered woven glass laminate using time signal processing and Neural Network (NN) is presented. In order to reduce noise in the experimental extracted signals, waveletbased denoising has been applied. After data mining and feature extraction from processed signals, NN as a classifier is employed to detect the damaged GFRP. Different NN structures were tested in order to enhance the damage detection performance to recognize the most remarkable performance. Also, the performance of the presented method was evaluated when different mother of wavelets at different decomposition levels denoise signals so that the best signal processing method is selected. The results demonstrate the effect of NN structure on the damage detection technique, which in this research the best NN performance was obtained with 75 hidden layers and allocating 80%, 10% and 10% of data to training, evaluation and testing, respectively. Furthermore, denoising using db3 and bior3.7 mother wavelets at 2nd decomposition level leads to the highest accuracy as well as suitable calculation time compared to other mother wavelets. The proposed method based on real data at the data acquisition points detects damage in composite laminate with high accuracy at reasonable calculation time, hence it can be used for condition monitoring of composite laminate either offline or online, provided that adding online data acquisition equipment.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
363
372
http://mme.modares.ac.ir/article_17200_a12c363a6732d449e91dd8f3e1a9de91.pdf
Buckling of FGM thickwalled cylindrical shell supported with third order shear theory under uniform Axial and lateral loads
Shahrooz
Yoosefzadeh
Department of Mechanical Engineering, Aligodarz Branch, Islamic Azad University, Aligodarz, Iran.
author
Mohammad Reza
Isvandzibaei
Department of Mechanical Engineering, Andimeshk Branch, Islamic Azad University, Andimeshk, Iran.
author
Majid
Gheysari
Department of Mechanical Engineering, Aligodars Branch, Islamic Azad University, Aligodarz, Iran.
author
text
article
2017
per
This research presents the study on mechanical buckling of thickwalled cylindrical shell made of functionally graded materials with ring supported under uniform axial and lateral loads. The mechanical properties of shell are variable along the thickness direction. First the governing equations on the buckling of the FGM cylindrical shell supported with ring are established based on thirdorder shear deformation theory. Then the governing characteristic equations were employed, using energy method and by applying the Ritz technique. In the following with solving characteristic equations, the critical load buckling of the FGM thickwalled cylindrical shell supported with axial and lateral loads are calculated. The boundary conditions represented by end conditions of the FGM shell are the following: clampedclamped and freefree. To verify the validity of the proposed analytical method the results of this research are compared with the results came from using the finite element software. Finally, the effects of the different parameters such as thickness variations, boundary conditions, loading conditions and geometrical parameters of shell and ring on the buckling behavior of FGM thickwalled cylindrical shell are investigated. The results showed that by increasing the FGM volume fraction power in the shell structure, the critical buckling load increases and the location of the ring support has the significant effect on the critical buckling load. The results presented can be used as an important benchmark for researchers to validate their numerical and analytical methods.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
373
385
http://mme.modares.ac.ir/article_17183_4ddf65ba8a0c0d07cee8e7cda1f10b5d.pdf
Imitation of Human Motion by a NAO Humanoid Robot Using an Analytical Method and Considering Balance of the Robot
Pourya
Shahverdi
Department of Electrical, Biomedical and Mechatronics Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran
author
Mehdi
Tale Masouleh
استادیار دانشکده برق و کامپیوتر دانشگاه تهرانآزمایشگاه تعامل انسان و ربات
author
text
article
2017
per
This paper investigated the imitation of human motions by a NAO humanoid robot which can be regarded as a humanrobot interaction research. In this research, first, human motion is captured by a Kinect 3dimentional camera through a Robot Operating System (ROS) package. Captured motion is then mapped into the robot’s dimension due to the differences between human and humanoid robot dimensions. After performing the mapping procedure, the solution of both forward and inverse kinematic problem of the robot are solved. To this end, a “Distal” form of forward kinematics solution of the NAO humanoid robot is computed and based on the latter form an analytical inverse kinematics solution for the wholebody imitation purpose is used. The foregoing issue, as one of the contributions of this paper, can be regarded as one of the main reason for obtaining a smooth imitation. In order to keep the robot’s stability during the imitation, an ankle strategy based on a Linear Inverted Pendulum Model (LIPM) and the Ground projection of the Center of Mass (GCoM) criteria is introduced. Moreover, the latter LIPM is controlled by a ProportionalIntegralDerivative (PID) controller for two cases, namely, double and single support phases. Considering the limitation on the motion capture device, from experimental and simulation results obtained by implementing the proposed method on a NAOH25 Version4 it can be inferred that the robot exhibits an accurate, smooth and fast wholebody motion imitation.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
386
396
http://mme.modares.ac.ir/article_17196_1309be7130990210485bdc2004233127.pdf
Equipping of a Hovering Type Autonomous Underwater Vehicle with Ballast Tanks and its effect on Degrees of Freedom
Abdollah
Karimi
Department of Mechanical Engineering, Hakim Sabzevari University, Sabzevar, Iran.
author
Reza
Hasanzadeh Ghasemi
 استادیار، مهندسی مکانیک، دانشگاه حکیم سبزواری، سبزوار، ایران
author
text
article
2017
per
Currently, hovering type autonomous underwater vehicles (HAUV’s) are very noteworthy, due to theirs unique capabilities and features. Appropriate maneuverability and controllability is the most important feature for a HAUV that, make it better than other AUV’s. In order to increase stability and controllability of robot, the ballast tank is applied for a HAUV. Using of ballast tank in HAUV was not common before. In this paper a new underwater vehicle is presented, including three ballast tanks and three thrusters. In this underwater vehicle, the number of thrusters is less than original robot. In this paper, dynamics modeling and tracking control of this new underwater vehicle is investigated. The results show that the heave and pitch DOF’s can be reachable by using of the ballast tanks and we don’t need to use extra thrusters for these degrees of freedoms.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
397
404
http://mme.modares.ac.ir/article_17186_15d83b7df00207d92bb489ee958abeca.pdf
Stress Analysis and Design Improvements of Rotating Drilling Pipe Tool Joints by Fatigue approach
Mohammad Hossein
Nodeh Farahani
دانشگاه تربیت مدرس
author
Mohammad Hossein
Sadeghi
استاد دانشگاه تربیت مدرس
author
Amir
Rasti
دانشگاه تربیت مدرس
author
text
article
2017
per
Nowadays, Ease of accessibility to natural oil and gas wells has fallen significantly due to continues drilling operations. Therefore, oil fields came after deep drilling and horizontal and directional drilling methods. However, due to more complex conditions in these wells, rods fails mostly. This failure occurs in rod joints as the weakest link. In this research, API NC46 standard tool joint has been investigated considering real oil well condition. The goal is to find the weakest points in the drilling rod and present an economical and practical solution to increase the life time. Results show that the maximum stress occurs in the first engaged thread of pin and last engaged thread of box which makes these areas more vulnerable. In the following, using optimization of joint main parameters including threads geometry, makeup torque and shoulder sealing design, a new plan will represent that have higher fatigue life than the similar API standard tool joint. Maximum stress concentration factor of improved tool joints relatively decrease from 3.47 to 2.86 compared to standard joint. In addition Experimental tests show that the average fatigue life of improved joint is 2.3 times more than the standard tool joint.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
405
412
http://mme.modares.ac.ir/article_17187_e935a72cbbe23319e4610b27b9322f39.pdf
Comparison of Back Stepping Optimized via PSO Algorithm and LQR Controllers for a Quadrotor
Niloofar
Parhizkar
Amirkabir University of technology, Aerospace engineering department
author
Abolghasem
Naghash
دانشگاه صنعتی امیرکبیر، دانشکده مهندسی هوافضا
author
text
article
2017
per
Comparison of Back stepping method optimized via particle swarm optimization algorithm and LQR method for hovering control of a quadrotor is presented in this paper. Quadrotor is not a stable dynamical system and development of high performance controllers for it is important. First the dynamic model of a quadrotor is introduced and statespace equations are presented in order to simulate the dynamic model. Then two Back stepping and LQR controllers are designed to control Euler angles and height of the quadrotor. In order to optimize back stepping controller, its parameters are determined using particle swarm optimization algorithm to minimize cost function considered for LQR controller. Also commands to the motors are calculated and plotted to show the feasibility of the controller. To obtain better comparison, the cost function is calculated for different weighting matrices of Q and R for two controllers and the results are compared. The results show that Back stepping controller has more ability to minimize the cost function in comparison to LQR and the cost function in Back stepping has less values for several choices of weighting matrices.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
413
420
http://mme.modares.ac.ir/article_17188_40b375be2d43ea3c70b5c83daf735a4e.pdf
A finite element viscoelastic model based on consecutive transverse ultrasound images of carotid artery
Effat
Soleimani
Medical Physics, Tarbiat Modares University, Tehran, Iran
author
Manijhe
Mokhtari Dizaji
استاد، گروه فیزیک پزشکی، دانشگاه تربیت مدرس، تهران، ایران
author
Nasser
Fatouraee
دانشیار، گروه مهندسی پزشکی، دانشگاه صنعتی امیرکبیر، تهران، ایزان
author
Hazhir
Saberi
استاد، گروه رادیولوژی، دانشگاه علوم پزشکی تهران، تهران، ایران
author
text
article
2017
per
In the present study, a finite element model has been presented using both the invivo geometry of a healthy man carotid artery, which was extracted from consecutive transverse ultrasound images and the pulse pressure waveform and Kelvin viscoelastic model parameters that were obtained from processing the consecutive longitudinal ultrasound images. Extracting the internal diameter waveform from longitudinal ultrasonic image processing and calibrating it via an exponential equation, blood pressure waveform of the carotid artery was extracted. A Gaussian function was fitted to the blood pressure waveform. Differentiating the fitted Gaussian equation resulted in the pressure differentiation of the carotid artery over the cardiac cycle. Kelvin viscoelastic parameters were estimated using an optimization method. Finite element model of the carotid artery was reconstructed in ADINA software and implemented by loading over three cardiac cycles. To validate the model, radial displacement waveform resulted from finite element model and that resulted from image processing were compares in nearly the same spatial position. Percentage of the mean proportional differences between the radial displacement resulted from finite element model and that from consecutive ultrasound images was 9.3. Since the appropriate mechanical models can calculate true stress/strain distribution of the carotid artry wall and plaque and distinguish the location of the plaque areas prone to vulnireability; and because of the capability of the ultrasonic model proposed in this study for describing the pulsatile behavior of artery wall accurately, it is expected that the introduced dynamic model to be applied for accurate evaluation of the arterial disease.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
421
430
http://mme.modares.ac.ir/article_17189_c83c3623e9d554d9ca77dda459915b03.pdf
Slab analysis of front and back tensions effects on decreasing force and pressure in asymmetrical rolling process of unbonded clad sheet
Milad
Masrouri
دانشجو کارشناسی ارشد، مهندسی مکانیک، دانشگاه تهران، تهران
author
Ali
Parvizi
عضو هیئت علمی دانشگاه تهران
author
text
article
2017
per
Some appropriate characteristics like corrosion resistance, higher strength, and higher thermal and electrical conductivities cause that applications of clad sheets have been recently increased significantly in industries like production of electrical and electronic switches. In this paper, an analytical solution based on the slab method analysis is presented to investigate the asymmetrical rolling of unbonded clad sheet. Roll radii, roll speeds, friction condition between surfaces, as well as the yield stress ratio of material of sheets are parameters of the asymmetrical rolling that considered in this paper. The nonuniformity of the shear stresses and the uniformity of the normal stresses at the vertical sides of each slab across the portion of the deformation material is taken into account through the plastic region. The behavior of material in plastic region is considered to be rigidperfectly plastic. The main goal of this paper is to investigate the simultaneous effect of back and front tension and asymmetrical parameters on normal stresses and pressure distributions along the contact area of rolls and sheets for the first time in order to decrease pressure and force in the process. The effects of these parameters on the positions of the neutral points on the upper and lower rolls are also investigated. Moreover, the maximum back and front tensions to avoid slipping of the sheet are determined. The results show that by applying the proper amounts of tensions to the sheet at the entry and exit of deformation zone, pressure and force values could be reduced, considerably.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
431
440
http://mme.modares.ac.ir/article_17191_684c7f78e0c541b44c3297250d9d0e6a.pdf
Development a new cutting tool by changing the surface texture for increasing the machining performance
Behnam
Davoodi
دانشیار دانشگاه علم و صنعت ایران
author
Seyed Hasan
Musavi
دانشگاه علم و صنعت ایران
author
Mohammad
Nankali
دانشگاه علم و صنعت ایران
author
text
article
2017
per
Machining processes are the most important method to production in the industry. In these processes, the friction in toolchip surface during the machining is one of the affecting factors on surface quality of work piece. The generated heat by friction, augment the tool wear mechanism and increase the wear rate of cutting edge which leads to reduction the surface quality. The high talent of aluminum to builtup edge formation during machining has the undesirable effect on the surface quality. In the present study in order to improvement the coolinglubrication conditions in machining of 6061 aluminum alloy, a new cutting tool with creating microgrooves on its rake face was developed to achieve the improving of cutting fluid transfer to machining zone and reducing the friction between toolchip surface. Two types of microgrooves have been created by laser machining process. Specimens by changing the machining parameters and types of the applying of cutting fluid to machining zone were machined. The experimental results obtained from surface roughness survey and prepared images of work piece surface by scanning electron microscope (SEM) and optical microscope showed that by creating the microgrooves, the delivery conditions of cutting fluid to machining zone has improved and its effect to reduction of surface roughness is clearly visible. By comparison the results of two microgrooves showed that direction of grooves is the most important parameters in its design, so that the perpendicular texture is not only improves the surface quality but also increase the surface roughness compared to nontexture tool.
Modares Mechanical Engineering
Tarbiat Modares University
10275940
17
v.
7
no.
2017
441
450
http://mme.modares.ac.ir/article_17197_fa602ad6144a93fd1747ef67316ebc6f.pdf