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Journal Cover International Journal of Advanced Design and Manufacturing Technology
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  This is an Open Access Journal Open Access journal
   ISSN (Print) 2008-1421
   Published by Islamic Azad University Homepage  [14 journals]
  • Numerical Study of Coupled Non-Gray Radiation and Separation Convection
           Flow in a Duct Using the FSK Method

    • Authors: Meysam Atashafrooz, Seyyed Abdolreza Gandjalikhan Nassab, Khosro Lari
      Abstract: In this research, the coupling between non-gray radiation and separation convection flow in a duct is investigated numerically. Distributions of absorption coefficients across the spectrum  are obtained from the HITRAN2008 database. The full-spectrum k-distribution method is used to deal with the non-gray part of the problem, while the gray radiation calculations are performed using the Planck mean absorption coefficient. To find the divergence of radiative heat flux distribution, the radiative transfer equation (RTE) is solved by the discrete ordinates method (DOM). The effects of radiation-conduction parameter, scattering coefficient and wall emissivity on thermal behaviors are investigated for both gray and non-gray mediums. In addition, the results of gray medium are compared with non-gray results as a real case. The results show that in many case, use of gray simulations are not acceptable and lead to significant errors, especially in non-scattering medium with high values of radiation-conduction parameter and wall emissivity.
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
  • Mechanical Properties and Microstructural Evolution of AA5083/Al2O3
           Composites Fabricated by Warm Accumulative Roll Bonding

    • Authors: Mohammad Heydari Vini, M. Sedighi, Mehdi Mondali
      Abstract: In this study, warm accumulative roll bonding (Warm- ARB) process has been used to produce Metal Matrix Composite (MMC: AA5083/-5% Al2O3). Starting materials were roll bonded as alternate layers up to 5 rolling cycles with 300°C preheating for five minutes before each cycle. The microstructure and mechanical properties of composites have been studied after different Warm- ARB cycles by tensile test, Vickers micro hardness test and scanning electron microscopy (SEM). The results revealed that during higher Warm- ARB cycles, breaking the layers of alumina particles led to the generation of elongated dense clusters with smaller sizes. This microstructural evolution led to improve the hardness, strength and elongation during the Warm- ARB process. The results demonstrated that the dispersed alumina clusters improved both the strength and tensile toughness of thecomposites.   Finally, Warm- ARB process would allowed producing metal particle reinforced with high uniformity, good mechanical properties and high bonding strength.
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
  • An Experimental Investigation of the Effects of Fiber Laser Percussion
           Drilling: Influence of Process Parameters

    • Authors: Mahmoud Moradi, Alireza Mohazab Pak, Ali Khorram
      Abstract: This study is focused on investigating the parameters of laser percussion drilling process of nickel-base superalloy Inconel 718 with thickness of 1 mm. Fiber laser with the power of 500 watts was used as laser source. Laser pulse frequency, duty cycle, laser power, focal point position, were assumed as the laser drilling process variables The hole geometry features, i.e. entrance hole diameter, circularity of entrance hole, and hole taper were measured. The results indicated that pulse frequency of laser has a direct influence on the entrance hole diameter. Increasing the duty cycle leads to increases in hole taper. By increasing the laser power, entrance diameter and hole taper increases.
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
  • The Influence of Vibratory Finishing Process by Incorporating Abrasive
           Ceramics and Glassy Materials on the Surface Roughness of CK45 Steel

    • Authors: Payam Saraeian, Mostafa Gholami, Amir Masoud Behagh, Omid Behagh, Hamid Reza Javadinejad, Mohammad Sajjad Mahdieh
      Abstract: The vibratory finishing is one of the important mass finishing processes. This can be applied for finishing of many metallic and non- metallic components using abrasive materials such as steel, ceramic, natural materials and etc. The vibratory finishing process is used for some purposes such as surfaces polishing, deburring, oxide layer removing and rounding the edges. Evaluation of surface roughness changes with time is one of the important parameters during the vibratory finishing process. In this study, the effects of the working time and abrasive materials are investigated on the surface roughness changes of CK45 steel samples. The ceramic, glass and mixed abrasive particles are used as the abrasive media. The experiments are performed at different time from 10 to 120 minutes in the dry environment. Finally, the surface roughness values of samples measured and then fitted by a regression equation for description of the surface roughness changes with time. According to the results, the maximum surface finish obtained after 120 minutes by using mixed abrasive materials. The surface roughness improved approximately 60%.
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
  • Analysis of Off-road Performance for a Tracked Vehicle

    • Authors: MohamadReza Elhami
      Abstract: Suspension system is one of the most important factors in provision of ride comfort and dynamic stability in any vehicle. Meanwhile the suspension systems of tracked vehicles, due to their continuous track, have particular specification in comparison with other vehicles. This specification causes tracked vehicles having an improved dynamic stability in off-road maneuvers compared to vehicles with discrete tiers, the issue which is analyzed and investigated in this article. First the mathematical model of a tracked vehicle suspension system with governing dynamic equations and the complete state-space model are represented. Then off-road inputs such as hill inputs, passing through Belgian block trapezoidal bump and irregular terrain are applied to the dynamic model and the system outputs, especially body hull vertical acceleration as one of the most important criteria of stability, are reviewed. The results show that the responses are in range of acceptable overshoot and there suggest the related critical speed of the vehicle. Furthermore, for model validation the results are compared with ACMP reference model using standard off-road inputs; and the deviations are trivial that approves the validation.
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
  • Tool Wear Modeling in Drilling Process of AISI1020 and AISI8620 Using
           Genetic Programming

    • Authors: Vahid Zakeri, Vahid Pourmostaghimi
      Abstract: In manufacturing industry, it has been acknowledged that tool wear prediction has an important role in higher quality of products and acceptable efficiency. Being an emerging area of research in recent years, drilling tool wear is an important factor which directly affects quality parameters of machined hole such as hole centring, roundness, burr formation and finished surface. In this paper, the genetic equation for prediction of drilling tool flank wear was developed using the experimentally measured wear values and genetic programming for two different materials, AISI1020 and AISI8620 steels. These equations could be used to compare the behaviour of wear in both mentioned materials and analyse the effect of materials characteristics on wear rate and wear pattern. The suggested equations have been shown to correspond well with experimental data obtained for flank wear when machining in various cutting conditions.The results of experiments and equations showed that properties of work material can affect drill bit flank wear drastically. It was concluded that greater toughness and strength of AISI8620, compared to AISI1020, lead to higher cutting stresses and temperatures, resulting more flank wear. 
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
  • Improving the Accuracy of Upper Bound Analysis of Bimetallic Rods
           Extrusion Using a new Velocity Field

    • Authors: Hamed Afrasiab, Mojtaba Qasemi-Mahallekolaei
      Abstract: In this paper, the direct extrusion process of bimetallic rods in conical dies is analyzed by an improved upper bound method. The deformation zone is subdivided into six smaller zones and by considering a non-spherical entrance boundary to the deformation zone, a velocity field is presented which is different from velocity fields employed in previous studies. The total power consumption of the process including internal, shear and frictional powers is obtained using this velocity field, and then the forming force is calculated by employing the upper bound theory. The superior accuracy of the proposed analysis is demonstrated by comparing the computed force with available experimental data and results of an upper bound analysis in the literature. Finally, the developed model is employed to study the effect of some process parameters on the forming load. It is observed that there is an optimal die angle that minimizes the extrusion force. The value of this optimum angle increases with friction coefficient.
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
  • A New Method for Measuring Perforated Surface by Coordinate Measuring
           Machine (CMM)

    • Authors: MohammadMahdi Amiri
      Abstract: Nowadays CMM machines are widely used in surface measurement and inspection. As inspection results from CMM machine are obtained by the means of measuring surfaces with direct contact, they are more precise than non-contact method (like optical measurement). However, CMM machines give more reliable and accurate results rather than non-contact methods but also these results come with error when outer surface contains porosity spaces. This paper proposes a new method for measuring outer surface of porous objects. In this method the probe will be located above the porous area and doesn’t enter inside. The proposed strategy could be utilized whether CAD model of object is available or not. If CAD drawing of object exists, the probing stylus will not enter into the hole. On the other hand, if the CAD drawing doesn’t exist a perpendicular plane to the surface will be virtually modeled and by this normal plane the outer surface of the object will be estimated. In addition in this research an effort has been made to reduce dependence on CAD drawing.
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
  • Effect of AFM Cantilever Geometry on the DPL Nanomachining Process

    • Authors: Ahmad Reza Norouzi, Mohammad Tahmasebipour
      Abstract: With the development of micro and nanotechnology, machining methods at micro and nanoscale have now become interesting research topics. One of the recently-proposed methods for sub-micron machining, especially nanomachining, is dynamic plowing lithography (DPL) method. In this method an oscillating tip is used for machining soft materials such as polymers. The geometry of the oscillating beam and its vibrational properties are the most important parameters in this nanomachining process. In this study, effects of the AFM beam geometry on its stiffness coefficient, resonant frequency, beam stability, and the maximum stress created in the beam structure were investigated for 12 different general shapes using the finite element method. The obtained results indicate that circular and square membranes are the most favourable AFM cantilever geometries because these structures provide higher machining force and speed; while for noisy conditions and environments, straight and V-shaped beams are recommended (because of their higher stability factor) for the DPL nanomachining process.
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
  • Studying the Shear and Discharge Rate of Proteins in Microfluidic
           Junctions, Under Electrokinetic EffectsStudying the Shear and Discharge
           Rate of Proteins in Microfluidic Junctions, Under Electrokinetic Effects

    • Authors: Babak kamali Doust Azad, Sasan Asiaei, Borhan Beigzadeh
      Abstract: Changes of hydrodynamic parameters in microchannel branches affect the suspended biological samples in blood. To prevent denaturation and hemolysis, we have numerically investigated the effect of divergence angle on shear rate and velocity at branch entrance (discharge rate), under electroosmotic flow. In such flow, hydrodynamic properties are also affected by zeta potential at the microchannel walls. We have also studied the effect of change of zeta potential (ξ) proportion at main channel wall (ξ1) to that of branch channel (ξ2), on the discharge rate to find its maximum for different divergence angles. In the divergence angle of 60° and while zeta potential at the branch wall is equal to its value at main channel wall, the tendency of particles to pass through the branch is the highest among all examined degrees. At the zeta potential proportion of ( ξ1/ξ2 =0.5), the change of divergence angle has almost no effect on the maximum velocity in the branch. In addition, with increase of divergence angle from 60° to 150°, the shear rate at the branch will become 2.1 times higher.
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
  • Pareto Optimal Design of Passive and Active Vehicle Suspension Models

    • Authors: Mohammadjavad Mahmoodabadi, Seyed Mehdi Mortazavi Yazdi
      Abstract: It would be difficult to deny the importance of optimization in the areas of science and technology. This is in fact, one of the most critical steps in any design process. Even a very small change in optimization can improve dramatically upon any process or element within a process. However, determining whether an optimization approach will improve on an original design is usually a question whose response in this study has led to an optimal design out of an existing car model. First of all, the optimization of a passive car-quarter model has been accomplished by means of a genetic algorithm. This initial optimization gives a figure of points named ''Pareto optimum points''. Secondly, through selecting a point amongst them, the design of active model has been completed and optimized based on genetic algorithm. Continuing with this thought, a similar process has been also accomplished with a car-half vehicle model with five degrees of freedom. Though the last optimized active model may prove a more reliable efficient design due to the more comprehensive feature related to the degrees of freedom, the results of each optimization should be considered and may supply equally attractive and diverse choices as well. Anyway, let's focus on the final purpose which is to reduce the vibrations as much as possible. This is what is observed through all the optimization jobs in this study. Comparison of these results with those reported in the literature affirms the excellence of the proposed optimal designs.
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
  • An Intelligent Knowledge Based System for CO2 Laser Beam Machining for
           Optimization of Design and Manufacturing

    • Authors: Morteza sadegh amalnik
      Abstract: This paper addresses the concept of CO2 Laser beam machining (LBM) and development of intelligent knowledge base system (IKBS) for CO2 LBM. Feature based design is used for acquires design specification. For optimization of laser beam machining computer based concurrent engineering environment is used. The IKBS links with feature base cad system. The IKBS also links with material database which holds attributes of more than 50 type of materials. It also links with Laser database which hold attributes of 3 types of laser machine. IKBS is also links with Laser machine variables and parameters. For each design feature, IKBS provides information such as machining cycle time and cost and machining rate. By changing machine parameters we can optimize machining cycle time and cost and cutting rate. The IKBS can be used as an advisory system for designers and manufacturing engineers. It can also be used as a teaching program for new CO2 laser operators in computer based concurrent engineering environment. 
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
  • Some Investigations on Surface Integrity and Electrochemical Behavior of
           Machined Co-Cr-Mo Bio-implant Alloy

    • Authors: Ketan Jagtap, Raju Pawade, K. V. Giradkar
      Abstract: A decisive constraint for the long-term stability of the artificial joint is to minimize the release of debris particles. The wear/debris induced osteolysis and aseptic loosening are the result of failure of metal-on-metal joint implants. SPD processes have been used to adapt the surface integrity properties by generating ultrafine or even nano-sized grains and grain size gradients in the surface region of work materials. These fine grained materials often show enhanced surface integrity properties and improved functional performance (wear resistance, corrosion resistance, fatigue life, etc.) compared with their predictable coarse grained counterparts. To identify the implant material’s post machined behaviour in biological environment, the experiments were planned by precision CNC turning process and accordingly post machined surfaces were analyzed by contact type and electrochemical measurement processes. The work includes effect of machining parameters on machined surface roughness and corrosion rate by an electrochemistry of Co-Cr-Mo bio-implant alloy. The minimum machined surface roughness value 0.450 µm shows minimum corrosion rate as 0.00002 mm/year. It is also shown that feed rate is having predominating effect on machined surface roughness and rake angle is on corrosion rate of Co-Cr-Mo bio-implant alloy.
      PubDate: 2016-12-24
      Issue No: Vol. 9, No. 4 (2016)
       
 
 
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