Materials and Energy Research CenterInternational Journal of Engineering1025-249524220110601Physical Nonlinear Analysis of a Beam Under Moving Harmonic Load10711371894ENEsfandiar MardaniCivil Eng., Urmia UniversityJournal Article19700101A prismatic beam made of a behaviorally nonlinear material is analyzed under aharmonic load moving with a known velocity. The vibration equation of motion is derived usingHamilton principle and Euler-Lagrange Equation. The amplitude of vibration, circular frequency,bending moment, stress and deflection of the beam can be calculated by the presented solution.Considering the response of the beam, in the sense of its resonance, it is found that there is no criticalvelocity when the behavior of the beam material is assumed to be physically nonlinear.https://www.ije.ir/article_71894_aabf55100ccc21c0e448d45b39870944.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249524220110601Single Machine Scheduling Problem with Precedence Constraints and Deteriorating Jobs11512271896ENHamid Reza GolpaiganiIndustrial Engineering, Iran University of Science and TechnologyNima HamtaIndustrial Engineering, Arak University of TechnologyUnes UnesIndustrial Engineering, Iran University of Science and TechnologyJournal Article19700101This paper considers the single machine scheduling problem with precedence constraints and deteriorating jobs. A mathematical model based on binary integer programming (BIP) is developed. By these precedence constraints, jobs can not start before completion of its all predecessors. The represented model is in two steps, in step one the earliest starting time of each job is computed, then the results are used in second step of the model, which determine a sequence between jobs by the aim of minimizing the total completion time. At the end a numerical example is presented and solved by the Lingo 8.0 mathematical software.https://www.ije.ir/article_71896_683bc62ca54dbb401bed8f31bb91795a.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249524220110601Synthesis of Nanostructure Ti-45Al-5Cr Alloy by Mechanical Alloying and Study the Effect of Cr Addition on Microstructure of TiAl Alloy12313071898ENRasoul Azazari.khosroshahi, Sahand Univ. of TechnologyFarshad Abbasi NargesiMaterials and Metallurgical Engineering Department, Sahand Univ. of TechnologyNaghi Parvini.ahmadiMaterials Eng., Sahand University of TechnologyJournal Article19700101In this work, mechanical alloying was employed to produce Ti-50Al and Ti-45Al-5Cr (at%) alloys. Alloying was performed in a planetary mill and the alloying time varying from 5 to 70h. Characterization of the powder mixture was performed by X-ray diffraction (XRD), SEM analyses and DTA test, during mechanical alloying and after annealing at 1100°c in vacuum oven. The results showed, after 50h of milling of TiAl powder mixture, only a complete amorphous phase was detected but with Cr addition (5at%) the Cr (Ti,Al) solid solution within the amorphous matrix were identified. After annealed of mechanically alloyed Ti-50Al for 50h, the γ-phase with high purity and nanostructured size was produced but for sample with Cr addition, TiAl(γ) and amount of Ti3Al(alpha2) were detected. Cr accelerated the production of duplex structure (gamma+alpha2). It suggested the Cr(Ti,Al) solid solution was dissolved in TiAl(gamma) and Ti3Al(alpha2).https://www.ije.ir/article_71898_21fccba5f3ee974387c9075597c7cba7.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249524220110601The Effect of Viscous Dissipation and Variable Properties on Nanofluids Flow in Two Dimensional Microchannels13114271900ENAbolfazl RanjbarControl, Babol Noshirvani university of TechnologyAbas Ramiar, Babol Noshirvani university of technologyJournal Article19700101Laminar two dimensional forced convective heat transfer of Al2O3 –water nanofluid in a horizontal microchannel has been studied numerically, considering axial conduction, viscous dissipation and variable properties effects. The existing criteria in the literature for considering viscous dissipation in energy equation are compared for different cases and the most proper one is applied for the rest of the paper. The results showed that nanoparticles enhance heat transfer characteristics of the channel and on contrast, viscous dissipation causes the Nusselt number and friction factor to decrease. The viscous dissipation effect may be emphasized by increasing Reynolds number and decreased by raising the exerted heat flux. Also, it was found that there is a critical Reynolds number below which the average Nusselt number of the nanofluid changes unusually with Reynolds number as a result of variable properties effect.https://www.ije.ir/article_71900_d5e6018909b1e4275b0b6d5229a3052d.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249524220110601Optimization of Meshless Local Petrov-Galerkin Parameters using Genetic Algorithm for 3D Elasto-static Problems (TECHNICAL NOTE)14315371902ENRouhollah Ehsanymechanical engineering, Guilan UniversityAhmad BagheriMechanical Engineering, University of GuilanMohammad Javad MahmoodabadiMechanical Engineering, Sirjan University of TechnologyGholam Hosein Baradaranmechanical engineering, Shahid Bahonar UniversityJournal Article19700101A truly Meshless Local Petrov-Galerkin (MLPG) method is developed for solving 3D elasto-static problems. Using the general MLPG concept, this method is derived through the local weak forms of the equilibrium equations, by using a test function, namely, the Heaviside step function. The Moving Least Squares (MLS) are chosen to construct the shape functions. The penalty approach is used to impose essential boundary conditions. The complete study of the effects of radius of support domain on the accuracy and efficiency of the solution is performed. The values of this parameter leave a great effect on runtime and accuracy. The Genetic Algorithm (GA) is used to determine the optimum values of this MLPG parameter to minimize the runtime and maximize the accuracy. Several numerical examples are included to demonstrate that the present method is very promising for solving the elasto-elastic problems. https://www.ije.ir/article_71902_a376f046d47b051b757e2a4f90363ba3.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249524220110601Optimization of GRI-mech 3.0 Mechanism using HCCI Combustion Models and Genetic Algorithm15516871904ENR. Khoshbakhti SarayMechanical Engineering, Sahand University of TechnologyAli Yousefzadi NobakhtMerchanical Engineering, Sahand University of TechnologyJournal Article19700101 This paper presents a modeling study of a CNG Homogenous Charge Compression Ignition (HCCI) engine using single-zone and multi-zone combustion models. Authors' developed code could be able to predict engine combustion and performance parameters in closed part of the engine cycle. As detailed chemical kinetics is necessary to investigate combustion process in HCCI engines, therefore, GRI-mech- 3.0 mechanism was used which includes 53 chemical species and 325 reactions for natural gas combustion. Although, single-zone model is useful to parametric study on variation of some engine combustion parameters such as start of combustion (SOC). But, it could neither be able to accurately predict other engine combustion related parameters nor engine performance and emission parameters. Hence, a multi- zone combustion model was developed to predict those parameters accurately. GRI-mech- 3.0 combustion mechanism was developed for natural gas combustion without considering Exhaust Gas Recirculation (EGR). To consider the effect of EGR on HCCI combustion, the mechanism's rate coefficients should be optimized. These coefficients were optimized using a developed genetic algorithm code. Predicted values show good agreement with corresponding experimental values for whole ranges of engine operating conditions.https://www.ije.ir/article_71904_908f4fd04cb31bd534643ec03be48065.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249524220110601A Simple Transformation Method in Skewness Reduction16917571907ENS.E. SeyedanIndustrial Engineering, Sharif University of TechnologyS.T.A. NiakiIndustrial Engineering, Sharif University of TechnologyB. AbbasiSchool of Mathematical and Geospatial Sciences, RMIT UniversityJournal Article19700101Statistical analysis of non-normal data is usually more complicated than that for normaldistribution. In this paper, a simple root/power transformation technique developed by Niaki, et al [1]is extended to transform right and left skewed distributions to nearly normal. The value of theroot/power is explored such that the skewness of the transformed data becomes almost zero with anacceptable error. The proposed method is then compared to the well-known and complicated Box, etal [2] transformation method for different left and right skewed distributions using Monte Carlosimulation. While the proposed procedure is easy to understand and to implement, the results of thesimulation study show that it works as good as the Box-Cox method.https://www.ije.ir/article_71907_76b3d469aa9abf4b36ba66f5c24d8fa6.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249524220110601Numerical Modeling of Two-Layered Micropolar Fluid Through an Normal and Stenosed Artery17718771908ENDr. SinghMathematics, HBTI KanpurJournal Article19700101In the present work a two fluid model for blood flow through abnormally constrictedhuman artery (stenosed artery) has been developed. The model consists of a core region of suspensionof all erythrocytes assumed to be micro-polar fluid so as to include the micro-structural effects inaddition to the peripheral-layer viscosity effects, and a peripheral plasma layer free from cells of anykind of Newtonian fluid. This model is used to predict the effects on physiological characteristics ofblood flow in normal and stenosed condition. The significance of the present model over the existingmodels has been pointed out by comparing the results with other theories both analytically andnumerically.https://www.ije.ir/article_71908_1289c7e252f6807c62132eae5ff78e10.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249524220110601Numerical Solution of Pricing of European Put Option with Stochastic Volatility18920271910ENU S RanaMathematics, D.A.V.P.G College,DehradunJournal Article19700101In this paper, European option pricing with stochastic volatility forecasted by well known GARCH model is discussed in context of Indian financial market. The data of Reliance Ltd. stockprice from 3/01/2000 to 30/03/2009 is used and resulting partial differential equation is solved byCrank-Nicolson finite difference method for various interest rates and maturity in time. Thesensitivity measures “Greeks” are also determined to validate the model. It is observed that the valueof European put option increases with maturity time and decreases with interest rate.https://www.ije.ir/article_71910_bceb534e49096278545699fd31599e6e.pdf