Materials and Energy Research CenterInternational Journal of Engineering1025-249523320101101A CLOSED-FORM NON- LINEAR SOLUTION FOR PLASTIC FLANGE WRINKLING OF CIRCULAR PLATES IN DEEP DRAWING PROCESS20321471858ENFarzadMoayyedianMechanical Engineering, Eqbal Lahouri Institute of Higher EducationM.Rezaiee Pajand0000-0002-8808-0011Journal Article19700101This paper deals with two-dimensional plane stress wrinkling model of a plastic annular plate. Based on energy method and the nonlinearity of strain-displacement law, a bifurcation function in polar coordinates is derived analytically. This technique leads to the critical conditions for the onset of the plastic wrinkling of flange during the deep drawing process. To find this solution, the Tresca yield criterion along with plastic deformation theory are employed. The material of the plate is assumed to behave perfectly plastic. This analytical closed-form solution is obtained by considering the nonlinearity of the material and geometry, simultaneously. The main advantage of the proposed solution is better agreement to the other researchers's experimental results. Moreover, the influence of the blankholder upon wrinkling, and also on the number of the generated waves, can be quantitatively predicted by the suggested scheme.https://www.ije.ir/article_71858_07b87b59ceb43c77b539036a3ae49a60.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249523320101101MATHEMATICAL MODELING AND PERFORMANCE OPTIMIZATION FOR THE DIGESTING SYSTEM OF A PAPER PLANT21522671861ENDineshKumarDepartment of Mechanical & Industrial Engineering, Indian Institute of Technology, RoorkeeJournal Article19700101This paper deals with the mathematical modeling and performance optimization for the Digesting system of a Paper Plant using Genetic Algorithm. The Digesting system of a Paper Plant has four main subsystems, arranged in series and parallel. Considering exponential distribution for the probable failures and repairs, the mathematical formulation of the problem is done using probabilistic approach and differential equations are developed based on Markov birth-death process. Then, these equations are solved using normalizing conditions to determine the steady state availability of the Digesting system. The performance of each subsystem of the Digesting system in a Paper Plant has also been optimized using Genetic Algorithm. Therefore, the findings of the present paper will be highly useful to the plant management for the timely execution of proper maintenance decisions and hence to enhance the system performance.https://www.ije.ir/article_71861_449b6d23ba5fb5703236558936fec083.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249523320101101GENETIC AND TABU SEARCH ALGORITHMS FOR THE SINGLE MACHINE SCHEDULING PROBLEM WITH SEQUENCE-DEPENDENT SET-UP TIMES AND DETERIORATING JOBS22723471863ENAbdolmajidYolmehIndustrial Engineering, Sharif UniversityJournal Article19700101 This paper introduces the effects of job deterioration and sequence dependent set- up time in a single machine scheduling problem. The considered optimization criterion is the minimization of the makespan (Cmax). For this purpose, after formulating the mathematical model, genetic and tabu search algorithms were developed for the problem. Since population diversity is a very important issue in preventing from being trapped in a local optimum, two methods were used to overcome this problem. Because of the novelty of the considered problem, there was no standard benchmark available to test the developed algorithms, so the results were checked by a lower bound which was calculated by a procedure that emphasizes on job deterioration effects. The tests and evaluations illustrate the effectiveness of the presented algorithms.https://www.ije.ir/article_71863_722b2d35a63e36bcda4a13526b9d5525.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249523320101101A HYBRID GENETIC ALGORITHM FOR A BI-OBJECTIVE SCHEDULING PROBLEM IN A FLEXIBLE MANUFACTURING CELL23525271865ENRezaTavakkoli-MoghaddamIndustrial Engineering, University of Tehran0000-0002-6757-926XJournal Article19700101 This paper considers a bi-objective scheduling problem in a flexible manufacturing cell (FMC) which minimizes the maximum completion time (i.e., makespan) and maximum tardiness simultaneously. A new mathematical model is considered to reflect all aspect of the manufacturing cell. This type of scheduling problem is known to be NP-hard. To cope with the complexity of such a hard problem, a genetic algorithm (GA) is proposed and hybridized by four priority dispatching rules. Different scheduling problems are generated at random and solved by both mathematical programming model and the proposed hybrid GA. The related results illustrate that this proposed algorithm performs well in terms of the efficiency and quality of the solutions. https://www.ije.ir/article_71865_bd75ddfbd3cf9f40fb09539fc3513250.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249523320101101AERO-THERMODYNAMIC OPTIMIZATION OF TURBOPROP ENGINES USING MULTI-OBJECTIVE GENETIC ALGORITHMS25326671868ENK.AtashkariMechanical Engineering, University of GuilanJournal Article19700101In this paper multi-objective genetic algorithms were employed for Pareto approach optimization of turboprop engines. The considered objective functions are used to maximize the specific thrust, propulsive efficiency, thermal efficiency, propeller efficiency and minimize the thrust specific fuel consumption. These objectives are usually conflicting with each other. The design variables consist of thermodynamic parameters (compressor pressure ratio, turbine temperature ratio, Mach number) and propeller geometric parameters (blade activity factor and integrated design lift coefficient). Main effect of the design variables are calculated to recognize which design variables has the effect on the objective functions. Group method of data handling (GMDH) type neural networks is used for modeling and prediction of propeller efficiency using aerodynamic variables obtained by some experimental data. Relationships among design variables and optimal objectives functions have been obtained by non-dominated sorting genetic algorithm, (NSGA-II) with a new diversity preserving mechanism in multi-objective optimization. The pareto solutions are obtained for both two and five objective optimization processes. For two-objective optimization, different pairs of objectives have been selected. More ever, these objectives have also considered for a five-objective optimization problem. Variables based on this pareto front, indicated the best design point of objective functions. These results also showed that Pareto solutions of five-objective optimization provide more choices for optimal design of turboprop engines. https://www.ije.ir/article_71868_4d1fb0454351d1c1c4226620b87094b2.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249523320101101HOMOTOPY PERTURBATION METHOD FOR SOLVING FLOW IN THE EXTRUSION PROCESSES26727271869ENM. M.RashidiMechanical Engineering, Buali Sina UniversityJournal Article19700101In this paper, the homotopy perturbation method (HPM) is considered for finding approximate solutions of two-dimensional viscous flow. This technique provides a sequence of functions which converges to the exact solution of the problem. The HPM does not need a small parameters in the equations, but; the perturbation method depends on small parameter assumption and the obtained results. In most cases, it ends up with a non-physical result, so homotopy perturbation method overcomes completely the above shortcomings. HPM is very convenient and effective and the solutions is compared with the exact solution.https://www.ije.ir/article_71869_60deb6d42d265ea5828136d3198a8534.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249523320101101A TRANSIENT TWO-DIMENTIONAL INVERSE ESTIMATION OF THE METAL-MOLD HEAT TRANSFER COEFFICIENT DURING SQUEEZE CASTING of AL-4.5WT%CU27328671871ENJournal Article19700101In this paper, a transient, two-dimensional and nonlinear inverse heat conduction problem in solidification process is considered. Genetic algorithm is applied for the identification of the interfacial heat transfer coefficients during squeeze casting of commercial aluminum alloy (Al-4.5wt%Cu) by assuming a priori information regarding the functional form of the unknown heat transfer coefficients found in open literature. In this work, simulated (noisy and filtered) temperatures are used instead of experimental data. The estimated temperatures are obtained from the direct numerical solution of a two-dimensional conductive model. A modified elitist genetic algorithm is used to minimize the least square objective function containing estimated and simulated temperatures. The accuracy of the proposed method is assessed by comparing the estimated with the pre-selected parameters.https://www.ije.ir/article_71871_8ebb0a64147c4b4b57c63d8ece4e0ad8.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249523320101101EFFECT OF TIME-DEPENDENT TRANSPIRATION ON AXISYMMETRIC STAGNATION-POINT FLOW AND HEATTRANSFER OF A VISCOUS FLUID ON A MOVING CIRCULAR CYLINDER28731271873ENA. A.Rahmanimining, imam khomeni international universityJournal Article19700101Effect of time dependent normal transpiration on the problem of unsteady viscous flow and heat transfer in the vicinity of an axisymmetric stagnation point of an infinite circular cylinder moving simultaneously with time-depended angular and axial velocities and with time-dependent wall temperature or wall heat flux are investigated. The impinging free stream is steady with a strain rate . A reduction of Navier-Stokes equations and energy equation is obtained by use of appropriate transformations. The general semi-similar solutions are obtained when angular and axial velocities of the cylinder and also its wall temperature or its wall heat flux vary as certain functions of time. The cylinder may perform different types of motions. It may move or rotate with constant speed, with exponentially increasing/decreasing axial/angular velocity, with harmonically varying axial/angular speed, or with accelerating/decelerating oscillatory axial/angular speed. The cylinder surface temperature or its surface heat flux may have the same type of behavior as the cylinder motion. Semi-similar solutions of the unsteady Navier-Stokes and energy equations are obtained numerically using a finite-difference scheme. All the solutions above are presented for different Reynolds numbers ( ) and different functions of dimensionless transpiration rate, , where is cylinder radius and is kinematic viscosity of the fluid. Shear stresses corresponding to all the cases increase with the increase of Reynolds number and decrease with the increase of suction rate. The maximum value of shear stress increases with increase of oscillation frequency and amplitude. An interesting result is obtained in which a cylinder moving with certain angular/axial velocity function and at particular values of Reynolds number is azimuthally/axially stress-free. Heat transfer rate increases with the increase of the rate of suction, Reynolds number, and Prandtl number. Interesting means of heating and cooling processes of cylinder surface are obtained using different rate of transpiration.https://www.ije.ir/article_71873_47781b997f017c8c3b2024272ed75cb7.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249523320101101MHD FREE CONVECTIVE FLUCTUATING FLOW THROUGH A POROUS EFFECT WITH VARIABLE PERMEABILITY PARAMETER31332271874ENAnilKumarApplied Mathematics, Echelon Institute of Technology, FaridabadJournal Article19700101In the present paper, we have studied MHD free convective two dimensional unsteady viscous incompressible flows through a porous effect bounded by an infinite vertical porous plate with constant suction. The permeability of the porous medium fluctuates in time about a constant mean, and the viscosity of fluid is assumed to vary as a linear function of temperature. The flow is permitted under the influence of a uniform transverse magnetic field, whereas the induced magnetic field has little effect on the flow and can be neglected. The governing equations are solved by perturbation technique based on computer extended series solution.https://www.ije.ir/article_71874_28e70bd9295f59220d9b027a85f37c50.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249523320101101TARGETING CUSTOMERS: A FUZZY CLASSIFICATION APPROACH32333671875ENAmirKhanlaribusiness administration, University of TehranJournal Article19700101Nowadays, marketing serves the purpose of maximizing customer lifetime value (CLV) and customer equity, which is the sum of the lifetime values of the company’s customers. But, CLV calculation encounters some difficulties which limit the usage of this technique. Nonetheless, companies looking for methods to know how to calculate their customers’ CLV. In this paper, fuzzy classification rules were used to determine customers’ CLV and segment them based on recency, frequency and monetary (RFM) measures. Data required for applying this method gathered from a steel firm in Iran. https://www.ije.ir/article_71875_420b786f66b4d1aa73b085827a4394c6.pdf