Taguchi Orthogonal Array Method Research Articles

Simulation and optimization of hot extrusion process to produce rectangular waveguides

In this study, the Taguchi method and genetic algorithm are employed to optimize the die geometry in order to obtain the minimum magnitude of extrusion force to produce the rectangular waveguides. Waveguides are hollow metal tubes for transporting electromagnetic energy from one region to another. A combination of process parameters was selected using orthogonal array Taguchi method. The results were then simulated by finite element method (FEM). By using the analysis of variance (ANOVA) method, the effective parameters and their interactions were determined. By using the FEM results, an artificial neural network (ANN) model was trained, and the effects of die factors on the extrusion force were studied for constant thermal and frictional conditions. Moreover, the optimum conditions were predicted by means of genetic algorithm (GA) method which was verified by experimental procedure. The optimum die length and billet hole diameter were obtained at L = 20 and D = 3 cm, respectively, for the initial billet temperature of 450 °C and friction coefficient of 0.1.

Analysis of Hardness by Parametric Optimization of Gravity Die Casting for A-356 Aluminium Alloy Using Taguchi Technique

This paper attempts to investigate Hkb Box (A-356 aluminium alloy) manufactured by Gravity Die casting process. Main objective of this research paper is to find the most influencing parameters on hardness of gravity die casting. Taguchi Technique is a powerful and efficient method for optimizing the process, quality and performance output of manufacturing processes. Taguchi's orthogonal array method and S/N Ratio were used for experiments and it was found that Pouring Time and Pouring Temperature are the most influencing parameters to improve hardness. Finally ANOVA was used to confirm the design of experiment.

Quality Kinetics and Storage Stability Studies of Ready to Eat Peanut Chutney

Ready to eat peanut (Arachis hypogaea) chutney was developed and the recipe was optimized by sensory evaluation. The effect of vinegar percentage, packaging material and storage temperature over the RTE chutney was studied. Taguchi orthogonal array method was adopted for designing experiment. Quality parameters viz. moisture content, pH, carbohydrates, protein, fat content and overall acceptability were estimated for 40 days at an interval of 10 days. Quality kinetics was studied and kinetic rate constant, activation energy (E a ) and temperature coefficient (Q 10 ) were estimated. Storage studies were analyzed based on t 0.9 (Shelf life period) and t 0.5 (Half life period). Based on the experiments, Treatment T 3 (10% of vinegar, packed in glass bottle and stored at refrigeration temperature) was found to be an optimal solution.

Optimisation of Process Parameters for Lower Leakage Current in 22 nm n-type MOSFET Device using Taguchi Method

In this article, Taguchi orthogonal array method was used to optimize the process parameters during the design of a 22 nm n-type Metal Oxide Semiconductor Field Effect Transistor (MOSFET) in order to decrease the leakage current (ILEAK) of the device. Titanium dioxide (TiO2) was used as the dielectric layer to replace the traditional silicon dioxide SiO2 and tungsten silicide (WSix) was used as a metal gate to replace polysilicon. The device’s fabrication and electrical characterization were executed using ATHENA and ATLAS modules from Silvaco International. Taguchi’s Power of Three Series L9 orthogonal array was used to optimize the device process parameters and to finally predict the best process parameter combination to obtain the minimum leakage current (ILEAK) using Smaller-the-Better (STB) signal-to-noise ratio (SNR). The optimization resulted in the attainment of the lowest ILEAK mean value of 0.25759 nA/µm which is in accordance to the predicted value given in the International Technology Roadmap for Semiconductors (ITRS) 2011.

Optimisation of Process Parameters for Lower Leakage Current in 22 nm n-type MOSFET Device using Taguchi Method

In this article, Taguchi orthogonal array method was used to optimize the process parameters during the design of a 22 nm n-type Metal Oxide Semiconductor Field Effect Transistor (MOSFET) in order to decrease the leakage current (I LEAK ) of the device. Titanium dioxide (TiO 2 ) was used as the dielectric layer to replace the traditional silicon dioxide SiO 2 and tungsten silicide (WSi x ) was used as a metal gate to replace polysilicon. The device’s fabrication and electrical characterization were executed using ATHENA and ATLAS modules from Silvaco International. Taguchi’s Power of Three Series L9 orthogonal array was used to optimize the device process parameters and to finally predict the best process parameter combination to obtain the minimum leakage current (I LEAK ) using Smaller-the-Better (STB) signal-to-noise ratio (SNR). The optimization resulted in the attainment of the lowest I LEAK mean value of 0.25759 nA/µm which is in accordance to the predicted value given in the International Technology Roadmap for Semiconductors (ITRS) 2011.

Fatty acid methyl ester production from acid oil using silica sulfuric acid: Process optimization and reaction kinetics

AbstractConversion of high free fatty acids (FFA) containing acid oil (AO) to fatty acid methyl esters (FAME) using silica sulfuric acid (SSA) as a solid acid catalyst was investigated. Process parameters such as reaction temperature, reaction time, catalyst loading, and methanol to oil molar ratio were optimized using the Taguchi orthogonal array method. Maximum FFA conversion (97.16 %) was achieved under the optimal set of parameter values viz. 70°C, 4 mass % catalyst loading, and 1: 15 oil to methanol molar ratio after 90 min. SSA was reused three times successfully without a significant loss in activity. Biodiesel produced from AO met the international biodiesel standards. Determination of kinetic parameters proved that the experimental results fit the pseudo first order kinetic law.

Machining Parameters Optimization for WEDM Based on Grey Relational Analysis

This paper presents an effective approach for the optimization of the wire electric discharge machining (WEDM) process with multiple performance characteristics based on the grey relational analysis. Twenty five experimental runs based on the Taguchi method of orthogonal arrays were performed to determine the best factor level condition. The response table and response graph for each level of the machining parameters were obtained from the grey relational grade. In this study, the machining parameters such as the machining voltage, the number of power amplifier tube, pulse width and pulse interval are optimized with consideration of multiple-performance characteristics, such as machining time and surface roughness. It is clearly shown that the above performance characteristics in WEDM process can be improved effectively through this approach. keywords: WEDM; grey relational analysis; parameter optimization; performance characteristics

COMPARISON OF METHODOLOGIES FOR IDENTIFICATION OF PROCESS PARAMETERS AFFECTING GEOMETRIC DEVIATIONS IN PLASTIC INJECTION MOLDING OF HOUSING USING TAGUCHI METHOD

This paper examines parameters that could influence geometric part deviation (shrinkage and warpage) of the Housing (Cycoloy, PC/ABS, Grade C2800) produced by plastic injection molding. Five parameters (temperature of molded plastic, injection time, cooling time, holding pressure, holding pressure time). Influence of the parameters is compared by simulation and real experiment with the results measured at five points. Taguchi's orthogonal array method is used. The simulation leads to unreliable results, with too many parameters influencing geometric deviation. Factor that has major influence is holding pressure time (HPT). The real experiment identifies holding pressure (HP) as a parameter with major influence. For further examination, the real experimentation is recommended, whenever it is possible.DOI: http://dx.doi.org/10.5755/j01.mech.18.6.3166

Investigation on the Turning Parameters for Surface Roughness using Taguchi Analysis

One of the important interests in the machining is attaining better surface roughness as well as dimensional accuracy. Polymer materials are continuously displacing the conventional materials. Their machining behavior is different in many aspects from machining of conventional metallic materials. Polymer based composite materials have superior properties for mechanical strength and stiffness, such as high strength-to-weight ratio and high stiffness-to-weight ratio. Fiber reinforced polymer composite materials are the one which are produced closer to the required shape, further machining is often necessary to achieve expected surface characteristics. This experimental study targets the machining of carbon fiber reinforced polymer material made into the form of tube. It examines various process parameters such as cutting speed, feed and depth of cut and their importance in deciding the surface roughness. Surface roughness was measured after machining is carried out under specified machining conditions. This experimental study focuses on the prediction of machining parameters that yield better surface characteristics in order to avoid machining of hard materials such as fiber reinforced composite materials so that enormous money spent in machining could be saved to some extent. For prediction this experimental study makes use of response surface methodology. The Taguchi method is used to solve many engineering problems. This work uses the Taguchi's orthogonal array method to find out the number of experiments to be carried out for turning operations. Also the analysis of variance is used to investigate the cutting parameters. In addition to the optimal cutting parameters for turning operations, the main cutting parameter that affect the cutting performance in turning operations could be found out.

High Performance Enzyme-Catalyzed Synthesis and Characterization of a Nonionic Surfactant

Sugar alcohol esters have a high potential for widespread application in various industries because of their surface active properties. In this work, fatty acid ester of a sugar alcohol was produced through Novozym 435-catalyzed esterification of xylitol and capric acid in nonaqueous media. Taguchi orthogonal array method based on three-level-six-variables (L27) and artificial neural network with Levenberg–Marquardt algorithm were applied to evaluate the effects of synthesis parameters and to optimize the reaction conditions. Both developed models have shown good quality predictions in terms of the conversion of xylitol caprate with a high R2 (>0.9) and a low mean square error (MSE). The maximum conversion of ester achieved was 88% requiring a small amount of enzyme and molecular sieve. Furthermore, the properties of the produced ester show that it is a suitable emulsifier for industrial application.

NEAR FIELD AND FAR FIELD EFFECTS IN THE TAGUCHI-OPTIMIZED DESIGN OF AN InP/GaAs-BASED DOUBLE WAFER-FUSED MQW LONG-WAVELENGTH VERTICAL-CAVITY SURFACE-EMITTING LASER

Long-wavelength VCSELs (LW-VCSEL) operating in the 1.55 μm wavelength regime offer the advantages of low dispersion and optical loss in fiber optic transmission systems which are crucial in increasing data transmission speed and reducing implementation cost of fiber-to-the-home (FTTH) access networks. LW-VCSELs are attractive light sources because they offer unique features such as low power consumption, narrow beam divergence and ease of fabrication for two-dimensional arrays. This paper compares the near field and far field effects of the numerically investigated LW-VCSEL for various design parameters of the device. The optical intensity profile far from the device surface, in the Fraunhofer region, is important for the optical coupling of the laser with other optical components. The near field pattern is obtained from the structure output whereas the far-field pattern is essentially a two-dimensional fast Fourier Transform (FFT) of the near-field pattern. Design parameters such as the number of wells in the multi-quantum-well (MQW) region, the thickness of the MQW and the effect of using Taguchi's orthogonal array method to optimize the device design parameters on the near/far field patterns are evaluated in this paper. We have successfully increased the peak lasing power from an initial 4.84 mW to 12.38 mW at a bias voltage of 2 V and optical wavelength of 1.55 μm using Taguchi's orthogonal array. As a result of the Taguchi optimization and fine tuning, the device threshold current is found to increase along with a slight decrease in the modulation speed due to increased device widths.

Improvement in Yield Strength of Deformed Steel Bar by Quenching Using Taguchi Method

This paper is on improvement in Yield strength of deformed steel bar by quenching using Design of experiment (DOE) for robust process design. The production of high quality deformed steel bar for concrete reinforcement will reduce the construction cost. It is found that the bar produced having variation in yield strength, this major quality problem is considered for improvement. Yield strength of bar is deviated from standard value specified in IS: 1786-1985. Here the study is focused on the robust parameter design for cooling system, to control the process of quenching to get the desired Yield strength of deformed steel bar. The controlling parameters of cooling system were controlled to improve the Yield strength of bar produced. Taguchi method of Orthogonal Array was used to find the effect of parameter on output quality parameter such as yield strength. DOE by Taguchi approach was used for the improvement in Yield strength. We got satisfactory result of yield strength of deformed steel bar having minimum variation from its mean value. Thus the Yield strength of bar has been improved by controlling the Quenching process parameters at optimum level which was found from factor effect plot using DOE by Taguchi Method. In this paper, the study of hot bar quenching process has been investigated. In order to predict the effect of noise factors and signal on response factor of water quenching process. The controlling parameters such as water pressure, speed of rolling, Cooling rate and Finish rolling temperature of bar were the four independent factors and each of them have three levels were considered for DOE and the response was yield strength. An orthogonal array- L9 had been used for the experiment. Here we used DOE by Taguchi method of orthogonal array to find the effect of parameter on Yield strength. Before conducting the experiment, the quenching setup was made ready with all respect to conduct experiment. The experiments were conducted and experimental data was recorded and analyzed by excel statistical method. The graph of main effect plot of factors was drawn, which was used to find the main effect on response. The parameters were controlled properly to minimize variation in yield strength and obtained the desired quality of bar. Here it is found that water pressure had the largest effect on the yield strength. The water pressure was controlled at different level for many experiments as per L-9 array and yield strength for each experiment was noted. The experimental data analyses were done by Minitab Statistical software. We found the optimum level of parameters setting to get optimum level of Yield strength. For this action plan was designed to control water pressure to a specific level as per the conclusion of this experimentation. Then the action plan had been implemented. The deformed bar were produced and checked for its quality; we found satisfactory quality steel bar having optimum Yield strength. The conclusion has been found that the cooling rate affects on yield strength, but cooling rate is controlled by water pressure which is operated using control valve. Hence water pressure has been controlled in quenching process to get the desired quality with minimum variation from standard value. The bar of 8 mm was produced by controlled rolling and quenching process. Speed of rolling was kept constant and PLC control water pressure valve was used instead of manual control valve for controlling the water pressure. II. Cooling system For the given operation conditions, the temperature and its distribution within the bar entering into the quenching play the crucial role in controlling the mechanical properties of the steel bar such as yield strength. Hence understanding of the cooling system is essential. There are three types of most frequently used cooling system in hot rolling; water jet cooling system, water spray cooling system, and mist cooling systems.(3)It is found that, the yield strength depends on cooling rate. Hence to control cooling rate we made the modification in the present system. The water pressure need to be controlled according the speed of rolling of bar and temperature of bar before entering the quenching system. Fig.1 shows the cooling system having water injector, a cooling tube, and a water stripper. As per size of bar to be produced, the length of cooling pipe is selected and the speed of rolling is controlled accurately.Fig.2, shows water pressure control valve in cooling system, the primary and secondary valves are used to control the water supply, another valve is used to control the air

Development of Efficient Fermentation Process at Bioreactor Level by Taguchi's Orthogonal Array Methodology for Enhanced Dextransucrase Production from <i>Weissella confusa</i> Cab3

The influence of medium ingredients on extracellular dextransucrase production by a new bacterial strain Weissella confusa Cab3 (Genbank Accession Number JX649223) was evaluated using fractional factorial design of Taguchi's orthogonal array. Four metabolism influencing factors viz. sucrose, yeast extract, K2HPO4 and Tween80 were selected to optimize dextransucrase production by W. confusa Cab3 using fractional factorial design of Taguchi methodology. Based on the influence of interaction components of fermentation, least significant factors of individual level have higher interaction severity index and vice versa for enzyme production from Weissella confusa Cab3. Sucrose and yeast extract were found to be the most significant factors which positively influenced the dextransucrase production. The optimized medium composition consisted of sucrose—5%; yeast extract—2%; K2HPO4—1.0%; Tween80—0.5%, based on Taguchi orthogonal array method. The optimized composition gave an experimental value of dextransucrase activity of 17.9 U/ml at shake flask level which corresponded well with the predicted value of 17.54 U/ml by the model. The optimized medium by Taguchi method gave significant (3 fold) enhancement of dextransucrase activity as compared to unoptimised enzyme activity of 6.0 U/ml. The dextransucrase production was scaled up in lab scale bioreactor resulting in further enhancement of enzyme activity (22.0 U/ml).

Chemometric analysis of lipase-catalyzed synthesis of xylitol esters in a solvent-free system

Immobilized Candida antarctica lipase B-catalyzed esterification of xylitol and two fatty acids (capric and caproic acid) were studied in a solvent-free system. The Taguchi orthogonal array method based on three-level-four-variables with nine experiments was applied for the analysis and optimization of the reaction parameters including time, substrate molar ratio, amount of enzyme, and amount of molecular sieve. The obtained conversion was higher in the esterification of xylitol and capric acid with longer chain length. The optimum conditions derived via the Taguchi approach for the synthesis of xylitol caprate and xylitol caproate were reaction time, 29 and 18 h; substrate molar ratio, 0.3 and 1.0; enzyme amount, 0.20 and 0.05 g, and molecular sieve amount of 0.03 g, respectively. The good correlation between the predicted conversions (74.18% and 61.23%) and the actual values (74.05% and 60.5%) shows that the model derived from the Taguchi orthogonal array can be used for optimization and better understanding of the effect of reaction parameters on the enzymatic synthesis of xylitol esters in a solvent-free system.

Parameter optimization of laser transformation hardening by using Taguchi method and utility concept

This paper presents the application of Taguchi method and the utility concept for optimizing the laser process parameters in laser transformation hardening of commercially pure titanium using a continuous-wave 2-kW, Nd:YAG laser. In this study, a set of optimal laser process parameters were evaluated through the Taguchi method of orthogonal arrays and utility concept. Taguchi method and utility concept, a powerful tool to design optimization for quality, is used to find the set of optimal laser hardening parameters such as laser power (LP), scanning speed (SS), and focused position (FP) on two multiple performance characteristics of hardened bead geometries, namely, hardened bead width (HBW) and hardened depth (HD), developed for laser transformation hardening of commercially pure titanium. The utility concept has been employed for the multi-performance characteristics optimization using Taguchi design. The experiments were planned as per Taguchi’s L9 orthogonal array. A Taguchi L9 orthogonal array methodology was used to optimize the conditions for laser-hardened bead width and hardened depth. Taguchi tools such as analysis of variance (ANOVA), signal-to-noise ratio, and additive model have been used to analyze, obtain the significant parameters, and evaluate the optimum combination levels of laser transformation hardening process parameters. The optimal levels of the laser process parameters were determined through the analysis of means. The relative importance among the process parameters were identified through ANOVA. The ANOVA results indicated that the most significant process parameters are SS followed by LP and FP, which affect the optimization of multiple performance characteristics. The confirmation tests with optimal levels of laser process parameters were carried out to illustrate the effectiveness of Taguchi optimization method. The optimization results revealed that a combination of higher levels of SS and FP, i.e., increase in defocused beam with negative focal length along with LP in the lower level, is an essential laser hardening parameter to simultaneously minimize the HD and maximize the HBW.

Manufacture of a spur tooth gear in Ti–6Al–4V alloy by electrical discharge

This paper proposes a method of manufacturing a spur tooth gear in Ti–6Al–4V alloy (grade 5) using a wire electrical discharge machine (Wire EDM). A geometrical model for the gear is drawn up and implemented using the program MATLAB. The electro-erosion parameters tested for this alloy are applied to an ONA PRIMA S-250. The parameters used (power, pause, voltage, …) are based on the ONA EDM charts. The Taguchi orthogonal array method was chosen to obtain the optimum values for cutting Titanium. The work presented follows established lines for manufacturing mechanical parts using general purpose machines and tools. In this case, the WEDM process was used. The MATLAB program was employed to obtain the interpolation points. This program simplifies the task of solving the equations originated by the mathematical model which allows the wire path to be calculated. The WEDM method used here is a commendable alternative for machining electrically conductible materials which are difficult to work with using conventional machine tools (milling, turning or boring). Furthermore, the WEDM process reduces or even eliminates the need for subsequent polishing processes due to the high-quality finish achieved.

An Improved genetic algorithm for the prediction of surface finish in dry turning of SS 420 materials

Determination of optimal cutting parameters is one of the most important elements in any process planning of metal parts. This paper presents a development of an improved genetic algorithm (IGA) and its application to optimize the cutting parameters for predicting the surface roughness is proposed. Optimization of cutting parameters and prediction of surface roughness is concerned with a highly constrained nonlinear dynamic optimization problem that can only be fully solved by complete enumeration. The IGA incorporating a stochastic crossover technique and an artificial initial population scheme is developed to provide a faster search mechanism. The main advantage of the IGA approach is that the “curse of dimensionality” and a local optimal trap inherent in mathematical programming methods can be simultaneously overcome. The IGA equipped with an improved evolutionary direction operator and a migration operation can efficiently search and actively explore solutions. The IGA approach is applied to predict the influence of tool geometry (nose radius) and cutting parameters (feed, speed, and depth of cut) on surface roughness in dry turning of SS 420 materials conditions based on Taguchi's orthogonal array method. Additionally, the proposed algorithm was compared with the conventional genetic algorithm (CGA), and we found that the proposed IGA is more effective than previous approaches and applies the realistic machining problem more efficiently than does the conventional genetic algorithm (CGA).

Robust design and numerical simulation on drag reduction by a mixture film for liquid turbulence in a channel

AbstractAn important way of increasing the speed and lowering the fuel consumption of ships is by decreasing the frictional drag. One of the most promising techniques for reducing drag is the use of air bubbles. The goal of this investigation is to establish a set of optimum robust parametric levels for drag reduction by a mixture (air–water) film in turbulent channel flow. Based on the conditions laid out by the Taguchi orthogonal array method, turbulent flows, with air bubbles injected into a channel, are simulated using commercial computational fluid dynamics software. The local shear stress on the upper wall is computed to evaluate the efficiency of drag reduction. Many factors can affect drag reduction. The factors investigated in this study are the rate of air injection, bubble size, area of air injection, flow speed, and measured position of the shear stress. These factors have been investigated through the analysis of variance, which has revealed that the rate of air injection and water flow speed dominate the efficiency of drag reduction by a mixture film. According to the results, the drag can be reduced by an average of 83.4%; and when the configuration of the parametric levels is optimum the maximum drag reduction of 88.5% is achieved. Copyright © 2008 John Wiley & Sons, Ltd.

Use of the grey relational analysis to determine optimum laser cutting parameters with multi-performance characteristics

This paper presents an effective approach for the optimization of laser cutting process of St-37 steel with multiple performance characteristics based on the grey relational analysis. Sixteen experimental runs based on the Taguchi method of orthogonal arrays were performed to determine the best factor level condition. The response table and response graph for each level of the machining parameters were obtained from the grey relational grade. In this study, the laser cutting parameters such as laser power and cutting speed are optimized with consideration of multiple-performance characteristics, such as workpiece surface roughness, top kerf width and width of heat affected zone (HAZ). By analyzing the grey relational grade, it is observed that the laser power has more effect on responses rather than cutting speed. It is clearly shown that the above performance characteristics in laser cutting process can be improved effectively through this approach.

Manufacturing process optimization for wear property of fiber-reinforced polybutylene terephthalate composites with grey relational analysis

This paper studies the optimization of injection molding process parameters using the grey relational analysis method. Nine experimental runs based on the Taguchi method of orthogonal arrays were performed to determine the best factor level condition. The wear volume losses of fiber-reinforced polybutylene terephthalate in different sliding directions were selected to be the quality targets. Volume losses were obtained using an Schwingum Reibung Verschleiss (SRV) “ball-on-plane” wear tester. The factor levels were assessed according to two chosen wear volume losses. The degree of influence that the controllable process factors exert on the wear volume losses was studied by investigating the correlation between them. By analyzing the grey relational grade matrix, the most influential process factor and the most easily influenced wear property could be picked. Melt temperature was found to be the most influential factor in both wear volume losses of different sliding directions. The wear volume loss of sliding direction perpendicular to injection flow was more easily influenced by process factors than was the wear volume loss of the sliding direction parallel to the injection flow. The sequences of the importance to the wear volume loss in the controllable factors were slightly different for the two sliding directions, but the melt temperature was still the most important factor.