Orthogonal Array Table Research Articles

3D FEM forming simulation optimization and experiment on bevel thread-forming screw

Abstract This study adopts 3 forming passes and 1 thread rolling process as the multi-pass schedule of bevel thread-forming screw. The finite element simulation software is used to simulate the plastic behaviour of forming and thread rolling processes. The geometry shapes, the part dimensions of each pass, the effective stress, the effective strain, the forming force and the die stress of each pass can be reached via FEM simulation. Moreover, especially Taguchi method for the maximum force pass is conducted to optimize the forming processes. Considering 4 control factors such as A: head arc radius (rH), B: flange thickness (t), C: corner radius (r), and D: frictional factor(m) and 3 levels to establish the orthogonal array table for optimum forming force, the influence rank and the optimal parameters combination are obtained to carry out the realistic experiment for confirming the feasibility of FEM simulation optimization. In a word, the influence rank of control factors: flange thickness (t) > head arc radius (rH) > corner radius (r) > frictional factor (m), and the optimal parameters combination is A3B3C3D1 (rH=42 mm, t=1.3 mm, r=0.7 mm, and m=0.12).

Optimization of the Outlet Shape of an Air Circulation System for Reduction of Indoor Temperature Difference

This study proposes an air circulation system that can forcibly circulate the lowest cold air to the top of indoor smart farms, and it has a width, length, and height of 6, 12, and 2.5 m, respectively, to reduce the effect of temperature differences between the upper and lower parts on the growth rate of plants in winter. This study also aimed to reduce the temperature deviation generated between the upper and lower parts of the target indoor space by optimizing the shape of the manufactured outlet of the air circulation system. A table of L9 orthogonal arrays, which is a design of experiment methodology, was used, and it presented three levels of the following design variables: blade angle, blade number, output height, and flow radius. Flow analysis was performed for the experiments on the nine models to minimize the high time and cost requirements. Based on the derived analysis results, an optimized prototype was manufactured by applying the Taguchi method, and experiments were conducted by installing 54 temperature points in an indoor space to identify the temperature difference between the upper and lower parts over time for the performance experiment. Under natural convection, the minimum temperature deviation was 2.2 °C and the temperature difference between the upper and lower parts did not decrease. For a model without an outlet shape, such as a vertical fan, the minimum temperature deviation was 0.8 °C and at least 530 s were required to reach a difference of less than 2 °C. When air was circulated in the air circulation system with the proposed outlet shape, the minimum temperature deviation was 0.6 °C and the time required to reach a difference of less than 2 °C was 440 s. Using the proposed air circulation system, cooling and heating costs are expected to be reduced in summer and winter because the arrival time and temperature difference between the upper and lower parts can be reduced using the outlet shape compared with the case without the outlet shape.

Simultaneous Determination of Escitalopram Impurities including the R-enantiomer on a Cellulose tris(3,5-Dimethylphenylcarbamate)-Based Chiral Column in Reversed-Phase Mode.

A high-performance liquid chromatographic method was developed for the simultaneous determination of the related substances-three potential synthesis-related chemical impurities and the distomer-of escitalopram. The separation capacity of seven different polysaccharide-type chiral columns, including three amylose-based (Lux Amylose-1, Lux i-Amylose-1, Lux Amylose-2) and four cellulose-based columns (Lux Cellulose-1, Lux Cellulose-2, Lux Cellulose-3, and Lux Cellulose-4) were screened in the polar organic and reversed-phase modes. Lux Cellulose-1, based on cellulose tris(3,5-dimethylphenylcarbamate) as the chiral selector with an acetonitrile-water mixture containing 0.1% diethylamine was identified as the most promising separation system. Using the "one factor at a time" optimization approach, the effect of column temperature, flow rate, and mobile phase constituents on separation performance was evaluated, and the critical resolution values were determined. A U-shaped retention pattern was obtained when plotting the retention factors of the citalopram enantiomers versus the water content of the binary mobile phases on the Lux Cellulose-1 column. A thermodynamic analysis revealed enthalpy-driven enantioseparation in both the polar organic and reversed-phase modes. For further method optimizations, an L9 orthogonal array table was employed. Using the optimized parameters (Lux Cellulose-1 column with 0.1% (v/v) diethylamine in water/acetonitrile 55/45 (v/v); 0.8 mL/min flow rate at 25 °C), baseline separations were achieved between all compounds. Our newly developed HPLC method was validated according to the ICH guidelines and its application was tested with a commercially available pharmaceutical formulation. The method proved to be suitable for routine quality control of related substances and the enantiomeric purity of escitalopram.

Detailed Successive Layer Modeling and Design Factor Analysis for Single Micro-LED Pixel

The major factors associated with the manufactured structures and photon emission intensity distribution must be accurately identified for the complicated optical design parameters associated with micro-LED pixels. This study presents the methodologies and reveals the sequential calculating protocol in each layer for pixel-level optical simulations, based on which the boundary condition errors associated with common optical simulations can be corrected. Moreover, the optical effect on each epitaxial layer of the micro-LED design is revealed, and the rationality of the setting of the finite-radius receiver with a pseudo-extended substrate material is also explained with respect to the intrinsic and extrinsic pixel-intensity distribution properties. Finally, the design of experiments DOE L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">18</sub> orthogonal array table is demonstrated by the Taguchi method to explore the principal factors for the parameter design of the micro-LED layers. The results indicate that the sapphire thickness, the P-GaN layer, the buffer layers, and an additional substrate plate are the four significant factors that primarily influence the luminous power and the corresponding uniformity on the exit pupil of micro-LEDs. Based on the luminous power uniformity, the signal-to-noise ratio in the sapphire thickness is 16.9, and the extended substrate plate is 9.8, which is ∼10 times > the interaction design parameter, such as the etching angle and reflective index of the extended substrate of the micro-LED pixel. These specific design factors can be the major optimization parameters for cost control and performance improvement.

Application of integrated CRITIC and GRA-based Taguchi method for multiple quality characteristics optimization in laser-welded blanks

There is a need to study the multi-objective optimization technique as the appropriate method to enhance welding qualities under optimal process conditions. Therefore, this study investigated the application of the integrated Criteria Importance Through Intercriteria Correlation (CRITIC), which is an objective weighting technique, and the Grey Relational Analysis (GRA)-based Taguchi method to solve multiple criteria optimization problem in the Nd:YAG laser welding process. The Taguchi-based L36 orthogonal array table was employed in this study to optimize six process parameters, including the beam diameter, laser power, flow rate, welding speed, laser offset, and pulse shape, with the aim to simultaneously achieve maximum weld strength and minimum weld width. The base metal JIS G3141 SPCC steel with 0.5 and 1.0 mm thicknesses was used in the present experiment. Following the welding process and optimization, the weld strength was measured using a Cometech QC-506M1 universal testing machine, while the weld width was determined under a Nikon SMZ25 stereomicroscope. Based on the results, the weight fractions of the weld strength and weld width from the applied CRITIC method were equal to 0.4157 and 0.5843, respectively. Meanwhile, the GRA revealed that the process parameters recorded an optimal setting for beam diameter of 0.8 mm, flow rate of 8 L/min, laser power of 0.6 kW, welding speed of 2.5 mm/s, laser offset of 0.2 mm, and pulse shape I. Furthermore, the weld strength and the weld width were enhanced from 236 to 328 MPa and from 1.13 to 1.04 mm, respectively. Additionally, the Analysis of Variance (ANOVA) indicated that the laser power and welding speed were the most influential parameters on the welding qualities. Most importantly, the findings of the confirmation experiment showed that the proposed approach was able to effectively identify the optimal laser welding parameters, which ultimately improved the multiple quality characteristics.

PREDICTION OF REGRESSION BASED WEAR BEHAVIOUR MODELS OF ALUMINIUM ALLOY 356 – ZrSiO4 COMPOSITES

The term composite is a combination of two materials with different physical and chemical properties. When combined, they create a specialised material to do a certain job, for instance, to become stronger, lighter or resistant to electricity. They can also improve strength and stiffness. Metal matrix composites have much improved properties, including high tensile strength, toughness, hardness, low density and good wear resistance compared to alloys or any other metal. Aluminium alloys are becoming important today, especially in the automobile, space and electrical industries. Unfortunately, due to poor wear resistance, aluminium alloy can deteriorate quickly. So the present investigation aims at developing Aluminium 356 alloy (AA356) composites reinforced with 5 wt.% Zirconium Silicate (ZrSiO4) with better wear resistance. The composites have been fabricated using the ‘stir-casting’ method in which the particles were added to molten metal during the stirring process at a rotating speed of 700 rpm. A wear test has been performed on a pin on the disc apparatus. Three process parameters have been considered: normal load, sliding velocity, and sliding distance at three different levels. An experimental plan has been made using Taguchi’s L9 orthogonal array table. The output responses such as wear rate and coefficient of friction have been considered for the investigation. Regression models have been generated for each output response. Using the generated regression models, one can predict the value of the output parameters even without actually performing the experimentation within the range of input factor combinations.

Optimization of operation parameters in machining of functionally graded metal matrix composite using TOPSIS

Aluminium Functionally Graded Composites are the leading engineering materials due to its different gradient properties within the single element. Machining is one of the major challenging subjects in the functionally graded materials due to its gradient dissemination hard ceramic particles. The present work aims to manufacture Aluminium reinforced with 20 wt% SiC Functionally Graded Metal Matrix Composites (FGMMC) using vertical centrifugal casting technique and machining the manufactured specimen using Electric Discharge Machining (EDM) with varied level of operating parameters such as pulse current (Ip), pulse on time (Ton) and zones from the outer periphery of the specimen. The performance considered are surface roughness and overcut. Taguchi L9 orthogonal array table was designed to conduct the machining experiments. TOPSIS technique was used to find the optimum operation parameters through closeness coefficient values. The optimal setting operation parameters are pulse current 5A, pulse on time 75 μs, and zone from the outer periphery 30 mm. ANOVA revealed that the pulse on time is the most influencing operation parameters on the response continued by pulse current and zone from the outer periphery. The results showed that the mixed TOPSIS and ANOVA was the successful method to improve the machining operations.

Study of the heat transfer and analysis of the surface characteristics of robot spray painting by using Taguchi method and ANOVA analysis

In this investigative research work, the surface characteristics of normal paint and multiwall carbon nanotube (MWCNT) paint-coated substrates are studied. The experiments are conducted using ABB IRB 1410 Robot and the end effector of the robot is retrofitted with a high-volume low-pressure atomizer paint spray gun. The nanopaint is prepared by ultrasonication by placing 1 gram of MWCNT in a polyurethane commercial base paint (500 ml). Taguchi design of experiments is used to identify the most efficient use of procedure parameters using the L9 orthogonal array table. Heat transfer of the substrate is found by temperature measurements of the convective heat transfer through extended surfaces. Surface morphology is studied by scanning electron microscope and upright microscopy. Analysis of variance technique is used to find the most influencing input parameters and contribution of values to maximizing surface finish and minimizing the heat transfer effect. The study shows that there is an enhancement in surface finish and minimization of heat transfer in the nanopaint coated substrate when compared with normal paint application using the ABB robot.

Investigating the construction parameters of deep mixing columns in silty soils

In the present research, the optimum condition of the grout consisting of cement, fly ash, superplasticizer, and water was determined to produce the most durable and impermeable deep mixing columns (DMC) on silty soils. It is aimed to reduce the grout cost and environmental pollution by using high-rate fly ash in the grout. Superplasticizer additive was used to increase the flow consistency of grout consisting of high-rate fly ash. The design of the experiments was made using the 5-parameter and 4-level L16 orthogonal array table specific to the Taguchi method. Accordingly, the unconfined compression strength (qu) and the permeability coefficient (k) of the soil-binder mixtures at the end of the 7- and 28-days curing time were determined. According to the test results, regression analyzes were performed and models with high reliability were created for qu and k. As a result of optimization studies, to produce DMC having high strength and low permeability, grout content should be consisting of 14% cement, 14% fly ash (ratio of fly ash in the binder is 50%), 2.68% super plasticizer additive, and 0.95 water/binder ratio. The pozzolanic reactions in soil-binder samples with different grout contents were examined by SEM analysis.

Experimental characterization of friction and wear behavior of textured Titanium alloy (Ti-6Al-4V) for enhanced tribological performance

Laser surface texturing (LST) is an effective surface engineering technique that can improve the efficiency and reliability of a tribosystem. In this study, surface textures with combined dimple patterns were prepared on a Ti-6Al-4V alloy surface using a Nd:YAG pulsed laser. Sliding dry and MoS2 solid-lubricated experiments were performed to assess the tribological characteristics of these specimens using a ball-on-disk mode. An L9 (34) orthogonal array table was used to prepare an experimental plan, which contained three parameters: the sliding speed, applied load, and the area density of dimple on the friction properties. The results show that the MoS2-added textured surface effectively decreased the coefficient of friction and reduced adhesion wear compared to an untextured surface. Analysis of variance (ANOVA) suggested that the texture area density has a major effect on the friction coefficient at a confidence level of 99%, followed by the applied load and sliding speed. Scanning electron microscopy (SEM) revealed that the wear mechanisms were adhesive and abrasive wear, and a transfer layer from the Ti-6Al-4V alloy was obtained on the counterpart ceramic ball. In conclusion, a higher texture area density is advantageous to increase the friction and wear performance of the Ti-6Al-4V alloy surface.

Optimal location of brake pad for reduction of temperature deviation on brake disc during high-energy braking

During the braking process, frictional heat generated between a disc and a pad can lead to high temperatures. The location of friction blocks on the brake pad can lead directly to differences in friction contact time and friction speed at each point on the brake disc surface, this can lead to non-uniform temperature distribution on the brake disc surface. In this paper, the optimum design for friction blocks on a brake pad is investigated using the design of experiments (DOE) of Taguchi approach and response surface method (RSM) with an aim to minimize the deviation in the rate of friction heating in each area along the radial direction of brake disc. 18 design variables on 2 levels are adjusted. A table of orthogonal arrays, L32 (218), is used. Finite element analysis (FEA) is performed to analyze the mean squared error (MSE) values in the temperature deviations from frictional heat, the disc’s thermo-mechanical characteristics are taken into account. Analysis of variance (ANOVA) is carried out using the data gathered from the DOE stage, we find 7 significant factors among the design variables. A meta-model using RSM is proposed for reduction of temperature deviations over the brake disc. An optimized brake pad is analyzed in terms of the temperature and thermal stress imparted on the brake disc, this optimized pad is then compared with the original pad. The maximum temperatures of the optimized pad and original pad were 399.8 °C and 480.6 °C, respectively. The thermal stress of the optimized pad and original pad were 640.4 MPa and 721.4 MPa, respectively. In the optimized model, the size of the hot band on the disc is larger than that from the original model, so the thermal stress distribution on the disc is smaller. Finally, the optimized pad was found to give significant performance benefits with a 16.8 % decrease in maximum temperature and 11.2 % decrease in thermal stress.

Investigation of Preferences in Working Environment of Students for Maintaining Uniform Geographical Distribution of Radiological Technologists

This study was designed to assess working environment preferences of students in the Department of Radiological Technology using conjoint analysis for establishing an efficient medical system. We carried a questionnaire survey on working environment preferences for 196 students in the Department of Radiological Technology in Japan. We defined eight characteristics for virtual medical facilities as follows: presence of colleagues who can be consulted, employment status, number of night shift per month, academic meeting participation, number of hospital beds, possession of nuclear medicine imaging systems and radiation therapy systems, location of medical facilities, and change rate in annual income. A total of 18 virtual medical facilities were selected by an orthogonal array table using above-mentioned characteristics. The acquired data by the pairwise comparison method were analyzed by conjoint analysis. Marginal rates of substitution that represent students' preferences were also calculated. The factors that influenced their preferences were the following: placement of medical facilities in great city, presence of colleagues who can be consulted, employment status is not non-regular employment, set up of nuclear medicine imaging systems and radiation therapy systems, the number of night shift is twice per month, and attendances at academic meetings. In summary, students in the Department of Radiological Technology tend to prefer the facilities with regular employment, great city, presence of colleagues who can be consulted, and possession of nuclear medicine imaging systems and/or radiation therapy systems.

Evaluation of wear resistance of Vanadis23 PM steel subjected to cryogenic treatment

In this paper, wear study is performed on the Vanadis23 PM steel using cryogenic treated tool steel and the results are analyzed using experimental and statistical method. The tool is subjected to various cryogenic treatments along with the conventional heat treatment method. Modified Taguchi’s orthogonal array table is used to conduct experiments. Analysis of variance and regression analysis is applied for the final results. Tool wear analysis is done and compared by using experimental and (statistical) predicted model.

Optimization of friction stir welding parameters during joining of AA3103 and AA7075 aluminium alloys using Taguchi method

This paper investigates the optimization of input parameters for the friction stir welding of AA3103 and AA7075 aluminium alloys. The properties of base materials AA3103 are non-heat-treatable alloy, which is having good weldability while AA 7075 is having higher strength. Therefore, the welding of these aluminium alloys will produce superior mechanical properties. Friction stir welding is a rapidly growing welding process which is being widely used in marine, automobile and aerospace industries. Rather than its widespread use, this type of welding has several advantages over normal welding processes like low production of fume, no consumable electrodes are used and can be used in any position. In this paper, optimization of input parameters were conducted based on Taguchi method using the L9 orthogonal array. There were nine experimental runs in total after creating the L9 orthogonal array table in MINITAB software. The input parameters selected for optimization are tool rotation speed, feed rate, tool pin profile the output parameters which are optimized hardness, tensile strength, impact strength. The ANOVA analysis was carried out in the Qualitek 4 software to find out the percentage influence of input parameters on the output parameters. This research work was carried out to find the optimized condition to carry out friction stir welding of above mentioned aluminium alloys.

The Experimental Process Design of Artificial Lightweight Aggregates Using an Orthogonal Array Table and Analysis by Machine Learning.

The purpose of this study is to experimentally design the drying, calcination, and sintering processes of artificial lightweight aggregates through the orthogonal array, to expand the data using the results, and to model the manufacturing process of lightweight aggregates through machine-learning techniques. The experimental design of the process consisted of L18(3661), which means that 36 × 61 data can be obtained in 18 experiments using an orthogonal array design. After the experiment, the data were expanded to 486 instances and trained by several machine-learning techniques such as linear regression, random forest, and support vector regression (SVR). We evaluated the predictive performance of machine-learning models by comparing predicted and actual values. As a result, the SVR showed the best performance for predicting measured values. This model also worked well for predictions of untested cases.

Enhancing the tensile properties with minimal mass variation by revealing the effects of parameters in fused filament fabrication process

The Fused Filament Fabrication is a revolutionary method for the manufacturing industry. However, there are still numerous challenges need to be tackled in order to standardize the procedure of printing process. In this study, the process parameters of line width, shell thickness, infill orientation and infill overlap, have been experimentally investigated over their affect on tensile strength properties and the mass of the produced samples. Design of experiments has been planned, conducted and evaluated using the Taguchi approach. A total of 25 combinations of the four printing parameters with five different settings have been set according to the L25 Orthogonal Array table. The sample parts have been printed via widely used type low-cost and open-source 3D printer. Afterwards, the printed samples are tested for their tensile strength. The best combinations of the parameters with relevant settings have been revealed by S/N Ratio analysis. In order to validate the statistical results, the sample with newly found combination has been manufactured. Then, the ANOVA has been applied in order to reveal the percentage contributions of parameters to the tensile behaviour. It has been concluded that infill overlap and orientation parameters are dominant factors over the ultimate tensile strength of the samples. As a widespread effect, generalized equations have been established and presented in order to calculate the occupied area by an overlap. By implementing the equations, the users will be able to configure their input parameters in behalf of increasing the tensile strength while controlling the material consumption.

Reduction of flow-induced noise in a household air purifier

In this study, we propose a design for a household air purifier that reduces the flow-induced noise caused by the impeller of the fan system. The noise of the air purifier was identified in experiments as induced by the air flow generated by the impeller of the purifier. This noise can be classified into tonal noise and wide-band frequency noise: The former is the noise from the impeller blade turning, and the latter is from air flow turbulence. Using a commercial computational fluid dynamics (CFD) analysis code, it was shown that flow separation occurs at the outlet of the scroll by the adverse pressure gradient, which significantly reduces the flow rate of the purifier. To avoid flow separation and maximize flow rate within the adjustable ranges of the design parameters, an improved air purifier was redesigned using an orthogonal array table. By CFD analysis, the improved design showed an increased flow rate without flow separation. Finally, after fabricating a prototype with the improved design, it was experimentally proven that noise was reduced by 4.2 dBA without sacrificing flow rate.

ANALYSIS ON VOLUMETRIC SHRINKAGE OF PLASTIC FOOD CONTAINER MADE FROM AN INJECTION MOLDING PROCESS

The plastic injection molding process is one of the widely used of the manufacturing process to manufacture the plastic product with high productivity. Moreover, the food packaging manufacturing industry undergoes the trials and errors to obtain the optimal setting of the process parameters in order to minimize the quality issues and these trials and errors are time consuming and costly. The aim of this study is to improve the quality of the butter tub by minimizing the volumetric shrinkage. This study is to deal with the application of Moldflow integrating with the statistical technique to minimize the volumetric shrinkage the butter tub which depends on the process parameters of the plastic injection molding. For this purpose, the rectangular shape of butter tub is designed by utilizing the SolidWorks. Molflow is used to simulate the plastic filling of the single cavity mold of butter tub based on the Taguchi’s orthogonal array table. In addition, the analysis of variance (ANOVA) is applied to investigate significant impact of the process parameters on the quality of the butter tub. Minitab is used to optimize the response of the volumetric shrinkage by selecting the most appropriate process parameters that maximizing the desirability value. Furthermore, the butter tub has a uniform thickness which was 1.2 mm and its factor of safety was 3.383 and the volumetric shrinkage response have optimized by 0.956 %. The melt temperature and mold temperature are found to be the most significant process parameters for the plastic injection molding process of butter tub and the volumetric shrinkage value obtained from the simulation is verified by the calculated volumetric shrinkage value.

ANALYSIS ON VOLUMETRIC SHRINKAGE OF PLASTIC FOOD CONTAINER MADE FROM AN INJECTION MOLDING PROCESS

The plastic injection molding process is one of the widely used of the manufacturing process to manufacture the plastic product with high productivity. Moreover, the food packaging manufacturing industry undergoes the trials and errors to obtain the optimal setting of the process parameters in order to minimize the quality issues and these trials and errors are time consuming and costly. The aim of this study is to improve the quality of the butter tub by minimizing the volumetric shrinkage. This study is to deal with the application of Moldflow integrating with the statistical technique to minimize the volumetric shrinkage the butter tub which depends on the process parameters of the plastic injection molding. For this purpose, the rectangular shape of butter tub is designed by utilizing the SolidWorks. Molflow is used to simulate the plastic filling of the single cavity mold of butter tub based on the Taguchi’s �!" orthogonal array table. In addition, the analysis of variance (ANOVA) is applied to investigate significant impact of the process parameters on the quality of the butter tub. Minitab is used to optimize the response of the volumetric shrinkage by selecting the most appropriate process parameters that maximizing the desirability value. Furthermore, the butter tub has a uniform thickness which was 1.2 mm and its factor of safety was 3.383 and the volumetric shrinkage response have optimized by 0.956 %. The melt temperature and mold temperature are found to be the most significant process parameters for the plastic injection molding process of butter tub and the volumetric shrinkage value obtained from the simulation is verified by the calculated volumetric shrinkage value.

Design of Magnetic Shield for Hall-Effect Current Sensor Using Integrated Magnetic Concentrator

This paper proposes a shield shape design for minimizing the integrated magnetic concentrator (IMC) hall current sensor shield. Inside flux density and outside magnetic field error rate aren’t satisfied with performance by reducing an initial U-shaped IMC hall current sensor shield’s width and height for an IMC hall current sensor minimization. In order to solve the problem, first, inside flux density is decreased by adding air gap in the shield. Second, outside magnetic field error rate is decreased by adding top shield. Finally, suitable shield shape for minimization is designed by adding top middle shield. The minimization design work is reduced the number of experiments by using the orthogonal array table and main effect analysis method, which are one of the methods of the experimental design method. The proposed model satisfied the design considerations, and the shield area is reduced by 83.7% from the initial model, proving that it was a suitable shield shape for minimization.