Response Surface Method In Order Research Articles

Investigation of sulfonation degree and temperature on structure, thermal and membrane's properties of sulfonated poly (ether ether ketone)

In this paper, the primary and secondary relationship among factors affecting the sulfonation of poly (ether ether ketone) (PEEK) was investigated in detail by a response surface method in order to solve the problem of performance deterioration caused by excessively high or low sulfonation. Acid-base titration, infrared analysis (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) proved that temperature had the greatest influence on PEEK sulfonation and the sulfonate group was successfully connected to the main chain and the proton conduction mechanism was in accordance with Arrhenius law. Under optimized conditions, 44% sulfonation degree of PEEK was selected to test the dimensional stability, microstructure and proton conductivity, and to explore the influence of temperature on the membrane's structure and performance. The result indicates that the microstructure has become more homogeneous at 60 °C, resulting in continuous proton conduction channels, demonstrating excellent proton conductivity (5.04 × 10−2 S/cm).

Investigations on a mega–sub isolation system under near-fault ground motions

The failure mechanism of the mega–sub isolation system under near-fault ground motions is studied in this article. 90 suites of near-fault ground motions collected from 23 earthquakes are adopted to investigate the ground motion intensity indices applicable for the mega–sub isolation system. Then, the sensitivities of the stochastic responses to the structural parameters are analyzed to determine the representative random structural parameters. Furthermore, considering the uncertainties of ground motion characteristics and structural parameters, the seismic fragility is analyzed by the response surface method in order to obtain the failure mechanism of this system under near-fault ground motions. Results show that different intensity indices have various correlation coefficients with the peak responses of the mega–sub isolation system. The correlations of acceleration-related intensity indices are the worst, whereas the correlations of displacement-related intensity indices show high linearity. The sensitivities of the structural responses are weaker to the sub-structure story stiffness but more sensitive to the sub-structure story mass and the stiffness and damping ratio of the isolation layer. The failure probability of the sub-structure is higher than that of the mega-structure under near-fault ground motion. While in the collapse state, the failure probability of the isolation layer is greater than that of the sub-structure.

Parametric automatic optimal design of USV hull form with respect to wave resistance and seakeeping

As the Unmanned Surface Vehicle (USV) plays an increasingly important role in ocean exploration, the performance requirements of the USV are becoming higher and higher. This paper presents a parametric automatic multi-objective optimization design of USV based on two-step optimization strategy. The focus of our work is on the parametric automatic optimization design of USV hull form with respect to resistance and seakeeping in waves. The wave resistance, the vertical acceleration of the center of gravity, and the pitch amplitude of the USV are selected as the optimization objectives. The parametric modeling and design variables are selected for the hull. Second order Response Surface Method (RSM) is used to build approximate model instead of numerical simulation in the optimization process to reduce the optimization time. The Particle Swarm Optimization (PSO) algorithm and Sequential Quadratic Programming (SQP) algorithm are used to solve the optimization model. Through the integration of NX, STAR-CCM+, and Excel in the intelligent platform, automatic optimization is realized. The effectiveness of the automatic optimization design method is verified by taking a 7 m USV as an example. This method provides a solution for the automatic optimization design of the USV hull form.

Tribological behavior of aluminum nanocomposites studied by application of response surface methodology

An aluminum Al-0.8Al2O3 and Al − 1.6Al2O3 nanocomposite was prepared by a novel ultrasonic assisted stir casting method. A three-level Box-Behnken design of experiment was developed using response surface methodology. Dry sliding wear tests were performed as per the experimental design using a pin-on disc setup at room temperature. Analysis of variance (ANOVA) was applied to investigate the influence of process parameters, viz., wt.% reinforcement, load and sliding distance, and their interactions on specific wear rate and coefficient of friction. Further, a mathematical model has been formulated by applying response surface method in order to estimate the tribology characteristics such as wear and COF of the nanocomposites. The specific wear rate and coefficient of friction are significantly influenced by % of Al2O3 and load. The wear test parameters were optimized for minimizing specific wear rate and COF using desirability function approach. A set of optimum parameters of combination for AMMNC was identified as Al2O3–1.1 wt.%; load, 34 N and sliding distance, 2931 m with specific wear rate, 1.06 g/N-m; and coefficient of friction, 0.305. The AFM image of Al6061–1.1Al2O3 nanocomposite at optimized condition confirms the improvement in the wear surface smoothness of the nanocomposite compared to Al6061.

Application of Desirability-Based Multiobjective Optimization Techniques to Study the Wear of Al Self-Lubricating Hybrid Nanocomposites

In this study, novel Al6061–SiC nanocomposites and Al6061–SiC–Gr hybrid nanocomposites were fabricated by ultrasonic cavitation method by adding silicon carbide (SiC) of 0.8 and 1.6% and graphite (Gr) of 0.5 and 1.0% by weight basis for each casting. A Three-level Box–Behnken design of experiment was developed using response surface methodology. Dry sliding wear tests were performed as per the experimental design using a pin-on disc set-up at room temperature. Analysis of variance (ANOVA) was applied to investigate the influence of process parameters viz., load, sliding distance, wt% reinforcement and their interactions on specific wear rate and coefficient of friction. Further, a mathematical model was formulated by applying response surface method in order to estimate the tribology characteristics such as wear and COF of the hybrid nanocomposites. The specific wear rate and coefficient of friction were significantly influenced by % of SiC followed by % of Gr, load and sliding distance. The wear test parameters were optimized for minimizing specific wear rate and COF using desirability function approach. A set of optimum parameter of combination for AMMNC was identified as: SiC 1.36wt%; Gr 0.63 wt%; load 35.65 N and sliding distance 2848 m with specific wear rate of 0.517 g/N-m; coefficient of friction 0.181. The AFM image of Al6061–1.36SiC–0.63Gr hybrid nanocomposite at optimized condition confirmed the improvement in the wear surface smoothness of the hybrid nanocomposite compared to Al6061–SiC nanocomposites.

Optimization of wear performance on aluminium die cast A360-M1 master alloy using response surface method

Abstract Aluminium die cast A360-M1 master alloy with mass fraction (0.4 wt%) Al-5%Ti-1% B light metal matrix composite (LMMC) was prepared using the stir casting method. A three-level principle composite design test was developed using the boxbehnken response surface methodology. Variation in parameters such as load, sliding distance and sliding velocity were made in the range of 10–30 N, 500–1500 m, and 0.5–1.5 m/s respectively. Tribological dry sliding wear tests were performed as per the experimental design, using a pin-on disc setup at room temperature. Analysis of variance (ANOVA) was applied to study the impact of process parameters and their interactions viz., Load, sliding distance, sliding velocity on specific wear rate (SWR), frictional force (FF) and coefficient of friction (COF). The objective of this research is to recognize the parameters that significantly affect the output features such as specific wear rate, friction force, and COF of the aluminium die cast A360-M1 master alloy light metal matrix composites. Further, a mathematical model has been expressed by relating the boxbehnken response surface method in order to estimate the tribological characteristics. This work shows this A360-M1 master demonstrating the minimization of SWR, FF, and COF with response of load, sliding distance, and sliding velocity.

An adaptive order response surface method for structural reliability analysis

Purpose Balancing accuracy and efficiency is an important evaluation index of response surface method. The purpose of this paper is to propose an adaptive order response surface method (AORSM) based on univariate decomposition model (UDM). Design/methodology/approach First, the nonlinearity of the univariate function can be judged by evaluating the goodness of fit and the error of curve fit rationally. Second, combining UDM with the order analysis of separate component polynomial, an easy-to-implement AORSM is proposed. Finally, several examples involving mathematical functions and structural engineering problems are studied in detail. Findings With the proposed AORSM, the orders of component functions in the original response surface can be determined adaptively and the results of those cases in this paper indicate that the proposed method performs good accuracy, efficiency and robustness. Research limitations/implications Because just the cases with single failure mode and single MPP are studied in this paper, the application in multi-failure mode and multi-MPP cases need to be investigated in the coming work. Originality/value The nonlinearity of the univariate in the response surface can be determined adaptively and the undetermined coefficients of each component function are obtained separately, which reduces the computation dramatically.

Dry Sliding Wear behaviour of cast Al/Al203/Gr hybrid nano-composite using response surface methodology

The newly engineered metal matrix nanocomposite (MMNC) of Al 6061 reinforced with 1.2 wt % Al203 and 0.5 wt % Gr (Al-1.2Al203-0.5Gr) hybrid nanocomposite was prepared by ultrasonic assisted stir casting method. A three-level central composite design test was developed using response surface methodology; parameters such as load, velocity and sliding distance were varied in the range of 10-30 N, 0.4-1.1 m/s and 500–1500 m, respectively. Dry sliding wear tests were performed as per the experimental design using a pin-on disc setup at room temperature. Analysis of variance (Anova) was applied to investigate the influence of process parameters and their interactions viz., Load, velocity, sliding distance on wear, and coefficient of friction (COF). The aim of the study was to identify the process parameters that significantly affect the output features. Further, a mathematical model has been formulated by applying response surface method in order to estimate the tribology characteristics such as wear and COF of the hybrid nanocomposites.

Aerodynamic and structural design of winglet with integrated VHF antenna

A new optimized winglet of a small aircraft is used to develop the solutions for structure, VHF antenna, systems as lights and lightning protection. The aerodynamic optimization has been based on the Design of Experiment and Response Surface method in order to find out the suitable shape of the winglet from the aerodynamic, structure and the basic operating frequency range for VHF radio communication points of view. The winglet’s structure has been designed based on the aerodynamic loads and took into account the appropriate technology. The improvement of the aerodynamic characteristics and handling qualities of the aircraft are discussed and the integration concepts and production moulds are presented.

Development of Tri‐Stable Rotary Solenoid Actuator

SUMMARYWe have designed and developed a tri‐stable rotary solenoid actuator, which has a simple structure and simple operation. The plunger has two stabilities at the extreme positions along an angular stroke and the third stability at the center of it. The third has been successively achieved by using the electromagnetic restoring torque, which is designed to be larger than the inertia torque. The dynamic characteristics were determined by utilizing an optimal design program that is specially constructed based on the response surface method in order to design the coil winding and the power supply for the coil excitation. A prototype solenoid was constructed and used to verify the tri‐stable motions and accuracy of the previously constructed design program.

鋭い圧子押込みにおける応答曲面法を用いたCowper-Symonds構成式定数の決定

Instrumented indentation is widely used to investigate the elastic and plastic properties of mechanical materials. During an indentation experiment, a rigid indenter penetrates normally into a homogeneous solid, where the indentation load and the displacement are continuously recorded during loading and unloading. It was known that the micro-indentation test was strongly affected by the strain rate in the materials with strain rate dependence of strength. In the second report, the new approach for the evaluation of the strain rate dependence of materials was developed using the loading curvature-displacement relation obtained from the sharp indentation. Therefore, we attempted to use the response surface method in order to determine the constants for Cowper-Symonds constitutive equation (dynamic constants). First, the relationship between the dynamic constants and the loading curvature was constructed by the response surface, and then those were determined using the inverse analysis. It was confirmed that the dynamic constants could be obtained by substituting the result of the micro-indentation for the unknown materials into the response surface up to the strain rate of 102 s-1. By using this method, it is possible to evaluate the strain rate dependence of materials in such a strain rate range.

Optimization of machining parameters for EDM operations based on central composite design and desirability approach

A novel aluminium metal matrix composite reinforced with SiC particles were prepared by liquid metallurgy route. Recent developments in composites are not only focused on the improvement of mechanical properties, but also on machinability for difficult-to-machine shapes. Electrical discharge machining (EDM) was employed to machine MMC with copper electrode. using EDM. Experiments were conducted using pulse current, gap voltage, pulse on time and pulse off time as typical process parameters. The experiment plan adopts face centered central composite design of response surface methodology. Analysis of variance was applied to investigate the influence of process parameters and their interactions viz., pulse current, gap voltage, pulse on time and pulse off time on material removal rate (MRR), electrode wear ratio (EWR) and surface roughness (SR). The objective was to identify the significant process parameters that affect the output characteristics. Further a mathematical model has been formulated by applying response surface method in order to estimate the machining characteristics such as MRR, EWR and SR.

Optimization of process parameters using a Response Surface Method for minimizing power consumption in the milling of carbon steel

Due to the urgent need for global reductions of environmental impacts, many studies have been carried out in different fields. One of the most important sectors is manufacturing, particularly due to the high power consumption of the production machines of manufacturing plants. This paper focuses on the efficiency of the machining centres and provides an experimental approach to evaluate and optimize the process parameters in order to minimize the power consumption in a milling process performed on a modern CNC machine. The parameters evaluated are the cutting speed, the axial and radial depth of cut, and the feed rate. A lubrication strategy has been chosen based on previous studies: all the tests have been carried out using dry lubrication in order to eliminate the environmental impact due to lubricant without substantially affecting the energy consumption. The process has been analyzed using a Response Surface Method in order to obtain a model fit for the fine tuning of the process parameters.

Reliability-based design optimization via high order response surface method

To reduce the computational effort of reliability-based design optimization (RBDO), the response surface method (RSM) has been widely used to evaluate reliability constraints. We propose an efficient methodology for solving RBDO problems based on an improved high order response surface method (HORSM) that takes advantage of an efficient sampling method, Hermite polynomials and uncertainty contribution concept to construct a high order response surface function with cross terms for reliability analysis. The sampling method generates supporting points from Gauss-Hermite quadrature points, which can be used to approximate response surface function without cross terms, to identify the highest order of each random variable and to determine the significant variables connected with point estimate method. The cross terms between two significant random variables are added to the response surface function to improve the approximation accuracy. Integrating the nested strategy, the improved HORSM is explored in solving RBDO problems. Additionally, a sampling based reliability sensitivity analysis method is employed to reduce the computational effort further when design variables are distributional parameters of input random variables. The proposed methodology is applied on two test problems to validate its accuracy and efficiency. The proposed methodology is more efficient than first order reliability method based RBDO and Monte Carlo simulation based RBDO, and enables the use of RBDO as a practical design tool.

Modeling and Optimization of EDM of Al 7075/10wt% Al<sub>2</sub>O<sub>3</sub> Metal Matrix Composites by Response Surface Method

The newly engineered metal matrix composite (MMC) of aluminium 7075 reinforced with 10 wt% of Al2O3 particles were prepared by stir casting method. Electrical discharge machining (EDM) was employed to machine MMC with copper electrode. The experiment plan adopts face centered central composite design of response surface methodology. Analysis of variance was applied to investigate the influence of process parameters and their interactions viz., pulse current, gap voltage, pulse on time and pulse off time on material removal rate (MRR), electrode wear ratio (EWR) and surface roughness (SR). The objective was to identify the significant process parameters that affect the output characteristics. Further a mathematical model has been formulated by applying response surface method in order to estimate the machining characteristics such as MRR, EWR and SR.

Optimize the process of ionic liquid-based ultrasonic-assisted extraction of aesculin and aesculetin from Cortex fraxini by response surface methodology

Ionic liquid-based ultrasonic-assisted extraction as an effective method was first successfully developed at room temperature to extract aesculin and aesculetin from the traditional Chinese medicine Cortex fraxini. A series of 1-alkyl-3-methylimidazolium, with different cations and anions, were investigated and [C 4mim]Br was selected as optimal solvent. Ultrasonic conditions including ionic liquid concentration, soaking time, ultrasonic power, ultrasonic time, ratio of liquid–solid and the number of extraction cycles were discussed by single factor experiments and the main influence factors were optimized by response surface method in order to extract aesculin and aesculetin effectively from C. fraxini. The proposed approach was demonstrated as a higher efficiency, shorter extraction time and a new alternative for the extraction of aesculin and aesculetin from C. fraxini comparing with traditional reference extraction methods. No degradation of the target analytes had been observed at the optimum conditions as evidenced from the stability studies performed with standard aesculin and aesculetin. The proposed method also shows high reproducibility, which demonstrates ionic liquid-based ultrasonic-assisted extraction is a rapid, efficient and simple sample extraction technique.

A New Adaptive Higher Order Response Surface Method

Response surface method has won numerous concerns in the reliability analysis of structure due to its simplicity and practicability, especially quadratic response surface taking no account of cross terms is most widely used. However, for the complex ultimate state curved surface corresponding to strongly nonlinear, the approximate accuracy of quadratic response surface is apparently not enough, causing a biggish error in estimation of reliability. Although, theoretically, higher order response surface method can resolve this problem, the sharp increase of undetermined coefficient reduces calculation efficiency, and even, cannot achieve. Therefore, on the basis of univariate analysis of multivariable function, an algorithm which can reasonably determine higher order response surface form is presented in this article, able to effectively reduce the number of undetermined coefficients in response surface, so as to reduce computational difficulties and put forward improving measures for possible problems; In addition, based on the tactics of number-theoretic setpoint, a type of scheme of number-theoretic selecting point applicable to response surface method has been developed. Finally, through the analysis of examples, the suggested algorithm was validated, with the result showing that the algorithm has good accuracy and efficiency.

Workpiece Surface Temperature for In-process Surface Roughness Prediction using Response Surface Methodology

As manufacturing technology has been moving to the stage of full automation over the years, one of the fundamental requirements is the ability to accurately predict the output performance of machining processes. The focus of present study is to predict surface roughness using the workpiece surface temperature of a turning workpiece with the aid of an infrared temperature sensor. Relationship between the workpiece surface temperature and the cutting parameters and also between the surface roughness and cutting parameters were found out for indirect measurement of surface roughness through the surface temperature of the workpiece. A 33 full factorial design was used in order to get the output data uniformly distributed all over the ranges of the input parameters. Response Surface Method (RSM) and analysis of variance (ANOVA) are used to get the relation between different response variables (Surface roughness and workpiece surface temperature) and the input parameters (speed, feed and depth of cut). Based on variance analysis for the second order RSM model, most influential design variable is feed rate and depth of cut on surface roughness and workpiece surface temperature respectively and the experimental results show that the workpiece surface temperature can be sensed and used effectively as an indicator of the cutting performance.

유출유동을 가진 정사각유로 내 열전달 향상을 위한 경사진 요철 최적설계

In the present study, the second order response surface method (RSM) is carried out to get optimum thermal design for enhancing heat transfer in a square channel with bleed flow. The RSM is used as an optimization technique. To calculate the heat transfer, RNG k-epsilon model and enhanced wall function are used. To design optimum rib turbulators, two design variables such as attack angle of rib (α) and rib pitch-to-rib height ratio (p/e) are optimized. In these analyses, the channel inlet Reynolds number was fixed at 10,000 in both non-bleeding and bleeding cases. The response surfaces of two design variables are constructed in cases with and without bleed flow. As a result, the optimum (or highest) heat transfer values are almost the same in ranges of two cases with and without bleed flow. However, the friction losses in the case with bleed flow are lower than those without bleed flow.

고강도강 프런트 사이드멤버의 응력분포 최적화를 통한 스프링백 저감

Optimization is carried out to determine process parameters which reduce the amount of springback and improve shape accuracy of a deep drawn product in sheet metal forming process. The study uses the amount of stress deviation along the thickness direction in the deep drawn product as an indicator of springback instead of springback simulation. The scheme incorporates with an explicit elasto-plastic finite element method for calculation of the final shape and the stress deviation The optimization method adopts the response surface method in order to seek for the optimum condition of process parameters such as the blank holding force and the draw-bead force. The present scheme is applied to design of the variable blank holding force in an U-draw bending process and the application is further extend ε d to the design of draw-bead force in a front side member formed with advanced high strength steel (AHSS) sheets of DP60. Results show that design of process parameter is well performed to decrease the stress deviation through the thickness and to reduce the amount of springback. The present analysis provides a guideline in a design stage for controlling the springback based on the finite element simulation of the complicated parts.