Papers by Keyword: Response Surface Method (RSM)

Abstract: The aim of the present paper is to report on a three-dimensional (3D) finite element modelling (FEM) of fabrication of multifilamentary composites using a restack bundle drawing process. The challenge arises from the complexity of the wire architecture. The reliability of the predictions ensues from the determination of the necessary mechanical data by means of the most realistic mechanical tests including billets drawing experiments. The simulations allow to determine response surfaces comparing the effects of the numerous fabrication parameters on the drawing force, the local stress triaxiality and the uniformity of deformation. The results agree with both experimental and theoretical data.

Abstract: t is well-established that fatigue crack growth process is one of the main process which can produce failure of structures and mechanical components. The aim of this work is to develop a model predicting an updating inspection time model for structural fatigue crack growth life based on updating reliability analysis taking into account the additional information generated by the previous inspection results. First order reliability method (FORM) and Surface response method are used to evaluate the reliability. The uncertainties such as material parameters and geometrical parameters which affect the lifespan of the structure were regarded as random variables. Updating reliability assessment based on Bayesian approach was introduced to determine the updating inspection time for target reliability. The method was illustrated through an application to a plate with an emergent rectilinear crack loaded with a constant amplitude cyclic stress. The results of the application are in a good agreement with the physical results and show that the proposed method is proved to be feasible and applicable in the general complex fatigue loading and able to give accurate updating framework for scheduling inspections. Furthermore the proposed approach leads to determine the optimal Inspection time strategy based upon cost-minimization by considering a single type or multiple types of inspections.

Abstract: In order to analyze the reliability and failure probability of the repaired shaft engineering, this article makes fail-safe analysis and instability risk prediction of the shaft engineering. A reliability analysis method was applied combining the improved response surface method which has improved sample points’ selection based on the traditional response surface method to decreasing the number of the structural analysis under the premise of the accuracy of the calculated results with numerical simulation. The limit state whose failure criteria was safe factor was constructed to analyze the reliability of the repaired shaft engineering, the reliability index of the repaired shaft engineering was computed by JC method. The results show the reliability index value of the repaired shaft engineering is 3.1127 slight fewer than design objective value and it’s failure probability value is 0.0929%, which show that the repaired shaft is stable and it’s deformation should be monitored to ensure it is safety application because of it is reliability index value slight fewer than design objective value.

Abstract: Ultrasonic technology was applied to polysaccharides extraction from Ottelia acuminata (Gagnep.) Dandy and Response Surface Methodology (RSM) was used to optimize the effects of processing parameters on polysaccharides yields. Three independent variables such as liquid-solid ratio (ml/g, X1), extraction temperature (°C, X2) and extraction time (hour, X3) were investigated respectively. The statistical analysis indicated that the three variables and the quadratic of X1 and X3 had significant effects on the yields and followed by the significant interaction effects between the variables of X1 and X3, X2 and X3 (p<0.05). A mathematical model with high determination coefficient was gained. The optimal extraction conditions of polysaccharides were determined as follows: liquid-solid ratio 43 ml/g, extraction temperature 90 °C and extraction time 3.45 hours. Under these conditions, the experimental yield of polysaccharides was 107.44 mg/g, which was agreed closely with the predicted value 108.71 mg/g.

Abstract: An anaerobic solid state fermentation (ASSF) of porcine blood by two ferment agents was investigated. The free amino acids (FAA) content was applied as reference indicator, response surface design of Box-Behnken (BBD) was used to select the optimum conditions of ASSF of porcine blood. The optimum conditions were determined as porcine blood moisture of 76.0%, fermentation time of 7d, fermentation temperature of 39.0±0.5 oC, addition of the components of the mixture as follows: wheat bran 10.8 g , corn flour 1.2 g, Active 99 ferment agent I 0.768 g, Active 99 ferment agent II 0.19 g, porcine blood 86.0 g, resulting in FAA content of 23.8 mg/g. Evaluation experiments revealed that FAA content of 22.9 mg/g, which was 96.2% of the predicted value using Eq.2, and achieved a 14-fold increase comparing with the 1.5 mg/g which is the FAA content of unfermented mixture. It was confirmed that the protein of porcine blood was degraded into small peptides by Sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE).

Abstract: In this work, the extraction of astaxanthin i.e. bioactive substance in the shrimp head and shell was studied. The extraction method of astaxanthin was established: the alkali method and organic solvents method were combined to extract astaxanthin, the solvent of the alkali solution was ethanol:water =4:1, dichloromethane was selected as the extractant. The best extraction conditions for astaxanthin were optimized: the concentration of sodium hydroxide was 1.4mol / L, the optimum extaction process was at 54°C for 24 h, and the ration of solid to liquid was 8:1. In this condition, the absorption value of astaxanthin was 1.2048, the concentration of astaxanthin was 3.26μg/mL, which was equivalent to 32.6 μg/g dry shrimp shell.

Abstract: The high antioxidant activity product was isolated from Pinctada fucata muscle by a method of Alcalase hydrolysis. Optimization using response surface methodology was performed and 3D response surfaces were plotted from the mathematical model. The results indicated that the optimal extraction conditions were as follows: pH 7.0, temperature 61°C, E/S 3.01%, hydrolysis time 3h, under the conditions of hydrolysis products of the DPPH radical scavenging rate of 67.3% and the degree of hydrolysis of 31.2%, which was in good agreement with the predicted model value.

Abstract: Pea meal was used as raw material to prepare protein foam agent. The parameters containing concentration of Ca(OH)2, reaction temperature and time were investigated and optimized by the response surface methodology in the modification process of foam agent. The optimum condition was obtained that the concentration of Ca(OH)2 0.78%, reaction temperature 92°C and 4 hours for extraction time. Under the optimal condition, the maximum forecasting foam stability was 16.2h and the verified value was 16.16h which relative error was 0.25% through confirmative test.

Abstract: Linoleic acid (LA) was extracted and purified from Idesia polycarpa Maxim.var. vestita Diels (IPMVVD) oil by urea adduction fractionation, and the response surface methodology (RSM) was successfully employed to optimize the process. The optimal conditions for purification of LA from mixed fatty acids by urea adduction fractionation were as follows: a weight ratio of 4.4:1.0:1.0 (w/w/w) of methanol/urea/mixed fatty acids, a temperature of -5°C and a time of 24.6 h, respectively. Under these conditions the experimental LA yield (48.65%) agreed with the predicted value and the purity of LA was 98.74%.

Abstract: The main factors affecting the drying process of RDX and the optimum drying conditions were investigated through single factor test and response surface methodology, the optimal drying conditions were gained. The results show that moisture content, vacuum, temperature are important factors in the drying process of RDX, the significance of main influencing factors is: temperature> vacuum> moisture content, the suggested drying condition is: 80°C for temperature, 0.05MPa for vacuum, 10% for moisture content.