Papers by Keyword: Uniform Design Method

Abstract: This paper mainly depends on experiment. Take theory and software analysis as supplement. Using pine and fir as test material, the quantitative analysis, using uniform design method to qualitative pine, fir wood block the relationship between mechanical properties and geometrical parameters in the case of triangle, failure characteristics through experimental phenomenon of different materials and different sizes of wood in the triangle block pressure, finally using finite element analysis software ANSYS/LS-DYNA to simulate and analyze test. By comparing the analysis result of test and software, find out the problems and corresponding correction. The final analysis laid the foundation for the whole static wood structure analysis and dynamic. To provide scientific and technical support for rural residential "seismic safety engineering", thus forming the new wooden structure node and reinforcement for clause.

Abstract: In order to study the coal and gas outburst similar simulation experiment, coal similar material was made up based on the similarity theory. Based on the previous similar material study, the cement, sand, water, activated carbon and coal powder was selected as the raw material of similar material. Meanwhile similar material matching program with 5 factors and 6 levels was designed by using Uniform Design Method. And the physical and mechanical properties of the similar material compressive strength was measured under different proportions circumstances. The relationship between similar material and the raw materials was analyzed. The results show that choosing different materials can compound different similar materials with different requirements. And the water-cement ratio plays a decisive influence on the compressive strength of similar material. The compressive strength of similar material decreases linearly when the water-cement ratio increases.

Abstract: Rear sub-frame is one of the important parts of automobile chassis. Tube hydroforming (THF) is a kind of the advanced manufacturing technology to produce the sub-frame. The success of a THF process is highly dependent on the loading paths (axial feed versus pressure) used. The uniform design method combined with the response surface method was used to optimize the loading path in this paper. The results obtained by numerical simulation demonstrated that product quality is good in the optimized loading path.

Abstract: Ypsizigus marmoreus is a newly cultivated medicinal and edible mushroom with higher antitumor activity. In this paper, a uniform design was used to optimize the medium formula with four factors each at six levels, and a regression model was constructed to predict the antitumor exopolysaccharide production. The optimal concentrations for the enhanced exopolysaccharide production were determined as 30% (w/v) glucose, 8.4% (w/v) soybean peptone, 3% (w/v) KH₂PO₄ and 30% (w/v) sweat potato flour. Subsequent experiment confirmed the validity of the model. Under the optimal condition, exopolysaccharide yield reached 3.39g/L in shake-flask culture, which was 3.53 fold higher than that obtained in the basic medium. The results highlight the future application of optimized medium for high yield production of antitumor exopolysaccharide by fermentation of Hypsizigus marmoreus.

Abstract: The response surface method (RSM) developed in recent years is an effective way to solve the structural reliability problems with implicit performance function. In order to improve the computational efficiency and make RSM suitable well to large and complex engineering structures, the reliability analysis method based on uniform design method (UDM) and support vector machine (SVM) was proposed. UDM is adopted to select training data and SVM is used as response surface. Structural reliability index is calculated in combination with the traditional reliability analysis methods (such as, the first-order reliability method (FORM), the second-order reliability method (SORM) or Monte Carlo simulation method (MCSM)). Numerical examples show that sampled with the UDM can greatly reduce the number of samples required for training by SVM model, and a very good approximation of the limit state surface can be obtained to get the failure probability. The reliability analysis of the under serviceability limit-state of a typical self-anchored suspension bridge——Sanchaji Bridge was carried out with the improved response surface method.

Abstract: Since the performance functions of large complex structures can not be expressed explicitly in the process of reliability analysis, support vector machines (SVM) with good ability of generalization are used as the response surface function based on the small training samples. The uniform design method was adopted in selecting the training data. The least support vector machines (LS-SVM) were used to find the support vectors. The limit state function was expressed by the LS-SVM regression. Reliability analysis was then performed by the usual reliability method (e.g., the first-order reliability method, the second-order reliability method or Monte Carlo) on the response surface. The results of calculations of numerical examples and a typical cable-stayed bridge show that LS-SVM using the uniform design method can well approximate the real response of complex structures which has a good efficiency and accuracy and can be applied in complex structures.

Abstract: According to frame concrete theory, Concrete was composed of mortar matrix, coarse aggregate, and transition zone between mortar matrix and coarse aggregate. Proper particle grading of fine aggregate can not only save cement, but also increase comprehensive properties of mortar matrix. Uniform design method was used to study the relationships between the grading of fine aggregate and workability, and the relationship with mechanic properties of mortar matrix and concrete. Based on fractal theory, the relationship between fractal dimension and modulus of fineness, and the relationship between fractal dimension and n value in Fuller equation were researched. It concluded that grading of fine aggregate affects the workability and mechanic properties of mortar matrix and concrete, significantly. There was a good linear relation between fractal dimension and n value in Fuller Equation, and fratatal dimension decreased with modulus of fineness increasing.