Applied Mechanics and Materials Vols. 602-605

Abstract: For the intake restrictors which are designed in line with FSAE race stipulations, this paper carries out compute simulation on the convergent section and divergent section of the intake restrictors via CFD software; the paper systemically analyzes the distribution characters of its flow field, thus obtaining optimal design scheme. It finds through simulation that: when the converging half angle of the restrictor is less than 45°, the outlet flow of the restrictor will decrease as the converging half angle increases; meanwhile, the divergence half angle will affect the outlet flow of the restrictor as the pressure difference between the restrictor inlet and outlet varies. According to the simulation results, the optimal scheme finally designed is: the intake restrictor has the best effect when the converging half angle of the restrictor is 10°, while the divergence half angle is 11°.

Abstract: Surface strengthening for H13 steel with powder mixed near dry EDM, research the effect of different discharge parameters on the microstructure and hardness of strengthened layer .The results show that the effect of pulse interval on microstructure and micro hardness is not obvious, the influence of the pulse width less than the peak current. As the increasing of peak current, strengthening layer surface quality get better, when the peak current reach to 14A , preferable microstructure of strengthening layer can be obtained.

Abstract: We use the finite element software Midas FEA to set up space entity model, and discuss various factors including the stiffness of bearing, counteracting force of adjacent beam, the influence of the stiffness of bridge pier on reaction at support. In the practical engineering. Coupling of shear lag, stiffness of beam, bending-torsional coupling and partial load can also affect the redistribution of reaction at support. Through the simulation of the finite element software, we check the support of a railway bridge in Guangzhou city. In the end we found that the stiffness of beam can make the middle support have a tendency to increase. If we take all the factors into account, the force of the middle support will be greater than on the both ends of bearing and the force on the both ends of bearing will be approximately equal.

Abstract: Aiming at the nonlinear features of Acoustic Emission reflecting the tool wear state, an identification method of tool wear state is proposed based on SLLE and lib-SVM. SLLE can overcome the problems of redundant parameters of the original nonlinear algorithms, low convergence rate, and tiny local areas in the reflecting process, etc. It can realize the reflecting from the high-dimensional data points into a global low dimensional coordinate system. It can also maintain the original topological structures of the lowered dimensional data. By using KC9125 cutting tools to cut 40CrNiMoA alloy steel to collect the acoustic signals, the collected data is vector space reconstructed. Then the high-dimensional space data are reflected into low-dimensional space data by means of SLLE in order to extract the features of the tool wear state. And LIB-SVM classification machine is used to identify and classify the tool wear state. The result shows: this method can accurately identify the tool wear state, and should be extended to a larger prevalence.

Abstract: AOD furnace Smelting Ferrochrome is a complex process. The discretion of the impurity content of phosphorus is one of the important factors affecting the quality of ferrochrome products. If ferrochrome phosphorus excesses, the product is easy to break. At present, the most detection methods of determination the end phosphorus content are artificial experiments, so efficiency is lagging behind. It is necessary to establish a model to predict end-point phosphorus content for improving production efficiency, reducing costs, saving energy consumption. The important influence factors of AOD furnace smelting ferrochrome end-point phosphorus content were determined based on analyzing response characteristics of hot metal dephosphorization pretreatment and thermodynamic condition, the control variables of the end phosphorus content were fixed. According to Sinosteel Jilin Ferroalloys Co., Ltd 5t AOD furnace smelting medium-low carbon ferrochrome technology and production data, a prediction model for AOD furnace smelting ferrochrome end-point phosphorus content has been established based on RBF artificial neural network in accordance with the ferrochrome smelting process for online prediction of end-point phosphorus content. Results showed that the prediction precision of target shooting is 85.7% within the error 0.003%, which has provided important theoretical basis on improving the smelting process and product quality.

Abstract: Because difference of formation model affects the potential distribution on the metal casing, the resistivity logging response can be obtained through casing by measuring the potentials on the metal casing. In fact, the logging responses are the comprehension effects of complex formation with Crude oil and metal casing, so that in the coefficients of transmission line equation (TLE), we should consider the effects of formation with Crude oil model in radial-direction. In the following, for the formation with Crude oil taking on nine --layer in axial-direction, and step in radial-direction, the resistivity logging responses through casing are researched and discussed, and given the recurrence formula with Crude oil to compute potential. Draw the curve of the resistivity logging response through casing of nine-layer formations with Crude oil. The conductivity of formation is computed is very approximating to that of formation with Crude oil model. The computing examples also show that this method has a fast computing speed (the run time of computing example is less than 1s). For analysis the logging response of nine-layers and block formations with Crude oil, and the design of logging instruments, the research is important significance and useful.

Abstract: Because difference of formation model affects the potential distribution on the metal casing, the resistivity logging response can be obtained through casing by measuring the potentials on the metal casing. In fact, the logging responses are the comprehension effects of complex formation with Crude oil emulsion and metal casing, so that in the coefficients of transmission line equation (TLE), we should consider the effects of formation model in radial-direction. In the following, for the formation with Crude oil emulsion taking on five-layer in axial-direction, and step in radial-direction, the resistivity logging responses through casing are researched and discussed, and given the recurrence formula with Crude oil emulsion to compute potential. Draw the curve of the resistivity logging response through casing of five-layer formations. The conductivity of formation with Crude oil emulsion is computed is very approximating to that of formation model. The computing examples also show that this method has a fast computing speed (the run time of computing example is less than 1s). For analysis the logging response of five-layers and block formations, and the design of logging instruments, the research is important significance and useful.

Abstract: Based on the shape features of corn seed, this paper proposes the modeling method of manual combination of eight spheres, which constructs the analysis models for corn seed Ji Feng 218 and Chang Dan 228 with the purpose of better simulation of corn seeds. Furthermore, another analysis model for Chang Dan 228 is also built with reference to the four-sphere combination method. The comparison between the simulation results from these two models demonstrates the feasibility and superiority of the model of combination of eight spheres.

Abstract: It is so valuable that models merging of Delaunay triangulation are used widely in many applications. This paper researches the algorithm of models merging for Delaunay triangulation. A method for obtaining merged intersection lines and a algorithm for searching fast triangles in the extent of merging intersection lines are proposed, and whole process of models merging are expatiated detailedly. The algorithm is tested in experiments, and the result of experiment shows that this algorithm is very efficient.

Abstract: Aerodynamic drag is one of the most important sources of the driving resistance suffered by an on-road heavy-duty truck. The previous studies have rarely involved the role of the external sun visor. Therefore, numerical method is used for the research of the influence of six kinds of sun visors differenced by shapes or layouts on the aerodynamic drag reduction. It is demonstrated that the sun visor has a great influence on the local flow field where it is fixed, while a relatively small effect on the global flow field. Moreover, compared to the original one, the C_D values of each case have different degrees of reduction which illustrates that an appropriate shape and layout of a sun visor benefits the air drag reduction, the largest decline is 4.7%.