Applied Mechanics and Materials Vols. 444-445

Abstract: Quasi-static method originated from the safety evaluation of structural engineering under earthquake. Compared with the time history analysis method, quasi-static calculation is simple and quick, and gradually applied in the analysis of slope stability. This article combined quasi-static method with three-dimensional finite difference method (FLAC3D), and applied it in the seismic stability study of a slope. The slope has a convex shape. Two tunnel anchorages and four bridge foundations built in central of it bearing bridge load, so it is a typical bearing slope. This article put forward a numerical calculation failure criterion to the slop of this type by calculating and analyzing the stress, displacement and plastic zone distribution characteristics when it under earthquake, and gave out the slopes seismic safety coefficient. The research results of this paper can provide a useful reference for the similar projects.

Abstract: The temperature and velocity distribution of melting pool fields is very important effect to the silicon purification in vacuum induction furnace. A numerical model for the electromagnetic-thermal hydrodynamic coupling field has been developed by using the finite element method (FEM) and a two-dimension numerical simulation for temperature of metallurgical-grade silicon melting in vacuum induction furnace was carried out by using a software Multi-physics Comsol 4.2 in this paper. The results showed that the temperature field was dependent on induction heating times and melting pool position and the maximum temperature grads was 400K in constant temperature stage. With the silicon was molted gradually two vortexes were come into being for electromagnetic stirring in the smelting poor.

Abstract: The pedestrian comfort and safety level in mass transit stations is now attracting more and more attention in the past few years for the reason that the congested pattern in stations resulted from complex pedestrian activities including using the ticket add value machine, buying a ticket, shopping, waiting for services etc. Thus multi-directional pedestrian flows interact with each other and finally formed a relatively complex pedestrian distribution. To evaluate the crowdedness of the station for the convenient of crowd control, the crowded pedestrians are simulated with a heterogeneous network model in combined with a collision avoidance model. Based on the network model, a spatial configuration related station network is constructed, on which pedestrian flow can be formulized. At last, a station flow scenario is simulated and discussed with the formulized model to evaluate the complex activities induced crowdedness in metro station.

Abstract: Numerical simulations of transport phenomena is one of the valid methods in investigation of crystal silicon growth by CVD for various types of reactors. The present review provides the key summary on the development of fluid dynamic simulations on polysilicon of CVD and hopefully aid in future improvement of this technology. In the solution of CVD reactor models for polysilicon production, the influence of the deposition process on temperature, the transport phenomena and the surface reactions have to be taken into account when discussing the silicon growth rate.

Abstract: In this article, through numerical simulation mechanic we investigated that charge structure, exploiting distinct radial detonation velocity explosives, has a remarkable influence on the forming process of shaped charge jet. Based on the numerical computational results, the contribution of charge proportion and filling mode to the shape and velocity of shaped charge jet are mainly analyzed, aiming to identify the best charge proportion. It is demonstrated from numerical experiments that, sub-munitions power is significantly enhanced premised on invariable size of sub-munitions. And this observation can be adopted to design of the warhead arrayed in net in the future.

Abstract: L shape traffic sign bar is composed of a stand column and a cantilever bar using bolted connection. The cross-section of stand column and a cantilever bar is closed thin wall with regular octagon and their cross sectional area is variable along axial line. The calculation formulas of stress for cantilever bar, stand column and flange bolts and calculation formulas of deformation for L rod are derived under gravities and wind loads, which provide theoretical basis for the design and use of L-shape bar. Calculation results using these formulas by comparison with finite element calculation results verify the correctness.

Abstract: To explore the screw centrifugal pump performance change, and the impact of solid-liquid two-phase flow on the screw centrifugal pump, the internal flow of type 150×100LN-32 centrifugal pump is used as the research object. Mixture multiphase flow model, standard k-ε turbulence model and the sliding mesh technique are used to carry out the unsteady numerical simulation to describe internal flow field in screw centrifugal pump. By Setting the monitoring point to get the pressure pulsation characteristics and predict the changes in the energy performance. Open laboratory bench tests are carried out to verify the reliability of the numerical methods. Based on this, the impact of the two-phase flow on the screw centrifugal pump is analyzed. The results indicate that the head-flow curve presents a hump-shaped with the increasing of the flow. The maximum of efficiency appears. At the same time, the change of the volume concentration of the solid phase has little effect on the energy performance of screw centrifugal pump. But at different times, the head decreases and the power increases with the increasing of the concentration.

Abstract: Based on a large number of statistical analyses on the highway landslide, landslide risk evaluation index system is established. According to expert experience method and analytic hierarchy process (AHP) to determine weights of landslide disaster risk index and vulnerability evaluation index, the fuzzy comprehensive evaluation method is used to analyze landslide hazard dangerousness and vulnerability, also to evaluate potential risk on the right side cutting slop of mountainous highway from Beijing to Zhuhai in section D blocks K46 + 375 to K46 + 500 before the construction is going on, therefore, the targeted slope protection design will be finalized on the analysis results. The research results can enhance the awareness of similar landslide disaster and provide analysis reference for the similar projects in the future.

Abstract: Designed the weld line quantization algorithm based on the moldflow secondary development of technology, obtained the numerical experimental data of weld line with this. Analyzed of the impact of the relationship between the process parameters and weld line, and optimized the process parameters by orthogonal experimental design. These provided an important basis for the forming process design.

Abstract: For getting rid trial-and-error method of polymer blending modification depends on experience, nonlinear relation of polymer ratio and its properties is obtained by Support Vector Machine and Genetic Algorithm. While the application of genetic algorithms to optimize the SVM model. Decision function in the relational model of SVM as the objective function, and optimized the value of polymer properties and its ratio by genetic algorithms. Experiments show that the method has some values.