Applied Mechanics and Materials Vols. 444-445

Abstract: In order to forecast the rotating speed of the hydraulic energy recovery turbine, Single centrifugal pump and single centrifugal pump with guide vane in reverse operation were adopted as turbines. 3D models were founded by pro/E software for turbines, Then the models were meshed by gambit and Simulated by fluent6.3 software. It was shown that before the best efficiency points, The higher the rotating speed, the lower the efficiency of turbine . but after the best efficiency points, the efficiency of turbine increased with the rise of rotating speed. with the rise of rotating speed ,the pressure in runner inlet was added, the amplitude of pressure pulse was added. the pressure distribution in runner inlet was more even of model B than that of model A. With a guide vane ,The steady scope of rotating speed in hydraulic energy recovery turbine was diminished,and the Controllability of rotating speed in hydraulic energy recovery turbines can be improved by guide vane. Some theories were offered for hydraulic energy recovery turbine researches.

Abstract: Vibrating screen is the most commonly used sieving machinery, how to improve its sieving performance is a major issue during the design and application. Discrete element method (DEM) was employed here to analyze and simulate the sieving process, and the influence of the various sieving parameters on sieving efficiency were studied. The curve of relationship between the sieving parameters and sieving efficiency was established. Contrasted with traditional methods, DEM has great superiority on the sieving study.

Abstract: In order to improve the accuracy of numerical simulation for injection molding process, a modified method for outlet condition was introduced. As the feedstock is regarded as incompressible fluid, the filling ratio should be a linear one with respect to time. But there remains a persistent trouble in previous researches that the linearity is not respected when the filling front approaches near the outlet boundary. The problem is caused by lack of adequate treatment on the outlet boundary. To remedy this defect, the present paper deals with the modeling and realization of suitable condition on outlet boundary for solution of the whole filling process. A simple straight channel mold was taken as an example to prove the proposed simulation method. The result shows that this modified method can suppress the distortion phenomenon and can be valid to realize the correct simulation for the filling of incompressible viscous flow at the ending stage. This long-term filling problem was finally solved.

Abstract: A fast and accurate infrared radiation calculation method was investigated. Reverse Monte Carlo (RMC) method was adopted to calculate the Infrared (IR) Radiation characteristic of surface. The computational code used Mersenne Twister (MT) method to generate random number, and bounding box method to accelerate computational speed. The Infrared Radiation characteristics of some typical geometric structures were calculated and verified. The effects of emission photons number and mesh number on calculation results were analyzed. The results show the error between calculation value and theoretical value is less than 0.02%. The calculation time is proportional to emission photons number and mesh number.

Abstract: On the basis of the global analysis method of slope stability, a nonlinear optimum model is proposed for the location of the critical slip surface. In this method, both the factor of safety and vertical coordinates of discrete points on the slip surface are taken as independent variables, and the factor of safety as the objective function, with the constraints including the global equilibrium equations and convexity on the critical slip surface. For non-homogeneous slopes, a smoothing scheme is proposed. Thus the optimization problem can be solved by the classic gradient-based algorithms. The examples show that the proposed method enjoys excellent numerical stability.

Abstract: The purpose of the paper is to simulate stress distribution of flexural members which is reinforced with CFRP with secondary load using ANSYS, so the flexural performance the beams containing with same layer of CFRP which is affected by different torque can be studied. As a result, the comparison of the stiffness and deflection of beams influenced by different load history (with initial load or not) and different layers of CFRP in this paper will provide guidance for project.

Abstract: The high strength steel wire mesh and polymer mortar reinforcement technology has the advantages of high strength, high temperature resistance,corrosion,resistant, etc. In this paper,we analysis the flexural properties of RC beams strengthened by it using ANSYS.To bear the same moment in the same area of the reinforcement steel strand, and then get effect of different span and different reinforcement methods (comparative beam, direct reinforced beams,and secondary load of reinforced beams) on flexural load-carrying capacity and deflection, then compare and analysis,and draws the conclusion which can provide reference for practical engineering.

Abstract: For the multisensor systems with unknown noise variances, by the statistics method, the mathematical model and the noise statistics are essential, and this limitation was settled by adaptive algorithm. The adaptive Kalman filter was proposed to solve the filtering problem of the system with unknown mathematical model or noise statistics in information fusion. Based on the probability method and the scalar weighting optimal information fusion criterion in the minimum variance sense, the algorithm can not only optimize the multi-channel data, but also obtain the minimum mean square error (MMSE) by introducing fusion equation, namely the algorithm is optimal under the sense of MMSE, and the error is the least than the original Kalman information fusion algorithm. The test result shows that the algorithm can precede information fusion effectively under the distributed acquisition system.

Abstract: The purpose of this article is to deepen the understanding and knowing for the limited efficiency of bearing of plate anchors by means of the calculation of the ultimate holding capacity (UPC) of plate anchors with different shapes. In the process of calculation of UPC, the commercial software MARC is employed. The soil is assumed to be elastic-perfect plastic with yield determined by the VON MISES condition. And displacement constraints are imposed and the corresponding ultimate anti-force can be determined. Then the ultimate bearing efficiency of anchor plates with different shapes can be obtained.

Abstract: In order to get a simulated earthquake wave whose response spectrum fitted well to the smooth design response spectrum, a model was established by making the standard error between the response spectrum of simulated earthquake wave and the design response spectrum as the minimal optimization objective. Simulated annealing particle swarm optimization algorithm, which was an improvement algorithm of particle swarm optimization, was used to solve the model. This spectrum fitting method was compared with the conventional spectrum fitting method, which adjusted Fourier amplitude spectrum in frequency domain. The results show that the method of response spectrum fitting by applying simulated annealing particle swarm optimization algorithm has a good convergence. And the response spectrum of simulated earthquake wave generated by simulated annealing particle swarm optimization algorithm agrees better with the design response spectrum than that by conventional spectrum fitting method.