Applied Mechanics and Materials Vols. 444-445

Abstract: Taking the schist as investigative subject, which is the weak layer widely distributed in Yun Fu pyrite, Guangdong province, the deformation characteristics and strength properties of the schist rock mass are analyzed through laboratory uniaxial and triaxial compression tests. Based on the tests on natural and saturated schist, the elastic constitutive equations of the schist, considering the closing of micro cracks, are established; and the deformation characteristics and strength properties of water-weakening influence is analyzed. Through the tests, the deformation characteristics and strength properties of the schist are further understood, which can give some advices to the design of rock slope containing weak layers of the schist.

Abstract: Numerical investigation on the fluid structure interaction in the cylindrical membrane inflation is performed by the Euler-Largrangian method. In membrane inflation, the vortex flow and wave system induced by the interaction between compressible jet flow and membrane appeared inside membrane. This phenomenon concentrates the stresses and generates a pair of bumps. The influences of oscillation and bumps on membrane working performance and safety are also investigated.

Abstract: This paper outlined the basic working principle of flip-flow Screen and and then established the screen surface kinetic equation of simplified geometric model. The midpoint motion law of the flip-flow Screen surface, the screen surface-particle trajectory and the inclination of the particle trajectory were studied. The characteristic curve made by Matlab showed unique dynamic characteristics of the screen surface, which provided a theoretical basis for its design and application.

Abstract: How to enhance the combustion and reduce the total pressure loss in scramjet combustor are very critical for the practical application of hypersonic aircraft. Based on the dominant thermal mechanism of arc plasma, the plasma generated in combustor is regarded as a promising method to improve the combustion. As a result, the combustor model with transverse fuel jet and plasma generated by two discharge modes at the upstream of flameholding cavity is established and it is used to study the mechanism of fuel mixing enhancement through numerical investigation. The results show that an oblique shock wave would be formed at the upstream of the pseudo small plasma hump, and interact with the separation shock wave induced by the transverse jet. This results in the recirculation zone at the upstream of fuel jet being enlarged obviously. Besides that, under the non-reaction flow conditions, the total pressure recovery coefficient increases due to the plasma generated. However, the total pressure recovery coefficient varies apparently and the shear layer above the cavity is fluctuant when the plasma is generated by periodical discharge mode. While under the reaction flow conditions, the shear layer develops thicker and the total pressure recovery coefficient decreases. And due to the existing of plasma, the mole fraction of product water increases. But compared with the steady discharge mode, the level of water is lower and the total pressure recovery coefficient decreases more under the periodical discharge mode. Though the plasma generated by steady discharge mode shows better performance in assisting combustion and reducing the pressure loss, considering the energy saving and the use of different parameters of the periodical discharge, the same effects of enhancing the fuel mixing through enlarging the recirculation zone located at the upstream of fuel jet and promoting the mass exchange of cavity can be reached. More numerical experiments have to be done to optimize the parameters of periodical discharge plasma to receive a best improvement on the performance of scramjet combustor.

Abstract: This paper introduces two models for calculating friction loss in slurry pipeline. Based on the comparison between the measured pressure loss of the highly concentrated iron ore concentrate slurry pipeline in Dahongshan, Yunnan Province, CHINA and the calculation outcomes of the two models, the model which can predict pressure loss in this kind of slurry pipelines has been found.

Abstract: This paper applies the terminal sliding mode control method to control the trajectory of a three axises Cartesian Pneumatic Manipulator. A mathematical model of the pneumatic servo control system was established at first, then the terminal sliding mode control method was used for trajectory control. The simulation results shows that the tracking error of the terminal sliding mode control method become large only in the time period of not fully reaching the convergence point in time when the manipulator tracks the space straight line, whereas it can fully track the target trajectory after reaching the convergence point.

Abstract: Weight function is related with the sensor structure of electromagnetic flowmeter (EMF). Because of complex boundary conditions, it is difficult to solve the voltage differentiation equation of EMF directly to get weight function. The finite element numerical analysis method is tried to solve the weight function for the point and large-electrode EMF in this paper. The results prove it is feasible and efficient to obtain weight function of EMA by means of finite element numerical analysis.

Abstract: Numerical simulation of the behavior of materials can be used as a versatile, efficient and low cost tool for developing an understanding of material behavior [. The numerical simulation methods include quantum mechanics, molecular dynamics, Voronoi cell finite element method and finite element method et al. These methods themselves are not sufficient for many fundamental problems in computational mechanics, and the deficiencies lead to the thrust of multiple-scale methods. The multi-scale method to model micro-scale systems by coupled continuum mechanics and molecular dynamics was introduced. This paper describes the basic methods of multi-scale and general simulation process of molecular dynamics was reviewed.

Abstract: Based on the development of nanomaterials and the research on performance parameters of materials, molecular dynamics simulation has been rapid development and application. It is widely found that the material's physical, mechanical and other properties are both closely related to its macroscopic state and microstructure [. In order to explore and understand the nature of the material properties we need to analyze various impact factors including macroscopic, mesoscopic and microscopic. This paper describes the basic concepts and methods of molecular dynamics. The contents are comprised of time step, formulas such as Lagrange equations of motion and Hamiltonian equations of motion. The basic principles and recent developments of molecular dynamics were reviewed.

Abstract: With industrial technology developed, belt conveyor is very important that improve industrial production. Conveyor belt can avoid slippage, run deviation, and in turn. Belt conveyor conveys material fast and improves the efficiency. For realizing flat belt conveyor turning, this article complete plane conveyor to create 3 d model using Solid edge V20, and use dynamic analysis software ADAMS kinematics simulation of plane conveyor virtual prototype. Through a series of parameters setting and correction, we get analysis data and compare simulation results with the theoretical design results. Desired results show that the turning conveyor conveying speed is 0.6 m/s, turning radius is 1500 mm delivery targets within the scope of design to achieve the desired effect. Conveying material: smoke box (length x width x height, mm) 580 x 460 x 460, single weighing 25 kg. Thus, the technologies reduce design errors, shorten the product development cycle, and reduce development costs of new products. So that it improves production manufacture efficiency and product quality for the enterprise.