Abstract: The elastic-plastic finite element mechanical model of hypereutectic Al-Si alloy was established based on ANSYS software. When the Si particles were circle, trapezium, rectangle or triangle, the microstress of Al-Si alloy under the external load were simulated. When the size of Si particles changed from 25μm to 45μm, the stress of Si particles and matrix interface was calculated. The effects of morphology and size of Si particles and loads on micro-mechanics characteristic of alloy were analyzed. The results showed that: under the same load, triangle or wedge angle Si particles make the biggest stress in the matrix, trapezoidal particles make the second and the spherical particles make the smallest. With the increase of the load, the stress and the stress concentration of Si particles in the matrix was increased, the stress of wedge angle particle increases remarkably, but the stress of spherical particles increases slowly. With the increase of the size of Si particles, the stress and the stress concentration of Si particles in matrix are increased.
Abstract: The function of the coupling in the connection device is to connect the two axises and transfer the movement. Due to the particular structure of the laminated coupling, the main function of the coupling is to compensate the misalignment generated in the operation process of the axises. In this paper, a new type of laminated structure coupling - four-hole Joint Bearing laminated coupling is proposed. By using this coupling the shaft misalignment compensation ability between the two axises is improved from 1.0 ° ~ 1.5 ° to 4 ° ~ 6 °. Classical mechanics method and ANSYS finite element analysis are employed to analyse 3 different sizes of joint couplings, respectively. From the analysis the position of the maximum stress and the shaft misalignment compensation ability of each kind of coupling which provide the theory basis for the design of the new type of the coupling can be obtained.
Abstract: Using the plane-wave ultrasoft pseudopotential method and generalized gradient approximation which based on the first-principles density functional theory, the bond length, energy band structure and density of states of the layer of Si/Ge were calculated. The results show that, compared with the single-crystal Si layers, Si-Ge bond length get longer and the population decrease in the layer of Si/Ge . It can be seen from the energy band structure that the band structure width of the layer of Si/Ge decreases. The optical properties calculations show that, compared with the single-crystal Si layers, the absorption band of the layer of Si/Ge get narrower, and the absorption band-edge obviously get red-shift.
Abstract: Smoothed particle hydrodynamics (SPH) method is used to simulate the lift-off phenomenon of sand particles in the air flow. Whether the sand particles make any form of movement in the air flow, firstly, they always jump into the air from a standstill condition, so it is helpfull to understand the saltation mechanism of sand particles. Because the computitional region is discreted into particles in the SPH method, the movement of each particle can represent the machnical behavior of sand particles if the particle dispersion has the same characteristic with the sand particles. The foundmental theory of SPH method and its key elements are reviewed in detail, such as the kernel function, the choice of smoothing length and their influence on the numerical simulation results.In this study a numerical simulation model of wind-blown sand two-phase flow using SPH model is proposed and then the model is discreted to simulate the take-off process of sand particles with adquate boundary conditions. Simulation results show that the proposed model can be used to simulate the dynamic characteristics of sand particles in lift-off.
Abstract: Steel tie rods are very important load-carrying components in places where high pre-stresses are required, such as in long-span buildings, docks, bridges and stadiums. Steel tie rods are connected by threaded connections. The bearing capacity of a steel tie rod is determined not only by the strength of rod’s body alone, but also by the strength of threaded connection. This paper reports the results of the full-scale tensile rupture experiments on a LG100-00 steel tie rod with trapezoidal threaded connection. The full-scale tensile rupture experiments were carried out to test the maximum axial working load under different numbers of turns of trapezoidal thread engagement. The minimum number of turns of trapezoidal threaded engagement such that the thread teeth do not fail in shear and bending is determined by the experiments and finite element analyses. The equivalent stress distribution and contact pressure on the engaged thread teeth under different axial loads are analyzed and compared. The concordant comparison provides strong guidelines and support for the design and fabrication of steel tie rods in practical operations.
Abstract: With the applying of computer technology in shipping building field, and the intelligence is becoming stronger and stronger, the management of the ship is tending to rationalization, intelligence and automation. Thus, the management information system’s level of the ship has became an important sign in measuring of the sophistication of the ship . Therefore, marine engine data scanning and displaying, marine engine auto-controlling have become a main researching field. So the paper based on such condition.
Abstract: On the foundation of the methods and mechanisms of electrochemical finishing with high-frequency group pulse we studied before, properties of the finishing process with ultrahigh-frequency group pulse were studied, effects of pulse effect on the finishing result were also researched. With the Ultrahigh-frequency group pulse power we designed, we designed a equipment with high precision and easy operation. After some single-factor experiments, we obtained the laws of how the main pulse influenced the result, from the Ra of 2Cr13 stainless steel surface.
Abstract: In the paper, a robust tracking controller is presented for a class of SISO affine nonlinear systems with unknown mismatched uncertainties and external disturbance in input channel.The designed controller has simple structure and concrete expression and include no Lyapunov function. So the proposed controller is easy to compute and complement.The practical stability of output tracking error and the states of the corresponding closed-loop system are demonstrated by Lyapunov stability theorem.Simulation results are presented throughout the paper to complement the theoretical developments.
Abstract: Three-dimensional animation is one of the greatest contributions made by computer sciences to the animation industry. The 3D animation has been widely used in movie special effects, commercials, computer games and computer-based education (CBE), and has become a well-known form of art in the world's pop culture. The rapid development of 3D animation also brings about fundamental changes in the materials used in animation production. This paper gives an introduction of the virtual materials in 3D animation, as well as the tools needed and methods of making the materials using 3D animation design software, especially Maya.
Abstract: A new Oil-Mineral Aggregate with bentonite and calsium hydroxide and sawdust has been done. Through several dozens of experiments, the coagulation efficiency with bentonite and Ca(OH)2 and sawdust is 94.53%. The functions of bentonite are coagulation, adsorption and emulsification. Calsium hydroxide is a good coagulant-mate, and strengthen the coagulating function of bentonite. It can be used as the source of calcium ions, which can strongly adsorb on both bentonite and oil droplets, and is helpful for the coagulation between bentonite and oil droplets. Sawdust is also very important in the OMA, its fouctions are buoyant, bridge-made and adsorbant.