Applied Mechanics and Materials Vols. 401-403

Abstract: A complete mathematical model of artificial feel system of a vehicle fly by wire flight control system was established after analyzing the heading mechanical structure of it. Modeling it by means of centralizing the distributed system parameters and establishing it to dynamic model, the nonlinear factors such as clearance and friction in the system were simplified reasonably. To establish a corresponding mathematical model, the dynamic model was established by means of dynamic equivalent model method resulting in a multi-freedom model. The mathematical model was simulated in Matlab/Simulink by modular way, and results were consistent to trial data. Friction as an important nonlinear factor have impact on system performance, analysis of its effect on dynamic characteristics of human feel system were in the condition of inputting different forms and amplitude signal . This provided guidance for designing system.

Abstract: Based on the observation of the data measured, the illumination distribution of single LED is set to follow Gaussian function, and with this hypothesis, two forms of light array are analyzed on their illumination distribution. The law of Spyro is used to optimize space between LED in array. Comparison and analysis of the two kinds of array arrangement are given for getting the uniform illumination. The general design method and the calculation example of LED array to produce uniform illumination are also given in this paper. Keywords: Plane light source, Gauss function fitting, LED light source, Uniform illumination

Abstract: The balancing device is the core component of top drive. Its role is to balance the gravity of top drive to prevent damage to the threaded joint in course of making up and breaking out of threaded joint of drill pipe. At the same time it can help male thread pop up from the drill pipe box in course of breaking out of threaded joint of drill pipe. Aiming at the problems of hydraulic system of the current balancing device that thread endures big normal force in course of making up and breaking out of threaded joint of drill pipe, a new hydraulic system was designed in this paper, and the simulation was analyzed based on AMESim. Through the simulation analysis, the new hydraulic system is reasonable and the normal force that screw endures is very small, which can reduce wear significantly.

Abstract: A necessary and sufficient condition is proposed for the incremental mass and stiffness matrices that modify some eigenpairs while keeping other eigenpairs unchanged, which requires the knowledge of only the few eigenpairs to be modified of the original undamped vibration system. The application prospects are proposed based on this formulation.

Abstract: This paper analyses the characteristics of parallel LLC resonant converter, and makes the comparison of the characteristics of the order switch shunt and staggered parallel switch circumstances converter. The circuit uses UC3863 chip as the core control chip switch power supply, circuit adopts the half bridge structure. This model is seldom put forward through the experiments prove the feasibility and practicability of the LLC, and greatly improving the working efficiency. Using SABER simulation software for the converter circuit simulation and analysis with the theoretical calculation of the device parameters. Example of 300v voltage input, 12-18v output voltage, 2.5 KW, 500 KHZ parallel LLC resonant converter design and simulation for model analysis. Sum up the advantages of the parallel LLC resonant converter compared with the traditional LLC resonant converter .The results of simulation verify the feasibility of the design and the accuracy of the conclusion.

Abstract: Radomes are adopted to ensure internal antenna systems work normally in severe environments. However, the presence of a radome will adversely affect the electricity performance of the enclosed antenna. A reasonable pre-process of the radome model is a prerequisite for completing electricity performance analysis successfully. Aiming at the difficulties of the design and assembly of curved surface parts, this paper presents a method of modeling and pre-processing by using Pro/E, Ansys and Ansys Workbench to extract element and node information effectively from the finite element model of the radome.

Abstract: In this paper, a method of using special shaped connection is proposed to redesign and optimize connection structure for improving manufacturing processing, enhancing equipment flexibility, and reducing parts costs on the basic of satisfying mechanical reliability. First, requirements of redesign and optimization process are addressed. Then an applied case is presented: 4-polygon shaped connection replacing involute spline connection in driving system. The result shows that the redesign and optimum structural demonstrate significantly the effectiveness.

Abstract: FDM process of rapid prototyping systems at present which can only reads the STL format file, based on this format can be get the 2-d layer is composed of straight line segments connected polygon contour, makes the model layer of information that are geometric distortion, leading to surface accuracy is poorer; Produced based on STL model for layered geometric distortion problem, this paper put forward to directly layering of entity model, and through the ObjectARX which is the secondary development tools of AutoCAD realizes layer directly in the software, the layer of 2-d contour for smooth curve, so as to ensure accuracy, it will be played an important role in the practical application later.

Abstract: In the wireless sensor nodes integrated with the solar PV micro-power supply, the solar energy conversion efficiency and utilization efficiency directly determine working life and stability of the wireless sensor nodes. Thus, a novel solar PV micro-power supply is designed which four solar cell arrays with same open voltage are designed and they are placed in top and three sides of the wireless sensor nodes. Simultaneous, the optimal voltage control technology is used to control work voltage of four solar cell arrays in the design. In addition, the prototype of wireless sensor node integrated with the solar PV micro-power supply is done. Moreover, the working characteristics of the prototype are tested in natural condition. The working voltages of four solar cell arrays are controlled in range of optimal voltage, and the solar cell arrays have high conversion efficiency. The output energy of system is increased about 50% by adding side solar cell arrays.

Abstract: Aiming at the disadvantage of existing equipment maintenance accessibility evaluation method, this paper studied the project of equipment maintenance accessibility evaluation. a method of equipment maintenance accessibility evaluation in the virtual environment is put forward based on Matrices Permanent and index correlation degree , at last an example is given. It is significant for developing maintainability verification and increasing Equipment Maintainability in the course of equipment digital mock-up designing.