Applied Mechanics and Materials Vols. 365-366

Abstract: Watermarks, which are often used as security features of banknotes to prevent counterfeiting, are made onto the banknote paper using the dandy roll that is a roller of copper net with white watermarks accurately welded on it. The positioning accuracy of the white watermarks on the copper net is critical. However, the current technologies are inefficient, inaccurate and/or expensive. Therefore, in this paper a novel design of automatic system for white watermark is proposed. It is realized by thorough analysis of the welding procedure of the white watermark, design of a novel mechanical structure for the automatic feeding and accurate positioning of the white watermark to its welding position on the copper net and integration with the available spot welder. Compared with the current technologies, the proposed design could greatly improve the efficiency and accuracy for welding the white watermarks, and its total cost is low. Therefore, the proposed design could be adopted in the banknote printing industry to realize the automatic welding of the white watermarks.

Abstract: Based on the principle of reversal method, the Motion Simulation module of NX8.0 is adopted to find the trajectory of the oscillating follower roller center relative to the cam with the IF function driving the oscillating follower .At the same time, the contour line of oscillating follower disk cam is also designed using the quintic polynomial spline curve and the motion simulation is verified. The cam design by the reversal method and the theoretical one are compared and analyzed.

Abstract: The inherent flexibility of a liquid container is usually treated as a problem since achieving a perfectly rigid container is practical impossibility. On the other hand container flexibility may be used as design parameter in control of free surface oscillations. Intentional container flexibility has been employed in this research to suppress excessive levels of liquid sloshing. This paper outlines numerical predictions for simulation of liquid sloshing in a flexible container and its design alternatives while maintaining effective control.

Abstract: In order to expand the use of water flow, this paper presents a generating device using the vortex-induced vibration to gather energy from the low speed water flow. The device consists four parts: bearing frame, transmission and power generation system, vibration system and the measuring system. A prototype was made according to the design scheme, and finished the experimental test in a circulating water channel. The experiment showed that: the vibration body could get higher amplitude to drive the generator by controlling its stiffness coefficient; the unidirectional rotation transformed from the vortex-induced vibration reciprocating motion fluctuate obviously, which can be transferred into smooth rotation by the energy storage flywheel to drive the generator. The design and study of the swing arm vortex-induced vibration generating device provided a new idea for gathering energy from low-speed water flow, it would also provide a reference for the theoretical study and engineering applications of using vortex-induced vibration for generating.

Abstract: The pedestal of the theodolite is the main load-bearing part for the installation of the thrust bearings and torque motor stator, which is used to support the weight of the turntable and the pitching shaft system. So that the stiffness of it will have a direct impact on the ability of the theodolites capturing and tracking targets. In order to improve the overall theodolites tracking ability, to increase the stiffness of pedestal becomes more important. The 12 ribs were adopted topology optimization analysis by using the finite element software ANSYS. Through appropriately partitioning topology optimization elements and non-optimized elements, and setting optimization method, the structure of the model was optimized. The optimal ribs shape weve got under the condition of the largest stiffness pedestal structure, which reinforces the overall stiffness of the pedestal, and reduces the total weight.

Abstract: A multiobjective optimization based vibration isolator design for space application is described. It is common to use passive isolator and isolate the platform noise in space applications. The design of a passive isolator involves a trade-off between the resonant peak reduction and the high frequency attenuation. The equation of motion and transfer function model for single-stage and two-stage connector model is derived by using basic principle. The multiobjective optimization model is proposed, where the design variables are the damping coefficients and stiffness coefficients, the objective functions are the resonant peak reduction and the high frequency attenuation, and the constraints are the natural frequency of the connector. The multiobjective optimization problems for the design of the passive isolator are solved by using the multiobjective evolutionary algorithm based on decomposition (MOEA/D). The Pareto front obtained can provide multiple candidate solutions for the designer. The method is effective for the design process of the passive isolator.

Abstract: In view of the characteristic that the bottom pressure of Coalbed Methane Wells (CBM wells) is low and the structure of coal bed could be easily destructed, the author designed a kind of jet pump. The jet pump could improve efficiency of washing bottom-hole coal particle in condition of protecting the structure of coal reservoir. In this paper, we have analyzed the structure of jet pump and working principle; and given the method of calculation the basic parameters of jet pump on the basis of calculating the working efficiency of jet pump from the point of cavitation.

Abstract: Screw refrigerators are widely used in subzero refrigeration and storage fields. The manufacturers always use rotor-type pumps as their lubricating oil pumps. This paper introduces the advantages of screw refrigerators, the usage of oil pumps and the working environments. It mainly studies the common faults of oil pump, proposes several design ideas for analysis and comparison and determines the final improvement schemes on the premise of comprehensively considering structure, performance and cost.

Abstract: In view of the problem that an assembly can not be cut out directly in Pro/Engineer, further development in asynchronous mode of Pro/Engineer is applied by using Visual Studio 2010 development environment and Pro/TOOLKIT development module of Pro/Engineer. The transformation matrixes of every part and sub-assembly are calculated with traversal method. Every part belonging to the imported assembly is cut out at appointed position input by users, and the mass property of the remainder is calculated by adding it up in order to replace the function to cut out the whole assembly and to get the mass property of the stations. Two virtual model is employed to demonstrate the accuracy and practicability of the mass station calculating application. The result is very encouraging and the calculating efficiency is markedly improved.

Abstract: With the development of CAD/CAM, reverse engineering, geometric modeling, animation and computer graphics. In the past fifty years, many kinds of spline curve fitting methods have been produced. But, to authors knowledge, quality evaluation criterion about different spline curves are still not established and there is a lack of a comparing standard for analyzing different spline curves. Two spline curve fitting method comparing theorem is given and several various spline curves affecting factors are analyzed in this paper. Some comparable results are obtained by using the proposed quality evaluating theorem to different spline curves.