Applied Mechanics and Materials Vols. 479-480

Abstract: This paper focus on the meshing efficiency of 2K-2H type planetary gear reducer. First, according to the concept of train value equation, the kinematic design of 2K-2H type planetary gear reducers is carried out. Then, based on the latent power theorem, the meshing efficiency equation of 2K-2H type planetary gear reducer is derived. According to the meshing efficiency equation, the meshing efficiency of 2K-2H type planetary gear reducer can be analyzed. The 2K-2H type planetary gear reducer has the following characteristics: 1. There is a problem of power circulation, 2.Larger reduction ratio makes less meshing efficiency, 3.For the same reduction ratio, larger value |ξ₄₂| (|ξ_α|) will get better meshing efficiency, and 4.The better quality of gears (manufactured by grinding) will produce much better meshing efficiency.

Abstract: BOP (Blow-out preventer)Gantry Crane is a crane which is used to move BOP stack saved in Drilling Platform to BOP trolley. However, such offshore plant equipment has not been developed in Korea but a lot of loyalty has to be paid to overseas companies. Thus, domestic production of it is necessary. In this research, ANSYS was used to apply into interpretation of rolling and pitching due to wave, wind load due to Drillship, and the crane's self-weight and structural interpretation was implemented. Moreover, Simulation X was used for control system design, and sub system was modeled and hydraulic system interpretation was implemented.

Abstract: Fermentation system is widely used for food manufacturing, materials processing and chemical reaction etc. Different types of blade in the tank for fermentation cause distinct stress distributions on the surface between fluid and blade, and appear various flow fields in the tank. So, this paper is mainly focused on analyzing the stress field of blades under different scales of blade with fixing rotational speed. The results show that the ratio of blade length to width influences stress distribution on the blades. At the same time, the inclined angle of blade is also the key parameter for the consideration of design and appropriate design will decrease the maximum stress. The results provide an effective means of gaining insights into the stress distribution of fermentation system.

Abstract: The general operation of a piezoelectric ultrasonic actuator is to convert the cyclic motion of the piezoelectric plate to a linear motion at the rotor or slider. The conventional piezoelectric ultrasonic actuator has two symmetric exciter electrodes on the front surface and each electrode covers one half of the front surface. The rear surface has only one electrode that severs as a common drain. In this paper, the design and simulation of the novel single-mode piezoelectric actuator with asymmetric electrodes were presented. The accomplishment of this study is to find the optimal dimensions of the piezoelectric plate and the asymmetric electrodes, and the stator tip on the piezoelectric ultrasonic actuator would have the larger vibrating amplitude. From the simulation experiment results, the optimal dimensions of the piezoelectric plate are 20×10×1 mm with 12 mm exciter electrode length, and the vibrating amplitude is from 0.73μm increasing to 0.91μm.

Abstract: The acoustic solid horns are the important parts in high power ultrasonic vibrating systems, and its design is critical to the quality and the efficiency of ultrasonic welding. The using of multiple function acoustic horn can reduce machining time very effectively. This paper performs the analysis and design of multiple function acoustic horns for ultrasonic welding of plastic by employing ANSYS finite element software. Firstly, the theoretical dimensions of the horns are calculated. Moreover, their natural frequencies and amplitudes are obtained through the simulations of ANSYS. Experiments are currently being set up to verify the validity of the analytical results.

Abstract: Machining processes on an inclined plane include mostly hole making, profiling, and pocketing. It comprises of 80% - 90% cutting process in five-axis machining and is therefore very important in multi-axis machining work. However, five-axis machining processes are normally difficult to introduce and to use because five-axis CAD/CAM and post-processor are normally demanded to generate five-axis NC program even though it is for the 2D contour machining on a plane with inclined angle. Therefore, this paper studies the inclined plane machining methods and extends traditional three-axis milling machining processes and methods so as to directly convert 2-1/2 and three-axis NC program into five-axis machining program to ease the application of five-axis machining processes. This study integrates the developed three-axis NC program interpreter, inclined plane coordinates transformation, and post-processor to simply the inclined plane NC programming. Two-dimensional NC program on a plane can be converted into five-axis NC program on the inclined-plane by the proposed methodology. Case study has been utilized to verify the utilization and correctness of the proposed methodology

Abstract: Front and/or rear suspensions of bicycles become popular for the purpose of riding comfort especially for mountain bicycle. Suspension system include damper for shock absorbing and spring for rebounding. Therefore suspension systems would increase bicycle riding effort since damper dissipates energy. ADAMS®/LifeMOD® are proposed in this research to establish a Bicycle-Human Integrated Multibody Dynamic Model to investigate the impact of bicycle suspensions on cyclists leg muscle forces under various pedaling conditions. Muscles compared include adductor magnus, rectus femoris, vastus lateralis and semitendinosus. Pedaling conditions include riding on flat road, over a road bump, and climbing slope. The results indicate that suspension system increases the pedaling forces of vastus lateralis and semitendinosus. However suspension system decreases the pedaling forces of adductor magnus and rectus femoris. The integrated model built in this research may be used as reference for designing bicycle suspension systems. In addition, the results of this study can be used as the basis of leg weight training for long-distance off-road cyclists to strengthen certain muscles.

Abstract: The application of traditional three-axis milling machine center is very popular and the related application technology is also much matured resulting in mechanical components to be machined with good quality. Machine tool has therefore become an inevitable facility in precision manufacturing. Furthermore, the pursuit of higher precision machining has thus demanding five-axis machine tool to be adopted owing to its flexibility and capability in machining more precise mechanical components in shorter time. However, one of the key factors for the popularity in smooth introduction of five-axis machine tool would be based on a very user friendly learning and teaching environment. This is partly because two more rotational axes in a five-axis machine tool could generate very complex toolpath movement that is out of the imagination of a general operator. Furthermore, the price of an industrial five-axis machine tool is not normally affordable by an educational institute; to the worse, the maintenance cost is also very high. There is very high risk for a novice to collide during the learning process and this will generally cause big worry of a teacher. This paper aims for the development of a virtual machining center simulation system with switchable modular components to ease the learning process in getting acquainted with a five-axis machine tool. A five-axis machine tool consists generally of two modules: (1) CNC controller and Operation panel, and (2) machine tool hardware. The developed system will provide the novice with four CNC controller with operation human machine interface (HMI), and three typical types of five-axis machine tool, Head-Head (HH), Head-Table (HT), and Table-Table (TT), are also supported. The developed modularized and switchable machining center simulation system has been successfully developed and is very helpful to both learner and teacher

Abstract: Hysteretic nonlinear characteristics and stochastic bifurcation of cantilevered piezoelectric energy harvester was studied in this paper. Piezoelectric ceramics was adhesively bonded on the substrate of cantilever beam to make piezoelectric cantilever beam. Von de Pol difference item was introduced to interpret the hysteretic phenomena of piezoelectric ceramics, and then the nonlinear dynamic model of piezoelectric cantilever beam subjected to axial stochastic excitation was developed. The stochastic stability of the system was analyzed, and the steady-state probability density function and the joint probability density function of the dynamic response of the system were obtained. Finally, the conditions of stochastic Hopf bifurcation were determined. Numerical simulation shows that stochastic Hopf bifurcation appears when bifurcation parameter varies, which can increase vibration amplitude of cantilever beam system and improve the efficiency of piezoelectric energy harvester. The results of this paper are helpful to application of cantilevered piezoelectric energy harvester in engineering fields.

Abstract: Anisotropic Conductive Film (ACF) is essential material in LCM (Liquid Crystal Module) process. It is used in bonding process to make the driving circuit conductive. Because the price of TFT-LCD is much lower than before in recent years, the ACF cost has relatively higher ratio in manufacture cost. The conventional long bar ACF cutting unit is changed to short bar ACF cutting unit in new bonding technology. However, the new type machine was not optimized in process and mechanical design. Therefore, the failure rate of new ACF cutting process is much higher than the one of the conventional process. This wastes the material and rework cost is considerably large. How to make the manufacturing cost down effectively and promote the product quality is the concern issue to maintain competition capability for the product. Therefore, the Orthogonal Particle Swarm Optimization is used to analyze the optimal design problem. The ACF cutting yield rate is selected to be objective function for optimization. The quality characteristic function is used in Orthogonal Particle Swarm Optimization. The plasma clean speed, ACF peeling speed and ACF cutter spring setting are selected to study the effect of the yield rate. Results show that the proposed method can provide good solution to improve the ACF cutting process for TFTLCD.