======================================================================                   ENGINEERING NEWS IN BRIEF                         E-Mail Newsletter                                No.66              Issued by the Asian TOP Panel, June 2007            The Chinese Mechanical Engineering Society (CMES)            The Institution of Engineers, Indonesia (PII)            The Japan Society of Mechanical Engineers (JSME)            The Korean Society of Mechanical Engineers (KSME) ======================================================================     According to the agreement made in the 2nd Asian TOP Panel Meeting, the ENGINEERING NEWS IN BRIEF (E-mail newsletter) has now been edited by the CMES for the year 2007. ====================================================================== [Contents] (1) Structure Eigen Vibration Control of Flywheel Suspended by Active Magnetic      Bearings (Source: CMES) (2) Gear Transmission with Meshed Medium Belt (Source: CMES) (3) Discrete Anticipatory Learning Control of Ram Velocity in Injection Molding      Machines (Source: CMES) (4) Sound and vibration simulation of the golf club (Source: JSME) (5) Toward eco-design of multilateral recycling system in Asia (Source: JSME) (6) A Study on the Micro-fracture Behavior of the MEMS Material at Elevated      Temperature (Source: KSME) (7) A Study on Rapid Mold Heating System Using High-Frequency Induction Heating      (Source: KSME) (8) Design Parametric Analysis of PEM Fuel Cell and Hybrid Systems (Source: KSME) (9) Classification of Surface Defects on Cold Rolled Strip by Tree-Structured Neural      Network (Source: KSME) (10)Surface Wettability in Terms of Prominence and Depression of Diverse      Microstructures and Their Sizes (Source: KSME) (11)Method of Particle Contamination Control for Yield Enhancement in the       Cleanroom (Source: KSME) ======================================================================== (1)Structure Eigen Vibration Control of Flywheel Suspended by Active Magnetic     Bearings     ZHANG Kai, Department of Engineering Physics, Tsinghua University     ZHAO Lei, Institute of Nuclear and New Energy Technology, Tsinghua University In a momentum wheel system suspended by active magnetic bearings, the stability of the system is influenced by two severe resonances coming from the structure of the system at a middle frequency band. Special controller designs are used to restrain them. A non-parametric frequency domain method is used to identify the system model to obtain structure vibration information. It is found that the frequency of one of the structure resonances varies markedly with controller stiffness. Modeling the resonances is difficult, and a convenient method based on an iterative process of identification and controller parameter tuning is used to deal with the resonances. In controller designs of the process, a zero-pole pair method and a μ-synthesis method are applied respectively. The experiments show that the iterative process is effect and two controllers designed by the two methods respectively are both suitable for restraining the structure vibrations. ======================================================================== (2)Gear Transmission with Meshed Medium Belt     ZHANG Guanghui, State Key Laboratory of Mechanical Transmissions, Chongqing                              University     TAN Hua, No.710 Research Institute, China Shipbuilding Industry Company A new type of gear transmission with meshed medium belt is developed. The proper tooth profile and tooth thickness calculation method of both the gear and its basic rack are presented. Tests are carried out on the closed electric power test-bed to contrast the performance of this new gear drive with inverlute gear drive, the former lubricated by oil and water separately. According to the tests results some types of medium belts are chosen and performance tests and endurance life tests are carried out. All these tests indicate that the flexible belt can improve the hydrodynamic lubrication of the gears, reduce noises and absorb shocks. The teeth profiles become less damageable, and the requirements on manufacture technics are reduced. Furthermore, this new drive can be lubricated by water. ======================================================================== (3)Discrete Anticipatory Learning Control of Ram Velocity in Injection Molding     Machines     CUI Cailian SUN, Mingxuan College of Information Engineering, Zhejiang University                             of Technology A discrete frequency domain design is presented for anticipatory learning control, and applied to ram velocity profile tracking in injection molding process by virtue of the repetitive nature. Two adjustable parameters, the lead-time and the learning gain, are designed in two steps, in contrast with the continuous counterpart. The monotonic decay of the tracking error is guaranteed by cutting off the frequencies beyond the learnable band with the aids of DFT/IDFT. The tracking performance is theoretically examined in the presence of initial resetting errors and measurement noise. Numerical simulation is conducted to demonstrate the effectiveness of the proposed anticipatory learning control, with the comparison of both P-type and D-type ones. ======================================================================= (4) Sound and vibration simulation of the golf club     Mitsuo IWAHARA, Hosei University Faculty of Engineering, Department of                               Mechanical Engineering At the present day, the discrimination can not be attempted concerning the flight-distance at the golf club, since the standard has been determined the performance of the golf club. And in the development of golf club, it begins to be asking the collision noise at the ball and golf club for the merchandizing. In this study, the computer program was completed which made collision noise of golf club and ball from modal parameters of FEM and experiments. The practicability of this program was examined using the iron club of the solid structure in the type of golf head. The research method was done by comparing surface velocity and sound pressure spectrum of the head with calculated value that experimented. The collision noise can be predicted in the stage of the drawing, if the result of calculation and experiment agrees, and if the practicability can be proven. And time and cost of the development can be reduced. Computation theory and content of the program are described in detail. ============================================================ (5) Toward eco-design of multilateral recycling system in Asia      Shinsuke KONDOH, National Institute of Advanced Industrial Science and                                  Technology (AIST) Environmental issues become more and more important recently, and establishment of a global recycling system including Asian countries (e.g., China, Vietnam etc.) as well as that of domestic recycling system is quite important. One major advantage of a global recycling system is efficiency in resource utilization. There exist significant disparity in economic situations among Asian countries, and this makes it possible to utilize resources more efficiently via second-hand market and remanufacturing / recycling processes with low labor cost. However, the difference in environmental regulations and recycling technology may result in the movement of environmental pollution. Therefore, adequate design and control of a global recycling system is eagerly required. This article reports current situation of global recycling system in Asia, and discusses its advantages and disadvantages from the environmental and economic viewpoints simultaneously. One of key success factors for realizing an adequate global recycling system is traceability of end-of-life products. To solve this problem, comprehensive management of product life cycle over multiple countries is effective approach. A practical example of this approach is also presented in this article. ============================================================ (6) A Study on the Micro-fracture Behavior of the MEMS Material at Elevated      Temperature     Byung Hoon Woo1), Yun Hae Kim1), Chang Won Bae2), Kyong Man Moon1), Sung     Yeol Bae, and Yakichi Higo3)      1) Korea Maritime University, 2) Korea Institute of Maritime and Fisheries      Technology, 3) Tokyo Institute of Technology The effective fracture toughness testing of materials intended for application in Micro Electro Mechanical Systems (MEMS) devices is required in order to improve understanding of how micro sized material used in device may be expected to perform upon the micro scale. γ-TiAl based materials are being considered for application in MEMS devices at elevated temperatures. Especially, in Alloy 4, both α and γ lamellae were altered markedly in 3,000 h, 700℃ exposure. Parallel decomposition of coarse α into bunches of very fine (α+γ) lamellae. Parallel decomposition of coarse α2 into bunches of very fine (α+γ) lamellae. The materials were examined 2 types Alloy 4 on heat exposed specimen(700℃, 3,000 h) and no heat exposed one. Micro sized cantilever beams were prepared mechanical polishing on both side at 25~30 and electro final stage polishing to observe lamellar orientation of same colony with EBSD (Electron Backscatter Diffraction Pattern).Through lamellar orientation as inter-lamellae or trans-lamellae, Cantilever beam was fabricated with Focused Ion Beam(FIB). The directional behavior of the lamellar structure was important property in single material, because of the effects of the different processing method and variations in properties according to lamellar orientation. In MEMS application, it is first necessary to have a reliable understanding of the manufacturing methods to be used to produce micro structure. ============================================================ (7) A Study on Rapid Mold Heating System using High-Frequency Induction Heating      Oh-Kyung Kwon1), Hui-Tack Jeong1), Jae-Ho Yun1), Keun Park2)      1) Korea Institute of Industrial Technology, 2) Seoul National University of      Technology Rapid mold heating has been recent issue to enable the injection molding of thin-walled parts or micro/nano structures. Induction heating is an efficient way to heat a conductive workpiece by means of high-frequency electric current caused by electromagnetic induction. Because the induction heating is a convenient and efficient way of indirect heating, it has various applications such as heat treatment, brazing, welding, melting, and mold heating. The present study covers an experimental investigation on the rapid heating using the induction heating and rapid cooling using a vortex tube in order to eliminate an excessive cycle time increase. Experiments are performed in the case of a steel cup mold core with various heating and cooling conditions. Temperature is measured during heating and cooling time, from which appropriate mold heating and cooling conditions can be obtained. ============================================================ (8) Design Parametric Analysis of PEM Fuel Cell and Hybrid Systems      Byung June You1), Tong Seop Kim1), Young Duk Lee2), Kook Young Ahn2)      1) Inha University, 2) Korea Institute of Machinery and Materials Performance of PEM fuel cell systems and hybrid systems combining a PEMFC with a gas turbine has been evaluated. Two different reforming methods(steam reforming and autothermal reforming) were considered. Performances of fuel cell systems with two reforming methods were compared and effects of various design parameters on the system performance were investigated. Configurations of PEM fuel cell systems with two reforming methods have been revised to accommodate a gas turbine, resulting in PEMFC/GT hybrid systems. Performance of the hybrid systems were analyzed and compared with those of PEM systems. Influences of major design parameters on the hybrid system performance were also investigated. ============================================================ (9) Classification of Surface Defects on Cold Rolled Strip by Tree-Structured Neural      Network      Chang In Moon1), Se Ho Choi2), Won Jong Joo1), Gi Bum Kim2)      1) Seoul National University of Technology, 2) POSCO Technology      Research Institute A new tree-structured neural network classifier is proposed for the automatic real-time inspection of coldrolled steel strip surface defects. The defects are classified into 3 groups such as area type, disk type, area & line type in the first stage of the tree-structured neural network. The defects are classified in more detail into 11 major defect types which are considered as serious defects in the second stage of neural network. The treestructured neural network classifier consists of 4 different neural networks and optimum features are selected for each neural network classifier by using SFFS algorithm and correlation test. The developed classifierdemonstrates very plausible result which is compatible with commercial products having high world-wide market shares. ============================================================ (10) Surface Wettability in Terms of Prominence and Depression of Diverse       Microstructures and Their Sizes       Seon-Woo Ha, Sang Min Lee, Im Deok Jeong, Phill Gu Jung, Jong Soo Ko       1) Busan National University, 2) Busan National University MEMS Cooperation       Program Superhydrophobic surface, with a water contact angle greater than 150°, has a self-cleaning effect termed 'Lotus effect'. This surface is created by the combination of rough surface and the low surface energy. We proposed square pillar and square shapes to control surface roughness. Microstructure arrays are fabricated by DRIE(Deep Reactive Ion Etching) process and followed by PPFC(Plasma Polymerized Fluorocarbon) deposition. On the experimental result, contact angle at square pillar arrays is well matched with Cassie's model and largest contact angle is 173.37°. But contact angle of square pore shape arrays is lower than Cassie's theoretical contact angle about 5~10%. Nevertheless, square pore arrays have more rigidity than square pillar arrays. ============================================================ (11) Method of Particle Contamination Control for Yield Enhancement in the        Cleanroom        Kwang-Chul Noh1), Hyeon-Cheol Lee2), Dae-Young Kim2), Myung-Do Oh1)        1) University of Seoul, 2) Samsung Electric Co., MCC TG The practical studies on the method of particle contamination control for yield enhancement in the cleanroom were carried out. The method of the contamination control was proposed, which are composed of data collection, data analysis, improvement action, verification, and implement control. The partition check method and the composition analysis for data collection and data analysis were respectively used in the main board and the cellular phone module production lines. And these methods were evaluated by the variation of yield loss between before and after improvement action. In case that the partition check method was applied, the critical process step was selected and yield loss reduction through improvement actions was observed. While in case that the composition analysis was applied, the critical sources were selected and yield loss reduction through improvement actions was also investigated. From these results, it is concluded that the partition check and the composition analysis are effective solutions for particle contamination control in the cleanroom production lines. ============================================================ Editor : Tian Ruizhu            The Dept. of Internationa Affairs            Chinese Mechanical Engineering Society

 

Please feedback us! wwwadmin@jsme.or.jp All Rights Reserved, Copyright (C) 2007, The Japan Society of Mechanical Engineers.