ENGINEERING NEWS IN BRIEF

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                  ENGINEERING NEWS IN BRIEF
                        E-Mail Newsletter

                               No.43
             Issued by the Asian TOP Panel, May 2005

           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)

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    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 KSME for the year 2005.

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[Contents]

(1) Experimental Research on Full Life by Few Samples Tests (Source: CMES)
(2) Study on Milling Process Dynamics Simulation System about the Process Parameter Optimization of NC Machine Tools (Source: CMES)
(3) Study on the Key Technologies of Carbon Nanotube Tib Fabrication (Source: CMES)
(4) Individual Finite Element Modeling Based on the X-ray CT Data (Source: JSME)
(5) Flow measurements by Magnetic Resonance Imaging(MRI) (Source: JSME)
(6) Design and Fabrication of a Micro PZT Cantilever Array Actuator for Applications in Fluidic Systems (Source : KSME)

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(1) Experimental Research on Full Life by Few Samples Tests (Source: CMES)

Chen Juhua Shi Yanbin An Yanqiu Shandong University

Facing to the difficulties in getting samples in life tests used for the complicated mechanical systems, Prof. Chen Juhua, Shi Yanbin and An Yanqiu provided two methods, i. e. fuzzy nearness and grey relational analysis method, to predict life by few samples tests. One big sample probability test on certain material gear was introduced in their paper. Based on big samples probability tests, the methods took the advantage of probability and fuzzy mathematics, and explored the unknown a few samples system with help of life samples of the known probabilistic distribution. The methods reduce test samples by some auxiliary information, and also converts the life tests into few samples and green tests for resources. Then engineering examples using the two methods are introduced to verify them.

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(2) Study on Milling Process Dynamics Simulation System about the Process Parameter Optimization of NC Machine Tools (Source: CMES)

Liu Qiang Yin Li Beijing University of Aeronautics& Astronautics

Considering the deficiency in process parameter optimization of milling process, based on the research of the dynamics model of milling process, a kind of dynamics simulation software was developed successfully in Matlab-GUIDE environment by Prof. Liu Qiang and Yin Li. The simulation system can provide some relative dynamics simulation such as the cutting force, spindle power, tools vibration, torque, chip and the surface of workpiece. Meanwhile, based on the modal analysis experiments, the effective chatter stability lobs were calculated. The process parameter optimization function can be accomplished effectively on the basis of relative simulations. The all above can provide some instructive directions and process parameters to NC operators. The main functions of the whole system have been tested on the cutting center FANUC-IIM successfully.

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(3) Study on the Key Technologies of Carbon Nanotube Tib Fabrication (Source: CMES)

Guo Liqiu Wang Rui Tsinghua University

Theoretical analysis made by Prof. Guo Liqiu and Wang Rui from Tsinghua University showed that for long nanotubes elastic response causes the nanotube tip to jump into contact with the surface and renders it unsuitable for imaging. Then the length of a nanotube tip was decreased by electrical etching on a conductive surface using AFM to reduce the amplitude of vibration to a level where it does not affect resolution. Consequently, key technologies of nanotube tip fabrication was studied.

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(4) Individual Finite Element Modeling Based on the X-ray CT Data (Source: JSME)

Michihiko KOSEKI: Tokyo Institute of Technology

Three dimensional imaging is a significant technique not only for medical methods but also for industries. However the enormous amount of information in the images has not been utilized efficient. My research group has a strong interest in the shape of a bone to mechanical environments. In order to examine mechanical characteristics of a bone, we develop an individual modeling method. The method automatically generates the finite element model based on the X-ray CT data. Moreover the method is applicable to soft tissues of living bodies or artificial materials as well as bones.
As the model reflects the exact shape of the object recognition of three dimensional structure of the object is easily realized. For this reason the method has a wide applicability such as an educational system or a diagnostic system that shows intelligible visual information. This paper describes some applications and discusses the possibility of the method.

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(5) Flow measurements by Magnetic Resonance Imaging(MRI) (Source : JSME)

Katsumi KOSE: University of Tsukuba

Flow measurements by Magnetic Resonance Imaging(MRI) have two complementary approaches: amplitude and phase methods. The amplitude method utilizes the amplitude of the nuclear magnetization, which visualizes fluid motion using a lattice or stripe pattern generated on the fluid. The phase method utilizes the phase of the precession of the nuclear magnetization which measures a distribution of a velocity component. Promising applications of MRI flow measurements are flows that cannot be measured by optical methods: Flow in porous media, multiphase flow, granular flow, and so on Although a lot of medical MRI systems are widely used in hospitals and medical institutes(about5,000in Japan),those systems are not used for flow measurements? In engineering research. MRI systems for small animals, those originally designed for chemical analysis, and those developed using permanent magnets are now used for flow measurements in this field. The MRI systems using the permanent magnets will be one of the standard flow measurement tools because flexible or combined flow measurement systems can be built.

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(6) Design and Fabrication of a Micro PZT Cantilever Array Actuator for Applications in Fluidic Systems (Source : KSME)

Professor Jongwon Kim of Seoul National University recently reported a micro PZT cantilever array actuator for microfludic systems. (Journal of Mechanical Science and Technology (KSME Int. J.), vol. 19, no. 8, 2005). The design features for maximizing tip deflections and minimizing fluid leakage were described in the article. The governing equation of the composite PZT cantilever was derived and the actuating behavior was predicted. The calculated value of the tip deflection was 15 Л at 5 V. The fabrication process from SIMOX (Separation by oxygen ion implantation) wafer was presented in detail with the PZT film deposition process. The PZT films were characterized by investigating the ferroelectric properties, dielectric constant, and dielectric loss. The 18 А/s leakage rate of air was observed at a pressure difference of 1000 Pa. Micro cooler and its possible application to micro compressor may be candidates utilizing this structure.

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Editor : Professor Mansoo Choi of Seoul National University,
           Director of General Affairs, KSME
           ksme@ksme.or.kr