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                  ENGINEERING NEWS IN BRIEF
                        E-Mail Newsletter

                               No.89
             Issued by the Asian TOP Panel, May 2009

           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 JSME for the year 2009.

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[Contents]

1)  Recycling Method for Initial Type of Aluminum Rolling Stock (Source: JSME)
2)  Noise Absorbing Sponge Technology (Source: JSME)
3)  Materials Inspection and Evaluation Using (Source: JSME)
4)  Hardness Tester Digitalizing Softness (Source: JSME)
5)  Disassembly Sequence Planning Based on Generalized Axis Theory(Source: CMES)
6)  Analysis and Optimization of the Internal Flow in Centrifugal Compressor Volute      (Source: CMES)
7)  Technology on Large Scale Numerical Control Machine Tool Condition Monitoring      Based on Built-in Sensors(Source: CMES)
8) Effect of Imperfections on the Mechanical Behavior of Wire-woven Bulk Kagome     Truss PCMs under Shear Loading (Source: KSME)
9) A Comparison of Residual Stresses in Built-up Steel using Hole-drilling Method     (Source: KSME)
10) Modeling of a Magneto-rheological (MR) Fluid Damper using a Self Tuning Fuzzy     Mechanism (Source: KSME)

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1) Recycling Method for Initial Type of Aluminum Rolling Stock

     Masao Tomeoka, Tokyo Metro Co., Ltd

 In order to establish the recycling method for initial type of aluminum rolling stock, authors estimated the component of secondary aluminum alloy melted from out-of service aluminum car-body.
 To recycle the initial type of aluminum rolling stock which is structured by welding many kinds of aluminum alloy, it is necessary to classify into each type of aluminum alloy. Because the method of extracting the alloy elements except aluminum is not established commercially. So, authors scrap the aluminum rolling stock and confirm the composition of that secondary aluminum alloy.
 As the result, yield rate of this scrap is 86.2%. And it is confirmed to turn this scrap on directly to the operating furnace, even though it contains 4.0% volume content of iron and the stainless steel. Finally the under-frame reproduction alloy with a high content of zinc is recycled to ADC12. The roof and side-plate with a low content of zinc is recycled to AC2C which is changed into engine component (cylinder head, intake manifold etc.)
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2) Noise Absorbing Sponge Technology

     Naoki Yukawa, Sumitomo Rubber Industries, Ltd.

In Japan, In January, 2006, Sumitomo Rubber Industries released a tire with sponge which absorbed a noise of the tire inside.
 By this technology, we succeeded in reducing a cavity resonance by the resonance of the air of the tire inside that had difficulty with reduction till now.
 It was difficult for the tire with the sponge to achieve many performance ? durability, heat-resistant, reliability, weatherability, strength - found on a tire till now.
 However, we succeeded in mass production for the first time in the world by developing appropriate material and shape.
 By adopting this technology with our existing noise reduction technology, I was able to give a tire the innovative quietness and new sense of values.
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3) Materials Inspection and Evaluation Using

      Hironori Tohmyoh, Tohoku University

 This article reports an acoustic technology called dry-contact acoustic microscopy for performing the high-resolution acoustic imaging of a sample under the dry environment. The dry-contact technique performs the transduction of broadband, high-frequency ultrasound via a solid layer inserted between water and the sample, whereat the pressure of about 0.1 MPa is applied at the layer/sample interface by evacuating air between them. Typically, the polymer films are used as the intermediate layer for water protection, and the film sometimes behaves as frequency filter for signal amplification or modulation. This is brought by the acoustic resonance phenomenon among water, film and the sample, and can be an advantage of the technique for getting high quality acoustic images of the testing samples. Moreover, by analyzing the acoustic resonance phenomenon among the three media, the acoustic properties of the freestanding thin polymer film, i.e., the acoustic impedance, velocity and density, can precisely be measured by the dry-contact acoustic microscope.
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4) Hardness Tester Digitalizing Softness

      Tadashi Mitsuhashi, Citizen Seimitsu Co., Ltd.

Energy-absorption material, foods, and so on are too soft to apply conventional standards of rubber hardness.
 Since measuring force can be set to minimum of 2mN utilizing voice coil motor systems, this product can respond to various needs.

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5) Disassembly Sequence Planning Based on Generalized Axis Theory

      Tian Ying, Wang Taiyong, He Gaiyun, Ding Baihui,
      Tianjin University

 How to obtain the compact and reasonable expression of all feasible disassembly paths has become the most important problem to be resolved in disassembly sequence planning. In order to optimize the sub-assembly clustering in planning of disassembly path, and to avoid combination explosion problem of calculation caused by traditional method, a theory of generalized axis conformed with the engineering semantic information and the concept about disassembly priority adjustment coefficient are put forward, considering the information about assembly structure and assembly process, quoting and extending the concept of matching relation which express the compact degree between parts. On operation procedure, itfs first to gain the coaxial membership matrix and its modified matrix by using the expression form of adjacency matrix, the coaxiality coefficient function and the disassembly priority distributing table. Then, it can be obtained considering related algorithms of fuzzy cluster analysis of transitivity fuzzy equivalent matrix and ? dynamic product clustering relationship graph. Using these, the sub-assembly clustering can be obtained in the end. The benefit of the proposed theory and method is illustrated through an example, which can improve the consistence with the actual engineering situation, and calculating work can be greatly reduced.
Key words: generalized axis theory; sub-assembly; disassembly sequence planning; fuzzy clustering_________________________________________________________________________________________________________________________________

6)
Analysis and Optimization of the Internal Flow in Centrifugal Compressor     Volute

      Ji Chunjun, Wang Yajun, Wang Xuejun, Yao Lixin
      Dalian University of Technology

 The 3D internal viscous flow in the last stage of a centrifugal compressor is analyzed numerically with commercial computational fluid dynamic software NUMECA. The geometric model includes the close-type impeller, the vaneless diffuser and the volute. Based on the analytic results, modifications to the constant width volute are proposed and the stage efficiency is increased by 4.5%. The same approach is applied on the last stage of another centrifugal compressor and the efficiency is also increased by 4.5%. Through summing up the effect of different parameters, the code for the aerodynamic design of the welding type volute is developed. The code is tested on another compressor with a constant height volute and the last stage efficiency is increased by 3%. Numerical experiments prove that the code can be used for the aerodynamic design of all welding type volutes.
Key words:centrifugal compressor; welding type volute; numerical simulation; efficency

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7) Technology on Large Scale Numerical Control Machine Tool Condition     Monitoring Based on Built-in Sensors

      Zhou Yuqing, Mei Xuesong, Jiang Gedong, Sun Nuogang, Tao Tao
       Xifan Jiaotong University

 A kind of large scale numerical control (NC) machine tool condition monitoring system based on AC servo motor encoder, linear or rotary scale and motor current (torque) is proposed. To obtain the state information, the test principles of motor torque, machine tool position and lubrication characteristic are profoundly investigated, and some different sampling methods for open NCs and commercial NCs are suggested. Furthermore, some constant speed tests and lubrication characteristic tests are carried out respectively. The analysis shows that it is feasible and reliable to use the motor current, position, instantaneous velocity, instantaneous acceleration for monitoring the mechanical parts state and evaluating the servo control characteristics, which lays the foundation for large scale numerical control machine tool on-line condition monitoring and fault diagnosis.
Key words: NC machine tool; built-in sensors; condition monitoring; fault diagnosis

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8) Effect of Imperfections on the Mechanical Behavior of Wire-woven Bulk    Kagome Truss PCMs under Shear Loading

      Sangil Hyun1, Ji-Eun Choi2 and Ki-Ju Kang3
      1.Simulation Center, Korea Inst. of Ceramic Eng. & Tech.,
      2.Automobile Research Center, Chonnam National University,
      3. School of Mechanical Systems Engineering, Chonnam National University

Abstract Wire-woven bulk kagome (WBK) materials are a new class of cellular metallic structures possessing desired mechanical performance and can be fabricated easily by assembling metallic wires. In previous studies, the WBK materials were shown to have high strength and weak sensitivity on imperfections under compressive loads. In this paper, we present numerical simulation results on the mechanical performance of WBK and its sensitivity on imperfections under shear loads. Two types of statistical imperfections on geometry and material property were introduced in the simulation models as likewise the previous studies. The simulation results were compared with the experimental measurement on the WBK made of stainless wire (SUS304). The WBK were shown to have a good isotropic mechanical strength under various orientations of shear loadings.
Keyword:Cellular metal-PCM (Periodic Cellular Metal)-Kagome truss-Imperfections-PBC (periodic boundary condition)-Random network analysis

9) A Comparison of Residual Stresses in Built-up Steel using Hole-drilling     Method

M.A.Nawafleh1, Y.M.Hunaiti2 and R.M.Younes3
       1. Department of Civil Engineering, Al-Hussein Bin Talal University,
       2. Department of Civil Engineering, University of Jordan,
       3. Department of Civil Engineering, Tafila Technical University,

Abstract Residual stresses have a significant effect on the stability resistance of metal building systems. An experimental program was conducted to measure these stresses in built-up steel beams using incremental hole-drilling method. The experimental results reveal that the predicted residual stress type of pattern for built-up I-sections with fillet welds on one side of the web is not the same as the pattern of residual stresses in built-up I-sections with fillet welds on both sides of the web.
Keyword: Beams-Residual stresses-Hole-drilling-Steel

10) Modeling of a Magneto-rheological (MR) Fluid Damper using a Self Tuning      Fuzzy Mechanism


     
Kyoung Kwan Ahn1, Dinh Quang, Truong1 and Muhammad AminulIslam1
      1. School of Mechanical and Automotive Engineering, University of Ulsan,

Abstract A magneto-rheological (MR) fluid damper is a semi-active control device that has recently begun to receive more attention in the vibration control community. However, the inherent nonlinear nature of the MR fluid damper makes it challenging to use this device to achieve high damping control system performance. The development of an accurate modeling method for a MR fluid damper is necessary because of its unique characteristics. Our goal was to develop an alternative method for modeling an MR fluid damper by using a self tuning fuzzy (STF) method based on neural technique. The behavior of the researched damper is directly estimated through a fuzzy mapping system. To improve the accuracy of the STF model, a back propagation and a gradient descent method are used to train online the fuzzy parameters to minimize the model error function. A series of simulations were done to validate the effectiveness of the suggested modeling method when compared with the data measured from experiments on a test rig with a researched MR fluid damper. Finally, modeling results show that the proposed STF interference system trained online by using neural technique could describe well the behavior of the MR fluid damper without need of calculation time for generating the model parameters.
Keyword: Magneto-rheological (MR) fluid-Damper-Modeling-Self tuning-Fuzzy
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Editor : International Affairs Committee
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