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                  ENGINEERING NEWS IN BRIEF
                        E-Mail Newsletter

                               No.92
             Issued by the Asian TOP Panel, August 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) The Outline of Improvement on Vehicle Dynamic Simulator (Source: JSME)
2) An Effective Internal Control Reflecting Companyfs Corporate Social Responsibility     Philosophy (CSR) ?To Eliminate Risks of being Committed with the Mislabeling
    Scandal Conduct- (
Source: JSME)
3) Development of Centerless Grinder with Automatic Changeover Function
    (
Source: JSME)
4) Quasi-linearization of non-linear systems under random vibration by probabilistic
    method
(Source: KSME)
5) A path Tracking Control Algorithm for Underwater Mining Vehicles
    (Source: KSME)
6) Dynamic Response Characteristics of Seismic Isolation Systems for Building
    S
tructures (Source: KSME)
7) Modulus of Elasticity and Yield Bending Stress of Coating Lubrotec 19985
   Produced by the Metal Spraying Process (Source: KSME)
8)  Orthogonal Design and Analyses of Hydraulic Bridge for Water Servo Valve
    (
Source: CMES)

9)  Optimal Motion Planning for Differentially Flat Underactuated Mechanical Systems      (Source: CMES)
10) Flow Analysis and Optimization of Port-plate Centrifugal Pump in Electric Motor
     Pump (Source: CMES)


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1) The Outline of Improvement on Vehicle Dynamic Simulator (Source: JSME)

     Tomohiro Otsuka, Central Japan Railway Company

 We have been carring out the development and verification of riding comfort improvement plan of TOKAIDO SHINKANSEN trunk line using vehicle dynamic simulator. As the result, the riding comfort of TOKAIDO SHINKANSEN trunk line has been realized in good condition. Recently, we improved vehicle dynamic simulator in order to carry out the deepening of further study(ex. the riding comfort in high frequency range).In improving vehicle dynamic simulator ,we changed control system and miniaturization and lighting of the equipment cabin in order to realizing high performance. As the result, we improved the double performance further than conventional vehicle dynamic simulator. In future, we will be verifing of the riding comfort in high frequency range and tackling the equipment development of improving the riding comfort of TOKAIDO SHINKANSEN trunk line by using result of study.

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2) An Effective Internal Control Reflecting Companyfs Corporate Social Responsibility Philosophy (CSR) -To Eliminate Risks of being Committed with the Mislabeling Scandal Conduct-

     Naochika Tamura, InterRisk Research Institute & Consulting, Inc.

 Japanese people have been quite familiar with the dairy news concerning new mislabeling scandals committed by Japanese companies. Once a company is revealed with its scandal, it will find itself caught in a cross fire of serious criticism by consumers and mass media, and then on the verge of crisis.  For a company, one of the most effective measures to eliminate risks of being committed with the mislabeling scandal conduct is to enforce its own internal control - consisted mainly of eCompliancef and eRisk Managementf.  Above all, in order to establish effective internal control (system), a company must be certain that its management policy fully reflects its CSR philosophy and that both of its executives and staff are acquainted with it sufficiently.

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3) Development of Centerless Grinder with Automatic Changeover Function

     Mohei Sagae, Micron Machinery Co., Ltd

 In centerless grinding, changeover time reduction has been an important element of lean thinking for a number of years. Especially in throughfeed grinding, some processes of changeover will be required as well as special training in order to adjust tooling. In 1994, Micron Machinery developed an MSL-600III model, equipped with the oblique cross slides that introduced the concept "contact point constant." Previously, the changeover method was to keep the workpiece-to-regulating wheel contact point constant before and after changeover, in order to omit any manual adjustments on the tools with contact to the workpiece. As a result, the automatic changeover function was realized in throughfeed centerless grinding. In 2008, the MFC-600VI model was developed in order to introduce the new concept "contact point control." By controlling the grinding wheel, regulating wheel, and workrest, which are in contact with the workpiece, the three contact points on the workpiece can be independently and precisely controlled in a changeover. This will expand the application of automatic changeovers and advance the quality and stability of the finished workpieces, in both throughfeed grinding and infeed grinding.
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4) Quasi-linearization of Non-linear Systems under Random Vibration by Probabilistic
    Method


     Sin-Young Lee,Kunsan National University

 Vibration of a non-linear system under random parametric excitations was evaluated by probabilistic methods. The non-linear characteristic terms of a system were quasi-linearized and excitation terms remained as they were. An analytical method where the square mean of error was minimized was used. An alternative method was an energy method where the damping energy and restoring energy of the linearized system were equalized to those of the original nonlinear system. The numerical results were compared with those obtained by Monte Carlo simulation. A new method was proposed from the comparison of those results. Finally the results obtained by the combined method showed good agreement with those obtained by Monte Carlo simulation.

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5) A path Tracking Control Algorithm for Underwater Mining Vehicles

     Sup Hong, MOERI/KORDI

 In this paper, a path tracking control algorithm is formulated for the use of tracked underwater mining vehicles. The algorithm consists of two parts, the forward velocity control and the heading angle control. The control algorithm is designed based on kinematics, and it considers the track slips and the longitudinal and yaw dynamic models of the tracked vehicle including the soil-track interaction force model. The desired heading angle is obtained by the so-called "Line of Sight" method. The suggested algorithm is tested by numerical simulations using the TRACSIM software developed by MOERO/KORDI, Korea. After the control gains are tuned by a series of numerical simulations, the algorithm is verified on a scale vehicle on air on a soil bin test bed containing the cohesive soil of the Bentonite-water mixture.

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6) Dynamic Response Characteristics of Seismic Isolation Systems for Building
    Structures

     Beom-Soo Kang, Pusan National University

 Isolation is an effective method of reducing effects of seismic events on building structures. Steel-reinforced elastomeric isolator (SREI) is one kind of isolation system which is used extensively, but there are some problems associated with its use, such as cost and weight. Fiber-reinforced elastomeric isolator (FREI) has been developed in an attempt to solve the problems of high cost and heavy weight for SREI. In this study, mechanical properties for the SREI and the FREI are investigated. Systematic dynamic response analyses are performed for three different models such as a fixed based, an SREI based and an FREI based low-story building structures. Two-dimensional and threedimensional dynamic response analysis results for each model are compared in terms of displacement, drift, acceleration and shear force in this study. In the two-dimensional dynamic response analysis, the SREI and the FREI based structures are proven to be the more effective isolation systems against seismic events by comparing with the fixed based one. As a result, the FREI has shown better isolation performances than that of the SREI. Furthermore, to extract the characteristics of the FREI on building structure resisting the seismic effects, two models of three-dimensional framed structure with fixed bases and FREI isolated bases are built, respectively. After the dynamic response analysis of these two structures subjected to bi-directional ground motions, the analyzed results are compared with each other. It is shown that the FREI could effectively absorb the seismic energy, and decreases the destructive effects acting on a building structure due to ground horizontal motions that could occur in an earthquake.

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7) Modulus of Elasticity and Yield Bending Stress of Coating Lubrotec 19985 Produced
    by the Metal Spraying Process (Source: KSME)

    Nabil B. Sada, Tafila Technical University

 Round bars of 13.6 mm diameter made from low alloy steel were sprayed by hard-coating Lubrotec 19985 under the following spraying parameters: the rotation speed varied from 500 to 900 rpm, the feeding speed from 0.1 to 1.0 mm/rev, and the nozzle tip distance from 100 to 200 mm; the sprayed bars were then subjected to bending test. Depending on the thickness of the produced coating, the modulus of elasticity and yield bending stress of the coating were calculated by applying the bending deflection formula and an equivalent cross-sectional area technique, respectively. The results obtained indicated that the thickness, hardness, yield bending stress, and modulus of the elasticity of coating were varied with the variation in spraying parameters. The optimum spraying parameter was a rotation speed of 700 r.p.m, a nozzle tip distance of 200 mm, and a feed rate of 0.1 mm/rev. This optimum parameter produced an acceptable thickness of 1.14 mm, a hardness of 148 HV, a bending stress of 404.9 MPa, and a modulus of elasticity of 91.47 GPa. The results obtained can also help determine the modulus of elasticity and yield bending stress of the various coating materials when a coated round bar is subjected to the bending test.
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8) Orthogonal Design and Analyses of Hydraulic Bridge for Water Servo Valve

     Nie Songlin, Kong Xiangcun, Jia Guotao
     Beijing University of Technology

 A new type of double nozzle-flapper water hydraulic servo bridge model is developed, in which the two tandem fixed dampers are adopted as prepositive dampers. The parameter sensitivity analysis for the hydraulic bridge is carried out. The relationship among the flapper displacement, the spool speed and the pressure at the two ends of the spool is investigated. The orthogonal design is employed to study the influence of the physics factors on the characteristics of the hydraulic bridge, such as the diameter of the nozzle, the diameters of the two tandem fixed dampers, the spool diameter and its sliding speed, the initial clearance between nozzle and flapper. The results reveal that (1) the smaller initial clearance between nozzle and flapper, the lager diameter of spool and the clearance between spool and valve body, the shorter overlap length of spool and valve body, and the higher system pressure, will lead to the better linearity of the control characteristics for the water hydraulic bridge;(2) for hydraulic bridge of water servo valve including the two-stage dampers, the smaller first damper diameter, the larger second damper diameter, the smaller pipe diameter before the nozzle, the larger diameter of spool and the clearance between spool and valve body, will bring the higher dynamic response in the water hydraulic bridge. These research results will lay the theoretical foundation for the development of water hydraulic servo valve.
Key Words: Water hydraulics, Servo valve, Hydraulic bridge, Two-stage dampe, Orthogonal design

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9) Optimal Motion Planning for Differentially Flat Underactuated Mechanical Systems

     He Guangping, Geng Zhiyong
     Peking University, North China University of Technology

 Underactuated mechanical system has less independent inputs than the degrees of freedom (DOF) of the mechanism. The energy efficiency of this class of mechanical systems is an essential problem in practice. On the basis of the sufficient and necessary condition that concludes a single input nonlinear system is differentially flat, it is shown that the flat output of the single input underactuated mechanical system can be obtained by finding a smooth output function such that the relative degree of the system equals to the dimension of the state space. If the flat output of the underactuated system can be solved explicitly, and by constructing a smooth curve with satisfying given boundary conditions in flat output space, an energy efficiency optimization method is proposed for the motion planning of the differentially flat underactuated mechanical systems. The inertia wheel pendulum is used to verify the proposed optimization method, and some numerical simulations show that the presented optimal motion planning method can efficaciously reduce the energy cost for given control tasks.
Key Words: Differential flatness, Underactuated system, Motion planning Optimization
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10) Flow Analysis and Optimization of Port-plate Centrifugal Pump in Electric Motor
     Pump

     Ji Hong, Ding Dali, Wang Zhengrong, Wang Xiuyong, Sun Lei, Hu Qihui
     Lanzhou University of Technology

 Based on the principle of centrifugal pump and the idea of compact design, an electric-motor-pump is developed. It is integrated by an electric motor, a hydraulic vane pump and a port-plate centrifugal pump as a compact hydraulic power unit. The vane pump is as the main pump of the unit. The port-plate centrifugal pump is designed specially for the main pump to improve the suction performance of the electric-motor-pump. The integrated pump demonstrates some attractive advantages such as more compact structure, lower noise, higher efficiency and no external leakage. By computational fluid dynamics (CFD) method, the effects of the main structural parameters of the port-plate centrifugal pump on its outlet pressure and the efficiency are investigated. The design rules for the port-plate centrifugal pump are concluded. This simulation results show that the port-plate centrifugal pump can raise the inlet pressure of the main pump obviously. When the slope angle of the eccentric tube is 45and the bias angle is between 45-60,the maximum power consumption is only about 0.41% of the electric-motor-pump, which also shows that the port-plate centrifugal pump almost do not influences the whole power characteristics of the electric-motor-pump. Its efficiency can be above 95%, and the whole efficiency of the centrifugal pump including the outlet channel is 22%. Power loss occurs due to eddy flow from the outlet of the centrifugal pump to the outlet channel to the main pump.
Key Words: Electric motor pump, Port-plate centrifugal pump, Flow analysis, Structure optimization
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Editor : International Affairs Committee
Published by The Japan Society of Mechanical Engineers
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