Transactions of the Japan Society of Mechanical Engineers Series C
Online ISSN : 1884-8354
Print ISSN : 0387-5024
Volume 55, Issue 513
Displaying 1-25 of 25 articles from this issue
  • Yoshio IWATA, Hidenori SATO, Junichi KAWAGUCHI
    1989 Volume 55 Issue 513 Pages 1151-1156
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    The critical speed and the unbalance response of rotors are calculated in consideration of a compliance which presents a dynamic characteristic of supportstructures of the rotors. The substructure synthesis method is applied on the total system modeled by the compliance matrix, which is experimentally identified at the bearing in the support structure, and the discrete mass rotor system in the method of transfer matrix. It is found that there is a possibility of calculating a false critical speed because experimental errors cause an imperfection in the compliance matrix indentified from experiments has been suggested. It is shown that this method is effective for such analyses as the critical speed and the unbalance response.
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  • Zhongwei JIANG, Seiji CHONAN
    1989 Volume 55 Issue 513 Pages 1157-1162
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    This paper is a study of the vibration and stability of a read/ write head disk system subjected to external disturbances. The analytical solution is obtained by applying the model expansion method to the disk governing the equations. In the analysis, the read/write head is modeled as a mass-spring system and the stiffness of the air film in the disk cover is approximated by the stiffness of uniform springs resting under the disk. The axial and the pitching sinusoidal excitations are considered as external disturbances. It is shown that the frequency range where the system has a high response amplitude is affected significantly by the location of the R/W head on the disk. Furthermore it is noted that there is on optimum value of the air film stiffness in disk cover to stabilize the whole disk system over a wide range of operating speeds.
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  • Yutaka KURITA, Hiroshi IWAMOTO
    1989 Volume 55 Issue 513 Pages 1163-1167
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    In this paper, the generation of squeal noise in electromagnetic friction clutches or brakes is explained by the energy which flows from a frictional surface into a disk. If an infinitesimal change of the bending moment caused by a frictional force effects positive work on the disk during a cycle, the energy flows into a disk and squeal is generated. When the thickness of the stationary disk is greater than that of the stationary disk, the waves of the self-excitation. The linear component of the spring characteristic on a contact surface is related to self-excitation. The positive work performed by the linear component is converted into the additional kinetic energy of the increased vibration. The work performed by the nonlinear component is always negative, and it dissipates the kinetic energy of the disk.
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  • Yoshihiro NARITA
    1989 Volume 55 Issue 513 Pages 1168-1172
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    Using the support position as the design variable, the optimal designs of vibtrating beams and plates are determined to maximize the defference between two adjacent natural frequencies. A previously developed gradient technique is used for optimization. Numerical examples include continuous nouniform veams and cantilever square plates. The transfer matrix and Ritz-Langrange multiplier methods are used to yield freqency equations. The iterative solution process for the optimal support is illustrated on frequency maps.
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  • Kiyoshi NAMURA
    1989 Volume 55 Issue 513 Pages 1173-1179
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    In order to calculate the natural frequencies of turbine blades connected loosely by tie-wires, a blade-group model. in which five kinds of springs are inserted between the connecting points of blade and tie- wire, is introduced. A procedure for calculating the natural frequencies of the model is obtained by a transfer matrix method. The effects of each spring constant on the natural frequencies are clarified by applying the calculation procedure on actual turbine blade-group. Then the five spring constant of the blade-group are estimated and discussed according to the comparison of calculated and measured natural frequencies.
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  • Yoshifumi MIYATAKE, Shinji HAYAMA
    1989 Volume 55 Issue 513 Pages 1180-1186
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    A numerical study on the fluid-elastic instability of a row of tubes in a crossflow is presented. The flow between tubes was considered to be a leakage flow and the theory of leakage flow-induced vibraion, recently published, was employed to obtain the steady and unsteady fluid forces acting on the tubes. In spite of a few hypotheses made in the calculations, the results obtained agree with the experimental results which have been published. The method proposed here is one possibile means of calculating the fluid dynamic forces without experimental data.
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  • Masataka TANAKA, Shiro YAZAKI
    1989 Volume 55 Issue 513 Pages 1187-1192
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    There is an increasing need for research and development to reduce the noise from vibrating bodies. In recent years the acoustic intensity (AI) has been attracting attention in this field. The AI is a time-averaged vectoral value of the product of sound pressure and particle velocity, and hence it can be used to visualize an acoustic field and also to identify the noise source. It is reported that the complex AI is more suitable for such purposes. This paper is concerned with development of an AI analysis system by means of the boundary element method.The Helmholtz equation is assumed to hold for the acoustic field under consideration. The corresponding integral equation is used to obtain an integral equation expression of the AI. The resulting expression is discretized by means of the usual boundary element method, from which one can compute the AI at any internal points in the acoustic field. The analysis system is applied to several example problems and the results obtained are discussed, whereby the usefulness of the system developed is demonstrated.
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  • Kenichiro OHMATA, Seiji ISHIZU
    1989 Volume 55 Issue 513 Pages 1193-1198
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    The mechanical snubber is an earthquakeproof device for piping systems under particular circumstances such as high temperature and radioactivity. It has nonlinearities in both load and frequency response. In this report the resisting force characteristics of the snubber and earthquake responses of piping (a simply supported beam) which is supported by the snubber are simulated using Continuous System Simulation Language (CSSL). Digital simulations are carried out for various kinds of physical properties of the snubber. The restraint effect and the maximum resisting force of the snubber during earthquakes are discussed and compared with the case of an oil damper. The earthquake waves used here are E1 Cintro N-S and Akita Harbour N-S(Nihonkai-Chubu earthquake).
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  • Fumiaki TAKAHASHI, Junji TANI
    1989 Volume 55 Issue 513 Pages 1199-1205
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    Theoretical studies on the dynamic stability and active control of a cantilevered beam subjected to the transverse follower force of a fluid jet are presented in this paper. In order to control the response of the beam, the active control force is derived from the bending moment produced by a pair of piezoelectric actuators partially attached to both sides of the beam. The equations of motion and the boundary conditions are first derived from the extended Hamilton's principle and then reduced to a finite degree of freedom system using Galerkin's method. A control law is determined using the optimal regulator theory. Numerical calculations are given displayed for various conditions. It is cantilevered beam subjected to a transverse follower force.
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  • Shiji KONDOH, Chikayoshi YATOMI, Koichi INOUE
    1989 Volume 55 Issue 513 Pages 1206-1214
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    A method for the determination of sensors and actuators positioning and feedback gains for the active vibration control of flexible structures is presented. This method is based on the minimization of the minimum function of a quadratic cost functional in the standard optimal control. The optimal criterion is determined via Riccati equations, and it is minimized with a recursive quadratic programming algorithm. The application of this method to a cantilever beam yields several dislocated sensor and actuator locations, which are locally optimal. An extension to the case when the model filters are used is also examined. In this case, the location of the actuator is found to be more sensitive than that of the sensors. This method is clear for the control efficiency, and has the freedom of varying the weighting matrix.
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  • Seiji CHONAN, Kazuhiko TAKAHASHI
    1989 Volume 55 Issue 513 Pages 1215-1220
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    A theoretical study is presented for the closed-loop displacement control of one-link flexible robot arms with a tip mass. The arm is driven by a DC servomotor located at the vase of the arm. Both rotational and translational controls of the tip displacement are considered. The \governing equation of the arm is solved by applying the method of the Laplace transform with respect to time and the inversion integral is calculated by the numerical inversion method. The displacement control using as the tip information is compared with the control based on the base information feedback. It is found that the control based on the tip information feedback is more effective than the other type of control in sifting the end-point of the arm rapidly to the position commanded/ This holds true both for the rotational and the translational controls of the arm.
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  • Hiroyuki KOJIMA
    1989 Volume 55 Issue 513 Pages 1221-1228
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    In this paper, first, a finite element formulation method for a horizontal flexible robot arm with two links is presented. In the analysis, the kinetic energy of the flexible arm is represented in brief compared with the previous method, and the matrix equation of motion in consideration of the nonlinear forces, such as the Coriolis force, is derived by the finite element method and the variational theorem. Then, the state equation of the mechatoronics system consisting of the flexible arm and the position control system is obtained. Second, the numerical simulations in the case of applying the path control based on the trapezoidal velocity curve are carried out by use of the Wilson-θ method, and the effects of the bending rigidity and the shape of the trapezoidal velocity curve on the dynamic characteristics of the mechatoronics system are demonstrated.
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  • Kazuo YAMAFUJI, Yasushi MlYAKAWA, Takashi KAWAMURA
    1989 Volume 55 Issue 513 Pages 1229-1234
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    This paper describes the methods and experiments on synchronous steering control of a parallel bicycle which has twin wheels on the outside of the parallel driving axes and an inverted-pendulum-type upper structure. The bicycle can be steered by controlling rotation of each wheel driven by each DC servo-motor. In order to drive the vehicle along an arbitrary path, both wheels must be steered and synchronously controlled. Both synchronous control methods are proposed. A gain changing method and a servo-reference method are each applied for the servo-control. The steering and driving control of the vehicle has been attained by using synchronous servo-control methods through here are available for steering and servo-control without losing stability of the vehicle.
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  • Isao SHIMIZU, Mitsuhisa OHTAKE, Shuuichiro ASAKAWA, Shun-ichi KAMEMARU
    1989 Volume 55 Issue 513 Pages 1235-1241
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    In order to simultaneously and instantaneously identify the shape, size, number density and position of particles in a given field, the new Matched Spatial Filter which uses a single exposure hologram was developed. This filter system was theoretically and experimentally investigated to discover it's capabilities in : (1) recognizing the shape of particle's position by the desired shape of particles, (2)searching the posibility and conditions for recognition of the shape of particles independent of the inclination of the particle, (3) clarifying the permitted limit of particles recognized as having the same shape and the same size as the master objects, (4) finding away to distinguish the intensities of the output light signals using auto-correlation and cross-correlation. The experimental results recognized for each particle shape, as found by this filter, are shown in this paper.
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  • Kazuyasu IZAWA, Yasuki NAKAYAWA, Toshio KANEKO, Katsumi AOKI
    1989 Volume 55 Issue 513 Pages 1242-1247
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    This study considers a fifth order theoretical model for an electrohydraulic servo system. The experiments were conducted with various values of load stiffness and inertia of the electrohydraulic servo system to compare with the fifth-order theoretical model. It was found that the theoretical results showed good agreement with the experiments. The load stiffness was found to give little influence on the frequency response at the frequency where the phase lag is less than 180 degrees. The higher stiffness ratio gives more damping to the servo system at the frequency where the phase lag is over 180 degrees: however, its influence on the response becomes less when the stiffness ratio exeeds 2, 6. The higher inertia ratio of the load to the servo drive gives more damping as well as slower speed of response.
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  • Mitsuru ENDO, Keita FURUSAKA
    1989 Volume 55 Issue 513 Pages 1248-1253
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    Transient acoustic radiation from a ring of rectangular cross section impacted by a sphere is investigated. In-plane movement of a ring is considered, and by modelling the ring as a series of contiguous doublet sources and by introducting a time dependent expression for sound radiation from a doublet source, a time history of the total sound pressure at a point is obtained by summation of the sound pressure from each doublet source. The impact sound is due to the forced vibration of the ring, and transient vibration response of the ring impacted by a sphere is analyzed by utilizing the Hertz contact theory. Theoretical results for time dependent sound radiation almost agree with those of experiments when the width of the ring cross section is moderately small.
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  • Koichiro ISHIHARA, Hisakazu KAWASHIMA
    1989 Volume 55 Issue 513 Pages 1254-1258
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    In order to develop a new high-performance wheel with high fatigue strength and light weight, a rigorous quantitative method for evaluating the induced stress of the wheel is necessary. In this study, a stress evaluation technique with three-dimensional finite element method is developed for an automotive steel road wheel during radial load fatigue test. The method of the determination of the load distribution loaded on the rim is proposed, by referring the stress measure with strain gage on the rim. According to the present method, the calculated results with a half model simulates well the actual stress distribution. The variation of the stress amplitude during a rotation of the wheel is obtained from the calculation, and the characteristic stress variation of the wheel, for example the three stress cycles at the rim per rotation, becomes clear. Also, the effect of the basic design parameters such as disc hat radius and rim thickness on the stress amplitude numerically.
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  • Hiromu HASHIMOTO, Sanae WADA, Masayoshi SUMITOMO
    1989 Volume 55 Issue 513 Pages 1259-1264
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    In this second paper, the effects of fluid inertia on the dynamic behavior of an imbalanced rigid rotor supported by the turbulent journal bearings are investigated theoretically and experimentally. Utilizing the expressions for the dynamic oil film force components considering the combined effects of turbulence and fluid inertia forces, the nonlinear equations of motion for the rotor are solved by the inproved Euler's method ahead of time. The journal center trajectories with imbalanced eccentricity ratios ε=0, 0.1 and 0.2 are examined theoretically for Reynolds numbers of Re=2750, 4580 and 5500, and the theoretical results are compared with the experimental results. It is found that the fluid inertia improves the stability of the imbalanced rigid rotor under certain operating conditions.
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  • Shigeo YANABE, Yoshikatsu NAGAYAMA, Akira OKADA, Nobuo YAMAGISH
    1989 Volume 55 Issue 513 Pages 1265-1270
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    New methods for both calculation and measurement of share loads in a star-type epicyclic gear train are proposed. The gear system is modelled as pulleys and connecting springs, and a new set of equations concerning transmission forces between engaging teeth and gear rotational angles is derived, considering the equilibrium of forces and moments. The equations are theoretically solved for some simple cases, and influences of gear position errors and various spring stiffnesses on the share loads are investigated. Further more, a new method for measuring both magnitude and position of a load acting on a planet shaft is proposed. Here, two strain gauges are used to detect bending strains at two different axial positions in a plane of planet shaft.
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  • Hisakazu KAWASHIMA
    1989 Volume 55 Issue 513 Pages 1271-1274
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    In order to clarify the sealing performance of seal-ring connections for API buttress thread casing, the effect of gasket compressibility on the leakage pressure was investigated with a newly designed fundamental leakage test apparatus. The height compressibility HR and area compressibility AR of the gasket were proposed as the sealing performance factors, because the gasket is plastically deformed by the thread and filled in the groove. As the HR and ARbecame larger, the sealing performance was increased by the higher pressure on the contact surface between the thread and the gasket. It is considered that the dimensions of API standard are determined to keep high sealing performance in consideration of tolerance.
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  • Yuichi MISAWA, Yasuo SATO
    1989 Volume 55 Issue 513 Pages 1275-1279
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    The fracture of brittle materials under tensile stress is utilized to cut glass plate. In this proposed new technique, tensile stress is induced at a longitudinal section by the frictional force occurring at the surfaces of the glass plate under uniaxial compression. Then the glass plate is cut along the notches of desired shapes on its one surface. The characteristics of the cutting method are; (1) Cutting can be carried out without dust, and the cutting sections are smooth. (2) The glass plate can be divided into many equal parts and cut simultaneously in square and triangular shapes during one compression. (3) Glass plate can be easily cut along various shapes such as a curve, a circle and a polygon.
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  • Sadamasa AMMI
    1989 Volume 55 Issue 513 Pages 1280-1284
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    Tool wear interferes with the precision cutting of plastics. There is a particular shape of a round arc of tool wear in the cutting of PVC resin. In this paper, the cause of tool wear in the cutting of PVC resin is investigated. The following results are obtained. 1)Hard particles are contained in PVC resin as additives. These particles scratch the tool face. 2) Tool wear increases with an increase in hard particles. 3) At high temperatures, degradation of PVC resin and reaction products are generated on the tool face, and tool wear increases quickly. 4) The round arc of the cutting edge by tool wear has a close affinity with symmetric stresses distributed on the tool face and the low elastic modulus of PVC resin.
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  • Tadao KAGIWADA, Tadahiko KANAUCHI, Masato TAKAHASHI
    1989 Volume 55 Issue 513 Pages 1285-1288
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    The machining of a nonrevolving solid has been carried out by means of a copying lathe. However, this method is limited to simple forms and low efficiency due to limitations in the ability to follow the stylus movements on the model. To improve efficiency and diversity of non revolution machining, a lathe incorporating an electro-hydroulic servo system for positioning the cutting tool in phase with the rotation of the workpiece has been developed. However, this system is very expensive. In the present investigation, an automatic programming system to machine a nonrevolving solid using regular NC lathe and NC language without other adoptations was developed. This system uses the nonfixed screw cycle to machine a nonrevolving solid. A wide variety of outlines can theoretically be machined with this system, but more work is necessary to develop the practical potential.
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  • Tamotsu NAKAMURA, Hideyuki KINPARA
    1989 Volume 55 Issue 513 Pages 1289-1295
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
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    An extrusion-type friction test has been carried out to examine the critical conditions for seizure initiation at various temperatures using a commercially pure aluminium as a work metal and paraffinic mineral oils as a lubricant. As the test temperature increased or the lower the lubricant viscosity decreased, the critical punch stroke for seizure initiation decreased. The oil film thickness trapped in the micro-pools on the tool-work interface was reduced with an increase in the temperature or a decrease in the viscosity grade of lubricant. As a result, it has been clarified that the critical oil film thicknesses for seizure initiation were approximately constant ; 0.20.25μm.
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  • Misumi OSAWA
    1989 Volume 55 Issue 513 Pages 1296-1299
    Published: May 25, 1989
    Released on J-STAGE: February 21, 2008
    JOURNAL FREE ACCESS
    The chain block is the most compact hoist. However, it has the disadvantage of the use of a heavy chain, non uniform velocity, and difficult prediction of breakage compared to the wire hoist. On the other hand, the typical wire hoist with a drum uses needless long space, moreover, some one produces the movement of the load along the direction of the drum axis through the length of the drum by asymmetrical reeving. The apparatus shown here can decrease the tension of the wire caused by the load to zero by means of several springs and links set in the inside of a sheave during one rotation. This idea is referred to in the german literature. The literature doesn't include, however, the deliberate design and an actual product. Furthermore, this hoist is not of a small size upon construction. The drumless hoist shown here is designed and manufactured for a 100 kg load and results prove is to be successful.
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