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Yoshimi ITO
1988 Volume 54 Issue 500 Pages
807-815
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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Kimihiko YASUDA, Shozo KAWAMURA, Koutaro WATANABE
1988 Volume 54 Issue 500 Pages
816-824
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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In a previous paper the authors presented a new technique of identifying a nonlinear multi-degree-of-freedom system. In this paper, the applicability of the presented technique under noisy measurements is discussed using examples. It is shown that a good accuracy of identification can be obtained (1) when the excitation frequencies are chosen appropriately, (2) when two or three terms are retained in the Fourier series expansion, and (3) when the magnitudes of the excitation are given appropriately.
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Katsuhiko YAMADA, Kazuo TSUCHIYA
1988 Volume 54 Issue 500 Pages
825-833
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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Equations of motion of a flexible multibody system are treated in this paper. First, the equations of motion of each body are derived using vibration modes of the body. Unknown hinge constraint forces are regarded as external forces in the equations. Then, kinematic constraint equations of each hinge are obtained, where the residual stiffness of truncated modes is considered. The constraint equations without residual stiffness are also obtained by ignoring the residual stiffness. These constraint equations are used to obtain the hinge constraint forces, and thus, the equations of motion of the system can be solved. When the residual stiffness is considered, the hinge constraint forces are easily obtained from the constraint conditions, and the accuracy of the system model is improved because the influences of the truncated modes are included. The effects of the residual stiffness are verified by a simple 2-beam model.
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Takuzo IWATSUBO, Takao OHI
1988 Volume 54 Issue 500 Pages
834-841
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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There are many papers dealing with the vibrations of a geared-rotor system. Recently, the dynamic behavior of the geared system has been analyzed. However many of them have studied only the dynamic load on the tooth, or have left the tooth rigidity and the flexural rigidity of the shaft out of consideration. But it is important to consider the effect of coupled lateral and torsional vibration. This study presents the experimental results of the vibrations and the noise of the geared-rotor system with a journal bearing. The following results are obtained. In response to angular acceleration in the gears, there are some resonant peaks caused by the excitation relating to the mesh frequency. and some other resonances appear in response to the lateral vibration and the torsional vibration caused by the mesh frequency excitation. The gear noise is concerned mainly with the vibration of the tooth.
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Atsuo SUEOKA, Takashi AYABE, Mitsunori KAWAKAMl, Hideyuki TAMURA
1988 Volume 54 Issue 500 Pages
842-850
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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This paper presents an approximate model with an infinite number of vehicles in which an infinite number of wheels are arranged with a certain periodicity on the top of an infinitely long and straight rail installed on a distributed spring in the vertical direction. This model is very effective for the analysis of the coupled vibrations between railway vehicle wheels and a rail for the case of a great number of wheels. Using the analytical model, the contribution of the rail to the coupled vibrations was examined for each section partitioned by wheels over the length per Shinkansen vehicle. As a result, it became clear that the vibration of the rail between the wheels of a truck is dominant in a frequency region lower than 2kHZ, and that of rail near a coupler between vehicles is also important in a frequency region higher than 1.5kHz.
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Kenji UEKI, Fumio HARA
1988 Volume 54 Issue 500 Pages
851-857
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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It is reported that a magnetic disk is vibrationally excited under high speed rotation in a fluid, but few studies have been carried out to clarify the mechanisms causing the unstable vibrations. This paper deals with the characteristics of unstable vibrations induced in a single flexible disk rotating in a confined fluid. Experiments showed the following major results: (1) the disk undergoes an in-phase unstable vibration with a moderate amplitude at the rotation speed of the first instability, and then another out-of-phase unstable vibration with large amplitude at the rotation speed higher than the first one when the rotation speed is increased. (2) There are three hysterisises in the vibration magnitude characteristics with respect to the rotation speed. (3) A large pressure fluctuation appears for the second unstable vibration, which has a phase lag to the vibration displacement of the disk. (4) The disk is half buckled when the vibrational instability occurs.
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Ichiro Hagiwara, Masamitu Yaoi
1988 Volume 54 Issue 500 Pages
858-865
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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Noise generated by engine block vibration has a great influence on engine noise. Therefore, in our first report we investigated the basis of BEM and presented the sensitivity coefficients of the generated noise at measurement points in relation to design variables. In addition, we developed techniques for qualitatively reducing generated noise using this sensitivity analysis. In this report, the sensitivity coefficients of acoustic power in relation to design variables is presented. We further developed techniques for quantitatively reducing generated noise at the measurement points using a combination of sensitivity and optimum analyses. In addition, we also developed techniques for reducing acoustic power quantitativly using this combined analysis.
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Noritoshi NAKAGAWA, Takuzo IWATSUBO, Shinsuke SAHARA
1988 Volume 54 Issue 500 Pages
866-873
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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The formative mechanism and characteristics of the initial transient sound field caused by the transient vibration response of a clamped circular plate are analyzed to the external point force with a squared half-period sine-wave time history. The dynamic response of circular plate and acoustic response are expressed by using both the dimensionless parameter β introduced by the group velocity of principal component and the dimensionless parameter γ introduced by the sound speed in the acoustic medium. From the analysis the following results were obtained. First, the propagation behavior of kinetic energy can be seen by observing the period of 0-2/β. Second, dimensionless sound energy radiation pattern from the plate relies on rather βthan γ. Third, the maximum instantaneous sound intensity on the axis of symmetry is formed by sound radiated from principal modal bending waves which are reflected at the edge of the circular plate.
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Seiji CHONAN
1988 Volume 54 Issue 500 Pages
874-881
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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This paper is concerned with the problem of the sound transmission loss through a three-layered cylindrical shell subjected to inner plane acoustic waves. Each layer of the shell is treated as a single shell, and the whole shell equations are connected together through the assumption that the displacements and the tractions are continuous at the shell interfaces. sound transmission loss TL is calculated for various combinations of the facings and the core with different physical properties. Further, the acoustic design method of the layered shell with high transmission loss is presented and illustrated with some examples.
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Takuzo IWATSUBO, Yoshihisa MISAWA
1988 Volume 54 Issue 500 Pages
882-889
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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This paper deals with the evaluation of cumulative damage of the shaft of the vertical pump subjected to earthquake excitation. first, the friction force between the wearing the impeller due to the breaking of water film is measured by experimental apparatus. Second, the fluid force between the impeller and the wearing is derived from Bernoulli's equation and is represented by a nonlinear equation containing added mass, added damping and added spring terms. Third, the equation of motion is derived and is integrated by Newmark's β method. fourth, the torsional moment due to impact is calculated. Then, the maximum shear stress of the shaft is counted by both rain flow method and hysteresis loop method in order to estimate the cumulative damage, and the probability of the failure of the shaft is evaluated.
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Satoshi ODA, Takao KOIDE, Kouitsu MIYACHIKA, Hideji YOSHIOKA
1988 Volume 54 Issue 500 Pages
890-896
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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A method for calculating the tooth profile of a WN (SymMarC) gear generated with a hob was indicated and a mapping function for the profile approximated to the tooth profile of a WN gear was obtained. The true root stresses of a WN gear calculated by 2-dimensional elasticity theory and mapping function were compared with those obtained by the 2-dimensional finite element method (FEM), and the validity of the root stress analysis of a WN gear by the theory of elasticity was confirmed, and the position of the critical section on the tensile and compressive sides of a WN gear was indicated. The stress concentration factors at the position of the critical section were calculated under different loading conditions. A practical formula for true root stress of a WN gear was derived on the basis of these calculated results.
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Norihisa ARAI, Tetuya TOYAO, Yuuji ASAOKA, Hiroya FUKUYAMA
1988 Volume 54 Issue 500 Pages
897-903
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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Recently, the reduction of cost in the gear field has become a serious problem and consequently, the force-fitted gear has become the suject of attention. Although some studies on force-fitted spur gears have been presented, there have been very few studies hitherto which deal with force-fitted helical gears. In view of such a situation, the force-fitted helical gear was chosen as the subject of the author's study. That is to say, by using the three-dimensional finite element method, stesses at the root fillet of a gear tooth caused by force-fitting were calculated. Practical formulas of these stresses can be introduced.
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Koichi TAKAHASHI, Norio ITO, Yukitaka TAKAHASHI
1988 Volume 54 Issue 500 Pages
904-912
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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The hypoid gear has had wide-spread use in industrial fields, but there has been no discussion about accurate design methods. for obtaining a satisfactory hypoid tooth form, some kinds o f cutting machines have been made, with individual hypoid design and production system. On the other hand, hypoid gear dimensions cannot be confirmed in the production, and the measuring systems are just their running test with the mating gear. sometimes, plant engineers are quite confused by the hypoid noise trouble. This paper discusses the relationships between the hypoid dimensions and depthwise tooth taper for duplex cutting, and makes it possible to design accurate enough gear dimensions for designing and gear cutting.
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Shigehisa FUKUI, Reizo KANEKO
1988 Volume 54 Issue 500 Pages
913-918
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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The characteristics of surface restriction bearings under an ambient pressure of 10
-1 kPa were experimentally investigated and compared with various numerical results, based on i) the Boltzmann equation, ii) the first-order slip theory and iii) the second-order slip theory. The experimental results agree with the numerical results calculated from the generalized lubrication equation based on the linearized Boltzmann equation.
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Yoshio HARUYAMA, Atsunobu MORI, Haruo MORI, Fusao MIKAMI, Tsuneji KAZA ...
1988 Volume 54 Issue 500 Pages
919-926
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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An analytic solution for the squeeze film flow of an incompressible Nowtonian fluid between circular parallel surfaces is presented. One surface undergoes sinusoidal oscillation toward the other. The solution is obtained in consideration of second order vibration. From a comparison of the conventional approximate solutions with the above one, and from experiment under condition of a large oscillation amplitude, it is concluded that the averaging approach in which the inertia term is averaged out across the film thickness gives fairly good approximations.
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Takuya SUGANAMI, Takahiro MASUDA, Hiromu NARUMIYA, Norio OISHI
1988 Volume 54 Issue 500 Pages
927-934
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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Analytical static and dynamic performances of a seal ring for a shaft seal are presented in dimensionless parameters. The effects of the seal ring load and its direction relative to the rotation stop pin to suppress the whirl under 360° full film and 180° film conditions are discussed. The experimental results on floating characteristics and ring stabilization agree with the analytical predictions.
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Takahisa KATO, Yukio HORI
1988 Volume 54 Issue 500 Pages
935-942
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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This paper presents an application of the method of "Matrix form of Reynolds Equation" [1] to the dynamic problem of the journal bearings. By this method the derivatives of the film forces with respect to eccentricity ratio, attitude angle, and with respect to their time derivatives are obtained by small number of vector calculations after obtaining the static film forces. The calculated stiffnesses and damping coefficients agree well with previous studies [2, 3]. The time required by this calucuculation with HITAC-M682H was only 0.10.3 seconds, which suggests the possibility of real time journal bearing designs without using the data base of the stiffnesses and the damping coefficients.
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Junichi ICHIHARA
1988 Volume 54 Issue 500 Pages
943-951
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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A Spiral Grooved Self-acting Gas Thrust Collar Bearing, which has high wear resistance is investigated. This thrust bearing has a washer made of hard, wear resistive material at its most inner part, and the surface of this washer stands out from the surface of the other part of the bearing, so that contact with the rotor at the start/stop of rotation occurs only on the surface of the washer. This bearing is also designed for take-off and landing at low rotational velocity to prevent wear. Here, thee design method of this bearing is presented. Also measured are the load-floating height characteristics and the floating height-rotation characteristics. These measured results are compared with theoretical predictions.
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Akira IWABUCHI, Tomomi HONDA, Toru SASAKI, Kiyoshi HORI
1988 Volume 54 Issue 500 Pages
952-959
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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In this paper, the fretting wear properties of copper, SUS316L steel, epoxy and polymide were examined at room temperature (293 K) and with liquid nitrogen (77 K). Fretting conditions were a frequency of 8.3 Hz, a peak-to-peak slip amplitude of 100 μm, normal loads of 4, 10, and 20 N and 5×10
4 fretting cycles. Frictional properties against fretting cycles were independent of temperature qualitatively for like-metal combinations. Temperature dependence were observed for metal and polymer combinations, that is, coefficients of friction increased after certain cycles at 293 K and were maintained constant at 77 K. Mean coefficients of friction at 77 K were higher than those at 293 K for like-metal combinations, while they were less than those at 293 K for polymers against metals. Wear volumes at 77 K were less than those at 293 K for all combinations. These properties were affected by the change in mechanical properties of materials, the change in oxidational process and the cooling effect by liquid nitrogen.
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Masataka NAKAGOME, Ichiroh SUZUKI, Kousuke YASUDA, Masao MIZUNO
1988 Volume 54 Issue 500 Pages
960-967
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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One of the important subjects of bolted connections is the study of the compliance of the clamped parts and the load factor. In this report, the equation of the axial load of the bolts is derived on the premise of separation and non-separation, and some experiments are carried out for comparison. The results of this study are concluded as follows: (1) the difference in thickness of the clamped parts scarcely influences the axial load. As the eccentricity of load is increased or the initial clamping force is decreased an extreme increase in axial load occurs more easily. (2) It has been recognized that the safty limit of bolted connections is partly separating limit, but it is recognized that it is extends to the center of the bolt hole. (3) The simplified theoretical equation for compliance of the clamped parts and the load factor is derived, and the axial load can be obtained from it because the calculated values agree with the experimental ones.
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Hiroshi OTA, Kazuki MIZUTANI, Tadao KAWAI
1988 Volume 54 Issue 500 Pages
968-975
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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The effects of the roundness of the cutting edge and the depth of cut on the static and dynamic cutting forces are researched experimentally under the condition with a gradually increasing depth of cut. And the behavior of the chip flow is observed by the use of a high-speed camera. The following findings were obtained: (1) the static cutting force doesn't depend on the cutting condition, i.e., the cutting speed and the feed rate in the rubbing and the rubbing-cutting transition regions; (2) the flow of the chip is unstable in the rubbing-cutting transition region; (3) the amplitude of chatter vibration depends on the time when the tool passes through the rubbing-cutting transition region; and (4) this unstable behavior of the chip flow is one of the causes of the primary chatter vibration.
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Ryozo KITAGAWA, Takeo FUJITA
1988 Volume 54 Issue 500 Pages
976-983
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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End mills of micro alloy, K-grade and M-grade carbide tools are prepared and a carbon steel of S48C is tested in cutting. The cutting temperature is below the recrystalization temperature of the steel. The conclusions obtained in this experiment are as follows: (1) The cutting forces were not influenced by the carbide grade. (2) The cutting temperature of the atomize-cooling method was about 45°C lower than that of the dry method. (3) The K-grade tools showed longer tool lives than those of M-grade is this experiment. (4) It is found that the cutting ability of the end mill was associated with microstructure, mean free path and fracture toughness.
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Yasushi KUROSAKI, Ikuya FUJISHIRO, Yoshiyuki MIYAKE, Yasushi FURUKAWA
1988 Volume 54 Issue 500 Pages
984-990
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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Piercing of a circular hole through glass sheets, difficult by conventional punching or drilling, is investigated by a manufacturing process using the impact compression of a viscoplastic pressure medium. Since the original method previously proposed by the authors is not available for a larger aspect ratio, an improvement on it is attempted. Two techniques are proposed for this purpose: a method based on the delay phenomenon in the elastic response of the specimen and a differential pressurizing method. As the result, both are shown to be useful. The later method is also effective to improve the accuracy of the formed hole.
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Tamotsu NAKAMURA, Kazuyoshi KONDO, Hiroshi SASAHARA, Kazuya NAKAMURA
1988 Volume 54 Issue 500 Pages
991-997
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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Pressure welding tests have been carried out by means of welding the ends of cylindrical specimens of aluminium, copper, mild steel, nickel and stainless steel. The critical conditions for obtaining the bond strength equivalent to the parent strength have been examined with various contact pressure p, surface expansion ratio X and temperature T. Consequently, the critical surface expansion ratio Xs could be reduced with increasing temperature in all the workmetals, and the complete bond strength could be obtained by a relatively small reduction in height of Re=1020% within the range of hot working temperature.
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Yasuhiro TANI, Junichi IKENO, Hisayoshi SATO, Makoto HIYAMIZU
1988 Volume 54 Issue 500 Pages
998-1003
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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As magnetic memory density increases, increased flatness of an Aluminium disk is required. to improve the flatness obtained by diamond turning, a porous sintered nylon was applied to a vacuum chuck. then the retention ability of the sintered nylon was investigated and the following points were clarified. First, it was found that the static friction factor between the chuck and an Aluminium plate was smaller than that of conventional chucks, but that the retention by suction was strong enough to bear the cutting force in turning. Secondly, a desirable surface hardness of the chuck was attained when the pore rate was from 40% to 52%. Thirdly a strong retention was obtained after the surface of the chuck was out.
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SHIGERU UENO
1988 Volume 54 Issue 500 Pages
1004-1008
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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The improvement of machine tool accuracy is the most important for recent highly advanced manufacturing technology. And highly sophisticated design techniques are required to realize ultra-accurate machine tools such as a diamond turning machine. In this study, alumina ceramic is introduced as a material for a machine tool bed to overcome many problems such as thermal deformation and bed rigidity, that are important for accurate machine tool design. A design methodology of light weight machine tool construction is also investigated for realizing easy-to-control thermal behavior and for improving the vibration performance. As a result, a developed diamond cutting machine with a ceramic bed shows good performance, surface roughness, temperature stability and vibration characteristics.
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Yoshihiro SAKAMOTO, Hiroaki FUNABASHI, Kiyoshi OGAWA
1988 Volume 54 Issue 500 Pages
1009-1016
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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In designing planar mechanisms, individual moving links have to be arranged separately on parallel planes, which are called layers in the present paper, to avoid mutual interference during a cycle of motion, and, in addition, the mechanisms have to be constructed in the smallest space possible. In this paper about planar multi-link mechanisms which are constructed with revolute pairs, a systematic synthesis of layer arrangement is discussed with consideration of the mutual interference of moving links. To determine the minimum number of layers required to construct crank mechanisms and profiles of links, relative loci of pairing points and positions of links in the mechanisms are analyzed. Moreover, conditions to avoid mutual interferences of moving links on the same layers are formulated, and a layer-arrangement system is obtained which determines the profiles and layer arrangements of links of planar multi-link mechanisms.
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Shinsuke AKAGI, Kikuo FUJITA
1988 Volume 54 Issue 500 Pages
1017-1025
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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An expert system is developed for engineering design based on the object-oriented knowledge representation concept. The design process is understood as determining the design parameters and their relationships which consist the design model. the design model is represented as a network in the computer system using the object-oriented knowledge representation. The system built with the above concept provides the following abilities: 1) flexible model building and easy modification, 2) effective diagnosis of the design process by using the rule-based knowledge representation, and 3) a hybrid function with numerical computations and graphics as well as AI Techniques by coupling the systems programmed with LISP and FORTRAN languages. The system is suitable for the wide domain of applications with the above various functions. Finally, the system's validity and effectiveness is ascertained by applying it to the basic design of a ship.
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Katsunori INOUE, Etsuji OHMURA, Koichi HARUTA
1988 Volume 54 Issue 500 Pages
1026-1034
Published: April 25, 1988
Released on J-STAGE: February 21, 2008
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The present paper deals with the heat flow and solid-state phase transformations during the laser transformation hardening of hypo-eutectoid steel. A finite-difference computer model was developed to analyze the changes with time of the heat flow, the carbon redistribution in austenite and the subsequent quenching to martensite during laser transformation hardening. The analyzed results were shown in the pseudo-color images on the display. Furthermore, experimental surface transformation hardening was carried out using a square laser beam of uniform energy distribution, and the results were in good agreement with the theoretical results obtained by the computer model. The transformation hardening process can be also simulated for any given hypo-eutectoid steel under any laser irradiation condition. The simulation method proposed in the present paper can be applied to determine theoretically the best combination of the process variables for the laser transformation hardening in advance.
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