Bulletin of JSME
Online ISSN : 1881-1426
Print ISSN : 0021-3764
Volume 17, Issue 111
Displaying 1-10 of 10 articles from this issue
  • Kosuke Nagaya, Hideo Saito
    1974 Volume 17 Issue 111 Pages 1121-1128
    Published: 1974
    Released on J-STAGE: February 15, 2008
    JOURNAL FREE ACCESS
    This paper deals with the problems of flexural wave propagation in an infinite thin elastic plate with circular elastic inclusions. As numerical examples, the problems of plates having two and three circular inclusions with same radius are discussed and influences of incident wave number, radius, separation, and flexural rigidity of the inclusions on the dynamical moment concentration are explored. The results obtained are compared with those of a plate with one inclusion.
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  • Juhachi ODA
    1974 Volume 17 Issue 111 Pages 1129-1134
    Published: 1974
    Released on J-STAGE: February 15, 2008
    JOURNAL FREE ACCESS
    Hertz's theory for an elastic contact problem has been very useful up to now, but many practical problems can not be analysed by it because this theory is established on the many assumptions. In this paper, a method of three-dimensional stress analysis for the contact problem between two arbitrary elastic bodies is described in detail. Particularly, concerning a contact problem, to decide the contact area, the displacement formulars at a contact surface and the contact conditions is very important and a specific technique is here presented using the point-matching method. Moreover, by applying this method, the indentation problem of a reactangular rigid punch on a semi-infinite elastic body is analysed.
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  • Yoshio OHASHI, Masataka TOKUDA, Sadao MIZUNO
    1974 Volume 17 Issue 111 Pages 1135-1142
    Published: 1974
    Released on J-STAGE: February 15, 2008
    JOURNAL FREE ACCESS
    With the appearance of electronic computer, more ditailed theories which can simulate accurately actual phenomena are evolved by taking into account the secondary effect hitherto neglected for avoiding mathematical difficalties in analyzing phenomena. In the plastic deformation, such a theory will be needed also for making precise estimations in the structural analysis and the deformation analysis of plastic work. According to the recent experiments, it has been made clear that the conventional plastic flow theory cannot simulate acculately the plastic deformation of metals under complex loading. In the present paper, as a first step of formulating in detail the plastic features of real materials under complex loading, an experiment is performed on the proportional deformation by applying a combined load of axial force and torsion to a thin-walled tube of mild steel. The stress-strain relation is formulated by using a fundamental tensorial equation from the experimental result.
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  • Hiroshi TAKAHASHI
    1974 Volume 17 Issue 111 Pages 1143-1150
    Published: 1974
    Released on J-STAGE: February 15, 2008
    JOURNAL FREE ACCESS
    In the preceding paper the author derived the expression for stress fields in a plastically deformed polycrystalline aggregate. This formula agrees with the one by K.B.W. model except for the term of interaction stress. The present paper is aimed to know the effect of interaction stress on the macroscopic stress-strain relation. Since the hexagonal crystal has less slip systems than F.C.C. or B.C.C. crystal, the interaction stress effect is expected to be remarkable. So numerical computations are done for a hexagonal metal subjected to a uni-axial tension. The results of this work show the effect of interaction stress is less than 4%.
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  • Masaichiro SEIKA, Satoru SASAKI, Kikuo HOSONO
    1974 Volume 17 Issue 111 Pages 1151-1156
    Published: 1974
    Released on J-STAGE: February 15, 2008
    JOURNAL FREE ACCESS
    The strees-concentration factors in bolt and nut fastening under tension are obtained by the copper electroplating method of strain analysis. In the bolt-thread roots, high stress concentrations occur at two locations, one being at the termination of the threaded portion and the other at the root of the first thread engaged in the nut. The mutual interference of the stress concentrations is examined by varying the distance between the above two locations. Stress concentrations in the bolt-thread roots engaed in the nuts with various shapes are also measured, in which one group of the nuts is different in height and the other group is the stepped nuts with tapered lips. By using a nut of different material from that of the bolt, the effect of the material property of the nut on the peak stress in bolt-thread roots is investigated.
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  • Seiich WASHIO, Tadataka KONISHI, Kenjiro OKAMURA
    1974 Volume 17 Issue 111 Pages 1157-1164
    Published: 1974
    Released on J-STAGE: February 15, 2008
    JOURNAL FREE ACCESS
    Three sorts of wave equations, i.e., (i) wave equations taking into account viscosity and radial velocity, (ii) wave equations assuming Hagen-Foiseuille flow and (iii) water hammer equations, are compared for unsteady flow in uniform lines. Both frequency and transient response experiments are carried out with use of a rotary sinusoidal flow generator and a quick closing valve, respectively. Experimental and numerical results make clear that the wave equations (i) can most accurately predict wave phenomena in hydraulio lines. The wave equations (ii) and (iii) are found to be applicable to sinusoidal excitations for the ranges of α2ω/ν<1.7 and α2ω/ν>4600, respectively. By utilizing "numerical inversion of the Laplase transform", transient responses can be calculated. Sample experimentations show that the procedure is considerably simpler and correcter than existing methods.
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  • Seiichi WASHIO, Tadataka KONISHI, Kenjiro OKAMURA
    1974 Volume 17 Issue 111 Pages 1165-1171
    Published: 1974
    Released on J-STAGE: February 15, 2008
    JOURNAL FREE ACCESS
    The basic equations for unsteady inviscid liquid flow through a linear-tapered tube are solved with the aid of the Laplace transform. Example computations reveal the remarkable effects of taper on wave propagation and the limit of the conventional step line approach to frequency analysis. The procedure to numerically calculate the Laplace-transformed wave equations with S=ζω can predict the frequency characteristics of viscous liquid tapered lines. A frequency response test on a linear-tapered line filled with oil is carried out; good agreement is obtained between experimental and numerical results. Transient waves are also observed in the same line and compared with the results calculated from Zielke's method of characteristics.
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  • Yoshihiro MOCHIMARU, Yukio TOMITA
    1974 Volume 17 Issue 111 Pages 1172-1181
    Published: 1974
    Released on J-STAGE: February 15, 2008
    JOURNAL FREE ACCESS
    Viscoelastic fluids such as polymer solutions show anomalous phenomena that are not observed in purely viscous fluids. In such situations, relating with heat transfer and possibility of using a hot-wireanemometer method in such fluids, the problem of the flow around a circular cylinder is a basic one to be solved. In this report, the problem of the flow field and heat transfer of a two-dimensional steady laminar flow past a cylinder located perpendicular to the uniform flow of a dilute polymer solution is treated analitically. From the results of the analysis the following are obtained : (1) the drag coefficient is larger than that of the solvent, (2) the separation point moves backward compared with that of the solvent because of the visco-elastic behaviour, (3) the heat transfer coefficient is small compared with that of the solvent when Reynolds number is relatively small such as for a flow past a hot-wire anemometer.
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  • Sanae WADA, Hirotsugu HAYASHI, Kenji HAGA
    1974 Volume 17 Issue 111 Pages 1182-1191
    Published: 1974
    Released on J-STAGE: February 15, 2008
    JOURNAL FREE ACCESS
    In the first paper, we already presented the equivalent Raynolds equation for a Bingham solid. In the second paper we applied this theory to a step bearing and carried out an experimental study on it using grease as a lubricant. The core profile and the performances in the step bearing were made clear. In this paper, we apply the equivalent Raynolds equation for a Bingham solid to a journal bearing and obtain theoretically the core profile formed in the bearing and the bearing performances such as the pressure distribution. On the other hand, we observe the core formation and measure the bearing performances, such as the pressure distribution, in the journal bearing lubricated with grease which is a sort of a Bingham solid. The experimental results agree well with the theoretical ones and it is confirmed that the core is formed at the middle of width of inlet side and adheres to the bearing surface when the eccentricity ratio becomes large. As the dimensionless yield stress increases, the range of core and the load capacity increase.
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  • Yosiro ANNO, Kunikazu HAYASHI, Susumu AIUCHI, Tsutomu WATANABE
    1974 Volume 17 Issue 111 Pages 1192-1199
    Published: 1974
    Released on J-STAGE: February 15, 2008
    JOURNAL FREE ACCESS
    Power transmission gears are usually used under fluctuating loads. But in the case of strength design of such gears we cannot get sufficient fatigue data and therefore the effectiveness of Miner's rule on fatigue strength is uncertain. This report deals with a new gear tooth pulsator for program and random fatigue tests and with the results of a test which was carried out under a programmed 16 steps loading. The frequencies of loads are distributed uniformly and the variation of mean load is like a saw tooth wave with positive and negative slopes. Normalized S38C and carburized SCM21 gears were tested. Every test gear had 27 teeth, 4mm module and 8mm width. Under the above condition the effects of loading sequence, changing rate and mean level of program load, gear material and heat treatment were investigated. And, though Hardrath has shown a program loading sequence effect for 7075-T6 aluminium alloy, the author's experiment indicates that its effect is not significant at the 5% level for both S38C and SCM21 gears. By arranging the cumulative damage statistically, it is concluded that Miner's theorem is not valid in the strict sense and further investigation is necessary to conclude whether Miner's rule is applicable to the fatigue design of gears.
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