In this paper lateral fluid pressure and combined loads of lateral fluid pressure and tension are applied on coated and naked graphite cylinders, and naked cast iron cylinder to study the size effect and the effect of pressure fluid on the bursting of brittle materials, and the following conclusions are obtained ; (1) On coated and naked graphite cylinders there is no size effect under lateral fluid pressure. (2) On naked cast iron cylinder there is size effect, and its bursting strength is different depending the kinds of pressure fluids under lateral fluid pressure. (3) Under combined loads of lateral fluid pressure and tension the bursting strengths of naked cast iron cylinders are different depending on the kinds of pressure fluids as in the case of lateral fluid pressure.

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The problems of elastic buckling and flexural vibration of annular plates under axisymmetric in-plane forces have been analyzed by the Galerkin method. By adopting natural vibration modes of an annular plate without an in-plane force as admissible functions, these problems have been dealt with under various combinations of boundary conditions at the outer and inner edges. Two cases, one the case with uniform in-plane forces along the inner and/or outer edges and the other with steady state thermal stress caused by the temperature difference between inner and outer edges, have been analyzed as examples of axisymmetric in-plane force distributions. The relation of the buckling load parameter with the hole size and the relation of the natural frequency parameters with the magnitude of the in-plane force have been evaluated. It has been found that there is possibility of buckling even in the case of tensile in-plane force or cooling, when the distributed in-plane stress has compressive components.

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Torsional tests of aluminium pipe specimens were carried out to obtain reliable data on Bauschinger curves at large strain. The experimental results revealed some features of Bauschinger curves, which suggest an interpretation that Bauschinger effect is a kind of back lash phenomenon.

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Bi-axial strain accumulations in both axial and circumferential directions are observed in the mechanical ratcheting tests conducted by subjecting thin-walled tubular specimens to combined steady internal pressure and cyclic axial loading. The direction and magnitude of ratcheting strain are examined, as functions of maximum stress, stress ratio, steady stress and number of cycles. The strain accumulated in the direction of steady stress increases with an increasing steady stress. The direction of ratcheting strain accumulation is independent of the maximum stress value and number of cycles. At a given maximum effective stress, a stress ratio and a number of cycles, the magnitude of strain accumulated in a bi-axial stress condition is nearly equal to the ratcheting strain in a uni-axial stress condition.

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Flow around a flat delta wing is investigated in order to establish a technique of visualization of three-dimensional flow by smoke wire method, considering application to the study of steady and non-steady responses of single and cascades of delta wings. It is found that the structure of the leading-edge vortices, in particular reference to the breakdown of the vortex core over the wing surface as well as the structure of the free vortex zone can be investigated in detail by choosig proper combinations of relative attitudes and locations between the wing and the smoke wire, and taking photographs from three perpendicular directions.

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An entirely new solution for a compressible potential flow past a given body of revolution at zero incidence is predicted. A complex velocity for the flow is solved exactly through a complex integral equation with use of pseudo-analytic function theories in just the same way as in two-dimensional cases given by the authors. Owing to nonlinearity and the existence and uniqueness of the solution successive iteration is introduced. The present method has a wide range of applicabilities to flow fields such as those on meridional through flows in three-dimensional cases and so on. Moreover, for inverse problems only a few supplemental arguments may be needed. Numerical illustrations of our method, which fully depends on correspondence between two-dimensional incompressible flows and those in the present case, are given for incompressible and for high sub-sonic flows past ellipsoids. Obtained results show a good agreement with experimental values.

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The flow of interactive vortex shedding behind a pair of flat plates arranged side by side to the approaching flow is numerically examined using the discrete vortex method. The calculated results for the plate arrangements of S/B=2.06, 1.1 and 0.5, where S is the space between two plates and B is the plate width, are compared with those of flow measurements in a wind tunnel and a water tank. The following characteristics are known. For S/B=2.06, the in-phase vortex shedding from the outer edges of both plates is more stable than the out-of-phase vortex shedding. For S/B=1.1, the flow through the space between two plates is biased and it switches quickly from one side to the other. For S/B=0.5, the switching of the biased flow does not appear.

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This experimental study concerns falling water films on a vertical cylinder to which a ring with a squared cross section of 1.5 mm×1.5 mm is attached. Film flows near the ring were observed while varying the longitudinal distance to the ring from the water distributor outlet from x₀=100 to 1100 mm and with the film Reynolds number from Re=50 to 800. The flow configuration was remarkably changed with x₀ and Re, and they were classified into several groups. Using the needle contact method, longitudinal distributions of film thicknesses were measured near the ring for two typical ring positions. When the ring was at x₀=100 mm in the non-equilibrium flow region with very weak waves, the waves were amplified downstream of the ring and the flow attained an equilibrium not far from the ring. When the ring was at x₀=500 mm, in the equilibrium flow with disturbance waves, the film flow disturbed by the ring seemed to be restored to the level of the upstream one.

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Experimental and theoretical analyses for turbulent boundary layers with and without adverse pressure gradient and suction through a porous flat plate are described in this paper. From an experimental investigation of velocity profile, turbulent energy, Reynolds shear stress, space-time correlation and energy spectra of these boundary layers, the influences of adverse pressure gradient and suction on the characteristics of turbulent boundary layer are discussed. Moreover, experimental data are compared with the results of numerical calculations on the assumptions of zero-, one- and two-equation models. And the applicabilities of these models to the turbulent boundary layer with suction are discussed.

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Some flow visualization experiments and measurements of surface pressure, Strouhal number, etc. around a finite circular cylinder on a flat plate have been performed in order to study the effect of a three-dimensional flow. The slenderness parameter of the cylinder is in a range of l/d=1∼8, where the slenderness parameter influences remarkably the flow behavior. From an analysis of mean and periodical motion in the near-wake flow, the following results are obtained. (1) The separation velocity at the side wall is lower than that of a two-dimensional cylinder, and this decreases the drag coefficients. (2) A pair of trailing vortices exist right below the free-end. (3) Down-wash flow and the trailing vortex near the free-end dominate the behavior of Karman vortex shedding. Finally, based on these results, the flow models around the finite height cylinder are presented.

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The loss coefficients and the power-loss coefficients for a smooth symmetrical 90° wye with diameter ratio of unity were determined experimentally for each of all configurations of flow through the wye. Empirical equations for loss coefficients and those for power-loss coefficients were presented for each configuration of flow. The experiments were also carried out for a screwed symmetrical 90° wye which was manufactured according to the specification of the Japanese Industrial Standards. It was shown that the loss coefficients and the power-Ioss coefficients are markedly different from those for the smooth symmetrical 90° wye, and that they arc much affected by the axial length of the internal threads exposed to the flowing fluid. The loss coefficients for dead end wyes, in which the dead end was formed by closing the valve in the downstream, were also given.

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Gas-solid two phase flow in sudden expansion of a vertical downward flow is experimentally examined by using different expansion ratios and different solid particles. The result shows that additional expansion loss takes a negative value when the flux Richardson number exceeds 0.0015 as in horizontal pipes under the condition that the velocity of solid particles is larger than that of air.

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The effects of a change in the breadth of a centrifugal impeller on unsteady torque are determined on the assumption of a quasi-three-dimensional flow. Small sinusoidal fluctuations of rotational velocity and/or flow rate are considered. The unsteady :torque is divided into three components : quasi-steady, apparent mass and wake. Numerical results show that the wake component is usually smaller than the other components. Apparent mass coefficients for the two disturbances are given for quasi-three-dimensional impellers. It is found that the outer to inner breadth ratio has little effect on the apparent mass coefficient for flow rate fluctuation but the coefficient for rotational fluctuation is larger for Smaller outer to inner breadth ratio impellers.

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The trajectory of a spherical particle settling freely in a circular cylindrical vessel is numerically analyzed to investigate the settling characteristics in a circular settling tank. Flow field used for calculation is a laminar one with recirculation in the circular vessel. The particles suspended in influent water almost settle while they traverse radially along the bottom wall, and some of the particles which enter a region where the vertical component of fluid flow is greater than the overflow rate travel recirculatingly or flow out, when the settling velocity of the particle in a still water is equal to the overflow Fate. From the numerical results, it is noted that in a practical settling tank, the settling process is similar to that of an ideal plain settling basin, and the settling efficiency is strongly influenced by the diameter ratio of the tank to the feedwell.

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First, the frictional force between a capsule wheel and the wall was measured by applying an equipment in which the load and revolutions of the wheel were changeable. Based on the measured values, an empirical expression of the friction term which is included in the equation of capsule motion was obtained. Second, combining a micro-computer for automatic data processing, a measuring system was developed on the transport pipeline, which was built by authors. The effects of various factors such as the diameter and mass of the capsule on the capsule motion were experimentally clarified in the transport pipeline. It has been found that the fluid drag coefficient of a moving capsule is larger than that of the corresponding stationary capsule by 20%.

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This paper presents characteristics of discharge pulsating pressure generated by an external gear pump. Based on the theoretical and experimental examinations, it is pointed out first that the former mathematical model for flow ripple is insufficient in the case of high working pressure or low pump speed. It is found experimentally that a large amount of leakage through relief grooves takes place intermittently in the vicinity of the central position of trapping. This leakage affects dominantly the fluctuation of a discharge flow (flow ripple), especially its higher harmonic components. The calculated values of discharge pressure pulsations based on the presentmathematical model for flow ripple taking the leakage mentioned above into consideration agree well up to about tenth harmonic with the experimental values.

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The characteristics of turbulent flow and mass transfer in divergent channels of rectangular cross-section were experinlentally investigated and the typical effects of main flow and the secondary flow on mass transfer were discussed. Sherwood number S_hx, could be suitably expressed by Reynolds number R_ex, and acceleration parameter K. Sherwood numbers S_hx, in the entrance region of mass concentration were proportional to R_ex, ^0.83 for every diver-gent angle in the present experiment. The velocity profiles in the upper region were recognized as a composite structure consisting of those for the inner and outer layers. but it was difficult to predict the velocity profiles in the lower region with the plane jet profile.

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By means of X-ray Beam Scanning Method, void distributions in horizontal pipes during blowdown were measured for various conditions. Two types of X-ray void fraction meters were used; One was scanning upward and downward across the pipes, and the other was highspeed scanning type using a rotating disc. Highspeed scanning type had a void distribution color display system that made it easy to recognize even a slug flow. The data were plotted on the flow regime map and compared with available data. For high mass flux. the flow pattern became annular and was weakly dependent on pressure. For low mass flux, the flow pattern became stratified due to gravity.

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The purpose of this paper is to clarify transient characteristics, effects of back pressure and ambient density of spray atomization and droplet size distrubution in the diesel spray. In the experiment, the diesel spray injected into a stagnant ambient atmosphere under high pressure is observed by means of taking photographs with photographing time, back pressure and ambient density changed. The result confirms that uniformity and mean diameter of the total distribution change with time. And it is proved experimentally how the efficiency of droplet production from spray changes with time. As back pressure increases, Sauter mean diameter increases because of a decrease in spray velocity. Further, its change is expressed in equations as a function of back pressure and ambient density. Transient changes in Sauter mean diameter and the uniformity are written in experimental equations as a function of back pressure.

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A method is presented to analyze the vibration of a complex mechanical structure by using the natural modes of its components. The structure is divided into some components. The natural modes of each component in the condition of its interface region fixed are calculated by the finite element method. The displacement of the total structure is represented with those natural modes. The equation of motion of the total structure is transformed into the one on a generalized coordinate. The response of the forced vibration is analyzed with these natural modes on the generalized coordinate by using the technique of the modal analysis. In the present report, the way of analysis of the forced vibration by the authors' proposed method is explained. And as an example of application of this method, the vibration of a continuous centrifuge is analyzed by the method. The calculated results of the machine are compared with the experimental ones.

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An estimation method of the fluctuation and position of a vibratory input to a mechanical structure is presented in this study. First, the condition of the invertibility and the stability of an inverse system are made clear. Second, by using the models of a tvo-degree-of-freedom system and a rigid bar supported elastically, it is demonstrated how easily the inverse system can be constructed by applying the inverse system theory if the system as an object is a lumped and minimun phase system. Furthermore, an inverse system for the elastic beam which is modelled as a nonminimum phase system is presented. In the method, the vibratory input can be estimated by obtaining as mar outputs as the truncation number of modes and position of input is determined by use of a ratio between mode functions. And in the case that there exists a detection noise a method of determining the allocation of measuring positions is presented.

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Axisymmetric forced oscillations of a shallow spherical shell subjected to harmonic excitation are investigated. Based on modal equations derived from the von Karman dynamic equations, a theoretical analysis is conducted of the harmonic oscillation as well as the subharmonic oscillation of order 1/2. The theoretical analysis reveals that in certain cases the response curve of the harmonic oscillation is of soft spring type, that the subharmonic oscillation of order 1/2 can occur, and that the characters of the subharmonic oscillation are greatly influenced by internal resonance. An experimental analysis is also conducted with use of a shallow spherical steel shell. The experimental analysis confirms the validity of the theoretical analysis.

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Much valuable research has been done on the phenomenon of hunting. However very little research make full allowance for nonlinear factors such as the clearances in wheelset suspension and in truck yaw restraining elements. (1) We have set up dynamic models of four axle vehicles with two-axle bogies that make allowance for the above mentioned clearances and some other nonlinear elements. (2) Simulation for some numerical examples was made by varying values of wheel-rail adhesion coefficient and values of above mentioned clearances. Simulation results coincided with actual tendencies, thus verifying the effectiveness of simulation based on this type of model.

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This paper considers radial truck configurations and improvement in the stability and curving performance of a truck It is shown that all possible inner-truck suspensions are characterized by four independent stiffnesses and two geometric parameters. Also all possible connections between a truck frame and a wheelset in it are characterized by one geometric and two independent stiffness parameters. By use of the linear approach to dynamic stability and curve negotiation, the performance of a truck with an anti-yaw damper and connections between a truck frame and a wheelset is calculated.

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Third-rail type current collecting devices are being adopted in some subway cars and monorail cars because of high strength and long service life of the contact wire. However, in some monorail cars, short service life of collector shoes has been a problem, and prevention of falling of wearing powder and sparks, as well as reduction of noise has also been a problem. Thus, these basic problems with current collectors i. e., service life, noise, contact loss ratio etc. were studied. Consequently a new type current collector and a collector shoe material have been developed. This newly developed device can realize about 5 dB reduction in noise level as compared with the previous device.

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In this paper, the performance characteristics of elliptical journal bearings in turbulent flow regime are studied theoretically and experimentally. Solving the turbulent lubrication equation by the semi-analytical finite element method, the static and dynamic characteristics such as the Sommerfeld number, the locus of shaft center, the friction coefficient and the whirl onset speed are obtained for various mean Reynolds' numbers and ellipticity ratios, and the results are compared with the experimental ones. It is found that the turbulence affects significantly the static and dynamic characteristics of such bearings and the stability limits of the bearings become larger with an increase of ellipticity ratio.

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This paper presents a study on the effects of addendum modification on root stresses and bending fatigue strength of helical gears. Theoretical analysis was made regarding the effect of addendum modification on the root stresses. Bending fatigue tests were performed on helical gears with various amounts of addendum modification, using a bending fatigue testing machine of hydraulic type. In the case of helical gears, the increase in bending strength due to positive addendum modification is much smaller than that in the case of spur gears and the effect of addendum modification on bending strength differs depending on the addendum modification coefficient of mating gear. Furthermore the validity of ISO and JSME formulas for bending strength of profile shifted gears was examined on the basis of the experimental results.

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This paper presents a study on the effects of key on bending fatigue breakage of a thin-rimmed spur gear. A stress analysis by means of the two-dimensional finite element method (FEM) and a bending fatigue test for thin-rimmed spur gear with keyway were carried out. The effects of rim thickness and the position of keyway on the root stresses, the stresses of keyway and the position of the fatigue crack initiation were investigated. The position of keyway should be taken such that the center line of keyway coincides with that of gear tooth. It might be sufficient to take 3m (m : module) as rim thickness. Press-fitting a gear on a shaft yields a large tensile stress at the fillets of keyway.

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The flash temperature generated at the meshing faces of copper-plated gears was calculated by the flash temperature equation of composite solids in which the thermal properties in the surface layer are different from those in the core of the solids. Further, using a power-circulating gear machine, the scoring resistance of copper-plated gears was examined. From the calculated and the experimental results it is shown that the scoring resistance of copper-plated gears is considerably high. The scoring resistance of the gear pair consisting of an unplated pinion and a copper-plated wheel is larger than that of the one consisting of a plated pinion and an unplated wheel. The gear noise of copper-plated pinion and wheel is about 7 dB lower than that of unplated pinion and wheel, and the copper-plated layer on the meshing faces can be considered to play an important role in decreasing the gear noise.

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Crossed helical gears have been used for a long time, but their usage is limited only to the transmitting of light load. because of a great deal of wear caused at their point of contact and high sliding velocity. Because their usage is limited, the load carrying characteristics of the crossed helical gears are not studied enough. Under these situations it is very important to carry out experiments about the above mentioned load carrying characteristics and to study the experimental results. In order to increases the load carrying capacity of these gears many surface treatments and lubricating oils were used in our tests. The limiting loads for scoring of the crossed helical gears expressed with Hertzian pressure were compared with those of the FZG spur gear tests and of the roller tests.

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This paper discusses on a distribution of the contact stresses when a circular flange is fastened with tap bolts to a base which is large enough comparing with the circular flange. In an analysis, by replacing the circular flange and the base with two finite cylinders. the distribution of the contact stresses is analyzed as a two body contact problem by three dimensional theory of elasticity. In order to know the distribution of the contact stresses near a bolt hole, the contact proble between two hollow cylinders is analyzed using three dimensional theory of elasticity. In addition, the force ratio, which is the ratio of an increment of a bolt axial force to an applied load, is analyzed. More-over, by taking a bending moment caused in bolts into consideration. the maximum stress is analyzed. For verification experiments are carried out and analytical results are in a fairly good agreement with experimental ones.

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