Elastic deformation of inhomogeneous materials such as polycrystals under multi-axial stress is investigated. To study deformation behaviour of inhomogeneous materials, the idea of constraint ratio proposed previously is used. Besides constraint ratio defined with strain, constraint ratio defined with stress is introduced and the relation between them is discussed. Constraint ratio is also defined for general multi-axial stress state. Several models of inhomogeneity, e.g., polycrystals and materials with inclusions are introduced and numerical calculation of constraint ratio under biaxial or multi-axial stress is made. It is found that the value of constraint ratio is not much affected by the presence of multi-axial stress if the geometrical configuration of inhomogeneity is symmetric in respective directions, while it is affected by multi-axial stress if the geometrical configuration is not symmetric. The change of Young's modulus under biaxial stress is also discussed.

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A quasi-static testing device for applying the combined loading of tension and torsion to a thin walled tubular specimen was devised. Using this device and the dynamic combined testing device reported in the previous paper, some experiments were performed on annealed commercial pure copper. And some yield conditions and stress-strain curves were obtained at the strain rate of 10^-4 ∼ 10² /s. Consequently the following were obtained. The yield stress of this material didn't agree with Mises' yield condition. And the value of θ = γ^^·_Pσ/ε^^·_Pτ was about 3.4 ∼ 3.9.

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This paper contains an exact solution for the stresses arising in an elastic circular cylinder with a prolate spheroidal cavity under tension. The solution can be reduced to a combination of the solutions, one being regular in the outside of a cavity and the other regular in an infinite circular cylinder, and is deduced with the aid of Dougall's stress functions. Two sets of simple harmonic stress functions are given by expressions referred both to the cylindrical and the prolate spheroidal coordinates. The boundary conditions on the surfaces of the cylinder and of the cavity are satisfied with the aid of the relations between the cylindrical and prolate spheroidal harmonics. Numerical results are given for some different equatorial semiaxes and shape ratios, and the stress distributions in the neighbourhood of the cavity are shown graphically.

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In this paper, an exact analysis of the axisymmetric elastic contacts between smooth circular plates, is made by using the three-dimensional theory of elasticity. Informations on the contact states in this general case are pointed out by the equation itself derived from the conditions of contact. Moreover, this equation is simplified by employing the theory of a thin plate with small deflection and as an example an analytical solution expressing the radius of contact domain is found from this simplified equation for the case of a thin plate concentrically loaded lying on a half-space. Finally, for various cases of two plates under the concentrated loads numerical solutions of the above equations are calculated to find out the effects of the shape, elastic constants, loads of the plates and the approximate methods in analyses on the solution of contact and the results obtained are represented in figures.

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A method is presented for estimating the asymmetry of flexural rigidity which varies along a rotor axis. The rotor is pendulously suspended with a couple of ropes and a pair of natural frequencies on two principal planes are measured. Such experimental results are combined with numerical ones for estimating asymmetry. The procedure is discussed in detail and proved to be useful with a simple asymmetric shaft model. The amount of asymmetry on an actual turbogenerator is also estimated and verified to be a sufficiently wide margine for the limit of unstable vibration.

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The paper describes an attempt to improve the weighing performance in measurement of mass and weight using a mechanical weighing machine. First, the relationship between weighing time and accuracy is clarified analytically on the conventional weighing method. Secondly, a new weighing method, Dynamic Weighing Method, is described in which the quantity to be measured is estimated by using the transient signal from a weighing transducer. As its estimation algorithm, use is proposed of the state estimation algorithm of the Kalman filter or of the truncated second-order filter. Finally, the feasibility of the proposed method is examined through practical experiment carried out with a digital computer, and the result is compared in weighing time and accuracy with the theoretical result by the conventional method. A discussion is also extended to the implementation of the proposed method by a real-time data processor.

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Flows around two tandem circular cylinders in a stream up to the range of much higher Reynolds numbers than the critical one were investigated in a low speed wind tunnel. By making the surface of the upstream circular cylinder rough with two types of surface roughness, the critical Reynolds number of the cylinders was reduced. Drag coefficients and Strouhal numbers of the two tandem circular cylinders were measured and the flow patterns on the cylinders were visualized by the surface oil-flow technique, in the subcritical flow regime, in the supercritical one where there were laminar bubbles followed by turbulent separation and in the transcritical one where purely turbulent separation occurred without laminar bubbles but with an extremely regular vortex shedding behind the cylinders. The flow characteristics of the two tandem circular cylinders were discussed and the effects of Reynolds numbers and the gap spacing between the two cylinders were made clear.

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A visualization study was made on flow separation s around a circular cylinder which was started impulsively from rest in a water tank. The experimental conditions were Re=Ud/v= 250 ∼ 1200, d/h=0.1 ∼ 0.63, where U is the cylinder speed, d the cylinder diameter, v the kinematic viscosity, and h the distance between side walls of the tank. The hydrogen bubble techniques and electrolysis methods were used to observe the behaviour of boundary layers and near wakes. Thickness of the boundary layers and reversed flow and the scale of the vortex formed were measured in course of motion. The measured values of location and time of the reversed flow appearing initially are in good agreement with those predicted by existing theories for flow separation. In the first stage, however, the reversed flow does not lead to an abrupt thickening of the boundary layer or a large scale break away of fluid. To examine these phenomena, the convective transfer of vorticity generated at the cylinder was traced by use of visualization techniques. The detail of vortex formation due to the flow separation was explained in terms of vorticity transfer and velocity field.

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An experimental work is carried out to investigate the hub ratio effects on the magnitudes of the stator secondary flow. A theoretical analysis based on the channel vorticity is made to confirm the experimental results. The outlet angle change due to the secondary motion is significantly affected in the main flow region by a changed hub ratio. This is attributed to the fact that the increase in hub ratio is associated with the approach of two vortices constituting a channel vortex pair, consequently with the enhancement of the induced velocity in that region. The flow rates of the swirling secondary motions are considerably suppressed at a higher hub ratio, while the secondary kinetic energy accounts for an increased fraction of the inlet kinetic energy, and an increased loss is observed particularly in the blade wakes.

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Lift fluctuations of a cambered blade with angle of attack under periodic gusts with ununiform amplitude were studied by using vortex theory under the assumption that the gust amplitude on an airfoil varies linearly as described W (b + ax). Consequently it was clarified that the developed theory is valid by comparing with other results and that the ununiformity of gust amplitude gives strong effects on the fluctuating lift for small reduced frequency but does not for large reduced frequency.

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Water was fed down into vertically supported, two-dimensional, discontinuously diffusing conduits. Reynolds numbers were taken to be low enough to keep flows within laminar regions. The results obtained are as follows. (1) For Reynolds numbers higher than a certain critical value, the Coanda effect occurs even if flows are laminar. (2) When the temperature difference between a reattached wall and water exceeds a certain value, a flow pattern changes into one in which the jet attaches to the opposite wall. (3) In an asymmetrically expanded duct, two different kinds of steady and stable flow patterns can be obtained.

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In this report are discussed the self-excited oscillations due to air slugs in a V-tube connected with two reservoirs. The experimental results and calculated results are summarized as follows : (1) The parameters which control the periods and the amplitudes of self-excited oscillations are the number of air slugs supplied in a unit time and the flow rate of supplied air. (2) The periods of self-excited oscillations are from one to five or six times as large as those of free oscillations without any loss. (3) The waveforms of self-excited oscillations, including the change of the water level in reservoirs, are similar to those of relaxation oscillations.

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In two-phase flows composed of a fluid and solid particles, the kinetic energy of the fluid mixture must include the energy of the perturbed flow caused by the presence of particles. The latter energy is assumed to be roughly proportional to the square of the relative velocity between the two component fluids. The proportionality constant is called the inertia coefficient which is equivalent to the virtual mass. In order to estimate the inertia coefficient, the method of cell model is applied to obtain a formula of the coefficient expressed as a function of the volume fraction of solid phase. The drag coefficient is also calculated.

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The coefficient of internal resistance in dispersive two-phase flow is considered. The method of self-consistent cell model is applied to determine the coefficient as a function of the volume fraction of particle phase. A certain spherical cell is formed around a randomly chosen particle. It is assumed that inside the cell the fluid is Stokesian while outside the fluid is Stokes-Darcian. The solutions in both sides are connected on the cell surface by suitable conditions. The condition of coincidence is considered, which is indispensable to determine the coefficient considered and supplements the boundary conditions. The numerical calculation is carried out and the prediction is reasonable.

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Based on the similarity law of jet pump, a new cavitation parameter σ is proposed which has the similar meaning to Thoma's cavitation parameter in turbo pumps. The σ values are determined theoretically and presented as the function of specific speed n_sj so that we may predict cavitation directly by using it in the designing. Experiments are carried out and σ values are confirmed. Comparing these theoretical values with the data previously reported, it is recognized that these are reliable.

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The longitudinal vibration of a pipe caused by oil pulsation in it is investigated. The coupled vibrations of a pipe and oil are theoretically analyzed with the following assumptions : (1) Oil pulsation and pipe vibration are coupled only at the ends of a pipe, except where they are independent of each other. (2) The attenuation of pipe vibration results from the solid viscosity of pipe material. A viscoelastic model composed of a Voigt model and a series spring is introduced to represent the pipe vibration with damping. Another theoretical analysis considering distributed interactions through a pipe wall is also made and their significance is numerically estimated. The vibration tests of a straight steel pipe containing oil are carried out. The dynamic pressures of oil and the longitudinal accelerations of a pipe are measured and the obtained frequency characteristics are compared with the theoretical ones. The results support the validity of the analytical treatment developed here.

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As an approach to the study on turbulent combustion, the authors introduce a new model in which the most effective combustion may be realized by a turbulence with an energy spectrum conforming to the "characteristic spectrum for combustion" inherent to the mixture. The latter spectrum is determined only by the physico-chemical properties of combustible mixture, such as the laminar burning velocity and the thickness of reaction zone. Furthermore, assuming that the general effect of turbulence on the burning velocity is given in the form of a definite integral of the product of both spectra, and that the quenching effect sets the upper limit of the integration, the turbulent burning velocities of several combustible mixtures are estimated. The results of calculations give a qualitatively proper explanation to the influences of the concentration, scale of turbulence and the energy spectrum on propane-air mixture, and are in a fairly good quantitative agreement with the experimental results by Sokolik et al.

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A study was made on the interaction between a two-dimensional premixed flame and a pressure wave generated by an exploding wire. City gas was used as the fuel in this experiment. The pressure wave was a short duration N-wave which propagated into the flame in the direction of the burner axis or the right angle direction. The response of the flame to the pressure wave was observed in detail by means of Schlieren high speed framing photography and was found, in consequence, to have a basic pattern. This pattern was compared and discussed with the change in flow field measured by a hot-wire.

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When designing machine tool structures considering the contact deformation, it is necessary to establish a simple equation to express the contact deformation. This paper describes the results of an investigation of the horizontal displacement of a bolted joint and the effects of the material, hardness, surface roughness, apparent contact area on this displacement are made clear. Investigations were mainly done for the tangential micro-displacement under high contact pressure.

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Dynamic characteristics of electro-servo feedback controlled automatic conveying and positioning machines affected by mechanical and electrical nonlinearities are studied from a mechanical point of view. Such nonlinearlities as the backlash and coulomb friction in a reduction gear train and the saturation of a servo amplifier are considered, and the stability of mechanism and the positioning error affected by them are determined theoretically and experimentally. A design guide of an exact positioning machine is presented on the basis of the above results.

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A way to calculate the state of tooth fillet stress, contact stress and flash temperature on tooth flank of large helical gears with profile-, longitudinal form error and simultaneous pitch error is shown. The calculated tooth fillet stress and the contact pattern on tooth flank are compared with the values and figures measured on large double helical gears of 366000 DWT tanker ship drive during test voyage, in order to show the reliability of this calculating method. A hint is shown, to decide the order of accuracy of transverse tooth profile and longitudinal tooth form as input data for this calculation.

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The impulsive pressure pulses arising from copper wire explosions are measured using Hopkinson pressure bar technique under various charging voltages up to 63 kV, charging energies up to 2.6 kJ, natural frequencies of the discharge circuit from 10 kHz to 50 kHz and various wire dimensions, and impulses which are defined as time integral of the pressure pulse are obtained. The decays of a pressure pulse and an impulse during propagation are represented by the ratio of stand-off distance to length of the wires. Taken together with the previous paper, the dependencies of peak values and impulses of the pressure pulses upon the energies consumed in exploding wires are obtained. It is also shown that, when charging energies are held constant, low voltage (and thus large capacity) and high voltage (and thus small capacity) are equally efficient provided that the optimum wire dimensions are chosen for each case.

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