Formerly, a method for analysing the stress state in the plastically flowing transparent plane model by using the stress birefringence was proposed as a model test for studying the metal forming process or creep deformation. In this paper, the values of constants contained in the fundamental relations of the method are determined by the calibration test with a softened celluloid specimen. From the results of calibration test, it becomes clear that the value of principal stress difference in the plastically flowing body may be estimated from the fringe order appearing in it within a few percent of error independent of the values of stress rate and principal stress ratio as far as the latter value is negative.

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To investigate the bending action of a piston ring assembled with the piston in the cylinder, we considered an eccentric circular ring with a cut-out portion subjected to a uniformly distributed pressure on its outer circumference. Using the theory of elasticity for plane stress and bipolar coordinates, we obtained exact solutions for stress and displacement of any part in the ring. Further we calculated the stress distribution and the displacement along the inner edge and the tangential deflection at the end on several examples.

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To make clear the bending action of crane hooks, we consider a curved bar with a narrow rectangular cross section and with a profile of two intersecting circular arcs bent by equal and opposite concentrated forces at the inner circumference. Applying the theory of elasticity for plane stress and bipolar coordinates, we obtained exact solutions expressed in Fourier integral, and evaluating residues, derived simplified formulas by which it is proved that the outside parts of the bar bordering on the loading points are free from stresses. Further we calculated the stress distributions along the inner and outer edges using our exact and approximate solutions, and compared them with the same obtained from the usual elementary theory.

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This paper is concerned with the analysis of the elasto-plastic bending of thin annular plates based on Mises' yield condition and Hencky's stress-strain relations. The fundamental equations for the purely elastic range are obtained from the usual ones by introducting a new variable representing the appearance of plastic state on the surface of plate, and the elastoplastic range is analysed by using the corresponding V.V. Sokolovsky's equations. Numerical calculation is performed for several combinations of edge conditions, loading conditions and the ratios of inner and outer radii. Propagation of the plastic range in the meridian section and distributions of the deflection and th components of bending moments for various magnitudes of load intensity are obtained for each case.

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In equations of equilibrium, amounts of the tyre tread radius, gyroscopic couples due to wheels and engine as well as special properties of conventional models which have a large angle of lean and a small steering angle in rounding a curve are taken into account. And both results of calculations and experiments are well agreeable with each other. The angle of lean is always greater than the balancing angle of gravitational and centrifugal force. This is due to effects of large tyre tread radius and low position of mass centre. Moreover, the gyroscopic effect of engine is considerably intensive, especially in lower gear. The main reason why the motor-cycle has the property of oversteering is in the geometrical relation of the steering system. The side slip angle of tyre in single-trackers takes a far smaller value than that of four-wheeled vehicles.

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Being situated in a frequent seismic area, aseismic analysis of nuclear reactor to be constructed in this country are strictly required in its safety consideration. For the JPDR, Japan's first nuclear power station, we have analyzed, in its design stage, vibration characteristics of Reactor Enclosure Structure, for the factors such as natural period, damping accleration etc., to check the validity of static design earthquake coefficient. After completion of the plant, many seismic sensors have been mounted on various parts of the Enclosure Structure to observe its vibration characteristics during earthquake. Using the data obtained so far from actual earthquake, the natural period, location of rocking centers, etc. were calculated. The calculated values show good agreement with the above mentioned analytical results.

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There are many reports available about the centrifugal-head flow meter but a few for its application. There upon we measured the discharge coefficient for seven (360??) centrifugalhead flow meters which were different in size in the range of R_s=10²?`10⁵. We obtained a simplified formula which expressed the relation between the discharge and the head as follows : For the range 4?10²<R_s<4.7?10⁴. Q=A {0.26+0.28 (B+log??h>)-0.03 (B+log??h>)²}??h> (cm³/sec) For the range 4.7?10⁴<R_s. Q=0.91??2gh>r₁??r₁R>??h>(cm³/sec)

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In order to apprehend the characteristics of axial plunger pumps and motors, it is very important to investigate their trapping phenomena thoroughly. For this purpose this paper gives the formula to calculate the pressure change in a cylinder during a trapping period in which a liquid flow from a cylinder is considered, and makes clear the effect of relief grooves, shaft speeds and inertia of the liquid in a cylinder on the trapping pressure. Then the efficiencies of pumps and motors are defined in consideration of the compressibility of liquid, trapping and relief grooves. Using this definition, power losses due to trapping are estimated, and then it becomes possible to decide the relief groove which is effective to reduce not only vibrations and noises due to trapping but also power losses.

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A theoretical and experimental investigation of the ripples of pipe-line pressures, shaft torques and rotational speeds in oil hydraulic systems where an axial plunger pump and motor are connected by a pipe-line and where a motor is connected to an accumulator is reported. The method to decide the trapping period and the relief groove to reduce the resonant ripples is derived from investigating the effect of the trapping phenomena of the pump and the motor on these repples for the former system. And the effects of system parameters on the latter system are made clear by defining the minimum stable rotational speed of the motor. Experimental and theoretical results coincide with each other qualitatively but not well quantitatively because it is impossible to measure the dynamic characteristics of components of the experimental apparatus correctly.

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The present study was initiated to determine the nature of flow in the suction pipe of centrifugal pumps. When a high specific-speed pump runs at partial discharges, it is known in general that some amount of liquid in the impeller flows back with a rotational component of velocity into the suction pipe and the liquid approaching the impeller is impelled to swirl before it reaches the impeller. Measurements of velocity and pressure distribution in this swirling flow were made at successive sections of the suction pipe and the distributions of energy were also evaluated. The results may help to make an analysis of three dimensional swirling flow in pipes.

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For the swirling flow created in the suction pipe of centrifugal pumps at partial discharges, the authors evaluated the distribution of shearing stresses by using measured velocity and pressure and compared it with strain velocity. The stress tensor at any point within the pipe is verified to be in proportion with the rate of strain velocity. Although the absolute value of the radial component of velocity exceeds hardly one hundredth that of the axial or rotational component, it contributes considerably to the stress tensor and can not be neglected. Eddy kinetic viscosity of the flow near the pipe wall ranges from 20 to 70 times the kinetic viscosity due to molecular causes.

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The swirling flow generated in an elbow suction pipe of a centrifugal pump at partial discharges was studied and the results were compared with that generated in a straight suction pipe. Distribution of velocity may be considered to be nearly in symmetry about the pipe axis but the wall pressures measured at four taps in a section of the pipe spaced 90 deg. circumferentially show a considerable difference. The averaged value of the pressure is elevated by the centrifugal action of the swirling motion and the increase of pressure is affected considerably by the piping installation. The swirling flow due to a back flow from the impeller can not penetrate a 90 deg-elbow but some of it passes through a 45 deg-elbow, resulting in a markedly complex flow picture upstream of the elbow.

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This paper presents a theory on the decay of a turbulent swirl in flow through the suction pipe of centrifugal pumps. When a pump of high specific-speed is operated at extremely low discharges, velocity profile of the swirling flow exhibits itself nearly in a typical forced vortex type. Maintaining the same profile, the swirl decays toward upstream of the pipe. On this flow, the theoretical analysis was found to be in good agreement with experimental data. The viscous stress between fluid particles of the flow and the wall friction together with the eddy kinetic viscosity were calculated theoretically. The friction characteristics is quite different from that in the parallel flow of a flat plate.

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Water in an open vessel was brought to the transition boiling from the outer surface of a vertical copper tube heated from inside with saturated steam. By analyzing the oscillograph record of the surface temperature and the steam film detecting probe, it was concluded that the transition boiling is a particular phenomenon in which the boiling surface gets alternately wet and dry. It was found that the boiling characteristic curve is smooth and continuous throughout the nucleate and the transition boiling, and a particular type of boining was observed in the vicinity of the maximum heat flux and was termed the burnout boiling.

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The low-frequency combustion, oscillation occurring in the combustion system comprising a combustion duct, inlet and outlet orifices and a capacity chamber was analyzed as a dynamic instability of "closed loop". From the analysis of experimental facts it was concluded that the exhaust temperature fluctuation as the result of distortion and necking of flame would be the chief feedback mechanism, and such distortion is caused by velocity fluctuation. This view was confirmed by a forced oscillation experiment applying a fluctuating velocity on a flame and fuel jet. Theoretical analysis was made of a jet placed in fluctuating velocity field. The theory predicts the necking and distortion of jet. The theoretical result was easily interpreted as the relation of exhaust temperature to velocity fluctuation. The dynamics of combustion thus obtained was used together with the dynamics of fluid flow to discuss the nature of self-exciting oscillation.

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The thickness of a carburized or decarburized thin layer of steel parts is found to be determinable by a newly developed method which utilizes the relationship between the depth of indentation made by a conical indenter and the indenting load. Qualitative considerations done on this method provide a good explanation for the experimental results. The authors propose this method as a quality control means instead of conventional non-destructive testing methods and microscopic examination which take time and are impractical.

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High capacity magnetic storage drums are obtained by making small clearance between head cores and drum surface. We are investigating a head supporting method named an air floating head mechanism, which is an application of self-acting gas bearings. In this report we described static characteristics of the mechanism, namely, influence of clearance ratio, slender ratio of the slider and difference of surface curvatures on pressure distribution or floating force of air film. These are calculated by an electronic digital computer and compared with experimental data.

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We investigated the dynamic characteristics of air floating head mechanism for magnetic storage drum. According to the results of numerical calculation on small vibrations of a slider near its equilibrium point, the smaller the clearance is, the larger the stiffness and coefficient of viscosity of air film are, and the larger the curvature is than that of the drum, the better the characteristics will be. Even in large vibrations, the smaller the clearance is, the higher will be the degree of stabilty. These were proved by experiments.

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In this paper, an analytical approximate solution for journal bearings of finite lengths is presented. The characteristic performances of steady loaded bearings, elastic and damping properties of oil-film, stability criteria and vibrations of a rotor-bearing system are studied. The results well agree with the Lund-Sternlicht's computer solutions and the experimental results.

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In making an efficient production of gears of high performance, it is considered best to have them hobbed and finished by shaving, with material of gears as hard as possible provided it can be cut fairly well. In the present paper the authors have made theoretical and experimental studies of a hob with such form and material, as well as cutting oil, as give it the largest durability in cutting large and hard gears. This paper also deals with the form of a hob which reduces the fluctuation of cutting force.

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Influence of the supply conditions of grinding fluids on grinding performances of free in-feed plunge grinding were studied experimentally. This influence was found to be great especially when an emulsion containing less emulsifier was used as the grinding fluid. It was also clarified from the present experiments that the grinding difficulties observed in the case of the emulsion of lower emulsifier concentration in the previous experiment were attributable mainly to the bad supply condition of the fluid, and that these difficulties could be overcome by the improvement of the supply conditions. When the grinding fluid performance is tested with use of such a grinding method as used in this experiment, it is necessary for the proper evaluation of the fluid that particular attention should be paid to the selection of the supply methods or conditions of the fluid.

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It is important to investigate the deformation modes of the outer flange portion of the blank during shear spinning operation, in order to know an optimum working condition or spinnability of sheet metal. According to the measurement of the radial and cirumferential strains and the periodic variation of curvatures on the flange portion, the magnitudes of these strains and curvatures change considerably at the contact point between the roller and the blank, and do not distribute uniformly on the flange. Then, though the radius of the blank is not changeable on shear spinning, collapse into waves or wrinkles occurs, when the thickness of the blank is small. The conditions of wrinkling can be simplified by using the ratio of displacement of z direction and blank thickness t₀, and flange width ratio w/r. The deformation of the flange portion is influenced mostly by feed of roller, roller diameter and blank thickness among the many working conditions, but the other conditions scarcely affect the deformation of the flange portion.

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