Notched and unnotched specimens made of S45C carbon steel were tested under the composite stress which consists of fundamental rotating bending stress of relatively low frequency and superimposed stress of high frequency. The ratio of the frequency of the fundamental cyclic stress to that of the superimposed stress was selected to about 12 for all types of specimens. From the test results, discussion was made on the dependency of the fatigue strength under the composite stress on the type of specimen. It was concluded that when the super-imposed stress was small, the superimposed stress did not affect the fatigue life and such a range of the superimposed stress was decreased with the increase of the stress concentration factor of the notch, and the when the stress concentration factor of the notch was small, the endurance limit under the composite stress was reduced by the effect of the superimposed stress.

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With the use of Fourier transform technique and the theory of distribution a class of exterior elasto-dynamic problems concerning a circular hole in an infinite elastic body has been solved. The circular hole is subjected to rotating loads quasi-harmonically or transiently. Some numerical examples are presented on definite cases, in which the loads distribute harmonically.

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The authors proposed a method to measure residual stress distributions in a multi-layered plate by utilizing strain gauge. The solution was derived from an integral equation of Volterra type in which strain to be measured were equated with those introduced with the axial force and bending moment by successive removal of thin layers. Formulas for a single plate and other special cases are derived from the general equation, and the former concides with the equation of Doi. It is noted that a multi-layered plate is constructed with materials of different linear expansion coefficients, so that the change of temperature in a test has some effect on residual stress distribution. The authors introduced a temperature compensating method for compensation coefficient upon measured strain. As applications of the theory, they measured residual stress distributions in 3-layered electrodeposited plates of copper-steel-copper and nickel-steel nickel. It has been confirmed that the residual stress distribution obtained by means of Strain Gauge Method is almost equal to that of Curvature Method, and the former is of sufficiently practical use.

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Analysis is performed, considering the energy equation, of the unsteady flow of gas in a long circular tube. Exact solutions of the pressure, axial velocity, radial velocity, density and temperature distribution on the cross section of the tube are obtained under the acoustic approximation. It is proved that the transfer constant of the pressure wave varies with the boundary conditions for the temperature. For the two typical boundary conditions, namely the adiabatic wall and the isothermal wall, numerical calculation is performed assuming the sinusoidal input. An important practical example of the above stated flow is the transfer characteristic of the pneumatic instrument line. To describe the transfer characteristics of the pneumatic instrument line, the transfer matrix is calculated and the graphs of numerical examples are given.

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The pump has vanes which are inclined at an angle with the radius. Experiments were carried out on the performance in each of the combinations of eleven angles of vane from 45° to 135° with four flow channels. The authors also observed the inner flow by means of a high speed camera and a few kinds of probes which contained a new type pitot tube. Their conclusions are as follows : (1) The pump performances are influenced by the vane angle and the sectional area of flow channel. (2) The ratio of the shut-off heat to the head at the maximum efficiency and the maximum power decrease with the increase of the vane angle. (3) There is a regular flow circulating through the flow channel and between the vanes, and the flow pattern depends upon the vane angle.

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In this report equations of viscosity, thermal conductivity and Prandtl number for water and steam were correlated as a function of temperature and pressure, while most of equation is previous investigations had been expressed as a function of temperature and density. Directly from values of temperature and pressure without knowing the value of density, property values can be calculated using equations in this report. Whole regions of up to 1000°C, 3500 bar for viscosity, up to 700°C, 500 bar for thermal conductivity and up to 600°C, 500 bar for Prandtl number are covered by three equations each, namely equations for the water, the steam and the critical regions. In the water and the steam regions those for the water, the steam and the critical regions. In the water and the steam regions those properties are expressed as the polynomials of pressure in two or three terms, while the narrow region near the critical point is expressed in a slightly more complicated form. Values calculated by the correlated equations were compared with the recent experimental values.

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A theoretical analysis of the dynamic behavior of pressure drop in long steam generating tubes is presented. The solutions of the dynamic response of the frictional pressure drop, the accelerational pressure drop and the gravitational pressure drop to changes of flow rate at the inlet of the tube and heat input are derived. The derivations are based on a long steam generating tube and heat input are derived. The derivations are based on a long steam generating tube with uniform heat flux and constant cross section and on the linearization of the fundamental equations. The characteristics of the response curves of the frictional pressure drop are discussed in detail. It is shown that the response curves to a step increase of the inlet mass flow rate show a special feature, for instance, the frictional pressure drop at first increase remarkably and then decreases gradually to a settling value which is lower than the initial value.

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A series of the combustion experiments has been made to study the effects of air distributions on the combustion processes in the high intensity combustion chamber of a jet propulsion engine using a box-type combustion chamber. The effects of air distributions on the combustion chamber performances, the flow patterns and the temperature distributions were examined in the first report. In the present experiment, the concentration profiles of various stable species in the combustion chamber were determined using a quartz sampling probe and a gas chromatograph. From the vertical and the horizontal concentration profiles, it is found that the main reaction zone exists near the inner edge of the fuel spray cone. The axial concentration profiles are changed greatly according to air distributions, and as the primary air flow increases, the concentrations of the combustion products increase and also they become uniform in the recirculation zone.

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Few papers which applied the finite-element method to hydrodynamic lubrication have been published, in spite of many literatures introducing the finite-element method in structural problems. In this paper, the applications of the finite-element method for hydrodynamic lubrication of infinite-width bearings are presented. It is claimed that the finite-element method is able to obtain the accurate results by using a few elements. The finite-element solution is compared with an exact solution and a finite-difference solution of step bearings, plane slider learnings and journal bearings.

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The application of the finite-element method to infinite-width bearing problems were presented in the first paper. In this paper, the finite-element method applied to the partial and the ordinary differential Reynolds equation is studied on finite-width bearing problems. The treatments of the boundary and the connecting condition at nodes in the finite-element method are presented. The finite-element methods for finite journal bearings have more advantages as compared with the finite-difference method and the analytical approximate solution.

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After overloading with a tangential load 7 to 15 times the allowable one for pitting gear endurance tests were conducted on hobbed gears of 0.45 percent carbon steel having Brinell hardnesses of 160 and 180. the results obtained are as follows : (1) The gears can be operated under a Hertzian stress greater than a shakedown limit, 4.0τ_K≒0.4H_B, which is calculated using the yield stress in a simple tension test. (2) When the gears were overloaded with a tangential load corresponding to a 0.96H_B Hertzian stress for 5×10³ rotations, and thereafter, interchanging the driving and following gears, rotated through another 5×10⁶ rotations at a Hertzian stress of 0.66H_B, only a a single pit occurred in the new driving gear and 7 pits occurred in the new following gear. (3) Increase in load carrying capacity observed n the overloaded gears, can be attributed to smoothing of the surface and work hardening of both subsurface and surface of the gear teeth. (4) A pit having many cracks in its bottom was found, and these cracks seemed to have been propagated by a hydraulic pressure mechanism of lubricating oil.

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