The rate equation and the equivalent rule of strain aging in carbon steel were derived from age hardening curves taken in the temperature range from 170°C to 250°C after a compressive prestrain. The maximum increment in hardness increased as the temperature rose and the prestrain became larger. The process of aging could be expressed by a rate equation of homogeneous and first-order reaction. The equivalent rule of strain aging was formulated in consideration of both the maximum value of hardening and the prestrain. It was shown that the applied rule permitted a precise estimate of equivalent aging time at the aging temperature range of second stage.

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The purpose of this investigation is to verify the theory of the surface reflected Caustics, which is one of the optical method for stress analysis, and then to establish how to determine the stress intensity factor exactly. The experiment was performed using plates of acrylic resin to examine the influences of the condition of measurement on an accuracy of the measured value such as the location of the optical system, the shape of crack tip, the thickness of plate and a loadind step. As a result, the relationship was found between the measured value and the condition of measurement. It was also found that there existed an invalid range in the previous theory. However, we could determine the theoretical value from the measured one using the procedure which was developed in this investigation.

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The authors proposed in this paper a new method of X-ray diffraction to measure three principal residual stresses in a hollow cylinder. With thin layers of equal thickness removed from both surfaces of a hollow cylinder, surface stresses are measured by X-ray on both surfaces, and then the residual stress distributions can be calculated from both surfaces at the same time. As an application of the new method, the authors measured the residual stresses of a heat treated hollow cylinder of STPT 38.

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Contact Stresses between two thick plates with a circular hole and a sandwiched solid-metal flat gasket connected by a bolted joint are studied to discuss the sealing behavior of the gasket. Assuming that the gasket is an elastic body, the three dimensional theory of elasticity is used to analyse the contact stresses and the deformations in three laminated disks with a circular hole whose both sides are compressed by axisymmetrically distributed loads. By neglecting shearing stresses on the contact surfaces, an exact solution satisfying the remaining boundary conditions is obtained. Numerical calculations are carried out for various rigidities and thicknesses of the disks and the loading conditions. In order to examine the results of the theoretical analysis, the contact stress is measured experimentally by using pressure-sensitive pins attached to a disk. It is confirmed that the theoretical results agree well with the experimental ones except the vicinity of the loaded area.

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An analytical method on the creep problems of general moderately thick shells of revolution subjected to asymmetrical thermal and/or mechanical loads is developed in consideration of the effect of shear deformations. The Norton-Bailey type equation having the thermal effect multiplier by Arrhenius is employed for the constitutive relation. The fundamental equations on the creep problems derived for incremental values are numerically solved by a finite difference method and the solutions are obtained by integration of the incremental values. As a numerical example, the creep deformation of a cylindrical shell under an asymmetrical thermal load and subject to an internal pressure is analyzed, and the results are compared with those from the classical theory which neglects the effect of shear deformations. It is shown from the comparison that in the creep problem of moderately thick shells the difference between solutions from the present theory and those from the classical theory becomes significant.

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An experimental study was made of the stratified two-component flow of polymer solutions through a rectangular duct with an aspect ratio of 14. The flows into the rectangular duct through the reservoir were visualized and the flow patterns were classified into three groups. Also, the pressure fluctuation due to the unstable flow was measured and these results showed that the phase and the period of the pressure fluctuations in the reservoir agreed well with those in the slit. The pressure fluctuation measured at the walls opposite to each other also agreed. For the theoretical study, the relation between the pressure gradients and the volumetric flow rate was examined by solving the equation of motion for the flow between flat parallel plates and by calculating it numericall for the flow through the rectangular duct, and these results are compared with the experimental results.

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Turbulent flows in a hydrodynamic entrance region of a plane channel with various inlet disturbances for Re=42000 were numerically simulated and compared with the experimental results reported earlier. The simulation was based on the parabolized Reynolds equation of motion together with three types of turbulence models-- mixing length mode, k-ε model and stress equation mode. The development of time mean quantities was well predicted except just downstream of the inlet section. The turbulence quantities in the downstream region obtained by the higher order models were also in good agreement with the measured data. The disagreement, which was most pronounce in the inlet region, was not improved even by the employment of the higher order models.

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A steady flow of liquid metals in curved circular channels under a transversely applied magnetic field is investigated theoretically and experimentally. firstly, a laminar flow at low Dean number region is analyzed numerically. And the internal mechanisms of the flow, which are velocity profiles, distributions of current densities and others, are made clear, and the resistance coefficient is found. Secondly, on the basis of numerical results, a laminar flow at high Dean number region is analyzed by means of the boundary layer approximate method, and the resistance coefficient is calculated. Finally, an experimental study is carried out for mercury flow. The resistance coefficient obtained by the experiments is shown to be in good agreement with that of the theoretical analysis. Furthermore, the effects of magnetic field on the resistance character in the transition and turbulent flow regions are examined.

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Spectral reflectivities and emissivities are measured on seven kinds of iron-, nickel- and cobalt-base heat resisting alloys in the near-infrared and infrared regions and at temperatures up to 900 K. Optical dispersions of the alloys are analyzed on the basis of an electronic theory of metals. Relations between optical constants and resistivities are discussed, and quantitative expressions of the near-infrared and infrared optical constants are given for temperatures up to 1600 K. Macroscopic properties of radiative heat transfer can be readily calculated. An approximate formula is proposed to estimate the radiative properties by using knowledge of electrical resistivities.

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The experiments of the collection efficiencies with the fly-ash particles of the arithmetic mean diameter Xp=2.06μm for the returned flow type (D1=90 mm), the axial flow type (D1=90 mm) and the cone type (D1=100 mm) of the tangential inlet cyclones were done. The feed concentrations of the particles were Co=5 - 45 g/m³. The best collection efficiencies were obtained by the ordinary returned flow type the cyclone and the worst collection efficiencies were obtained by the axial flow type of the cyclone. The main differences of those collection efficiencies were elucidated by the generation of the couple circulation zones based upon the analysis of the equi-flow rate lines in the axial flow cylindrical cyclone.

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In this paper, the flow and the sensing characteristics of the annular jet proximity sensor are discussed theoretically and experimentally. First, the annular jet with and without a flapper facing the sensor nozzle is analysed by applying the theory of the reattachment jet flow model and the theoretical sensing characteristic of the sensor is derived and compared with the experimental one. Second, it has been experimentally indicated that the proximity sensor exhibits an instability of flow in a certain range of the distances between the sensor nozzle and the flapper. In order to qualitatively explain the cause of this instability, a simplified two-dimensional potential flow model for the annular jet is presented and analysed. From the result, it has been concluded that the instability of the flow is caused by a vortex in the recirculating flow region.

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Regarding rotating machines with overhung weight as a system with one shaft and one rigid body, the extreme value problems of the static natural frequencies, forward and backward critical speeds under constant volume of the shaft are formulated by using the matrix method by which the spring constants of the axial symmetric structure are directly calculated. In this case, the shaft of a rotating machine consists of some uniform beams which are connected in series with one another. Besides the length, inside and outside diameters of every beam that is an element of the shaft, the distance between shaft/rigid body connection point and center of gravity of the rigid body is used as a design variable.

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A computational method is presented for obtaining the steady-state temperature responses of 1-2 pass heat exchangers subject to sinusoidal flow rate changes of large amplitude. The frequency- and amplitude- dependent describing functions between the input sinusoidal flow rate changes and the fundamental component of the steady-state response of the outlet temperature of tube-side or shell-side fluid are also derived. Numerical examples are given and it is shown that this method can reduce the computation time remarkably. Experiments are carried out: the steady-state responses to input sinusoidal flow rate changes are recorded for various values of amplitude. The experimental input-output relations of the fundamental components are determined from the recorded data using a Fourier analysis technique on a digital computer, and the experimental data are shown to be in good agreement with the theoretical results obtained by the present describing functions.

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This paper presents static characteristic of a cicumferentially grooved hydrostatic gas journal bearing which is characterized by two circumferential grooves located near its ends wherein compressed gas is supplied through a small number of supply ports. Bearing efficiency, optimum clearance and flow rate of the novel bearing are analyzed numerically and its superiority in load capacity, stiffness and flow rate to the conventional discrete source bearing is shown at low supply pressure of less than about 10⁵N/m². Optimum design method is discussed. The numerical results are verified experimentally.

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This paper introduces a developed simulator on a rotational vibration and a strain at a root of a tooth, on a power transmission spur gear. The simulator solves a differential equation with one degree of freedom in consideration of the behaviour of the stiffness around tooth tip meshing. The stiffness function is discussed and determined with static and dynamic meshing tests under load. The developed simulator has one more distinctive feature that the errors of the gears are put into the simulator with a newly developed automatic gear accuracy measuring instrument. The simulated outputs depict precisely the experimental behaviours. Through the development of this simulator, the the discussion becomes easier on the effectiveness of a spur gear for the decrease of vibration.

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An internal gear which meshed with three planet gears in the same bearing condition, the angles between those planet gears being same and 120° respectively, and which was supported through a thin cylinder, was chosen as the subject of study. The bending moment, the bending stress and the radial displacement in the rim of the internal gear were obtained theoretically, and by using these results the form of an internal gear model was determined. Furthermore, the stresses in the internal gear models were analyzed by the photoelastic method, and the effects of rim thickness and number of teeth of the internal gear on the magnitude and the position of the maximum stress produced in the internal gear were clarified.

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In order to develop the most suitable design method of the threaded joints in an ultrasonic vibration system, the effects of dimensions of threaded joint, form accuracy of bearing surface and tightening force on the characteristics of transmitting ultrasonic vibration are investigated experimentally and theoretically. The obtained results are as follows: 1) The methods, which evaluate the characteristics of the threaded joints in the ultrasonic vibration system by detecting the critical stress amplitude at bearing surface and the motional admittance, are proposed. 2) In the case o high accuracy of bearing surface the critical stress amplitude is approximately equal to the mean stress on contact surface and the mechanical resistance is close to that of solid bar. In the case of low accuracy of bearing surface the critical stress amplitude is much lower than the mean stress on contact surface and the mechanical resistance is larger than that of solid bar.

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A pressure-volume-temperature relation in aluminum was calculated by pseudopotential method and Mie-Gruneisen relation. The thermal dilatation data of aluminum showed good agreement with this calculated value. The calculated results under very high pressure and high temperature environment were compared with NaCl scale by a newly designed X-ray diffraction system with a LiF monochrometer at the receiving slit. Both scales just fitted within an error range. It can be concluded that the proposed aluminum scale is acceptable under very high pressure.

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Experiments on high speed bulging are presented under various die diameters and sheet thicknesses, and the results are compared with the analytical results of the first report. The final deflections of the sheets can be estimated by the impulse of the pressure pulse measured by Hopkinson pressure bar. The process of the bulging measured by a high speed camera differs from the analytical one; the differences between them are discussed by the theory on wave propagation and reflection. Supplementary experiments on two dimensional bulging of rectangular sheets are made and the effect of the cavitation beneath the sheet on the bulging is examined.

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