A constitutive equation of cycle creep is introduced after an experimental investigation of the effect of increasing maximum stress on the strain accumulation behaviors under various increasing true-stress controlled and load controlled conditions. A strain hardening type constitutive equation can describe the strain accumulation quantitatively under a gradually increasing maximum stress condition. The calculated results of the cyclic creep behaviors in load controlled tests agree fairly well with the experimental observations. A method of determination of material constants in the constitutive equation by the load controlled tests is proposed.

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This paper is concerned with a numerical method of solution by the finite difference technique for unsymmetrical bending of thin elastoplastic shells of revolution. That is, the basic relations in Sander's Linear theory of thin elastic shells are expressed in terms of increment, and the constitutive relation based on the incremental theory of plasticity is applied. A set of the governing differential equations are derived by using a Fourier series expansion in the circumferential direction of the shells, and they are solved by the finite difference technique. The solutions at an arbitrary deformation state are obtained by numerical integration of the increments. Some examples for a cylindrical shell and a circular plate are computed, whereby the effectiveness and the appropriateness of the proposed method are demonstrated.

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In order to grasp the unsteady aerodynamic force acting on blades due to a rotating stall, properties such as velocity, pressure fluctuations and vibrations of blades are measured and relations between them are studies by using a single stage compressor. Consequently, the following conclusions were obtained. (1) It is clear that the velocity (rotating speed) and the width of stall cell are significant factors governing the aerodynamic force. (2) It is reasonable to regard the square wave of the velocity fluctuation as the aerodynamic force acting on a blade.

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An experimental study of suction performance was carried out on the centrifugal pumps with impellers made by extending every other blade of the ordinary impeller with six blades toward the suction opening and tandem-bladed impellers made by cutting off the extended blade section of the above impellers from the original impeller. Principal results are as follows. (1) A suction specific speed comparable but not superior to that of the tandem-bladed impeller was obtained by the impeller with extended blade. (2) The suction periformance of tandem-bladed impeller is strongly affected by the relative axial and tangential position of the front blade row to the rear blade row. (3) The suction performance deteriorates rapidly in the excess flow rate range of the extended blade type impeller, but it is not so severe as for the tandem-bladed impeller.

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This paper deals with a method of theoretical analysis on the flow in a three-dimensional impeller or turbomachine. By considering the stream surface of revolution as Riemann's space (Einstein's space) and by introducing the stream surface with a constant Gaussian curvature, a conformal and projective transformation is used, in which a flow on Riemann's plane corresponds to one on the spherical or pseudo-spherical surface under a hydrodynamical condition of isometric transformation. In this paper the numerical examples in the case that the aerofoil profile on Riemann's plane is logarithmic spiral, are reported. They give the basic slip factors for the arbitrary three-dimensional pumps and compressors and by using the geometrical representation of aerofoil profile and theoretical analysis show in this paper, the potential flow may be nearly realized when the viscosity of fluid is relatively low.

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Co-current stratified flow of liquid metal and water was investigated in a horizontal rectangular channel. Position of the interface, pressure drop and direct contact heat transfer between these immiscible liquids were measured in a fully developed flow. A turbulence model was proposed to explain the experimental results considering that the turbulence is damped near the liquid-liquid interface by surface tension. The analytical results are that (1) position of the interface mainly depends on the flow rate ratio of both liquids, that (2) the pressure drop is approximately proportional to square of the average velocity of water, and that (3)heat transfer rate at direct contact interface is several times higher than that of co-current flow separated by a thin solid plate.

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The present paper deals with experiments of air-water mixtures flow pattern and their mean void fraction in horizontal tube bundles. The tube bundles are staggered with equilateral triangular arrangement of three different pitch/tube diameter ratios (1.4, 1.28, 1.08) and they consist of six different tube rows (7, 9, 11, 13, 15, 20) for each ratio. Experimental ranges are as follows ; Superficial air velocity (cm/s) 1.5 - 50 Superficial water velocity (cm/s) 0.032 - 0.32 Flow direction upward flow The observed mixture flows can be classified into 1. bubbly flow 2. slug flow 3. froth flow 4. spray flow with liquid forming a film around the tubes and spraying from tube to tube downstream. Besides, a simple empirical equation for void fraction is proposed.

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For the purpose of generating the most reliable and internally consistent selected values from the available experimental information about the thermodynamic properties of fluids, a new statistical method of error analysis is proposed in the present paper. The established method has been applied to the available PTV-data of the compressed water for the range of pressured up to 200 Mpa and temperatures up to 600 K. The evaluated results seem to be quite satisfactory and here a set of selected PVT-values with the estimated uncertainties is proposed in a form of the most reliable tabulated values for this property of water of essential importance.

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Temperature, velocity, and turbulence intensity distributions were measured in the separated, reattached, and redeveloped regions of two-dimensional air flow over blunt flat plates of various nose shapes. Especially investigated are the nose shape effects upon the flow and thermal boundary layer characteristics. It is found that they are strongly dependent on the nose shape far downstream from the reattachment point.

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This paper deals with the analytical and the experimental studies to clarify the impact characteristics, such as force of restitution, impulse, a coefficient of restitution and contact time, in the harmonic resonance of a nonlinear system with collision subjected to a sinusoidal excitation. The system consists of an oscillator and reflectors at both sides. The force of restitution is modelized in two manners. One is based on Hertz's theory and represents the exact relations between the impact characteristics and impact velocity. The other is described by an exponential function and is convenient to the analysis of the periodic solution of a three-degree-of-freedom system. Employing both models, the periodic vibration and the impact characteristics in the harmonic resonance of the system are analyzed. Good agreement between analytical and experimental results is obtained for the resonance curves on the impact characteristics as well as that on the amplitude of the oscillator. It is shown by numerical examples that the damping of the reflector has a considerable effect on the impact characteristics.

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Vibrations of a system with periodically variable coefficients are treated and a new method of determining regions of instability is presented. A solution of such a system is introduced according to Lyapunov's theorem. Substituting the solution in the equation of motion, two kinds of characteristic equations are obtained. Eigenvalues of those kinds of characteristic equations are obtained. Eigenvalues of those equations are determined by approximating them by a characteristics equation with a finite order. All eigenvalues can be described by only two representative eigenvalues which are classified into three cases : (i) two imaginary numbers, (ii) one imaginary and one real and (iii) a pair of complex conjugate numbers. Cases (ii) and (iii) correspond to the unstable solutions.

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A modified transformation method in which the convergence rate had been improved for static optimization problems was applied to the optimal control problems with constraints. First, the dimension of constraints was considered, and the effectiveness of this method was verified by numerical examples. Moreover. as an application to the mechanical engineering, an optimal control problem of a refrigerant compressor was formulated, and a modified transformation method was applied to a practical problem. As the result, a proper solution was obtained, and it was confirmed that the present method was effective in the practical application.

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In this paper approximate lumped parameter models by the method of Weighted Residuals (MWR) are given for a cross flow heat exchanger and compared favourably with the Finite Difference Method (FDM). Two kinds of weighting function (Collocation Method). Several numerical examples show that the FDM model must be a considerablly higher order to secure the same accuracy as the MWR model does to simulate the static and dynamic characteristics.

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The paper describes an attempt to develop a simple estimation algorithm of mass and weight which can be applied to a nonlinear dynamical weighing device, First, a new estimation algorithm is induced by considering a deterministic version of weighing dynamics. Second, the estimation accuracy of the algorithm is investigated on the basis of the simulated transient data. Third, the algorithm is applied to the actual data obtained through the displacement pick-up and/or the velocity pick-up attached to the weighing device. As the result, it is made clear that the accuracy in case of using the velocity pick-up is better than that in case of using the displacement pick-up. Finally, a method of real-time data-processing utilizing a microcomputer is briefly described in case of using the velocity pick-up.

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The equations of motion of the plane four-bar mechanisms have been derived for all of possible numbers and positions of clearance-connections except the input-shaft position when the mechanisms rotate at constant speeds in a vertical plane. Applying the equations to a crank-and-rocker mechanism, the effects of the numbers and positions of clearance-connections, the magnitudes of clearances and the crank-speed upon the relative motions of pairing elements, the dynamic deviations of rocker angle and the input torque have been discussed together with experiments.

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This paper presents an investigation into the effect of helix angle on the root fillet stresses and the bending fatigue strength of helical gear teeth with a comparatively small face width. The root fillet stresses were investigated based on the principle of superposition and the moment-image method and compared with the results of strain-gage investigation. The maximum root stress occurs under the condition that the meshing point in the central transverse plane coincides with the outer point of single tooth pair contact for any degree of helix angle (β₀ <__= 30°). Furthermore the effect of helix angle on bending fatigue strength was also investigated using the bending fatigue testing machine for cylindrical gears, which has been developed by the authors. It was found that the bending fatigue limit loads (circumferential loads) for helical gears are almost the same regardless of degree of helix angle.

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Casehardened helical gears with different degrees of helix angle and comparatively small face width were tested using the bending fatigue testing machine of hydraulic type. The bending fatigue limit loads (circumferential loads) were found to be almost the same regardless of degree of helix angle (β₀ <__= 30°). The effects of partial loading (maldistribution of load) on the root stresses and the bending fatigue strength of helical gear teeth were investigated experimentally and the relationship between the bending fatigue strength of a helical gear and that of its virtual spur gear was discussed by carrying out a bending fatigue test for the virtual spur gear. Furthermore the existing equations for bending strength of cylindrical gears were compared on the basis of the experimental results. It was found that there exists a considerably large difference between the calculated allowable transmitted loads for gear teeth according to the equations used.

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The large-sized machine tools are often made of welded steel and to increase their damping capacity a jointed beam or a damping joint is often used. The behaviour of the damping capacity relating to the first, second and third modes of vibration of the jointed beam had experimentally been studied in the previous report, however, the method for the theoretical calculation of damping capacity of it has not been established yet. In this paper, the relationships between the slip ratio and the damping capacity have been theoretically investigated considering the first and second modes of vibration of the jointed cantilever beams used in the previous study. Through comparison between the experimental values obtained from the previous study and the theoretical values, it has been confirmed that the damping capacity of a jointed cantilever beam can be well estimated by using a method proposed here.

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This investigation has been performed in order to examine if it is possible to fill the die cavity with aluminum alloy through a nozzle and to examine the mechanical characteristics of the injected and formed products. It is clear that it is possible to fill the die cavity with an alloy and form the products when the die temperature is equal to the temperature under coexisting state of liquid and solid of the alloy. The tensile strength of the products becomes maximum when the die temperature is fixed in the middle of the temperature range under coexisting state of liquid and solid. The filling-up process of a billet is as follows. The billet is injected through a nozzle in the shape of a bar and after reaching the top inside the die it flows and spreads down along the wall and the following billet fills the center part.

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