This paper describes an approximate method to analyse the steady state creep in rotating disks under axial loads and having asymmetrical profiles. The bending moments caused by the axial loads and the asymmetry of the profiles are taken into consideration to obtain basic equations. It is concluded from the numerical examples that the bending stresses cannot be ignored even if the axial loads and the asymmetry of the profiles appear to be negligibly small.

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There are several methods to measure mechanically residual stresses in simple shaped objects such as flat plates, cylinders (solid or hollow) and shells. In all these cases, directions of principal stresses are already known and coincide with those of geometrical axes of the bodies. The author has published the Deflection Method to measure the two principal residual stresses in a plate and has given an analytical formula to calculate them by solving the integral equation. In general, there are some cases where the directions of the principal residual stresses are unknown and their directions and values should be determined. In this report, the author proposes an analytical formula to find out unknown directions and values of principal residual stresses existing in plates by applying the relations of elasticity in plate bending to his Deflection Method and shows examples of measurements in rolled band saw strips.

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When a thin cylindrical pipe of finite length with a groove cut out through the length axially is twisted with both ends fixed on grips as shown in Fig. 1, the influence of fixed ends on the angle of twist and the stress is discussed, using the fundamental differential equation for cylindrical shell introduced by one of the present authors. The angle of twist per unit length of the short pipe with a groove is very small compared with that of the pipe of infinite length and this difference is so extremely great that the application of the equations for the infinitely long pipe to a short pipe may be inadequate. Besides this remarkable difference, there exist great axial thrusts at both fixed ends. These theoretical results are ascertained by experiments.

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In this paper the fundamental equations for bending states of cylindrical shells are derived in the terms of stress function and radial displacement component. These equations have the same accuracy as Flugge's equations. We can easily give the solutions of these equations especially for a stress boundary value problem. Stresses in a cylindrical vessel with a local radial load were calculated as a specific application. We obtained a good agreement with the results calculated by P.P. Bijlaard.

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The impact problems of an elastic body treated by Saint Venant, Bousinessq and Donnel are only about the transient state in the shocked surface of the body. Pipes transformed a shocked system into the equivalent electric circuit and solved it with the operative method. In this paper the authors introduce Dirac's δ (t)-function into the boundary condition in the parallel system of a coil spring and a damper, and solved it with the method of Laplace transformation. The results are summarized as follows : (1) The condition that a falling body separates from a spring after impact is obtained. (2) The maximum stress at the fixed end of a spring and the approximate equation for it are found. (3) The effects of a damping coefficient of the restitution coefficient are made clear. (4) The behavior that a damping coefficient affects the spring stress due to impact and the transmission force at the fixed end of the spring is known.

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In this paper the author discusses a trial and error type decision function which may seem suitable for a large scale plant control program. This decision function consists of random sampling and measure preserving linear transformation, and plays the same role in the control program as the safety factor dose in machine designs. Dynamic characteristics of this equation are described by a set of so-called Ricatti type differential equations. Solutions of these equations in the case where natural circumstance of the plant is independent of time or varies periodically are proved to be stable. Experiments are carried out using the electrical computer (OKITAK 5090 A) at the Computing Center of Tokyo University and the results are shown graphically.

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Results of some experimental investigations of a flow in rotating impeller passages of a radial turbine are presented. Velocity and static pressure measurements were made with a yawmeter probe fitted within the impeller channel of a rotating impeller. The influences of two performance parameters, i.e. non-dimensional weight flow and non-dimensional rotation speed on the flow behavior within the impeller passage are shown. Further, the flow patterns in blade-to-blade surfaces are shown for three different passage depths. In addition, a theoretical analysis of the mixed flow type is made, including the inward-flow type as a special case. For the necessary boundary values at the inlet of the impeller in the theoretical study, we use the values observed in the experiment. Theoretical results show a fairly good agreement with the experimental data.

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A number of theoretical and experimental studies on the growth and collapse of bubbles have been made in order to clarify the boiling phenomena. Most of those experiments, however, have been made with heating surfaces of smaller size than bubble diameter. Authors have been doubtful of the validity of applying such experimental results to boiling with a larger heating surface. In order to clarify the dependence of the bubble growth and collapse upon the shape and size of heating surface, they carried out experiments by means of the heating surfaces of horizontal circular brass plates 100 mm and 140 mm in diameter respectively and of horizontal small platinum wire 0.5 mm in diameter and found that : (1) Bubble growth and collapse are independent of heat flux. (2) Bubble collapse is strongly influenced by the degree of subcooling. (3) Bubble growth and collapse which essentially dominate the boiling heat transfer are considerably affected by the size of heating surface.

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The mechanism of the generation and the characteristics of the noise associated with combustion are studied. It is shown that the dominant factors on the generation of the combustion noise are the velocity turbulences and the entropy turbulences, acting as equivalent acoustic dipoles and monopoles, respectively. Especially, concerning the diffusion flame of rich-premixed gaseous fuel, the noise in the laminar flame is mostly due to the entropy turbulences and of monopole-like characteristic, and that in the turbulent flame is mainly attributed to the velocity turbulence and of dipole-like characteristic. The noise intensities are proportional to the second and the fourth power of the mean flow velocity, respectively, and to the cubic power of the diameter of the nozzle.

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In the paper, the reflective conditions of pressure wave in some exhaust pipe systems were measured by the shock-tube method. This method was based on the characteristic relation of pressure wave and the shocktube principle. The results obtained were as follows : (1) As to nozzle, the experimental results showed coincidence with the theory for a weak shock wave, but as the strength of its incident pressure increased, the discharge coefficient became larger. (2) Judging from the theory and the experimental results, the diffuser effect could not be improved for the area ratio above 4. (3) As to bends or elbows, the experimental results agreed well with the theory. (4) These results were able to clearly explain the phenomena in the last experiments obtained by using a uniflow two cycle diesel engine.

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This paper deals with the rigidities of machine tools and their components. Static deflections which are the indication of static rigidities are measured on the columns of an upright drilling machine, and it is pointed out that the rigidity of the jointed portion can not be neglected. Natural frequencies and vibration modes which have a close connection with the dynamic rigidity are measured on upright drilling machines, lathes, milling machines and cylindrical grinding machines, and the vibrational characteristics of them are discribed. The relations between the natural frequency and the condition of support are described for the bed, main spindle and work. Finally a trial to improve the rigidity of the lathe bed is planned and carried out, and the effects of improvement on the cutting capacity are discussed.

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There have been many studies on electrohydraulic forming in which the relationship between the deformation characteristics of metallic material of a given shape and the stored electrical energy is investigated, but few studies on pressure pulse which has direct relation with the deformation. In a previous paper the authors presented a fundamental study on this relation within the stored electrical energy up to 180 J. This paper presents the investigation, in which a capacitor discharge circuit employed as an electrohydraulic forming machine is used to explode various kinds of fine wire (diameter : 0.20 mm, length : 5 cm) submerged in a water tank, and the resulting pressure pulse at a position 15 to 50 cm from the pressure source is measured as a function of time using a calibrated gage (barium titanate) and an oscilloscope. The effects of various kinds of fine wires and discharge circuit conditions, such as initial capacitor voltage and inductance, on the shape and amplitude of pressure pulse are presented, and the efficiency of these apparatus is also mentioned and discussed. Initial capacitor voltage is varied up to 11 kV, and the total stored electrical energy in the capacitor bank is varied up to 1400 J.

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There have been many studies on electrohydraulic forming in which the deformation characteristics of metallic material are investigated. In most of the studies the wires used as pressure source were very fine. A clear-out account has not been given of the relationship between the dimensions of wires and the initial discharge circuit conditions such as capacitor voltage and circuit inductance, and then for a given stored electrical energy there have been few studies showing what kinds and dimensions of wires to use as effective pressure source. By the reason of F.H. Webb's experimental fact that, when sufficient energy is placed in a wire to vaporize it, the delaying time of boiling is of the order or less than the time required for a sonic wave to traverse the wire at boiling temperature, the longer the delaying time, the higher will be superheating. This paper presents the results of experiments where a capacitor discharge circuit for an electrohydraulic forming machine is used to explode a fine copper wire, diameter of which is 0.14 to 0.40 mm. The best condition for creating a pressure pulse is investigated and discussed.

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As regards a plane linkage mechanism which has only turning pairs of one degree of freedom, the synthesizing of the mechanism in which the follower is able to obtain our desired displacement of the swinging angle in case of giving the turning motion to the driving link is to be required for all the persons who are concerned not only with irregularly moving mechanisms but also with computing mechanisms. The author has previously performed the synthesis of a 4-bar linkage, and, in addition, has found out that its mechanism is not capable of satisfying all the demand for more complicated displacements and that a 6-bar linkage mechanism can fulfill this requirement. Furthermore, as the result of his study on the method of the synthesis in regard to only one type which remains still unresearched among the 6-bar linkages, he has been able to present a new rapid method of geometrical synthesis of the type A·3. Next, in order to increase the accuracy of the synthesis of the type A·3, the numerical equation and vector diagram methods of this type in case of giving some precision points on the displacement curve in addition to some conditions enlarging Freudenstein's method have been described. Examples of the synthesis have been shown in connection with the practical displacements. In this way, it is expected that the design of the type A·3 is to be improved and its accuracy increased. This paper has been compiled from two articles "Researches on the Synthesis of the Six-Bar Linkage" and "Researches on the Synthesis of the Six-Bar Linkage (A·3 Type)" which are both written in Japanese.

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In the case of measuring flatness of a surface plate by sensitive spirit level method, i.e., the so-called two-point connecting method, a series of level readings made in each position are connected. But their connection is generally troublesome. In this paper, the author proposes a method by which the flatness of a surface plate can be found mechanically.

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