The fatigue tests under varying repeated stresses, which consisted of two different bending stresses (the first and second stress waves), were carried out by the specially designed testing machine, using notched specimens of 0.22 and 0.61 per cent carbon steels and super duralumin. These test results were compared with the calculated ones which predict the fatigue life of metallic materials subjected to such varying repeated stresses. And the following are concluded : (1) The analytical fatigue life of 0.22 per cent carbon steel and super duralumin under the varying repeated stresses has a good agreement with the test results. (2) In the case of 0.61 per cent carbon steel, the second stress wave has no influence on the fatigue life, when the ratio of the second stress wave to the first stress wave, λ, is smaller than about 0.8, and the analytical fatigue lives have a good agreement with the test results, only when λ is greater than about 0.8.

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In Part I, a phenomenological fracture criterion of polycrystalline metals under conventional loading conditions is presented on the premise that there exist generally two modes of fracture ; ductile shear fracture and brittle cleavage fracture. The two major effects on fracture ; that is, triaxiality of stress and plastic strains preceding fracture are formulated mathematically in this criterion. The experimental results under combined stresses on ductile metals are well explained on the basis of this criterion. In Part II, the tensile fracture tests of mild steel cylindrical bars having circumferential hyperbolic notches are performed, and the plastic stress and strain distributions at fracture necessary for an application of this criterion to practical problems are analysed approximately. The various fracture behaviors in these tests are well explained and a view as to the notch brittleness are given.

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This is a report of an experimental study for the lateral buckling of a narrow rectangular cantilever beam with an end load. These experiments were carried out systimatically in a wide range of the dimension of beam. The test pieces used for the experiment were of thin plates of mild steel end aluminum with varying heights and spans. The results obtained have enabled us to decide the range of beam dimension applicable to the theoretical formula of the buckling load, and also enabled us to establish an experimental formula for a range in which the old formula does not hold.

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An approximation method for a flat plate with large deflection is proposed : firstly the deflection and bending stresses are calculated, assuming the radial membrane stress to be distributed uniformly, then membrane stresses can be obtained by using the result of the deflection. Computations are carried out for the uniformly loaded circular plates with edges clamped or supported. The deflections and stresses agree with the exact solutions within the accuracy required for engineering purposes.

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Theoretical analysis was performed for the lateral vibration of an axially moving linear material which is supported by pullies. The oscillation of this kind has some peculier characters, by the effect of centrifugal force the oscillation degenerates to unstable character, the modes of natural oscillation take a form of wave motion, the frequencies of free oscillation deminish with increasing velocity and there occur self excited vibrations over the critical speeds. The boundary conditions in the analysis are assumed to be constant curvature at two points of support ends. The method of solution is to simplify the characteristic equation and to unify the unknown variables. The numerical calculation by the iterative method leads to the solutions of frequency curves. Another method of analysis by the complex Fourier series gives an approximate but clear perspective of the solution.

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It is well known that Shore hardness number is effected by various factors. The author has carried out a series of study on these factors that effect on Shore hardness. As the first step of the research, the author studied on the effects of the factors related to operating condition of the tester and made the basis of the later researches. And then, the author continued researches on other factors under the fixed operating condition. In the present report deals with the successive investigation of the end effect on the Shore hardness number. After the experiment which was carried out with a Shore scleroscope of D-type and many specimens of various hardness and material, under the fixed operating condition, it has been revealed that the so-called end effect gives no influence upon the hardness number in such a long distance from the end of the specimen as hitherto mentioned and there exists a linear relation between the critical distance for the end effect and the hardness of the specimen.

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The rate of combustion of liquid fuel spray injected into the combustion chambers of diesel or gas turbine engines is calculated in the following way : (1) As the distribution functions for the number and the weight of the sprayed drops are expressed generally by the equations (7) and (10), the experimental indices α and β have been determined for various atomizers and found to be α=-0.5∼2 and β=1. (2) Assuming that combustion rate of the sprayed drops obeys the same law of the combustion of a single fuel droplet expressed in equation (11) and considering that the number of sprayed drops remains constant during the course of combustion, the equation for the weight distribution of the sprayed drops are derived as (17) and (20), the graphical integration of which, up to the maximum diameters, gives the total amount of drops unburned. (3) Thus the amount of burned drops w_b are given as a function of time t and the distribution indices α and β the approximate formula for which is given as (24).

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The flow through the passage of rotating impellers with single and double shrouds (full shrouds) has been studied experimentally by means of a test rig, so designed that it is possible to measure directly the relative velocity, flow direction, total and static pressure on several points in the passage while the impeller is rotating. On the other hand, the theoretical analysis was made under the assumption of two-dimensional potential flow, and the calculated results are compared with the measured results in terms of relative velocity under the given operating conditions. The velocity distribution and the flow direction obtained in the experiments indicate that secondary flows in the boundary layer tend to shift the low-energy air toward the negative surface (Suction surface) of the blade in the passage. In case of single shrouded impeller, there is observed a counter effect along the casing surface apparently caused by the leakage through the clearance space between the blade and the casing. This results in a voltex flow in the passage. It can be concluded that the secondary flows consequently dominate the flow condition, and make it so complicated that it is impossible for us to conjecture it by means of theory.

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Experiments on the flow through cascade of steam turbine blades were recently carried out and the results obtained are summarized in this report. All of the experiments were carried out on the blade profiles of the impulse type turbine, and investigations were made on the following subjects. 1. Comparison of the performances of the several typical blade profiles, 2. Effect of the blade turning angle, 3. Effect of Reynolds Number and the blade surface roughness, 4. Effect of the boundaries of jet from the turbine nozzle.

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This paper deals with experiments on surging phenomena. The results may be summarized as follows : 1. The air column in the pipe-line vibrates in a certain form resembling that of free vibration. 2. The more rapid revolutions of a blower become, the more violent the surging grows, and the more important role the characteristic of a blower plays in determining the amplitude of the surging. 3. When the length and area of a cross section of the pipe-line are fixed, the surging is apt to be built up according to the volume of the tank. 4. The feature of the surging is considerably influenced by the conditions under which the energy is dissipated from vibrating air column.

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The authors determined experimentally the discharge coefficients c of inlet nozzles, whose diameters range from one inch to 10.6 inches to measure air, water and oil flow quantity. Experimental formula of c correlated to Reynolds number coincides with the experimental results as shown in Fig. 7.

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Though numerous studies of disc friction of smooth surface were already carried out, but the detail discussions of disc friction of rough surface have not yet been performed. Experiments were carried out for both cases of discs with smooth surface and rough surface, consisting of sand-grain of various size and shape. The main results obtained may be sumarized as follows : 1) Resistance Coefficient C_f in turbulent flow region tends to a certain value with increasing R_e for rough surface. 2) For a certain small value of clearance, coefficient C_f takes a minimum value. 3) Resisting moment of cast-iron disc is equal to that of the disc with rough surface IV. 4) When geometrical similarity is held for the dimension of apparatus, C_f depends on R_e only. 5) For increment value of resistance coefficient induced by roughness, the relations C_f1≒2C_f2≒4C_f3 hold.

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In this paper, cylindrical surfaces, which mesh, with each other at one point at a constant angular velocity ratio, are investigated. In the first place, the possibility of this case is investigated, and it is clarified that this is possible when one of the pair is convex and its partner with line contact exists. Then curvatures of these surfaces are made clear. And interference of these gears is studied basing on this result. When one of the pair is given, the partner's generator direction is limited by asymptotic direction of surface which contacts with the given cylindrical surface along the line. Lastly, when one of the pair and the partner's generator direction are given, the theory that the partner's profile is calculated is clarified. These results are the foundation of cutting gears by milling or shaping.

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O.W. Boston and others have introduced a mean value of flank wear of 0.03" as a reasonable indication for the tool life. However, our experiments have revealed that the critical value of flank wear is not always constant, but it should be controlled by the kind of carbide grade, material cut, cutting condition and tool shape. Arranging the experimental data, we have proposed a summary table of the critical value of flank wear.

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As factors of generating roughness in cutting, first we consider the replica of the cutting edge roughness, and estimate clarity of the replica with multiple correlation coefficient between edge profile and generated profiles on a work after cutting. Next we consider the after-effect of the surface roughness of works before cutting, and estimate the degree of after-effect with singular correlation coefficient between the initial and refinished profiles. Both the replica and the after-effect depend on the properties of materials and cutting conditions, but the after-effect can no longer be recognized after the feather cutting. Lastly abnormal roughness, which is generated by disturbance of built-up edge, is estimated with partial correlation coefficient, and auto-generated roughness, which is caused by the non-uniformity of grain size and hardness of materials, is estimated with auto-correlation coefficient. These abnormal and auto-generated roughnesses also depend on both the properties of materials and cutting conditions, but the latter may be found only in the case of fine cutting.

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It has been shown by the present author that the critical conditions for the wrinkling in the deep drawing operated with flat dies depend mainly on the holding-down force and the rigidity, i.e., its changing rates due to deformations as regards the blank holding systems. The present paper deals with the results of the systematical experimental investigation with reference to the wrinkling behavior of the various types of the blank holding systems, including the new systems proposed by the author. Further, the result of the present, experiment has clarified the mechanism of the wrinkling and the characteristic of blank holders of these types.

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