The effects of orientation, stress ratio, frequency and temperature on the fatigue crack growth rate are investigated in polycarbonate.A stress intensity factor is used to normalize the crack growth rate data.It is found that the crack growth rate can be expressed by the power law of the range of stress intensity factors and the constants of the power law are functions of the factors mentioned above. A crack growth law to explain the observed results is proposed. The growth rate law obtained may be applicable to the case of metals and their alloys, although it is introduced by the experiment of the fatigue crack growth in high polymer.

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The greater part of the service load is occupied by the stress amplitudes below the fatigue limit. And the effect of this kind of stress amplitudes on the fatigue life is a quite important factor in estimating fatigue strength under service load. A fatigue test with a normalized 0.35% carbon steel under programmed rotating bending load was carried out. Cracks were initiated by the stress amplitudes above the fatigue limit, them they were propagated by the stress amplitudes below the fatigue limit, and the rate of crack propagation was measured. The test results show that the condition of crack propagation under the stress ampltudes below the fatigue limit is decided by the magnitudes of them and the crack length which was initiated by the stress amplitudes above the fatigue limit. And the behavior of crack propagation in cracked specimens is similar to that in sharply notched specimens.

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This paper presents a stress analysis at the root of a bolt thread by the finite element method and the copper-electroplating method which were used for the stress analysis of V-groove in the 1st report. Firstly, as a three dimensional axially symmetrical problem, the load distribution at the bolt thread which is screwed in a nut thread, is computed by the finite element method combined with the point matching method. Then, the stress concentration factor under this load distribution is computed. Secondly, a measuring method of the stress concentration factor by the copper-electroplating method presented in the 1st report, is applied to the bolt threads with three.root radii. The obtained results are as follows : (1) The numerical solution of the stress concentration factor by the finite element method shows a fairly good agreement with the experimental value by the copper-electroplating method; (2) the deviation of the maximum stress point at the root of a thread toward the loaded flank becomes larger with an increase of the root radius; (3) even if the root radius is increased over the range which is specified in ISO Standard, the stress concentration factor is scarcely improved.

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Swelling and deswelling processes are presented for a new mechanochemical system, which is phosphorylated polyacryl acid cross-linked with polyvinyl alcohol originally synthesized here. The dynamical properties of the mechanochemical piston, in which a cylinder is packed with mechanochemical particles, and the improvements of the piston are reported. Some applications of the particles piston to machines (punch, jack etc.) are also presented.

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An analysis of the pump performance is carried out, applying the momentum theory and the turbulent transfer theory. The results of the analysis are compared with the experiments in which the pump performance in the various combinations of the pump elements and the viscosity effects are investigated. The following results are obtained. (1) The applicable equations for the pump performance are deduced for two types of head capacity curves corresponding to the difference of fluid viscosity. These equations are approximately consistent with the experimental results. (2) The equations due to the momentum and the turbulent transfer theories almost agree with each other in disregard of the fluid viscosity or in large dimensions of the flow channels. (3) The coefficients of of shut-off head, maximum capacity, the torque and the maximum internal efficiency, as the characteristic factors for the pump performance, are examined by the equations and consequently the relation between the pump elements and the coefficients is made clear.

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The subject of this paper is to make clear the basic characteristics of the AFH. To calculate the characteristics of the AFH with single conduit, the AFH containing a separator and the three-phase AFH, three matrices, namely exact matrix, approximated matrix using the Poiseuille's law and matrix approximated by lumped parameters, are considered. When the input frequency of the AFH is lower than the fundamental characteristic frequency of the conduit, the calculations based upon the approximated matrices induce no important error. The frictional force on the separator caused by the sealing material lowers remarkably the power transmission efficiency of the AFH. With the three-phase AFH, the pressure variation does not become sinusoidal even if the displacement of the input pistons is sinusoidal. In this case a high input frequency can not be taken because some resonance will be induced in the system by a higher harmonics in the pressure wave.

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The starting torque of a swash plate type axial piston motor was analyzed, and oalculated results were compared with the experimental results. In this paper, the starting torque was derived from the friction forces appearing at the piston, the oylinder block, the valve plate and the shaft seal. The values of the friction coefficients at these sliding surfaces were measured experimentally. Using these measured values the starting torque was calculated and its agreement with the experimental results was relatively good. As the result of this investigation, it has become clear that the starting torque of a swash plate type axial piston motor is can be calculated analytically.

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Heat and mass transfer by free convection from humid air to a vertical plate of different heights(4, 8.5, 17cm) under frosting conditions was investigated experimentally.It is found that the conception based on steady boundary layer theory can be applied on the whole though the frost surface conditions (temperature, roughness etc.) vary with time and that there is a little influence of surface roughness on heat and mass transfer. To establish a method to estimate surface temperature, time dependency of specific weight of a thin frost layer near the surface and the relation between thermal conductivity and mean specific weight of the frost layer are assumed. The estimation agrees with experimental results within engineering accuracy.

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As a sequel to the high-speed photographic studies on combustion in direct-injection diesel engines, the progress of combustion in a quiescent shallow-dish chamber with a multi-hole nozzle centrally located has been investigated by taking a crosssectional view of the combustion chamber. This has been attained with a two-cycle engine with specially designed cylinder-head and piston, which simulates only a sector of the injector and piston-cavity arrangement. As the result of observation, it has been revealed that a considerable amount of the fuel is conveyed to the cylinder head after the spray hits the wall of piston cavity, governing the flame development in the middle and later stages of burning, and that the fuel which penetrates into the clearance space makes a substantial source of soot cloud. Further, the influences of the direction of the fuel spray, the opening pressure, and the profile of the chamber on the progress of burning have been evaluated.

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Using soft carbon steels which are very likely to cause grooving wear on high-speed steel cutting tools, studies were conducted on the mechanism of grroving wear and its prevention and following results were obtained : (1) Without changing both the tool shape and the cutting speed, the authors worked out a method by which grooving wear could be absolutely prevented or severe grroving wear could be produced according to the will of the authors. (2) It was estimated that grooving wear is caused by the corrosive action due to the lack in uniformity of positive catalytic action at the surface of work-material just behind the cutting edge. (3) Therefore, the amount of grooving wear can be decreased to a great extent by taking some effective means, e.g. by adding surface active agents to the cutting fluids and/or by using tools with a large side-cutting-edge angle. (4) Moreover, a non-soluble cutting fluid containing a certain extreme pressure additive (viz, a sulphide, which seems to promote the catalytic action caused by the virgin surface of work material) was responsible for producing a very deep groove at the boundary between work and tool (where catalytic action seems to be large). (5) Although very severe grooving wear occurred during cutting in air (dry cutting), this was entirely prevented by removing air from the cutting region by flooding some cutting fluid containing no extreme pressure additives (mineral and plant oils). (6) Increase in cutting force per unit length of cutting edge at the points where the grooving wear occurs is not the main cause of grooving wear because grooving wear can be fully prevented even with the existence of burrs (side flow) of work material and detached particles of built-up edge.

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Internal gears have disadvantages that fewer machine tools can produce them. The most commonly used techinique to produce internal gears is a gear shaping with pinion-type cutter which generates gear flanks with rotating motion and removes chips by reciprocating action. Hobbing and rack shaping are impractical on internal gears. Gear skiving is a new and high productive method to produce internal gears with rotating tool. Skiving tool for internal spur gear is a pinion-type cutter. Skiving cutter and gear blank are mounted on non-intersecting and non-parallel shafts which are at helix angle of pinion-type cutter. In this paper the geometrical relationships between skiving cutter and internal spur gears have been analyzed according to the analytical theory of tooth profile.

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