The values of mechanical and X-ray elastic constants of polycrystalline metals are closely related with the condition of restriction of grains during deformation. The idea of constraint ratio which is introduced to express the condition of mutual restriction and deformation behavior of grains in polycrystals quantitatively is now extended to a three-dimensional case. General relation between an arbitrary condition of three-dimensional restriction of grains and elastic constant of polycrystals in derived. Numerical discussion is made on the relation between deformation of grains and elastic constant of polycrystals for several metals with cubic lattice. The mean values of constraint ratio calculated from experimental values of elastic constant of the polycrystalline metals are 0.50-0.74. Based on three-dimensional constraint, discussion in also made on X-ray elastic constant which is necessary for X-ray stress measurement, especially on the restriction of surface grains as well as interior grains in specimen. It is concluded from the comparison with experimental data that the influence of specimen surface on X-ray elastic constant is relatively small.

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Based on Clifton's theory we obtained the stress and strain paths for combined longitudinal and torsional impact loading of a semi-infinite tube initially pre-stressed to the plastic range by combined static longitudinal and torsional loads. We found that there were three types of stress paths according to the value of combined step loading, and that paticularly there was a region which can not be reached without unloading in spite of the loading side. Meanwhile, in order to compare the theoretical results with experimental ones, we designed an apparatus which can prestress the tube to arbitary values of tensile and shear stresses and can give incremental impact loading. Using this apparatus a tube is statically pre-stressed in the plastic range, and then sujected to an incremental longitudinal or torsional impact loading. Measurements are made of strain-time profiles at some stations along the tube. In the case of longitudinal impact, the strain response at the gages qualitatively corresponds to the arrival of a fast wave for which torsional strain decreases while longitudinal strain increases followed by a slow simple wave for which both torsional and longitudinal strains increase. But in the case of torsional impact, the strain response does not correspond to the theoretical results. In all cases the velocity of propagation of wave front was found to be that of the elastic one.

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In order to estimate the residual stress in railroad solid wheels, a new technique called plate-cut out method has been developed. Fundamental ideal of this method consists in that the residual stress in the wheel can be separated into two constituent components, σN+M and σi, by taking account of wheel geometry. σN+M is the stress produced by force N and moment M which are the interaction between rim and plate. σi is the residual stress which remains in the rim and plate. σi is the residual stress which remains in the rim and plate after σN+M has been released by cutting the plate out of the wheel. These constituent components of the residual stress are determined respectively through simple strain measurements and elastic stress calculations. It is confirmed that stresses obtained by the "plate-cut-out method" have a fairly good accuracy in practical use as a result of comparison with superficial residual stresses measured by using wire strain gages.

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The residual stress distributions by turning were measured by X-ray under several cutting conditions changing the cutting speed, the feed and the depth of cut. Also the effect of cutting oil was examined. The conclusions obtained in this study are summarized as follows. A decrease of cutting speed decreases the tensile residual stress near the surface, and increases the depth of the residual stress layer. An increase of feed shifts the surface residual stress layer. On the other hands, an increase of depth of cut does not affect the residual stress distributions. The effect of cutting oil on the residual stresses is seen when the cutting speed is below 50 m/min. An empirical formula of surface residual stresses is obtained for present cutting conditions.

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The tilting vehicle of a pendulum type can be regarded as a car with a suspension system which puts constraints on the relative motion of the lateral displacement and the inclination angle of the body for tilting the body on curved track. In this paper a tilting vehicle with inclined strut suspensions is investigated as an example of the vehicle of this type and the characteristics of its vibration are analyzed. We have derived a vibration model that can be used for digital computer analysis and calculated principal modes, frequency responses, and transient responses to a curved track. These calculations have been carried out on three cases by changing the parameters of the tilting link. The first and the second cases correspond to tilting vehicles with different heights of the tilting axis. The third case corresponds to a non-tilting vehicle. Discussions are made on the effects of the tilting suspension on the characteristics of the vibration by comparing these numerical results in each case.

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The cascade interference effect is considered to be a very important factor of the cascade flutter problems in the actual compressors or turbines, but the cascade flutter discussed so far is restricted to the case of single cascade. So, the experiments on the effect of interference between the stationary and moving blade rows on the non-stall flutter of flexural mode are performed under the actual operating conditions of axial flow compressor, using a measuring stator cascade composed of specially designed flexible blades and rotor cascades composed of rigid blades. From this experiment, it is made clear that the aerodynamic effect of interference between cascades is a very important factor in the flutter and that the effect of the rotor cascade upstream of the measuring stator cascade decreases the flutter velocity, while the effect of the rotor cascade downstream of the measuring stator increases it.

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The method of matched asymptotic expansions is applied to the first-order theory on the flow past a two-dimensional supercavitating jet-flapped foil in a wall tunnel, and a solution (=the slope of the jet) of the governing integro-differential equation is obtained and represented as the series expansion in ascending powers of δ and logδ multiplied by functions of the distance from the trailing edge, where δ is a small perturbation quantity proportional to thee jet momentum coefficient. Moreover, the lift derivatives with respect to incidence and jet deflection are obtained as the series expansions in ascending powers of δ and logδ. From the comparison with the previous paper (Ref.1), it is shown that the values of the lift derivative with respect to jet deflection agree closely with the numerical results, even if δ approaches unity.

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The stability of a diffusion flame anchored at impinged point at right angle between air and fuel gas was studied. The stability of the flame may be affected by the flow and mixing field between fuel and oxidizer in the vicinity of the burner port where the flame attaches. To make such circumstances clear, velocity and concentration profiles were studied experimentally using a cold model. Results were as follows : (1) In the vicinity of the burner port, a pair of recirculation zones could be found out. And in the circulation zone, velocity was so small that the zone itself was not so effective as to control the profile outside of the zone. (2) In the outer region of this zone, the dimensionless velocity and concentration profile could be obtained.

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Piston slap is the collision of the piston of a reciprocating machine onto the inner surface of the cylinder through the clearance between them due to side forces and moments around the piston pin. It is a source of noise in internal combustion engines and also induces cavitation pitting of their liquid cooled cylinder liners. The authors for the first time clarify the dynamics of the piston slap, so that the calculated velocity and phase of collision near t.d.c. and also near b.d.c. of a 2-stroke cycle simulated combustion engine fairly agree with the measured ones in case the friction forces at five bearing surfaces are appropriately assumed.

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In order to have a better understanding of the effect of pilot injection, the influence of the waveform of injection rate on the course of heat release during the earlier stages of combustion has been studied theoretically, based on the theory of combustion knock presented earlier in the first report. A systematic calculation shows that the pilot fuel injected prior to the main injection can minimize the peak rates of heat release and of pressure rise, if correct pilot quantity and timing are given. This effect is attributed to the decreased ignition delay of the main fuel associated with the fact that the pilot charge preheats the burning zone. The result of calculation further shows that the pilot fuel should be kept least but much enough to reduce the ignition delay of the man fuel, otherwise a high rate of heat release would arise from the pilot fuel itself.

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The static balanced theory of a rotation-reciprocation mechanism is established, and it is described that this theory is general one which can be applied to the perfectly balanced rotation-reciprocation mechanism and the known piston-crank devices. From the theoretical and experimental comparisons between the perfectly balanced rotation-reciprocation mechanism and the four kinds of known balanced piston-crank devices (containing the static balanced piston-crack device), it is ascertained that the former is much superior to the latter in the vibration, the friction loss between a cylinder and a piston, and the load to a connecting rod. However, the former is a little more complex than the latter in the construction. And it is clear that the static balanced piston-crank device can not be put to practical use without any improvements.

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The outer surfaces of test rollers were cut on a hobbing machine using a flycutter having a semicircular or straight tip. The surfaces of rollers thus finished have three dimensional roughnesses constituted from two relative motions, namely, rotation of roller during one rotation of flycutter (roughness at transverse section) and the feed of flycutter during one rotation of roller (roughness at axial section). When the test roller (Brinell hardness = 160 HB) finished by the flycutter was combined with a superfinished roller with a hardness of 420 HB and was rotated under pure rolling conditions, no pitting occurred up to 10⁷ revolutions at a Hertzian stress of 0.64 HB although the initial peak-to-valley roughness R_max of the 160 HB roller was about thirty times the theoretical oil film thickness h_min built between the rolling contact surfaces. In this case, the surface roughness of 160 HB roller after running became less than h_min. When two cut rollers with very rough surfaces (65 μm R_max and 20μm R_max) and of equal hardness were used in combination, the total surface roughness of both rollers after 10⁷ revolutions was about 30 times h_min although no pitting occurred on the driver and only a single pit, small in size, occurred on the follower. However, when the circumferential roughnesses of the pair of rollers were comparatively small (15μm R_max), they became smaller than h_min due to shifting of the contact points on the roughness peaks of rollers during a long period of running and pitting did not occur until 10⁷ revolutions at a Hertzian stress of 0.71 HB. When the cut rollers with a hardness of 230 or 300 HB were combined with a 420 HB superfinished roller, many pits occurred before 10⁷ revolutions at Hertzian stresses less than 90 kg/mm² even when an initial overload (P_max = 130kg/mm²) for 10² revolutions was applied for smoothing the surface of cut rollers. It was concluded that rolling fatigue strength of cut rollers was extremely affected by running-in abilities of roller materials.

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When machined surfaces are divided into directional asperities and nondirectional ones, the analysis of normal deformations at metal joints are classified as follows. (i) Contact between directional asperities and a flat surface. (ii) Contact between two surfaces with directional asperities whose directions are crossed each other. (iii) Contact between two surfaces with nondirectional asperities. (iv) Contact between directional asperities and nondirectional ones. In this report, the elastic deformation and the plastic one for the 4th case were analyzed. Projections of directional asperities and nondirectional ones were assumed as wedge shape and conic one respectively. The elastic deformation and the plastic one at metal joints were synthesized by statistic of surface asperities in contact. Results were as follows. (1) Relation between the deformations and the normal pressure is linear on a double logarithmic paper. (2) The deformations are classified by the contact surface coefficient.

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