This paper describes the mechanical behavior of the polycrystalline aggregate in terms of that of the single crystal using the Finite Element Method or the Finite Element and the Monte-Carlo Methods. In section 2 the mechanical behavior of coarse grained specimens of pure aluminum (99.99%) is simulated by the three-dimensional Finite element Method using the deterministic model. The agreement between the results of the calculation and the experiment about the location and direction of slip lines which appear initially at the surface of the specimen is good. In section 3 combining the finite Element and the Monte-Carlo Methods the mechanical characteristics of the polycrystalline aggregate consisting of a large number of grains with various orientations are obtained using the probabilistic model. Young's modulus and Poisson's ratio by the calculation coincide well with the experimental values.

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Behavior of viscoplastic material under dynamic load was considered for two cases; that is, a longitudinal impact of a rigid mass on a finite rod and a normal impact of a finite rod on a rigid wall. Constitutive equation of Bingham type was modified by taking strain-hardening effect into account. As governing equations of the problems were of nonlinear type with moving boundaries, the difference method was employed to solve them. Numerical results for distributions of particle velocities and of strains and their variations with respect to time differed even qualitatively from the results obtained by a theory without strain-hardening. Experiments on a soft mild steel containing 0.015% carbon were conducted. It was found that the numerical results and experiments for permanent strain distribution agreed well. Variations of strain distribution with respect to time during impact were observed by a high speed camera and numerical results were found to predict the behavior qualitatively.

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In the present paper, as a series of investigations on a cylindrical shell under concentrated loads, a cylindrical shell under a circumferential concentrated load, which is simultaneously accompanied by a circumferential concentrated couple, is discussed by applying the same procedure as adopted in the previous report. The solutions due to an in-plane load are deduced in the present paper and those due to a couple are found from those in the 1st report. Solutions obtained are all represented in the form of uniformly converging series and closed terms. The singularities of the cylindrical shell are discussed in detail and it is found that in the case of an in-plane load, the bending stresses have (h/a) order of the membrane ones, in the case of a couple, the membrane stresses have (h_a) order of the bending ones; where a:radius of cylinder, h:thickness of cylinder. The numerical results are also confirmed by the experimental ones.

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In the present paper, the displacements and stresses as well as the singularities in a thin cylindrical shell subjected to an axial concentrated load with both ends built-in are discussed. In this state of the load the cylindrical shell is subjected to two kinds of loads, that is, an in-plane concentrated load and a concentrated couple in the axial direction. Solutions obtained are all represented in the forms of uniformly convergent series and closed form expressions. The singularities of the displacements, the stress resultants, the stress couples, etc., at the point of application of the load in the cylindrical shell are explained in detail and compared with those in a plate. For practical applications in engineering some numerical results are shown for the displacements, the membrane stresses and the bending stresses.

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As bridges becomes larger in size, the members become slenderer and a severe vibration sometimes occurs in the cylinder members because of a Karman vortex caused by gentle winds. A lot of studies have already been conducted on this phenomenon, but there are still many unknown factors left about the behaviors of cylinders, qualititatively and quantitatively. In this study we carried out a few wind tunnel tests in the subcritical range and investigated the vibrating characteristics of the cylinder and the aerodynamic force working on the vibrating cylinder. The following facts were made clear. (1) The vibration of cylinders caused by Karman vortex is self-excited and the range of self-excited vibration is effected by the damping factor of the system. (2) Strouhal's number at the resonant condition reduces to 0.17 as vibrating amplitude increases. (3) Life coefficient at the resonant condition is effected by vibrating amplitude. In the case of the large amplitude, it can be arranged from the view-point of the forced vibration to some extent.

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In this report, Truckenbrodt's method of analyzing the turbulent boundary layer with adverse pressure gradients has been extended to explain the properties of the turbulent boundary layers with injection. Applying the Truckenbrodt's method, and based on the fact of the One-Parameter Family advocated by Doenhoff and the others, the author intended to find a method of calculating the velocity profiles from the momentum thickness θ and the shape parameter H(=δ*/θ). As it was confirmed through many experiments that the concept of One-Parameter Family is applicable to the velocity profiles of turbulent boundary layers with injection, the author established a simple analytical method of calculating θand H from the momentum equation and the energy equation. Accordingly, the velocity profiles are easily determined as functions of given Reynolds number (R_x=u₀ x/ν). Here, the theoretical equations of θ and H were examined by the author, and it is confirmed that the semi-empirical values of θ and H are in good agreement with measured ones. Moreover shearing stress at the wall and frictional work in the turbulent boundary layer were examined for the turbulent boundary layer with injection.

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In this paper, the apparent viscosity which is one of the most important apparent mean physical properties in a two-phase flow, has been measured by a specially designed rotation viscometer. The experiment has been carried out using a small air bubbles-liquid tow-phase mixture. From the experimental results, the relationship between the specific viscosity η_sp and the void fraction φ has been expressed with an experimental formula involving the dimensionless number T_a, which shows the amount of the deformation of bubbles in shear flow.

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In order to study the optimum design conditions of exhaust and scavenging time areas in a poppet valve uniflow two stroke cycle engine, a series of fundamental equations and methods of estimating the engine performance were derived by developing generalized dimensionless expressions. The possibility and accuracy of this calculation method could be checked by some calculations on a high speed three-cylinder diesel engine equipped with a mechanically driven blower.

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The influence of the design parameters of exhaust and scavenging time ares on the engine performance was calculated, assuming various operating conditions and various characteristics for the engine, blower, and so forth. Some general principles and suggestions in determining optimum exhaust and scavenging time areas were shown. In addition, the peculiarity and restriction of exhaust and scavenging time area designs are briefly discussed for the poppet valve uniflow type engine, as compared with the opposed-piston type and the loop scavenging type engines.

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Four-link coupler curve is discontinuous at the change point, and is separable into two or four curves by reversing the driven link about the fixed link. Nevertheless, in former algebraic analysis of singular points, it was not able to distinguish between the singular points on one curve and those on two curves. For practical uses of mechanisms it is required to analyze the singular points on one curve and to synthesize a mechanism having such singular points. In the present paper, the authors first obtain the number of singular points on one coupler curve of planar four-link crank-and-rocker mechanism, and derive the conditions for syntheses. Second, calculating the inclinations of tangents at the singular points, they synthesize the mechanisms satisfying the number and the positions of singular points and the inclinations of tangents at the singular points. As a result, it became possible to apply the coupler curve to automatic assembling and conveying machines.

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As the first step to find the noise reduction methods for toothed belt drive, the authors investigated the characteristics of the noise and its generating mechanism experimentally. The results obtained are as follows: (1) In general running condition the impact sound which is generated periodically with tooth meshing frequency is the most powerful component in the noise. And it was ascertained that the impact sound is caused by the collision of tooth tips of the driving wheel against bottom lands of the toothed belt. (2) When the belt tension is large enough the transverse vibration (string vibration) of belt resonates badly with the meshing frequency and this resonant sound sway the noise level. (3) In a case where both impact and resonant sound are not predominant, the toothed belt drive runs silent enough.

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In this report the authors investigate the influence of the construction and the dimension of toothed belt and some running conditions on the noise of toothed belt drive, and show some running noise reduction methods and their effectiveness. The running noise level varies with belt speed, belt tension and polygon-effect of the wheel, but there is no difinite tendency between noise level and number of teeth and module of the wheel. The effective methods to reduce the meshing impact sound and to keep the toothed belt drive silent are: (1) to soften the bottom lands of toothed belt or the tooth tip lands of wheel, (2) to make belt width narrow, (3) to cant the belt of tension side with an idle pulley, (4) to make the wheel noncylindrical, especially as barreled-shape.

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