In this paper, on analytical method for solving the elastoplastic problem of solid bars subject to combined bending and twisting is represented, using the total strain theory of plasticity. Considering that the shearing strains are obtained by combining shearing strains due to twisting new parameters in stress field. Provided that Ramberg-Osgood's law is employed can be linearized respectively, by adopting the new parameters in stress field. Provided that Ramberg-Osgood's law is employed as the nonlinear stress-strain relation, the twisting and bending functions can be described in the form of a hypergeometric series. The components of strain and the corresponding coordinates are also represented in terms of these new parameters. The components of stress, bending moment and twisting moment can be evaluated by the numerical calculation. In a special case where the secant moduli are equal to moduli of elasticity, the results obtained by this method agree with those by the theory of elasticity.

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The moire method and the holographic interferometry, which are effective for the measurement of large and small deformations respectively, are developed. The moire method proposed in this paper is founded on the interference between the grating printed on a specimen and Young's interference fringes instead of the reference grating. If Young's interference fringes are projected on to the specimen from two directions, two components of the displacement are obtained. Measurement of an incremental deformation is also possible when some sensitizer is affixed to the specimen and Young's interference fringes are projected on to it two times during deformation. As for the holographic interferometry, Enno's method is improved so that two families of the interference fringes corresponding to two components of the displacement may be obtained on the congruent images to each other. Fundamental data are provided about these methods.

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Two criteria of ductile fracture strain are suggested. From the theory of plasticity for porous materials, the following criterion of fracture for a triaxial state of stress is obtained: [numerical formula] where ε_e_q_f is the equivalent fracture strain, σ_m the mean stress, σ_e_q the equivalent stress, a₀ and b₀ are constants. Except under certain conditions, this criterion shows reasonable agreement with experiment. To improve the accuracy of the prediction of the fracture strain, the above criterion is modified as follows: [numerical formula] where c₀ is a constant. It is found that this criterion provides a greater accuracy for prediction of the fracture strain.

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Swirl flow in a long pipe is experimentally investigated. In the major part of the pipe, that is, except at the entry zone with a very weak swirl, the circumferential component of the velocity is proportional to the radius near the wall. The axial component of the velocity is minimum at the center and the radial distribution is similar to the velocity profile of the wake behind a body in a uniform flow. The intensity of swirl is indicated by a parameter. The variation of the parameter and the wall pressure along the length is examined for three pipes with different relative roughnesses and semiempirical equations are derived. Using the equations, the velocity distribution and the wall pressure at any section may be predicted if the conditions at an upstream station and the relative roughness of the pipe are specified.

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The pressure gradient of a bubble and slug flow after the confluence of air and liquid in a vertical small tube, and the condition of existence of a fish scale type slug flow, are investigated. For the decision of nondimensional empirical equations of pressure gradient, the following nondimensional quantities are taken into consideration, that is, supplied air -liquid ratio, liquid Reynolds number, Froude number and, Weber number. The maximum pressure gradient of the fish scale type slug flow is affected by the length and diameter of bubbles and the surface tension. It is very difficult to analyze the effect of surface tension on a two-phase flow with surface active agent solution. It is because the dynamic surface tension is very different from the static surface tension.

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A study of pressure gradient of an air-liquid two-phase flow which streams upward after confluence in a small tube is made. In this paper, the pressure gradients of flows in the region of high ratio of supplied air and liquid flow, that is, piston, froth, annular and long piston flows are reported. In these flow patterns, the tendency of an unestablished flow is strong, and especially the difference of pressure gradient between upper and down streams in forth flow is large. Depending on conditions of mixing air and liquid, there is a region in the part of froth flow in which a steady rate of air flow can not exist. The pressure gradient of piston flow is small, and we must be cautious about the definition of its pipe friction. The nondimensional empirical equations for the pressure gradient of each flow pattern are obtained, and one equation which covers the whole region, is also obtained for supplementary purpose, though it is an estimation somewhat short of preciseness.

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There is a very distinctly discontinuous region at the boundary between fish scale type slug flow and froth flow in a vertical small tube. This involves a possibility of leading to the relaxation oscillation of a stream, when the air line has an air chamber, and the inlet hole to the chamber has a fairly high degree of resistance. In the case of constant rate of liquid flow, the condition of generating the relaxation oscillation is as follows Cc^<1/q%gt;<Q_gB^1/q-Q_gA^1/q/P_VA-P_VB where Cc:Q_g3/(P₄-P_V)^q=constant q: constant P_V: pressure of air chamber Q_g3 : rate of air flow which streams into air chamber Q_g2: rate of air flow which streams into tube Subscripts A and B: Upper limit of fish scale type slug flow region and lower limit of froth flow in steady state

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The relationship between the coefficient of drag and the Reynolds number on a sphere in the polymer solutions was studied experimentally through on the measurement of terminal velocity and the observation of flow about a falling sphere. And then, the effectiveness of Stokes's law and Perry's curve for the concentrated polymer solutions (CMC & PED) in the range of low Reynolds numbers (less than 10³) was examined using R_e* instead of R_e and the drag reduction of very dilute polymer solutions (PEO) in the range of high Reynolds numbers (more than 5×10³) was confirmed. Besides, it was shown that such a drag reduction was characterized by two dimensionless numbers, Reynolds number (R_e) and Weissenberg number (R_n*: Reiner-Rivlin model or N_e*: Combination model).

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The experimental results are described on the transfer rate of liquid droplet onto the duct wall, the distributions of the droplet volumetric fraction, the droplet and gas velocities, and the pressure loss for a two-phase (Air-water) annular mist flow through a horizontal rectangular duct. The mean diameter of droplets was in a range from 27 to 40 microns in this experiment. The droplet transfer coefficient onto the wall derived from the experimental results indicates that it is affected by the droplet concentration as well as the gas velocity. Therefore, for investigating the mechanism of droplet transfer, the effect of the eddy diffusivity of the gas flow containing the droplets is discussed from the relation between the distribution of velocity and that of shear stress in the gas stream.

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The increase of heat transfer coefficient due to roughness on a heat transfer surface is well-known, and several researches on the effect of roughness size, shape and its arrangement have been reported. This paper purports to clarify the cause of this increase of heat transfer coefficient by roughness. An experiment was carried out in a rectangular duct 37×77 mm² with a cylinder 5.66 mmφ as a two-dimensional roughness. Measurement was made about static pressure distribution, time averaged mean velocity profile, turbulence intensity in the flow and near the wall and the distribution of heat transfer coefficient in the flow direction. It is shown that the distribution of heat transfer coefficient is closely similar to that of turbulence near the wall and the increase of heat transfer is considered to be caused by the change of mean velocity and temperature distributions due to intense turbulence near the wall.

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In the first report the relation between bubble characteristics and heat transfer was investigated for the surface film boiling from horizontal cylinders of comparatively small diameter. This report deals with the result of some experimental study performed to clarify the effects of the diameter of cylinder and of system pressure on heat transfer. Water, n-pentane, n-hexane, ethanol, carbon dioxide and Freon 22 were used as the test liquid. The diameter of cylinder range from 0.05mm to 16mm and the system pressure was varied from 0.005 to 1 (expressed by reduced value). It was observed that the disturbances of interface between liquid and vapor become intense with an increase of diameter of cylinder. By comparing the experimentally determined heat transfer characteristics with the result of the theoretical analysis already presented by the authors, it has become evident that the experimental results can be correlated by modifying the analytical results in terms of vapor film Reynolds number.

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In a diesel engine, by a systematic controlling of the burning rate, the performances i.e., thermal efficiency, maximum pressure, maximum rate of pressure rise, combustion noise emission and maximum combustion temperature which affects the density of NOx emission, etc. may be controlled. In this paper, the performance values, for example the indicated thermal efficiency, were calculated stepwise based on Wiebe's combustion function, and the relationships between the combustion rate and each performance value were investigated. In addition, the harmonics of engine noise were considered to be related to that of the cylinder pressure variation, hence the harmonics of cylinder puressure variation were calculated for the estimation of noise emission. As a result of the calculations, it was clarified that when the combustion rate was controlled to a desired free value with a low compression ratio, the performances, i.e. indicated thermal efficiency, maximum pressure, combustion noise etc., could be improve simultaneously. Thus, a theoretical guide to improving the performances of a low compression ratio diesel engine was obtained.

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In former studies for the cusps on coupler curves, only the number of cusps for some special types of six-link mechanisms was obtained, and mechanisms having cusps have not yet been synthesized. In the present paper, the Stephenson-I mechanism among three types of six-link path-generators is described. First the types of cusps are classified, and the number and positions of them are defined. Then considering the four- and degenerated six-link mechanisms which are equivalent to general six-link ones in the neighbourhoods of cusps, the inclinations of tangents at cusps are obtained. Further, a new method for expressing the error between the ideal and generated curves is suggested, and as a result, the synthesis of a six-link mechanism is carried out such as to satisfy the number and positions of cusps, the inclinations of tangents at cusps, and the shape of the ideal curve.

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In the previous paper, the wear tests were carried out in the lubricating oil containing hard abrasive particles, and an equation was derived considering the wear being a phenomenon of plastic fatigue due to rolling contacts of particles. In the present paper, wear tests of some metals are carried out varying the diameter of SiC particles and the contact pressure, and their effects on hardness and roughness of the worn surface and on diameter of wear fragments are studied. The wear rate equation is modified rationally. However, exceptions are observed with very small particles between the mating surfaces and also under the pressure over a fixed value of materials, and the reasons are explained.

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In this paper, the deflections of a rack-shaped cantilever plate with finite width due to a concentrated load are studied. The numerical solutions for the deflections obtained by applying calculus of finite differences to the basic differential equation, show a few similar characteristics on condition that pressure angles of rack-typed cantilevers are equal. An approximate formula for defections has been established to make use of these characteristics. This formula coincides with the numerical solutions and with the experimental results. The effects of the number of teeth of gear on the characteristics of deflections are discussed in comparison with experiment on a gear tooth profiled cantilever.

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