The tensile properties in a 21-4N austenitic engine valve steel containing pearlitic nodules due to grain boundary reaction have been investigated. The theoretical consideration has been also made on the deformation and fracture behavior in this steel. In the steel with grain boundary reaction nodules, the ductility decreased considerably at room temperature, while it increased at elevated temperature. Although the grain boundary reaction also decreased the tensile strength and 0.2% proof stress, its effect was more noticeable on ductility than on strength. A theory is developed to explain the work hardening behavior as well as the fracture mechanism using a model for composite materials and a good agreement between theoretical and experimental results is obtained.

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The principle of heat treatment by ultra-sonic heating lies in using the calorification originated from internal friction in metals caused by ultra-sonic vibration with large amplitude to the materials. Therefore, this heat treatment is a partial one which depends on the vibration mode and also is a kind of thermomechanical one. In this paper, we establish a method of ultra-sonic heating and make clear the properties of quenched material by ultra-sonic heating and make clear the properties of quenched material by ultra-sonic heating. From the results of material tests, it becomes clear that mechanical properties of metal treated by ultra-sonic quenching are by no means inferior to those of metal treated by the conventional quenching (electric furnace), and their hardened microscopic structure is extremely fine. Particularly, from the fatigue tests, interesting results are obtained.

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The specimens prestressed at 200°C and 375°C were fatigued at room temperature in rotating bending. As long as no fatigue crack initiated during prestressing at 375°C, the number of cycles required for crack initiation at room temperature, n_c, was increased. The increase in n_c becomes greater as the prestress becomes higher. The prestress at 375°C contributes to a decrease in crack propagation rate, dl/dn. the wellknown relationship dl/dn=c(ΔK)^m has been proved to be applicable regardless of the precrack length. Both constants c and m become smaller and larger, respectively, as the prestress becomes higher. The increase in n_c and the decrease in dl/dn may be explained as the result of a rapid strain aging occurring during cyclic stressing at 375°C. With the specimens prestressed at 200°C, the decrease in dl/dn depended on the prestress too, but the effect was less remarkable than that at 375°C.

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According to the one dimensional theory a thin-walled open-cross-section member is studied considering the multi-digree-of-freedom of the cross sectional distortion. Generalized equations are obtained including the conventional warping torsion theory. In these equations at number of the extended Saint-Venant's torsional constants are obtained by a definition of simple distortion. The existence of a number of distortional bimoments, corresponding rigidities and shear centers of distortion in plural is also confirmed.

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A dynamic structural analysis involving material and geometrical non-linear characteristics is proposed and applied to a practical problem. This analysis is based on the finite element method and the direct numerical integration, and can be used to predict the crushing behavior of various structures. This paper treats a problem of axially symmetrical collapse of a thin-walled cylinder under axial compressive impact load. The result of the calculation was compare with the experiment, and the dynamic characteristics of the thin-walled cylinder at the time of collapse were investigated.

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Experimental investigations about the plastic deformation behaviours of brass at an initially isotropic state are performed along the strain trajectories with one or two corners starting at the zero-strain state in a vector space corresponding to strain deviators. Experimental results along the trajectories with one corner show that the history effect of a corner having a corner-angle less than 120° disappears with an increase of deformation along the trajectory after the corner. This feature verifies the existence of the so-called "Fading Memory". From the experimental results along thee trajectories with two corners, it is found that the effect of the first corner on the deformation behaviour after the second one disappears for arc length between both corners longer than a certain value, if the trajectory does not contain a reverse in the direction of strain increment. On the contrary, the deformation behaviour along the trajectory with a reverse is affected by a generalized Bauschinger effect.

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A numerical method is proposed for analysing the transonic flows through an arbitrary shaped cascade on an arbitrary surface of revolution. The method which is an improvement of the streamline curvature method developed by Katsanis and Wilkinson needs very short computer time and has practically sufficient accuracy. The method is applicable to the flow conditions which considerably deviate from the shockless entry, to the transonic flows with locally supersonic regions and without shock wave, and to the blades which do not have large radius of curvature at the leading edge. As numerical examples, the pressure distributions on the blade surface, the streamlines, and the contours of Mach number for compressor and turbine cascades are calculated. The pressure distributions agree well with the previous experimental and numerical results.

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A precise solution of the problem of determining a two-dimensional potential flow of inocomplessible fluid around arbitrary shaped slotted blades in cascade was obtained by conformal mapping. This solution facilitates precise evaluation of the extrmely complicated calculations around the slot even if the slat and the main aerofoil are approximated close to each other. Utilization of a modified Milne-Thomson's circle theorem together with Milne-Thomson's circle theorem, as a means of analysis, gives simple expressions of mapping function and complex potential function, suitable for electronic computer calculations. Wind tunnel tests, with comparison between slotted and unslotted cascades, were also conducted. Slight slot effect was obtained in both outer regions of flow inlet angle. However, in the middle region of inlet angle, slot effect was insufficient due to the divergent shape of slot employed.

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It is experimentally made clear in this paper that discrete tones appear in the frequency band lower than the blade passing frequency, when a rotor has manufacturing errors of stagger angle, pitch, camber or chord length, which is at variance with the general understanding that the frequency of discrete noise corresponds to the blade passing frequency and its harmonics. The relations between the magnitude of the deviation of the blading parameter from a design value and the induced sound pressure level of discrete tone and the resulted change of fluid dynamic characteristics of the fan are also examined. analytic considerations of measured wave patterns of pressure fluctuation indicate that this type of discrete noise originates in a distortion of circumferential distribution of mean flow rates through the rotor from the uniform distribution and the consequent circumferential variation of mean pressure level, arising from the unequal blade loading of each blade of a rotor due to the error in manufacturing the rotor.

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For a fully developed flow through a horizontal polyacrylic pipe with inner diameter of 50 mm, a formula giving friction factors for an additional pressure drop attributed to the solids was derived in the case of high solids loadings and low air velocities, and it was confirmed that the formula agrees fairly well not only with authors' experiments but also with the results calculated from the experimental data obtained by Welschof.

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The coefficient of internal friction and one of viscosity of disperse two-phase fluids are simultaneously determined by utilizing a self-consistent cell model and expressed as the functions of the volume fraction of particle phase. It is assumed that the fluid inside the cell is Stokesian and the outside fluid is Stokes-Darcian. Careful examination on the macroscopic notions is necessary to derive the conditions to determine those coefficients. the predictions obtained are satisfactory.

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The effective coefficients of transport phenomena in disperse media are estimated conveniently by utilizing the so-called cell model method. This method, however, loses its capability in cases where the media are absorptive. A cell model method is proposed in the present paper which is capable of dealing with the case of absorptive disperse media. This method is derived by approximating the actual fine temperature field by a smoothed-out field as closely as possible on the basis of a certain estimate function. The proposed method will be effective in more complicated cases such as spray combustion.

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An analysis is presented for the radiative transfer in the semi-infinite medium of an absorbing vehicle containing thee absorbing and anisotropically scattering particles of the pigment to predict the reflection properties of an optically thick painted layer in the wave length range of 0.35-20μm. The effects of the volume concentration (v=0.005-0.55) and the optical property of the pigments (TiO₂, Fe₂O₃) on the bidirectional and hemispherical reflectance are examined. A generalized relation between the hemispherical reflectance and the scattering albedo is obtained. The procedure of expressing the bidirectional reflection intensity as a continuous function of cosine of polar angle and the interpolation method to obtain the hemispherical reflectance at the intermediate optical thickness between the small and the infinitive ones are presented.

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Theoretical equations which give transmission losses are presented for newly invented mufflers which have a gas reservoir in their expansion chamber so that the normal to the free surfaces agrees with the direction of sound propagation. Transmission losses of many mufflers, which have different axial dimensions, are calculated theoretically and measured experimentally. It is found that this type of mufflers are superior in the low-frequency ranges to those that have no gas reservoir. The effects of axial dimensions are discussed.

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In this paper, stability has been considered of a prosthetic gait obtained with an artificial knee-angle feedback system. For a biped gait, the swing leg has a more important role than the stance leg. But, in an above-knee prosthetic gait, the learning control of a prosthetic knee is the most difficult task for an amputee. Then, swing motion was observed, and its performance was described with four parameters. Based upon the theory of learning control, simulated experiments were performed, assuming the process of amputee's progress in his gait to be an optimal feedback gain adjusting process. From simulated experiments, validity of our modeling and analysis was confirmed.

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This report deals with the bonding mechanism in friction welding. The structure and the temperature are investigated near the bonding interface of S15C (JIS G 4051) steels, using a machine built as a trial. The following results are obtained. The process of friction welding is characterized by three phases ; generating of frictional heat, up-setting and bonding. There is a transition zone near the center of the weld. The temperature is measured by the following three methods : metallurgical observations, numerical calculations and measurements by thermocouples. According to these results, the temperature at the rubbing surface increase about 1300°C, but remains lower than the melting point. Within the limits of this experiment, it is assumed that the mechanism of friction welding is considered primarily a mechanical mixing in the transient zone in solid state.

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This paper deals with the problem of facilities location, sometimes called plant layout. Some facilities location algorithms are developed based upon such graphic theory as spanning tree, planar graph and dual graph. In this paper, nodes are defined as facilities and arrows are defined as materials flow, the information of intraplant movement of materials being described by use of oriented graph. An algorithm, which finds out "the minimum backward materials flow location" is developed to rationalize the intraplant facilities location, on the assumption that the facilities locate in a straight line. The feature of this algorithm is in the ability to select the optimal solution, only by using easy matrices manipulation. For verification of it, a trial of this algorithm in regard to 6 actual facilities data is made.

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This paper describes a new gas sampling method which makes it possible to sample cylinder gas in individual cycles fast and successively, and obtain the other combustion variables from the engine at the same time. Two microprocessors were introduced in the system, one for control and the other for data processing. They were operated in parallel online real time depending on the engine speed. It was proved that the gas sampling in the cylinder could be achieved in 16 successive engine cycles. At the same time, the indicated mean effective pressure was calculated easily by either adding or exchanging the programs of the microprocessor. In addition, the value of each air-fuel ratio in 16 successive engine cycles was calculated from the gas concentrations of the sampled burnt gas in the cylinder.

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