The interaction of edge and internal cracks under a tensile load has been investigated using a Ni-Cr-Mo-V alloy rotor forging at - 75°C. Four kinds of crack configurations were used ; all the specimens has one internal crack and one edge crack. The length of the internal crack was kept constant but the length of the latter as well as the distance between cracks was varied systematically. At each crack tip, K_I value was estimated by the FEM calculation and the strength zone width, SZW, was measured. SZW at crack tips mutually interacting was larger than the predicted value from Bates' relation using the K_I values, although at the innermost tip, SZW and K_I values were well correlated by the relation. The influence of the internal crack on the edge one became larger as the edge crack became shorter.

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This paper is concerned with the dynamic stability or cylindrical shells subjected to periodic axial load or periodic external pressure. The equations of motion taking into account the in-plane inertia and the in-plane disturbance are derived. Applying the Bolotin method, the effects of the in-plane inertia and the in-plane disturbance on the principal instability regions of the cylindrical shells are examined. Some of the results show that their effects are remarkable in the case of periodic axial load at low frequencies and in the case of periodic external pressure at high frequencies. This study also includes the comparison of the results for the theories due to authors such as Mizoguchi, Flugge and Donnell.

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A transversely isotropic circular cylinder subjected to two diametrically opposite loads is considered in the framework of the three- dimensional theory of anisotropic elasticity. A general solution to this nonaxisymmetric problem is obtained by using a set of three stress functions introduced by Elliot and Lodge, and the numerical calculations are carried out for the concentrated loads which are the limiting case of the partially distributed loads. Numerical results are presented for the stress distributions in magnesium and cadmium single crystals and fiber- rein- forced plastics (FRP) composite materials, and they are compared with those of the isotropic materials to show the effect of anisotropy.

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Elastic-plastic deformation behaviour of inhomogeneous materials such as polycrystals is investigated analytically using a plane geometrical model of inhomogeneous materials and finite element calculation. The deformation behaviour is expressed quantitatively making use of constraint ratio calculated from strain distribution in the model. The change of mean constraint ratio for polycrystals during elastic-plastic deformation is obtained. It is found that deformation proceeds between the conditions under constant strain and under constant stress for the most of the calculated range of plastic strains. When elastic inhomogeneity or anisotropy is present, however, the deformation mode becomes close to the constant strain deformation in the elastic-plastic transition stage. The difference between macroscopic yield of polycrystals and microscopic yield in grains due to the presence of elastic inhomogeneity is also discussed.

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The procedure of analysis of harmonic waves propagate in elasticwave guides is applied to harmonic waves in linear viscoelastic wave guides. The formal solutions which satisfy the frequency equations of guides wave motions in a linear viscoelastic plate are thus obtained. The frequency spectra of guided waves in a viscoelastic plate are compared with those of elastic waves, and their differences are discussed. The displacement and the phase lag profiles in L and SV modes are obtained at specific frequencies, and it is shown that the viscoelastic waves of these modes are not plane waves.

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The present paper shows a new measuring method of impact force applied to a plate. The principle of the method is to obtain the force in terms of a finite difference of strains in the neighbourhood of the impacted point on the plate. We measure the variations of the impact force with time under several kinds of impact rods and confirm that the present method gives better results over load time than the conventional method. The method can be also applied to measure the impact force on the plate impacted by an arbitrary shaped body. As an example, we show the variations of the force with time in the cases of being impacted by steel spheres.

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In this paper, the intensity of cavitation shock-noise is measured by using 8 models of elliptical cylinders of various eccentricites for the purpous of knowing the effect of a change of the shape of a body in a cavitating flow. In a model which has a longer axis, the maximum intensity of shock noise is lower and the cavitation number corresponding to the maximum noise is smaller. When long elliptic bodies are set inclined to the flow, the maximum noise becomes larger as the angle of inclined to the flow, the maximum noise becomes larger as the angle of incidence increases and at the same time the cavitation umber corresponding to it becomes larger. The periods of cavitation shock are also measured. The period for the semi-circular elliptical cylinders shows a tendency of being reduced as the cavitation number becomes small, but for the long elliptical cylinders having the angle of incidence, contrarily the period increases as the cavitation number becomes smaller.

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With the development and use of electromagnetic pumps in metallurgical and atomic industries, the investigation of the flow of electrically conducting fluids in channels under an applied magnetic field is growing in importance. Here is reported an experimental study of transition and turbulent flows in curved channels with rectangular cross section under a transverse magnetic field. Mercury is run in curved channels with relatively small radii of curvature where the secondary flow exerts a strong influence. Several phenomena are reported, which can not be encountered in flows in curved channels of non-magnetic case and MHD flows in straight channels. Besides, the influence of the Reynolds number, the Hartmann number, the channel radius of curvature and the aspect ratio on the resistance coefficient of transition and turbulent flows in curved channels is made clear.

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Flow patterns for a self-preserving region on the axisymmetric radialwise wall jet on the impinged wall were experimentally studied. Denoting a distance H between annular nozzle and impinged wall and the corresponding critical distance Hc, it was ascertained that flow patterns for the region of H>Hc were similar to those of circular impinging jet. On the other hand, it was ascertained that flow patterns for the region of H<Hc might be represented by two new parameters defined experimentally in this study.

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The influence of heat transfer on the stability of a liquid layer which flows down an inclined plane under the action of gravity is investigated taking variations in density, viscosity, thermal conductivity and surface tension with temperature into account. A perturbation method is used to obtain information regarding the stability for the case of small wave number and small temperature difference between the wall and free surface. The effect of heat transfer on the stability of a liquid layer is clarified in terms of the critical Reynolds number, neutral stability curve, phase velocity and amplification factor.

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Starting from a substantial model of heat conduction, we obtained Lagrangian and Hamiltonian forms in heat conduction, in which the degree of non-equilibrium played an essential role. Next, we explained a general method of analysis and clarified the structure in phase space. Then we applied these techniques to rather difficult problems of heat conduction in solids, demonstrating that they can thus be solved.

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Condensation cycles for power generation using carbon dioxide as a working fluid have higher efficiency than conventional steam cycles at a turbine inlet temperature higher than 650 °C. Also, turbines can be constructed compactly owing to a small specific volume of carbon dioxide at the operating pressure, and the arrangements of the plant are simple as compared with those of the conventional steam cycles. Therefore they are suitable for large capacity steam and nuclear power stations. A power-generating plant of liquid phase compression, supercritical pressure cycle using carbon dioxide as the medium was designed and manufactured as an experimental apparatus of small scale, which comprises a pump, a regenerator, a heater, a turbine and condensers. In this report the experimental results of the static characteristics of respective components are described to obtain the basic data for practical plants.

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A quantitative indication method of gas-liquid interface structure and its transient property in an existing two-phase flow was investigated with the object of predicting flow patterns. The relation between flow pattern and statistical property of local void fraction fructuation was discussed. The first moment distribution function of local transit length was chosen as the indication function, and it was shown reasonable to plot the function on a logarithmic probability graph paper. In a broad experimental range of vertical flows with continuous liquidphase, some kinds of indication curves were obtained : a single straight line or a simple refracting curve consisting of two or three straight lines. The information obtained by this method and the relation between the curve and flow pattern were shown. It was demonstrated that the method was useful to indicate, compare an predict the flow pattern.

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A problem of randomness existing in the constituting elements and shape of structures arises inevitably in actual products. This affects the response and eigenvalues of the structure. Then, it is necessary to decide design standards rationally. In this paper a method of regulating the allowable deviations of the random parameters is investigated, when the allowable deviations of the displacements (stresses) are given. Linear deviation analysis by the partial derivative method is presented, and its applicability and characteristics are examined.

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A problem of randomness existing in the constituting elements and shape of structures arises inevitably in actual products. This affects the response and eigenvalues of the structure. Then, it is necessary to design standards rationally. In this paper a method of regulating the allowable deviations of the random parameters is investigated, when the allowable deviations of the eigenvalues are given. Linear deviation analysis by the partial derivative method is presented, and its applicability and characteristics are examined.

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This paper deals with a technique to suppress the self-excited chatter vibration in machine tools by servodamper method proposed by the authors in the previous papers. Firstly, it is shown that the servodamper designed by applying an output feedback control theory is capable of increasing stability in cutting process against the occurrence of the chatter. Secondly, from a viewpoint of model cutting experiment, the capability of the servodamper to eliminate the chatter is presented. Thirdly, by installing the servodamper in a large-scale vertical lathe which has been required a countermeasure for the chatter occurring frequently, this paper shows the results of a cutting experiment in which a servodamper proves to be effective for eliminating the chatter under various cutting conditions.

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This paper treats analytically the vibration prevention effect of the Houde damper which is attached to a main vibration system with positive or negative damping. Analyses about the damper of this type been done in the past only in the cases of a main system without damping. In this paper, the analyses are done both in the case of the main system with negative damping, that is a self-excited vibration system, and in the case of the main system with positive damping which is subjected to various alternate disturbing external forces. It is shown that better effect can be obtained in each case, if the optimum value of damping is given to the Houde damper with consideration of the damping of the main system.

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In balancing a flexible rotor effectively, the selection of the correction planes is a very important problem because ill-selection of the correction planes occasionaly results in excess of correction mass which may be impermissible for that rotor. From this viewpoint, the authors proposed in preceding report a theoretical balancing technique by the quadratic programming method in which the sum of the squares of the residual vibrations after balancing is minimized under such conditions that the amount of correction mass applied to each plane does not exceed a certain limit permissible in that plane. The optimum correction masses can be calculated by means of a computer program based on the quadratic programming problem. This paper deals with a method applied to a flexible rotor with overhung masses and its usefulness is verified by some experiments.

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The free vibration of an annular plate of radially varying thickness is analyzed by use of a spline technique method. For this purpose, with the plate divided into small ring-shaped elements, the transverse deflection of each element is expressed by a quintic spline function with unknown coefficients. These coefficients are determined and also a frequency equation of motion of the plate at each dividing circle and also satisfies the boundary conditions at both edges. The method is applied to annular plates with linearly, parabolically and exponentially varying thickness ; the natural frequencies and the mode shapes of the plates are calculated numerically and the effects of the varying thickness on them are discussed.

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It is study, effect of the clamping force of double nuts on fatigue strength of bolted connection was investigated under the conditions of clamping in elastic and plastic regions and also in the case of applying pre-load torque to bolt. The results are as follows : From a standpoint of fatigue strength, it is by the optimum clamping method of double nuts that both lower and upper nuts can be clamped with the same clamping torque. Upper nut (lock out) of double nuts not only prevents a relaxation of bolted connection buy also gives an effect on the clamping force and fatigue strength of it. When a bolt is clamped in plastic region, fatigue strength of bolted connection is improves. Fatigue strength of bolted connection depends on the total clamping force of double nuts.

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In order to investigate the influence of dynamic behaviors of a gear system with many degree of freedom on the tooth load, a new method to measure quantitatively the dynamic increment in the tooth load is presented. Then, by using this method, the dependency of the natural frequencies of the gear system on the dynamic increment in the tooth load is investigated experimentally and theoretically under two different operating conditions. As the result, it is made clear that, under a regulated operating condition, the dynamic increment in the tooth load is dominated by a specific natural frequency of the gear system and on the other hand, under a rough operating condition, the dynamic increment is closely connected with plural natural frequencies of the gear system.

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Surface durability of the H_B &ap; 340 (hardened and tempered) hobbed gears was investigated by using a 2-roller-type fatigue tester and a power circulating-type gear tester. It is found that the initial surface roughness has much more influence on the rolling contact fatigue of the H_B &ap; 340 steel than that of the H_B &ap; 150 (annealed) one, and therefore, that the pitting limit of the H_B &ap; 340 hobbed gears is P_max &ap; 0.2H_B kgf/mm² due to the rough initial surface. Thus, the tooth surface of the H_B &ap; 340 hobbed gears should be finished as smooth as possible in order to obtain higher surface durability by the effect of hardness.

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The authors studied theoretically the vibration of a single-stage Stoeckicht planetary gear (Type 2K-H) constructed with spur gears, and calculated the fillet stress, the dynamic tooth load and the load distribution, Furthermore they indicated that the calculated results nearly coincide with the measured ones. The results are as follows. (i) The inequality of load distribution due to the run-out error can be eliminated by using the floated sun gear. Therefore the mean load distribution rates for each planet gear are nearly equal. (ii) But it is difficult to eliminate the inequality of load distribution due to the vibration of tooth profile error and tooth stiffness. (iii) The run-out errors bring about the torque variation of lower and higher speed shafts.

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When a brittle body falls under its own weight and strikes a rigid surface, tensile stresses are set up that cause fracture. This is called self friability. A recent paper (1) has experimentally investigated the self friability of disc shaped bodies with central hole. This paper applies dimensional analysis to this problem in order to gain a better understanding of the physics involved. It is found that a nondimensional quantity that is proportional to the ratio of the specific elastic energy at the critical point of crack initiation to the specific kinetic energy at impact is controlling. This nondimensional group(the self friabilitu number=N_SF) is useful in understanding the relationship between the uniaxial francture stress in tension (σ), the modulus of elasticity (E), the specific weight of the material (γ) and the height of fall (h). [numerical formula]It is also shown that the maximum tensile stress criterion for uniaxial tension may be replaced by a maximum tensile elastic energy per unit volume criterion when an applied force is replaced by an energy per unit volume as the input to the body. The paper suggests a new method of proof testing grinding wheels and the relation of the self friability test to the droppinf weight type of impact test employed in testing spectacle lenses and other brittle objects.,

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