A reverse J-shaped rod used as the post for a street light is assumed to be a rod composed of a straight line portion and an arcuate portion. The sectional area of the rod is reduced gradually from the fixed end towords the free end. In the present case, however, it is assumed that the section varies stepwise at the point bordering the straight line and the arc. A frequency equation is set up of transverse vibration, within the plane including the center line, of a J-shaped and stepped rod with fixed-free supports. Then the relationships are clarified such as the dimensionless natural frequency to the central angle of the arcuate portion, or the ratio of the diameter of the arcuate portion to that of the straight line portion.

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An analysis is presented for the three-dimensional vibration problem of determining the natural frequencies and the mode shapes of a truncated quadrangular pyramid. For this purpose, the body is transformed into a right quadrangular prism with unit edge lengths, by a transformation of variables. With the displacements of the transformed prism assumed in the forms of algebraic polynomials, the dynamic energies of the prism are evaluated, and the frequency equation is derived by the Ritz method. This method is applied to quadrangular pyramid-shaped solid bodies in which the base is clamped and the other sides free, and the natural frequencies (the eigenvalues of vibration) and the mode shapes are calculated numerically up to higher modes, from which the characteristics of various types of vibration arising in the bodies are studied. The results are presented in some figures and compared with those obtained by the beam theories.

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Impact motions of a mass on a harmonically and vertically vibrating table are considered. So-called 1/n-periodic motions (one impact per n periods of the vibrating table. n : integer) are determined analytically and their stability is analyzed. At the boundaries of a stable region of a 1/n-periodic motion one of the characteristic roots is equal to +1 or -1. At the boundary where one root is +1, saddle-node bifurcation occurs, and at the boundary where one root is -1 period doubling bifurcation occurs. Chaotic behaviour can be seen after the period doubling bifurcations. The strange attractor of the chaotic behaviour and the invariant curves are obtained.

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This paper shows the comparison of the experimental and the analytical results of the 1/3-harmonic and parametric combination resonance generating in a chain system treated in the previous report. The influence of a phase angle between the forced displacement and the prescribed tension fluctuation upon the 1/3-harmonic and parametric combination resonance are examined in the experiment using a chain with small friction. As the friction decreases, the characteristics of the combination resonances become complicated and develop many stable branches. The characteristics and the 1/3-harmonic vibration are also compared with each other. A fine agreement between experimental and analytical results was confirmed.

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The large amplitude vibration caused by high-speed steam-water two-phase flow is reported. A similar phenomenon for conditions of almost atmospheric pressure and room temperature is mentioned in the first report. This second report shows the test results operated under conditions of up to 5.8 Pa and up to 270°C, and the analytical approach based on the balance of energy. Small size test tube bundles tuned to the adequated low frequency are excited by steam-water two-phase cross flow. The water velocity is increased step by step while the steam velocity is kept constant. The criteria of unstable oscillation caused by steam-water two-phase flow is proposed as being as likely as that of the air-water two-phase flow.

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When a hanging articulated pipe is vertically excited at random in water, the dynamic behavior of the pipe is analysed as a dynamic problem of a system with random parametric excitation and nonlinear damping. Though this system may become unstable under certain input conditions, the response will not diverge due to the fluid drag force being proportional to the squared velocity. In this study, the response under the instability condition is analysed. A model experiment is also carried out to confirm the analytical model. As a result, a simple equation between the response and the input is derived, and it is confirmed by the model experiment. It is seen that this simple equation is valid for small input, and the root mean square of the response velocity is proportional to the power spectral density of the parametric excitation at twice the natural frequency of the excelling mode of the system.

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This paper is an extended study of a practical combination method of dynamic loads proposed in the previous paper in which problems of the maximum response calculation of piping systems to multiple support excitations were discussed. In this paper, experimental and numerical investigations are carried out in order to confirm the validity and feasibility of the proposed method. Using a simple Z-beam shaped piping model for a shaking test, the maximum response of piping in the fundamental mode is measured and the combination law is applied to various correlation cases among two vibrational loads. From the experimental results, it has been made clear that the proposed method could be reasonable by comparison with other combination laws, like the square root of the sum of the square (SRSS) method.

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The equation of motion whose general restoring terms are modified from these derived in the previous paper is analyzed to show the physical explanation of the instability phenomena of the previous system. This analysis shows that the instability characteristics are decided by the symmetry of the non-diagonal elements of the restoring term. Based on this result, the instability analysis of the previous system is performed more exactly than in the previous paper. As a result of the analysis, the following new points are found : the difference of the instability tendency between models M-4 and S-4 is caused by the instability type i.e. statical or dynamical instability ; Statical instability as well as dynamical instability can occur in model M-4 ; Statical instability can occur also in model S-2.

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The dynamic analysis of link structures, including elastic vibrations, is presented. A truss element, a truss element with pulleys, and a beam element are adapted to simulate link structures, such as robots and construction machines. The theory is based on the three-dimensional static load increment method and is extended to dynamic response analysis. Some examples, such as a rotating pendulum, the free vibration of a cantilever rod, and the dynamic buckling of a shallow arch, are calculated. The three-dimensional movement of a crane is also calculated. It has been clarified that the proposed method is useful to predict the dynamic behavior of link structures, including elastic vibrations.

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Experimental modal analyses are performed to investigate the dynamic characteristics of marine diesel engines. In order to increase the efficiency and accuracy of modal analysis measurements, the authors have developed a modal analysis system that has the capability of multichannel frequency response measurement by stepped sine excitation. By using this system, modal testings of a 6-cylinder engine on a test bed and the same type of engine on a board (including the double bottom of the engine room) were carried out. In this paper, the results of those experiments are presented. Also, an example of predicting the influence of stays on engine vibration behaviour using the modal synthesis method is described, which demonstrates the accuracy and suitability of these methods.

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It is useful for the optimum design of journal bearings if each element of the reference function is weighed easily and quantitatively. This paper proposes a method to normalize the reference function for the optimum design of the journal bearings of a rotor-bearing system. Next, this paper presents a method for the stochastic optimum design of journal bearings. In this case, the chance-constraint technique is adopted to design the journal bearing considering reliability, in which the constraints and the reference function are treated as random variables. In numerical examples, design variables with errors in the design stage are considered and an optimum solution is obtained by the stochastic approach. This shows that the reliability of the optimum solution obtained by the deterministic approach is low since it is nearly always on the boundary values. And it is also known that the feasible region varies depending on the variance of design constants.

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A method is proposed to analyse directly the time history and power spectrum of random response of vehicle on uneven road. The uneven road is represented as one-dimensional filtered Poisson process, and the vehicle displacement is formulated with the aid of complex modal analysis and Duhamel integral. It is found in this procedure that the displacement can be expressed also as another filtered Poisson process .Then it turns out that the power spectrum of the displacement can be obtained directly from the second filtered Poisson process without making use of the power spectrum of the road contour as input. Numerical example is taken in regard to a passenger car modeled as a beam and two sets of mass, spring and damper for the front and rear wheels on very poor road.

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Through quantitative analysis of the mechanism of a hydraulic engine mount with a simple structure, it has been found that the mount functions as a "Velocity Amplifying Dynamic Damper". It was also found that effective utilization of this function provided the following advantages : the dynamic damper can be tuned to an extremely low frequency resonance range and given a compact structure, while the requirement for vibration damping effect can be satisfied at the same time. Then, this function was proven practical through applying it to analysis for reducing vehicle vibrations.

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Detailed theoretical calculations and eigenvalue analyses of self-excited vibration during slippage of parallel cardan drives were made. The influences of the stiffness and damping of flexible couplings and gearbox suspension rubbers were studied, and the measures to suppress the self-excited vibration were clarified. Experiments on two cases with a leaf spring coupling were made by varying the stiffness and damping of the coupling and the gearbox suspension rubber. The experimental results were confirmed to agree well with theoretical results. Experiments on another case with a gear coupling were also made, and it was clarified that this case generates less vibration. Furthermore, available adhesion coefficients μ_a were measured for both cases with self-excited vibration and with no self-excited vibration, and it was shown that the latter case can attain larger μ_a.

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The dynamic response of a plate and the impact noise are considered experimentally and analytically, when a steel sphere strikes a polymethyl methacrylate circular plate. The experimental results are compared with the calculated results, and the formative process of the sound pressure is studied by the calculation. At the initial stage of the impact noise measured on the central axis of the plate, the initial peak and the plateau are observed, and afterward the sound pressure attains the maximum value. The calculated results agreed with the characteristics of these results. By calculation it is found that the formation of the plateau at the initial stage is based on the response of the acceleration in the central area, r/a<le>0.6 of the plate, and the formation of the positive maximum sound pressure is based on the response of the acceleration in the lap area, r/a<le>0.7 of the plate. The wave form of the impact noise outside the central axis of the plate becomes simpler by decreasing the higher modes.

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Cavity resonances sometimes occur in pipe-like structures such as boiler exhaust ducts or heat exchangers. They are due to the self-sustaining oscillation mechanism. The noise is often eliminated by shifting the resonant frequencies away from the frequencies of the vortex generation. Thus the estimation of the resonant frequencies is of great importance in a practical sense. The calculation method of the resonant frequencies on the multi-coupled pipe system with equally spaced connecting holes was studied. It is found that the simultaneous equations derived by the acoustic modal analysis method can be divided into several independent groups due to the structural periodicity.

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The principle of the noise control device and its design methods were described in the previous reports, and it was indicated that a great noise reduction can be obtained when the noise control device with an appropriate barrier, that is, the noise control device system was used. Before the noise control device system is applied to a real noise source, for example, a machine noise, a traffic noise, etc., it is necessary to estimate the noise reduction effect. For this purpose, the noise reduction effect of application to a machine noise was measured and its prediction method by a scale model experiment was considered. In this paper, the noise reduction effect of application to a real noise source and its prediction method are described.

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In order to investigate load position errors due to dimensional errors, the strain changes caused by infinitesimal shape altering are calculated by using the three-dimensional finite element method. The strain changes which result in load position errors take place not only in the region of the beam which has been altered, but in all regions where the strain gage has bonded. In the case where the horizontal bending forces rise from a transverse load position movement, being some dimensional errors in the vicinity of one of the strain gage elements, both the local shift of the neutral axis for the bending in that region, and the global deformation due to the asymmetry of beams give rise to error in measurement. From the results presented in this report, particular modes of dimensional error resulting in serious load position errors are charified, so that the accuracy of dimensions to avoid load position errors may be estimated.

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The purpose of this paper is to present the optimum structural design method for nonlinear dynamic response. Much of the work in dynamic structural optimization has been mainly concerned with the linear system, because the iteration procedures in both nonlinear analysis and the optimization might require a large scale computation efforts and much computation time. To solve such difficulties, the incremental transfer matrix method is utilized and is combined with the midpoint Runge-kutta scheme to improve the accuracy of the non-linear analysis. The validity and effcetiveness of the proposed method are then confirmed through several numerical examples of beams which are supported by nonlinear springs and a rotor which is supported by nonlinear bearings.

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The dynamic characteristics of heat exchangers are described by partial differential equations .But the expressions are rather complicated and not well suited for practical use, so it is necessary to develop a simple lumped-parametered model to estimate the dynamic behavior of systems with heat exchangers and also to design optimal control systems. The aim of this paper is to present a relatively simple dynamic model for steam liquid heat exchangers via the method of weighted residuals (MWR). A 2nd-order MWR model is derived with a good approximation, which is represented by the three parameters, i.e. k_p which depends upon the steam and liquid temperature in steady state, τ_p which is the residence time of the liquid, and k_s which is the ratio between the shell-side time constant and τ_p. The results of an experimental study are also represented to validate the analytical results.

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Although a hydraulic excavator equiped with two arms and a bucket possesses great flexibility, it is not so easy to control it manually with two levers. In this paper, a new mono-lever system by which an operator can easily command the velocity vector of the top of the second arm, and the angular velocity of a bucket, is proposed in the following manner : Firstly, the principle of a new mono-lever system has been introduced. Secondly, a controller implemented by a 16 bits microcomputer has been designed by the method of model matching. Finally, the successful experimental results have been shown, and the problem which remain in order to realize a practical system have been also referred to.

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The surface durability of hardened and tempered gears (HB<sime>340) having a gear ratio of u≠1 was investigated by using a power circulating-type gear testing machine. The test results reveal that the gear ratio has a great influence on surface durability in the case of gears with rough tooth surfaces, such as hobbed gears. The endurance limit of medium-hardness gears is summarized as follows : Under the condition of rough initial tooth surface, (i) P_max<sime>0.1 HB kgf/mm² in the case where the gear ratio u is not unity, (ii) P_max<sime>0.2 HB kgf/mm² in the case that u equals unity. But, if the initial tooth surface is very smooth, (iii) P_max<sime>0.3 HB kgf/mm² regardless of the gear ratio. In conclusion, the tooth surface should be finished as smoothly as possible in order to obtain a high load-carrying capacity because the influence of roughness is more remarkable in conventional gears having a gear ratio of u≠1.

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Recent research indicates that tooth surface roughness has a significant influence on the surface durability of gears. In order to obtain smooth tooth surfaces economically, the authors have developed new finish-hobs, which have many numbers of gashes and a positive rake angle to control the occurrence of built-up edges. By applying these hobs to the finish-hobbing of medium-hardness gears(HB<bcong>340), the surface roughness is reduced to a half or a third compared with usually hobbed gears. The surface durability of finish-hobbed gears is investigated by using a power circulating-type gear testing machine. The relation between tooth surface roughness and pitting area ratio can be grasped quantitatively. And it is clear that these new finish-hobs are practical for obtaining a high load-carrying capacity of the gears.

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There are many factors, which have effects upon the load carrying characteristics of the spur gears. The surface roughness of tooth and viscosity of lubricating oils, furthermore the concentration of additives are the very important factors for the determining the load carrying characteristics of the spur gears. As main factors for determining the load carrying characteristics, the limiting load for scoring and the specific wear were chosen here. The roughness of the tooth surface for our experiments was in the range of 1.1∼7.5 μm. The kinematic viscosity of the lubricating oil for the experiments was 2.9∼4.0 ×10^-6 m²/s at 90°C. The experimental equipment was the FZG spur gear testing machine and the test gears had also the original tooth form of FZG test gears but our test gears were specially crowned in direction of tooth trace and effective width was reduced to b=8 mm in order to get the higher Hertzian pressure. This tooth width is very narrow in comparison with the original one.

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Modified tooth profiles of the work are analysed theoretically to produce a true involute profile on the helical gear teeth finish rolled by dies with a true involute profile. The finish gear rolling experiment is done to confirm the validity of the theoretical analysis. It is proved that finish rolled tooth profiles with good accuracy are produced on gear teeth having modified profiles before rolling, using dies with a true involute profile.

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In this paper, the deforming properties of the model asperity of SUS304 were researched experimentally at elevated temperatures when the asperity was flattened by a flat punch. The shape of the asperity was a two-dimensional wedge. The asperity angle 2θ was 100°, 120°, 140° or 160°, and the temperature range was from 200°C to 600°C. The load to flatten the asperity was constant throughout the experiment. Two ways of loading were adopted to flatten the asperity with a flat punch : one was that the asperity was flattened again at an elevated temperature after being flattened at room temperature ; and the other was that the asperity was flattened only at an elevated temperature. The former is called the condition of loading at room temperature and the latter is called the condition of not loading at room temperature. The deformation of the asperity increased with a rise in the temperature. The deformation under the condition of not loading at room temperature was larger than the one under the condition of loading at room temperature. The real contact pressure decreased with an increase of the asperity angle. The deforming properties are discussed in more detail.

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Three kinds of pressure boundary conditions at the inlet edge of hydrodynamic thrust bearings under turbulent operating conditions including inertia effects are theoretically discussed. The turbulent lubrication equation considering the inertia effects is solved for infinitely long thrust bearings, in which three kinds of pressure boundary conditions are applied at the inlet edge of the bearings in accordance with three types of lubrication conditions, namely : the flooded condition, the overflooded condition and the starved condition ; and an analytical solution for each condition is presented for the plane slider bearings. Sample results are indicated in graphical form and the relationships between three kinds of pressure boundary conditions and the static characteristics of bearings are discussed for a wide range of Reynolds numbers.

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In this paper, we treat of the friction properties in the contact between a surface covered with soft metal surface film and the single protuberance of a large radius of curvature corresponding to the waviness and/or the surface composed of surface roughness and waviness. First, the frictional coefficient of the single protuberance of a large radius of curvature is fairly small and always decreases with an increase in the vertical load. These tendencies are due to the small ploughing effect. The friction properties of the surfaces composed of surface roughness and waviness approaches those of the single protuberance of large radius of curvature corresponding to waviness when the curvature becomes large. The difference of frictions properties can be understood by the comparison of distribution functions of small protuberances on each surface, and the influence of waviness on the friction properties becomes clear.

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This paper deals with a method for solving dynamic stress problems of a non-cylindrical viscoelastic coil spring subjected to base excitations. The analysis considers the effects of ends of the coil, and applies the three dimensional curved beam theory for obtaining the exact solution of the element of the coil. The resultant forces and the resultant moments in the vibrant coil are decided by means of the transfer matrix method for an arbitrary shape. Both the shear and the normal stresses are obtained by use of the curved beam theory as just mentioned. Numerical calculations have been carried out for two cases of a barrel spring and a hyperboloidal spring.

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Bolted flange connections with full face gaskets have commonly been used for low pressure piping. No stress calculation method is given in J.I.S. and A.S.M.E. codes. The analyses on stresses, bolt loads and gasket loads of this type of flange were made by taking into consideration the gasket properties and the flange bending flexibility. The experiments were performed under gasket seating and pressurized conditions by using integral flanges with a small size hub simulating the weld part in a pipe-flange ring junction. The flanges of 280mm in outer diameter and 20mm in thickness were made of aluminium alloy and steel. Two kinds of PTFE gaskets of 2mm thickness were used for the tests. Calculated results showed a good agreement with the test results. It is clarified that the stress analysis of the flanges with ring type and full face gaskets can be performed on an identical basis.

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Using a specially designed die with a very slightly inclined face, the punch load is decreased to a lower level than that for the usual flat die. This is because the lubricant trapped on a slightly inclined die face enters on the die radius in the course of the punch stroke, so that friction on the die profile decreases. The punch penetration, at which point the decrease of the punch load starts, can be estimated by calculating the volume of lubricant initially trapped and the change in the intervening space between the die face and the deforming flange during the press. The increase in the limiting drawing ratio (LDR) is brought about by the decrease of maximum punch load, and it depends on the inclination of the die face. The experimental results show that the LDR is increased by about 0.15 at the optimum inclination.

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The mechanisms of the fracture of metal cups during ironing process have been examined, using aluminum cups under various lubricating conditions on the die and punch surfaces. When the welding occurs, the cup ruptures even though the average axial stress in the cup wall at the die exit is far smaller than the tensile fracture stress (σ_cr) of the ironed wall with a smooth surface. This is mainly because of the ununiform distribution of the axial stress in the cup wall due to the partial welding. The surface damage of the ironed wall caused by welding has a little effect on the tensile strength of the ironed cup wall. In any case, the initial cracking arises at a point of the cup wall, where the axial stress reaches partially the tensile fracture stress σ_cr. The critical condition for the fracture during ironing process has been clarified.

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Many kinds of recently developed materials are very hard and brittle and it is very difficult and expensive to process these materials. So it is necessary to develop an easier and more economical method to process these materials. As an example, punching holes in sheet glass was studied in this paper. Because punching holes in sheet glass by ordinary methods is impossible, this paper presents a method for punching holes in sheet glass under statical high pressure. This research confirmed that it is possible to punch holes in sheet glass, and clarified the conditions needed to obtain good holes without defects.

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Simple method to measure surface roughness by scanning electron microscope has been developed, which integrates the back scattered electron signal along the horizontal scanning. However, the method was hard to be applied to the surface, the slope of which has inclination to arbitrary direction. This paper is concerned with measuring the surface shape for such case. Small ball was closely placed by the objective in the observation chamber, which is to be a standard of the signal intensity of the image. The normal direction of the ball sphere can be obtained for the respective signal intensity. 4 detectors were used to identify the image of the ball. The signal intensities of the image of the objective were identified by looking for the equal intensities on the ball. The normal direction of the objective can be replaced by that of the ball where the signal intensities were identified. An algorithm to form the surface shape from the normal directions on the objective was also proposed. This was applied to measure the indentation of Vickers hardness test and good results were obtained.

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A shape design problem is studied for the linkage mechanism of a power shovel, based on a mathematical optimization method. Kinematic relationships of the mechanism are treated statically, and they are investigated as constraints in the optimization problem. The sum of the respective maximum values of three driving forces is considered as the objective function to be minimized, and the design problem to determine the optimal shape of the linkage mechanism is formulated as a nonlinear optimization problem of the minimax type. By adopting the generalized reduced gradient algorithm, the optimal solution is calculated for a numerical example, and it is ascertained that the shape of the mechanism can be determined rationally, based on the optimization technique proposed here.

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This paper gives a method of analyzing human facial expressions by measuring the shape of the eye, brow and mouth, and of identifying emotional expressions. Facial expressions play a very important role in communication in our dailylife. Without any verbalized words we can often get considerable information about the emotional states of a person from their face. In order to analyze facial expressions, computer graphics of the human face is developed. In this experiment 4 parameters are selected. The automatic recognition of expressions is done by processing a digital image of a human face which is obtained by a video camera. Our final goal is to develope a method of identifying facial expressions which can be applied to Man-Machine interface.

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