A dynamic load combination method proposed in previous papers for seismic analysis of a liquid storage tank has been developed for response calculations of piping systems subjected to multiple support excitations. This method has an advantage in which cross·correlation among support excitations are properly taken into account. The correlation factor can be semi-automatically evaluated by using a stationary random vibration approach. Investigation is mainly devoted to a maximum acceleration response calculation of a simple piping model to two-input excitation. Results for the system corresponded fairly well with the exact numerical results through analytical simulation. On the other hand, the SRSS procedure and the absolute value summation which neglect cross-correlation among excitations can lead to large errors. Finally, the authors have also proposed the idea of generating a ""multi-excitation floor response spectrum"" using the results.

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Liquid-filled piplines are expected to undergo transient hydraulic effects due to pressure rise during earthquakes. The object of this study is to investigate the coupled seismic responses of piping and liquid columns, and to show the difference between ""the dead mass model"" and ""the coupled model"". For this purpose, a large scale shaking table test and analysis was carried out using a straight piping model. In this report, continuing the 1st report, the experimental results and analysis of random responses are described. In the numerical simulation, the Runge·Kutta method for a pipe support system, and the characteristics method for a liquid column were used. The simulated responses had good agreement with the experiment, and the availability of the method was confirmed. The dead mass model showed a very different response from the real response for ""hard support systems"", but it was available for ""soft support systems"",

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Impact vibration in a spring·mass system with a degree of freedom is simulated on analog computer, and chaotic motions are observed by kind of mapping. The chaotic motions have complicated strange attractors. These results agree with those by a digital computer. When the static clearance between the mass and the stopper changes, a periodic solution changes into chaos in the form of (a) the period doubling bifurcation at the stability boundary s_-1 of the periodic solution, (b) the jumping at the stability boundary s₊₁ and (c) the jumping at the boundary of existence of the periodic solution.

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A mathematical model of a large-scale wind turbine composed of a flexible two-bladed rotor and a flexible tower is described, and results of the stability analysis are presented in this paper. The model includes each component's property as well as blade aeroelasticity, and is described with minimum degrees of freedom using the Rayleigh-Ritz approach : a rotor is modeled as two degrees of freedom and a tower as three degrees of freedom. Aerodynamic forces are predicted quasi-statically with the annular momentum theory including angular momentum. Floquet theory is used to evaluate the stability of a periodic coefficient system. Applying this model to a 100 kW class wind turbine with a rigid-hub rotor, existence of stall instability, parametric instability and gyrostatic instabilitiy and their conditions of occurence are clarified, and whirl flutter, aerodynamic divergence and mechanical instability are also examined.

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The influence of gapped supports on the steady-state random response of a beam-like structure was examined, mainly by means of digital simulation. Two kinds of models were assumed as the restoring and damping effects of gapped supports : one is the parallel composition of the Hertz-type contact spring and dashpot ; and the other is that of a linear spring and dashpot. In order to ascertain the validity of digital simulation, the experiment was carried out. Then, on the basis of digital simulation, the applicability of the equivalent linearization method was examined, and it was proved to be valid only when the stiffnes of gapped supports is moderately soft. Finally, as a result of digital simulation, it was shown that the relative displacement response does not change so much even if the stiffness of gapped supports changes greatly ; while the absolute acceleration response and impact force are remarkably affected by the stiffness of gapped supports.

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Free vibration of variable thickness annular plates of which deformation at the inner and outer edges are elastically constrained has been analyzed by the Galerkin method. By adopting eigen functions of free vibration of constant thickness annular plates, solutions that exactly satisfy the boundary conditions have been obtained. This method produces exact solutions in cases of constant thickness annular plates. The relation of natural frequencies with the taper ratio and with the stiffnesses of elastic springs have been evaluated for annular plates in which the thickness linearly varies in the radial direction. It has been confirmed that when the stiffnesses of elastic springs become larger or smaller than certain values, the natural frequencies nearly agree with those of the state when the edges are completely constrained or free. The changes of natural frequencies when the stiffnesses of elastic springs change from zero to infinity have been shown quantitatively.

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For a motorcycle running on asphalted and unpaved roads, from 10 km/h to 60 km/h, the correlation between the standard deviation of the steering angle and the evaluation of stability by the rider's feeling is analyzed by a statistical method. we find that this correlation satisfies the Weber-Fechner's law. Also, from an examination of the frequency of the steering angle, we estimate that the 10w frequency comes from the handling of the rider.

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Mooring and towing systems are required to have minimum deviations from the fixed position and depth, and to be statically and dynamically stable under marine environments. To meet these requirements, a designer should predict the response of the systems to these environmental disturbances. This paper proposes the mode-separation method that can analyse unsteady motions of these cable-body systems. This method assumes that the propagation speed of the cable longitudinal wave is infinite, and simulates cable-shape motion separate from cable-elongation motion, Stability analysis of the numerical solution based on the Fourier method shows that the present method requires one-tenth of the computation time compared with previous methods. The calculated results are in very good agreement with experimental values and the validity of the present method is confirmed.

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The effects of vibration isolation of the new type of mechanical damper applied to a single-degree-of-freedom system and a simple beam are discussed numerically and experimentally. The damper is composed of a ball screw, a flywheel and centrifugal brakes, and possesses nonlinear characteristics. The Continuous System Simulation Language is used for the digital simulations of the nonlinear vibration systems. The results may be summarized as follows : (1) The damper is effective for suppressing the amplitude of the single-degree·of-freedom system as well as of the beam at the point of attachment of the damper, at the resonances. (2) The damper approaches a snubber for smaller values of lead L of the ball screw (or larger values of moment of inertia J of the flywheel), and acts like a damper whose damping force is proportional to the square of the velocity for larger values of L (or smaller values of J) .

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The slip of a locomotive wheel is one of the sources of torsional vibration of the axle. Great efforts to prevent such vibration have been made by locomotive builders and railroads. But now they are trying to use this vibration in order to prevent slipping and to utilize adhesion. This paper describes the results of the experiments carried out on a test-rig which is a one-third scale model. An occurrence of vibration at the axle immediately before slipping is confirmed, and this vibration is common almost under all conditions. When the driving torque approaches the adhesion limit, the damping due characteristic near the adhesion limit decreases. Then axle-vibration can easily occur by the changing of the axle load and the traction coefficient. Experiments confirmed that this phenomenon can be used for adhesion control.

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Ensuring cleanliness is a key factor in LSI production. Of particular importance here is the generation of dust particles at the current collector of the transfer carriage. This paper describes the development of a new current collection mechanism. A rolling contact collector has been developed which collects current through a current collection ring which rolls on the power line. Use of this new collector was seen to result in a decrease in dust particle generation down to a tenth of the case for a conventional collector.

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A system using ultrasonic sensors was developed to track a moving target. In Part l, a new technique for sharpening the ultrasonic beam and for attaining a higher accuracy in the determination of the direction of a moving target was proposed. Furthermore, a new electronic technique for sweeping of the emitted beam for searching more rapidly a moving target in space was proposed. In Part 2, an outline of the system and its experimental performance are described.

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A system using ultrasonic sensors was developed to track a moving target. In Part 1, the new techniques for sharpening the ultrasonic beam and for electronically sweeping the axis of emission of the beam, and their theoretical bases were described. In Part 2, the outline of the system is described. The performance verified by experiments is as follows : The maximum trackable velocity of a moving object at a distance of 1.2 m from the ultrasonic sensor system is 480 mm/sec. The measurement error in the position of a target moving with this maximum velocity is 91 mm.

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An automated system using a microcomputer for a two-dimensional surface roughness measurement with a stylus is developed. The block diagram and flow charts for the surface roughness measuring method are described, together with the measured examples. It is found that this programmable system obtained at a low price is very useful for such a measurement and for data processing In the Appendix Assembler subroutine programs for measurement and control using an 8 bit microcomputer are given.

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The regulator system, which maintains constant engine power output in spite of the change of parameter value with optimalization, was mainly studied as a first step of the investigation. The regulator is a closed loop system which has an indicated work detector as a feed back signal, a digital filter, and a pulse motor throttle actuator. The results of the experiments for air fuel ratio control showed normal working of the regulator under a certain engine operation condition. Moreover one optimalization algorithm was tried using the regulator and an increase of the thermal efficiency was obtained. The regulator is not tuned optimumly in this step, but it has a high speed performance of time response, essentially. Therefore, there are good possibilities for the next step of the investigation.

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A newly designed small sized inspection robot consisting of two modules, such as a locomotion module and a diagnostic module, has capabilities of moving along the inside of pipelines the internal diameter of which is about fifty mm, and freely passing through an L-joint by rotating its head in the direction to be turned by sensing and recognizing the L-joint with four infrared ray proximity sensors in front. This inspection robot equiped with a diagnosis sensor can detect flaws on the inside surface at the time of inspection when moving along the inside of pipelines. Diagnosis sensor outputs have been analized statistically in order to discriminate small flaws from disturbances caused by the robots movement, and fluctuations of the inside surface of pipelines.

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With respect to the effect of the hardness of a material on seizuring resistance, there are a lot of test results obtained with four ball machines and roller machines. In this report, the gears ground with high accuracy after high-frequency quenching are tempered at various temperatures under a comparatively high degree of vacuum. Gears having the same chemical compositions and characteristics of the working tooth surface are produced. From the scoring tests of the gears, varied from low to high hardness, it was found that the effect of the hardness of the tooth material on the scoring resistance of the gears was significant, and the scoring resistance of the gears increased with increasing hardness of the tooth material.

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On a pair of power transmission helical gears with a comparatively narrow facewidth, the relation between the characteristics of gear vibration and the parallelism of the axes have been investigated by measuring the acceleration level and carrying out a frequency analysis of the gear vibration signals. It is found that the deviation exerts an influence on the characteristics of gear vibration more strongly than the inclination ; and the deviation as well as the inclination which gives the leading side bearing exerts an influence on those more strongly than that which gives the trailing side bearing.

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Hypocycloid reduction gears produce a maximum reduction ratio, if the difference in the numbers of teeth between the internal gear and pinion is reduced to 1. However, such a limit design is very difficult, because such a reduction of the difference in the number of teeth induces various interferences. An internal gear having a zero difference in the number of teeth is best suited for a planetary gear mechanism that transmits its absolute rotation to the driven shaft at the ratio of 1 : 1. However, such a special gear set needs an operating pressure angle of 90 degrees, and thus cannot be designed by conventional formulae for ordinary internal gears. The author has so far devised an optimal designing system for the automatic design of internal gears. This paper presents an advanced application of the optimal design system to the automatic design of the above-mentioned special internal gears that require an extraordinarily difficult and special designing technique. Trial fabrication was also undertaken to confirm the designing computations obtained.

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TiN-coating on the flank surface of HSS hobs by the PVD method can lessen the flank wear and lengthen the life of hobs. Therefore, recently, hobs for mass-production gears are almost all treated with TiN-coating. In this study, the authors examine what mechanisms decrease the wear of hobs after TiN-coating, in the case of typical flank wear (Corner wear, Extraordinary corner wear, Extraoridnary side wear). As a result, the authors report on how to design the roughness on the flank surface, the clearance angle, and the tooth profile with protuberance, to be suitable for TiN-coated high speed steel hobs.

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In order to elucidate the effects of dispersed molybdenum disulphide and its quantity in EP gear oil on the fatigue life and surface failure of steel rollers, sliding-rolling contact fatigue tests were performed on through hardened high carbon chromium bearing steel rollers. These were carried out using four kinds of single-type EP gear oils which contained different quantities of molybdenum disulphide. The experimental results regarding fatigue life and surface failure were discussed, referring to the measured results of the roller surface temperature and the friction coefficient between the rollers and the result of Weibull analysis on fatigue life.

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In order to elucidate the effect of energy saving type lubricants on the surface failure and surface durability for the pitting of steel rollers, thermally refined 0.45 percent carbon steel rollers were fatigue-tested under a sliding-rolling contact condition. The EP gear oils dispersed with various quantities of molybdenum disulphide were used. The relationship curves between Hertzian stress and fatigue life were obtained, and the Weibull analyses were applied to the results regarding pitting life and failure. The effect of the quantity of molybdenum disulphide dispersed in oil on the surface durability, the life and the failure was discussed. The results for the fatigue life and the surface failure mode were also discussed by the amplitudes of the ratios of stresses to hardnesses beneath the roller surfaces.

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The tests of gear tooth failure and for predicting allowable surface durability of gears lubricated with grease material were conducted. Grease made from the penetration of NLGI NO. 0 contained non-lead EP additive and lithium soap thickner. The gears used for the tests were spur gears with 2.5 module, 31 and 35 teeth, and addendum modification factor X₁/X₂=0 2/-0.18. The value of the tooth load was changed from P_n=101.0 to 557.0 kN/m and the value of the pitch line velocity was also changed from V=1.59 to 6.19 m/s. The following test results were obtained : (1) the scoring type of failure mainly occured, and at higher load conditions, spalling was also observed. (2) allowable tooth load Pn could be predicted from the specific wear of tooth surfaces.

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A study was made of the effect of extreme pressure additives (the chloric and sulphuric compounds) on the working surface of diamond wheels in grinding. The results are summarized as follows : (1) The amount of chips and ground metal deposited on the grain coating zone and the bond surface is reduced by the reaction of the extreme pressure additive on the metallic coating zone of grains, the metal powder contained in a resinoid bond and metallic zone of a metal bond. (2) The amount of chips deposited on the working surface of a diamond wheel, and chips deposited on each other, is reduced by the reaction of the extreme pressure additive on chips cut from ground metal. (3) If the dilution is raised in applying the water type grinding fluid, the degree of action of the extreme pressure additive is lowered. The fracture of the diamond grain is increased by the thermal shock effect of the fluid.

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The leakage rate of fluid is strongly affected by the magnitude of the contact pressure between packing and the stem or stuffing-box. If the packing is tightened by a high gland load to prevent leakage, the friction between the stem and the packing becomes larger. From the practical viewpoint. the distribution of the contact pressure and the friction at any given gland pressure or at any given compressive displacement of the packing are required in order to make an analytical prediction. In making the first step toward analyzing the contact pressure and the friction for various combinations of packing, this paper describes the mechanical properties of various asbestoid and graphitic packing. A testing method to determine the normal to axial pressure ratio K, the coefficient of friction μ and the axial pressure-strain relation Pz-|ε_z| is presented. The experimental equations for these values, K, μ and e_z, are found as functions of the axial pressure P_z K=K_oP^a_z, μ=μ_oP^b_z, |ε_z|=E_oP^c_z, where K_o, a, μ₀, b, E_o and c are material constants.

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This paper presents a method to calculate the distribution of the contact pressure between some packings and the stem, the change in the height of the piled-up packings and the axial-frictional force, at a given gland pressure for various combinations of asbestoid and graphitic packings. The analytical contact pressure between the graphitic packings and the stem is greater than that compared to using of asbestoid packings, because the value of the normal-to-axial pressure ratio of the graphitic packing is larger than that of the asbestoid one. The contact pressure on the packings tightened initially under the free-stem condition, and at the pushing and pulling of the stem, is larger than that tightened under a fixed-stem condition. The reaction pressure at the oposite side of the gland, the displacement of the packings and the axial-frictional force, under pulling and pushing of the stem, were experimentally obtained. These experimental observations agree fairly well with the analytical results.

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The influence of material, heat treatment, tooth profile and surface roughness on the surface durability of surface-hardened gears was investigated. First, the effect of surface roughness on rolling/sliding contact fatigue was studied in detail using a 2-roller-type fatigue testing machine. From these results, it is found that the initial surface roughness has a considerable influence on the surface durability of surface-hardened steel, and that the decrease of surface roughness with running does not always have an advantageous effect. Secondly, the load-carrying capacities of case-carburized gears and induction-hardened gears were investigated using a power circulating-type gear testing machine. The phenomenon of ""grey-staining"", which consists of many micro-cracks and -pits, occurs on the ground tooth surface under a heavy load. In these tests, it is found that the grey-staining failure, which causes the degradation of tooth profile and the spalling, is most influenced by the initial tooth surface roughness. Furthermore, the effect of initial surface roughness on the surface durability of surface-hardened gears can be grasped quantitatively.

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In order to simplify the calculation of automatic transmission planetary gear trains, it is useful to classify both the various combinations of the rotational members in the gear train and the overlapping gear ratios. It was found when applying this method to two sets of planetary gears t, hat 3rd gear becomes the direct drive. Whereas it is possible to build a 5-speed transmission with two planetary gears, this calculation method shows that only 4-speeds are practical. Therefore, three planetary gears should be used is constructing a 5-speed transmission.

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It is the purpose of this paper to evaluate the cooling effect to the ball screw by external forced cooling using oil, when the ball screw is rotating, and to determine what cooling conditions satisfy and maintain the required accuracy of the ball screw. Therefore the transient temperature changes on the center axis of the ball screw are measured, and the heat transfer coefficient a is calculated using the measured values obtained when the revolution speed of the ball screw is 0∼1 500 rpm and the quantity of oil per unit area and time is 0∼0.17 m³/ (m²·min). In addition, the empirical formula is derived from the results of a in the experimental regions on the basis of the appearance of oil flow.

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The effect of the magnitude of lead on the static characteristics of hydrostatic screws and nuts has been examined theoretically. By using the lubrication theory, the governing equation for pressure distribution between the flanks of external and internal threads has been derived. The effect of the magnitude of lead on the load capacity and the flow rate is investigated theoretically. Consequently, its effect is shown to be negligibly small for most screws and nuts.

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An ironing test of aluminum cups has been carried out under various conditions of lubrication of the punch and die. The surface appearances of the ironed cups are divided into five classes according to the intensity and the amount of the damage caused by welding, i.e. rubbed surface (bright surface), scratched surface, gouged surface, surface with microtearing and surface with micro-tearing and-cracks. The extent of the damage has a good positive correlation with the frictional coefficient μ_d on the contact surface between the die and the material for each lubricating condition on the punch. As the viscosity of the lubricant on the punch increases, indicating the decrease of μ_p, the damage is reduced. μ_p is the frictional coefficient on the punch surface. By using two parameters of μ_d and μ_p, it is possible to know what class of surface appears. A bright surface has been obtained under the condition μ_d≤-0.51μ_p+0.13.

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When cold roll-formed products are cut by a press or a band saw, distortion occurs on the flanges : one side of the cut-off edges flare and the other side edges close. This paper deals with the method of eliminating distortion of the cut-off flange edges of the steel channel section with 4.5mm wall thickness and 75mm flange height. The principle of the method is as follows : Apply compressive force to the flange out of the flange edges, and cause new plastic deformation there. Then the residual stress which occurred during the cold roll-forming process changes and the elastic recovery during the dimensional cutting reduces. A prototype experiment was carried out and high accuracy products were obtained.

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The strain-hardening characteristics of 28 lots of non-heat-treatable]e aluminum alloy sheets (containing A1000, A3000 and 5000 series) were studied mainly under equi-biaxial tension. The following was clarified: (i) To evaluate the press-formability, the equi-biaxial test is more applicable than the uniaxial test, particularly, for hard metal; (ii) The stress-strain relation could be relatively accurately expressed by one of the 3 representations of strain-hardening laws, that is, the conventional power law (1), the power law containing the initial stress (2) and the saturation stress law (3), from zero strain to limit strain for all materials tested; (iii) The ratio of equi-biaxial limit strain to uniaxial limit strain was closely related with this type of the law. (iv) The stress-strain relation of commercially-pure aluminum was represented by the law (1). The law (2) holds for harder material, and the law (3) holds for the material with higher Mg contents.

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The press-forming tests of the precipitate-hardening aluminum sheet, A2024, were conducted under the various pre-aging conditions, such as quenching and full annealing, as the preliminary test of a thermomechanical treatment to aim at the coexistence of the strengthening of sheet and the improvement of the press-formability. The main results are summarized as follows : (1) This metal deforms locally and ununiformly, and then initiates shear crack without the necking. (2) In deep-drawing, three types of fractures which occurred over the flange to the wall, i.e., ""Bending and unbending-"", ""Tip-shear-"" and ""Wall-fracture"", were observed in addition to the punch-profile fracture. (3) The former three fractures are controlled by the strain accumulation in the flange, the bending on the die shoulder and anisotropy of the material, so the drawability correlates with the new measure, γcr=(1-1.5|Δr|/r^^-), where γcr is the fracture strain in the in-plane shear test, r is the normal anisotropy, Δr=r₀+r₉₀-2r₄₅)/2 and r^^-=(r₀+r₉₀+2r₄₅)/4.

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There have been many studies on chatter vibration in machining, but there seems to be no regulations to decide the commencing point of chatter objectively. The development of an objective method which can estimate chatter commencement is very much in need for automatic manufacturing systems dynamic performance tests for machine tools, and so on. In this study, therefore, the estimation of chatter has been experimentally investigated for the chuck work turning process. Consequently, the commencing point of chatter can be decided from the behavior of the mean square value of the work piece deflection, where the mean square value is suddenly increasing with the chatter commencement. Then the commencing point of chatter can be estimated practically by this method before the occurrence of excessive vibration.

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Some correlations between the microstructural factors and the grinding force have been investigated experimentally on the spheroidized cementite structure of 0.1-1.0 %C steels. The diameter of the cementite, the ferrite grain size and the cementite quantity were determined by micrographs, and multi-regression analysis was conducted on the relation of these factors to the grinding force. An example of the linear regression obtained is given by F_H=41.049+1.897X-5.511Y+0.492Z F_v=54.872+1.829X+16.940Y+1.082Z where F_H, F_v, X, Y and Z denote the tangential grinding force, the vertical grinding force, the inter-carbide distance (μm), the mean free-ferrite-path from grain boundary to grain boundary (μm) and the amount of cementite (%), respectively.

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An algorithm for the accurate evaluation of a cutting area considering the tool tip radius and the multiple regenerative effect was proposed. This made it possible to follow time historical behaviour of the cutting area during self-excited vibration. The cutting area which was accurately evaluated showed good agreement with the cutting force. The ratio of the cutting area to that for stationary cutting becomes about 3 at the maximum. The ratio was about 4 for cases where the tool tip radius and the multiple regenerative effect were neglected. These evaluations are kept constant even though the amplitude of the vibration was varied. The behaviour of the number of multiple regenerations during the vibration was also obtained. It is related with the amplitude. It was shown that the number was 4 or 5 while the amplitude was kept constant. However, it reached 12 when the vibration was disturbed by varying the rotational speed. The correlation of the cutting area with the cutting force was evaluated by adopting a factor to minimize the square root of the sum of the squares of the difference for both quantities.

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As FA and OA have been popularized in various stages of the production system, heavy mental work is extremely increased now. The CFF (critical flicker fusion frequency) measured at the central retina of both eyes has been used widely to evaluate the mental workload. In this paper, we develop the equipment measuring CFF at the central and the peripheral retina (MCFF). The CFFs at the central retina of both eyes, or each eye, show high correlation with each other, as do those at the peripheral retina. But there is a different tendency between the former and the latter. The variation of spectrum of brain waves (α, β, θ, δ) can be estimated from MCFF, except for CFF, at the central retina of both eyes (usual CFF). From these results, it is considered that MCFF proposed can be used to estimate the mental workload more precisely.

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A basic concept of a software support tool for the production, maintenance and updating is presented employing a structure of the expert system interacting with both software and documentation. This support tool can include knowledge bases, data bases of target softwares, and also other related knowledge bases. As a first step toward this direction, a small sized support tool for software development has been developed by introducing software grammers, syntactics and semantics in a small world as rules and documents analizer. Three types of the contradiction detection method are incorporated in this system so as to detect contradictions in documentations and an additionally inserted knowledge in the expert system itself, based on the semantics and the knowleges, which are applicable for many expert systems. This system has two types of checking methods, such as a software based checking and a documentation based checking, depending upon the applications. Some experiments of the system have been carried out as a man-machine interface.

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