An experimental and analytical investigation to identify the frequency response characteristics of a beam system with a minute gap at the support was conducted. A L shape beam was adopted for the system, which made it possible to compare the results of both investigations easily by restricting the direction of the vibration at the gap. The frequency response characteristics of the system was evaluated in terms of the equivalent linearization method using the describing function. This is a fundamental method which can be extended by the nonlinear building block approach to the general beam system with multinonlinearities. The length of the gap was accurately controlled by adjusting the position of the stopper attached to the micrometer head. Jump phenomena around the natural frequencies, which are specific to the nonlinear system, were obtained by analysis. However, the frequency range obtained by analysis of the jump phenomena, which are not affected by the disturbance of the higher harmonics, was wider than that by the experiment

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This paper present a method for synthesizing the structural modification in problems concerning compliance shift on the Bode diagram by use of the finite element sensitivity analysis. The basic notion employed is to search for the objective design in the vicinity of the baseline design. The constraint intensity and damping are adopted as design variables. The shift syntheses of the compliance transfer function is carried out numerically by means of setting several target frequencies on the Bode diagram in regard to the vibration of a straight pipe and a doubly bent pipe with Rayleigh damping. The numerical examples verify that the shift synthesis can be completed by a small number of iterations, usually less than ten.

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The deflation of an airspring deteriorates the riding comfort of railway vehicles due to an increased bending vibration of the car body. This paper describes the results of a calculation analysis for the car body-bending vibration with deflated airsprings excited at the car body. The results are summed up as follows. The bending vibration characteristics are affected to a large degree by the damping force acting to the primary suspension (axle spring). In case of the bogie structure in which the frictional force of high damping acts on the axle spring, the natural frequency of car bodybending increases when its airsprings deflate. The natural frequency decreases in the bogie structure which has a low damping force such as the usual oil dampers for the axle spring. Unless the oil damper fails, the acceleration amplitude of the latter structure is less than the former one under the deflation of airsprings.

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In the previous report, a method of vibration multiwire sawing was devised as a technology utilizing mechanical vibration energy to slice hard and brittle materials such as various ceramics. The results showed that the vibrational machining efficiency was two times the nonvibrational machining efficiency. In this report, the efficiency was two times the nonvibrational machining efficiency. In this report, the effect of applying vibrations are considered by means of theoretical analysis and experimentation, and the cutting accuracy of a wafer is examined. The findings are as follows : (1) When the amplitude exceeds 0.42 mm, the effective working load is increased. (2) The machining efficiency increases with an increase in slurry concentration. (3) The machining efficiency is in proportion to the wire running speed. (4) When the amplitude is 0.42∼0.75 mm, the effect of effective grains entering into the processing part increases. (5) When the frequency is 0∼30 Hz, the machining efficiency increases rapidly with an increase in frequency. (6) The thickness of the wafer decreases a little with an increase in amplitude, and the amount of scatter is decreased. (7) The affected layer of the wafer possesses the same volume in both nonvibration and vibration cutting.

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This paper proposes a dynamic model that enables calculation of seismic response simulation in corner tube boilers and supporting frames for use in the fundamental planning of the design of refuse incinerator. In this dynamic model, boilers and supporting frames are replaced by concentrated mass, beams and springs. The maximum degree of freedom in this model is 20. To illustrate the effectiveness of the proposed model, the simplified dynamic model was applied to a model prototype. For both the model and prototype, it has been shown that the dynamic model proposed in this paper gives simulation results which are almost sufficient.

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The self-excited vibration of a slender cantilever beam with a square section was examined experimentally in a uniform smooth wind stream. Five kinds of beams with 200 mm length and 2, 2.5, 3, 3.5, 4 mm square sections were placed vertically in a low turbulent wind tunnel. Galloping oscillation of the beam was measured by use of the Laser-Doppler vibrometer. It was found experimentally that the excited amplitude increased when the wind velocity exceeded a certain value at which vortex shedding frequency equaled the secondorder natural frequency of the cantilever beam. Further, the steady state amplitude was indicated by a curve using a new parameter of wind velocity.

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There are many problems of the vibration of tube arrays induced by the gas and liquid two-phase normal flow compared to a single phase flow. Until now, it was unclear whether the main feature of the vibration was random or self-excited. In this study, the following two kinds of experimentt were performed. First, the induced vibrations of three rows of tube arrays in the two-phase flow were measured. Second, the tube arrays in the two-phase flow were vibrated using a link mechanism and the resultant unsteady hydraulic forces generated on the tube were measured. As a result, it became clear that the vibration is induced by self excitation and the unstable region spread by increasing the void ratio.

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Submerged long span gates which dam a wide river undergo violent streamwise vibrations caused by vortex shedding beneath the gate. This study presents flow-induced vibration characteristics which were obtained in a model gate test. From the measured vibration frequencies and damping ratios in air and water, respectively, the level of fluid excitation and the added mass for small amplitude gate vibrations were calculated and reduced to a dimensionless form, and thus the vibration onset criteria were obtained. In addition to the average value of the maximum amplitude of gate vibration, was measured. The results of these experiments, taken as a whole, suggest that the flow-induced vibration characteristics of the long-span gates are well predicted by the dimensionless parameters, such as the reduced gate opening height and the reduced velocity.

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A conveyor system, which consists of a magnetically levitated vehicle with a suspended carriage and a guideway, is made on an experimental basis. The remarkable feature of this system is that the magnetic lateral force acting on the vehicle is basically zero by means of the contact support. The static and dynamic characteristics of the magnetically levitated vehicle with a suspended carriage are investigated theoretically and experimentally. The levitating force with the height of the magnetically levitated vehicle and so on are discussed. Furthermore it is shown that the ratio of the natural frequencies in the pendulum oscillation of the suspended carriage and the bouncing oscillation of the vehicle has a significant effect on the transient oscillations of the carriage and the vehicle.

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In this paper, the finite element modeling of a flexible rotating plate, in consideration of both the bending vibration and the rotating motion, is presented. The frequency responses of the system consisting of the flexible rotating plate and the rotating axis with a torsinal spring and damper are investigated. In the finite element modeling of the rotating flexible plate, the element mass matrix of the rectangular plate element modeling of the rotating flexible plate, the element mass matrix of the rectangular plate element modeling of the rotating flexible plate, the element mass matrix of the rectangular plate element is formulated by use of the shape function derived by Melsoh. This element mass matrix, consists of three parts that correspond to the bending vibration, the interaction between the bending vibration and the rotating motion, and the moment of inertia. By using the element mass matrix, the equation of motion is obtained. Furthermore, the effects of the rigidity of the torsional spring on the frequency responses are demonstrated.

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A mathematical five-degrees-of-freedom model is presented to describe the approximate behaviors of horizontal-axis wind turbine generators with teetered rotor blades. Taking as unknown the teeter rotation, flap defection of the two blades, pitching rotation and yawing rotation of the nacelle, we employed an energy approach to derive Lagrange's equation of motion. Quasi-steady blade element strip theory was applied to evaluate aerodynamic forces on the teetered rotor blades upwind or downwind of the tower, taking boundary-layer shear wind and wind speed reductions due to the tower shadow into account. Numerical solutions for steady-state responses show that the downwind rotor undergoes heavier oscillations than the upwind rotor, and that the aerodynamic damping force due to teetering compensates for most of the imbalances in bending moments at each upwind rotor blade root.

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The truss-type parallel arm has been proposed as a flexible arm with a large number of DOFs and has been discussed from a conceptual point of view. Toward the realization of this arm system, its practical structure as a link mechanism is proposed and the kinematics of a prototype is studied by introducing relative offset between the passive rotational joints connecting the active prismatic members at the nodes. A kinematical equation of motion is formulated in the total form as well as in the incremental form. The motion of the prototype is demonstrated through an experimental unit as well as numerical simulation.

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A systematic synthesis of location arrangement of links and pairs which construct spatial mechanisms is studied with consideration of the mutual interferences among moving links. A reference plane which is arbitrarily fixed on one of the moving links to be analyzed is introduced, and loci of the intersection points of the other moving links with this plane are formulated. With use of the loci, the profiles and locations of pairs and links on the reference plane are determined so that they do not interfere with the other moving links. Based on the above analytical results, a link-arrangement system is proposed which determine the optimum location of links and pairs and optimum profiles of links of spatial mechanisms.

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In this paper, the authors theoretically analyze the forced hunting of a high-speed vehicle, which runs on a rail with sinusoidal irregularity, in reference to lateral direction of the rail. The authors used the half-body vehicle model having a small clearance in the connection position between the truck frame and the bolster anchor, where the spring and friction are connected in series against truck turning. Consequently, the authors clearly showed that there appeared some very complicated nonlinear phenomena in comparison with the resonance curves of no body. Then, the authors showed the influence of various values on the vehicle vibration, for example, the frictional force of the side bearer, the wheel tread conicity, the yawing damper, and the turning stiffness of the truck. Further-more, the authors proposed target values for the designing of vehicles.

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A unified method for dynamic analysis of electromechanical systems with nonlinear properties is proposed. Then the optimum design method, the optimum control method and mixed optimum design and control method based on the unified method are developed individually. To treat complicated mechanical systems with nonlinear properties, the electrical part is replaced by a mechanical one through the analogy existing between them. The nuified method is developed together with any of three methods : the large matrix methods based on the Hamiltion's principle and Toupin's principle and the incremental transfer matrix method. Optimum design and optimum control methods by making use of the sensitvities (or gradients) are shown individually and then the method to treat the mixed optimum design and optimum control problem is shown. The detailed considerations of the proposed methods are to be given in the following reports.

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The problem of a turbidity judgment should be equal to that of cognition of suspended fine particles with visual sensation, however the research from this viewpoint is very limited. In this study, the authors analyzed the cognition process in relation to visual resolution. The results are as follows. First, the judgment standards consist of brightness, a haze degree, and a sum total of particle plane areas. Second, the cognition process of turbidity is hierarchical. Turbidity is at first judged by brightness of the uniformized visual space for the increase of the visual threshold, and if it can not be judged by brightness, it is judged by the haze degree or the total plane area by means of the minimization of the threshold.

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This paper considers the design problem of controllers for electrohydraulic valves. First, the identified model for the system composed of a valve and an amplifier is obtained using an extended least squares method. Then, an approximate model matching method is applied to design a digital controller. The approximate model matching method is suitable for practical design problems in the sense that we are free to specify the complexity of the controller. The simulation results show the effects of the controller's complexity on the accuracy of the approximation to the reference model. The experimental results agree with the simulated ones. It is shown that the control system achieves good stability and three times faster response than uncontrolled valves.

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A design method for a new type of repetitive control system is proposed. By considering a reference signal generator to be a model which a controlled system should track in a typical repetitive control system, a model-following structure is derived. It is shown that state feedback can further be added in this repetitive control system without affecting the repetitive control. The tracking error of the proposed repetitive control system can be made extremely small by adjusting the gains in the feedback loop. In case that there are inaccessible state variables, a minimal order observer is useful to construct the repetitive control system although the observer does not estimate the exact states of the system due to disturbances.

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Current robot manipulators are controlled by decentralized or independent joint controllers. That is, each joint is locally controlled using only local information. The high-gain feedback is adopted in the control of industrial robot manipulators because of its robustness to parameter variations and disturbances. We discuss the asymptotic behavior of the closed-loop eigenvalues of such systems. In this paper, we propose a method for assigning the multivariable pivots of the multivariable root-loci. We also propose a method for approximate assignment of closed-loop eigenvalues of manipulator systems, which are controlled by independent joint controllers, with high feedback gain.

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For the purpose of estimating the thermal condition of machine devices, we investigate a new method of measuring temperature using an encapsulated liquid crystal (ECL) film and a charge-coupled device (CCD) camera. When an ECL film is placed in direct contact with subjects, it exhibits some colors accompanying temperature change. But even if these colors are obtained, it is difficult to judge values for temperature or extension of isothermal line with the naked eye because of optical noise. In solving the above problems, we investigate a new photogaraphical recording method of intensifying colors using a CCD camera and graphical processing with a personal computer. The availability of this method is confirmed by analyzing heat conduction in the plate.

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A new accurate measurement of displacement by means of sound frequency variation in a resonant pipe has been investigated. This paper deals with the experimental analysis of the characteristics of the sound frequency variation which is generated in the pipe. In the experiments, the effects to sound frequency variation were examined by changing some sounding conditions. Then, it was made clear that a low sounding mode, short length of the pipe and small inner diameter introduce good results for the measurement of the displacement. By adopting such good conditions, the displacement smaller than 0.1μm can be measured under non-contact conditions with the object.

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It is very important to know the load distribution on the line of contact and the tooth root stress of a bevel gear. These are difficult to calculate, however, because the tooth depth and the tooth thickness increase from toe to heel and the mesting of a bevel gear is complicated. Accordingly, there have been few studies on these problems. Before calculation of the load distribution on the tooth flank and the tooth root stress of a bevel gear, the deflection of the fan-shaped cantilever under a condition where the concentrated load is placed on the cantilever is calculated. In the method used, the fundamental differential equations devised from the static balance on a minute part of the cantilever are represented in the difference equations, which are then solved.

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To determine the load distribution on the line of contact and the tooth root stress of a bevel gear, in the previous paper, the authors calculated the deflection of the fan-shaped cantilever under a condition where the concentrated load acts on the cantilever. In the present paper, using some characteristics of deflection which were found from the calculation values of deflection, an approximate equation of tooth deflection is deduced

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Various configurations of thin-shaped bevel gears are widely used such as in the main reduction gear of helicopters and hovercraft. But a reasonable and concise design guide for these bevel gears has to be obtained, since the tooth of the bevel gear has a complex from. The purpose of this study is to establish a design guide and to propose the desirable configuration for thin-shaped straight bevel gears. In this report, the desirable configuration is examined numerically using the finite element method. The results are summarized as follows : (1) As a desirable configuration of a thin shaped bevel gear, it is recommended from the viewpoint of root stress that the rim is supported by a web at the center of its width. (2) When the rim is supported at the center of its width, a flat web, a cone-shaped web, a web composed of cone-shaped and and flat plates and a web composed of root stress. (3) For practical use, it is recommended that the bevel gear has a flat web at the center of rim width and a rim whose thickness varies in direct proportion to the change of tooth height.

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A theoretical analysis of a transmission error with the condition of the contact state of the belt and the pulley teeth in the quasi-static condition under an initial tension was made for a situation in which a radial runout by an eccentric pulley occurs in a synchronous belt drive. The computed and the experimental results were compared. It was confirmed that the transmission error occurring with use of the eccentric pulley is mainly caused by periodic variance of the belt tension, and that it appears with a period of one pitch of the pulley and one revolution of the driving pulley. The tendencies of the experimental results and the computed ones coincided well. Further. it was found that there is an appropriate initial tension which lessens the transmission error having a period of one revolution of the driving pulley.

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This paper describes the friction loss of internal gear drives. Friction loss of internal gear drives was obtained by the oil immersion formula, which measures the temperature of lubricating oil for test gears, with varying pinion surface finishing. The gear friction loss ratios were between 0.28% and 0.84%. Then, statistical analysis of the experimental data was performed. It was found that the friction loss ratio of the internal gear is influenced most largely by gear speed, next by applied torque and slightly by pinion surface finishing. Furthermore, the friction loss of internal gear drives was calculated. The calculated value agreed approximately with the experimental data.

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Two types of traction-drive testing machines were designed and made to analyze changes in the speed ratio and the power transmission efficiency of a planetary traction drive. One of the trial testing machines is of the two-roller-type with two continuously variable speed drives. This machine is used to analyze the effects of spin motion upon both the shape of the traction-coefficient curve and the power transmission efficiency between two taper-rollers. The other trial testing machine belongs to a planetary traction drive with a contact-pressure control device. Changes in the speed ratio and power loss caused by the spin motion in the planetary traction drive can be exactly predicted by the two-roller-type testing machine. Prediction of the total efficiency of the planetary traction drive becomes almost complete when the oil churning and rolling bearing losses are taken into account in the calculation.

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This paper describes the analysis of variable-reluctance magnetic thrust bearings which are applied for the rotating system suspended by self-acting gas journal bearings. The bearing consists of the iron rotor and the stator with the permanent magnet. These are arranged coaxially, and the magnetic circuit is made up of the stator, the rotor, and the air gaps between the stator and the rotor. The permanent magnet supplies the magnetic flux into the circuit, and the magnetic energy is mainly stored in the air gaps and the space near the magnetic circuit. The axial displacement of the rotor changes the magnetic resistance of the circuit wihch consequently changes the magnetic energy. The change of the magnetic energy is converted to the thrust which generates the bearing stiffness. This bearing has advantages such that it floats the rotor without electric power, control circuits, and a high-pressure gas supply. However, the radial attractive force is similarly generated by the radial eccentricity of the rotor. This force turns into the journal bearing load and accerelates the bearing wear. In this paper, the theoretical analysis of the bearing load and accerelates the bearing wear. In this paper, the theoretical analysis of the bearing thrust is carried out using the conventional permeance calculation method. The theoretical results are compared with the experimental results and the characteristics are discussed. Also, the bearing radial attractive force is analyzed experimentally.

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Compressibility effects of rough lubricating films on film thickness averaging are studied numerically in order to grasp the applicability of average film thickness theory to compressible lubricating films. The effects are found to be segregated in four regions depending on the amount of two bearing numbers:Λ, defined using bearing length; and Λ^*, defined using roughness wavelength. In regions I and II, Where the Λ^* value is sufficiently small, the same averaging method as that for incompressible films is applicable, no matter how large the Λ value is. In region IV, where compressibility effects with respect to Λ^* are almost saturated, Greengard's averaging method can be applied. In the intermediate region (region III), any averaging method using only roughness amplitude distribution is ineffective. It should be noted that averaged film thickness can be determined physically in regions I and II, while it is defined mathematically in region IV.

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The grinding properties of an aluminum alloy cylinder end with a float were experimentally studied. Only the contact interface between the cylinder end and the float was ground, and a flat ground surface and sharp edge at the cylinder end were obtained. The removal rate with the float was 360 times larger than the removal rate without the float. The maximum removal rate was 3.38×10^-3 mm³/m. The removal rate was observed as a function of the initial grinding load, revolution speed, abrasive grain concentration and abrasive grain size. It was concluded that the end of an aluminum cylinder could be ground effectively and accurately shape wise by magnetic fluid grinding with a float.

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The grinding properties of a ceramic cylinder and an aluminum alloy cylinder were experimentally studied. The removal rate was observed as a function of grinding load, revolution speed, abrasive grain concentration and abrasive grain size. The maximum removal rate was 20×10<-3> mm³/N·m in the case of the aluminum alloy, and 3.0×10^-3 mm³/N·m in the case of silicon nitride. The surface roughness decreased with abrasive grain size, but was independent of grinding load, revolution speed and abrasive grain concentration. The minimum surface roughness was 0.02μm R_max in the case of silicon nitride. The nature of the material of the float influenced removal rate and surface roughness. The stainless steel float yielded the largest removal rate, and the rubber float had the smallest surface roughness. Therefore, at the optimum conditions for magnetic fluid grinding, the ceramic and aluminum alloy cylinders were ground sufficiently well for the practical usage.

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The object of this paper is to clarify the surface flattening mechanism in the drawing-ironing process based on the lubrication mechanism. A new experimental apparatus for the drawing-ironing process was made and experiments on ironing were carried out with aluminum cups using various lubricants and reductions in thickness. The experiments revealed that on the die surface the friction coefficient becomes minimum under the appropriate conditions of viscosity of lubricants and reduction in thickness. It was also confirmed that the cup surface is best flattened under conditions were the minimum friction coefficient appears.

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This paper presents a study on the residual stress of a case-hardened splined shaft with straight-sided teeth. A heat conduction analysis of the temperature in a cooling process and an elastic-plastic analysis of the residual stress of the case-hardened shaft with straight-sided teeth are carried out by finite element method (FEM). The effects of the tooth profile of the spline and the case depth on the residual stress are clarified. The optimum case depth for the residual stress is also examined.

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The purpose of this paper is to propose a new scheme using the finite-element method for modification of a three-dimensional shape. When designing a curved surface, we need to have the following processes. First, various regions on a curved surface are transformed into flattened forms. Second, a curved surface is recovered from the flattened forms. Third, a new surface has to be made on the basis of the modified flattened shapes. We have already proposed methods for developing any curved surfaces and for recovering curved shapes with the use of the finite-element method. We now introduce a new idea for modification of 3D-curved surfaces using reformed flattened shape lines and additional information. To illustrate the usefulness of the method, We apply it to a shoe model as a typical and practical application.

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The control system of the magnetically supported positioning servomechanism was synthesized using characteristic matrices which describe the mechanical characteristics of displacement sensors and magnetic actuators. An experimental model that embodied the design concept of decoupling the six-dimensional motion in Cartesian coordinates was fabricated by mechanostructural design, in spite of the strong coupling of sensing signals and actuating forces in local coordinates. The contradictional characteristics of high response and vibration isolation are both realizable only by means of decoupling. Dynamic response was measured using a dynamic analyzer, and the results were compared with numerical analyses of the mathematical model of the mechanism. The design method based on the mathematical model was confirmed to be valid.

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This paper is concerned with the fundamental design of the FMS. The problem considered here is twofold. First, given a demand pattern, which provides a set of the kind and volume of parts to be produced. the problem is to determine the machine requirements and workload allocation among the machines so as to minimize the total production cost subject to the capacity and technological constraints. This problem is formulated as an integer programming problem and an efficient solution procedure based on a branch and bound method is proposed in detail. Second, the problem is to select the most robust manufacturing system over several demand patterns which will be realized according to their estimated probabilities. The robust system will have the minimum expected value of opportunity loss over these demand patterns. The methodology is presented and demonstrated via an example problem.

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