Using the averaging method and Melnikov techniques, we study the dynamics of microcantilevers in tapping mode atomic force microscopy. When the distance between the tip and sample surface is relatively large and the van der Waals force has only a secondary influence on the dynamics of the microcantilever, theoretical explanations for some findings of numerical computations and experimental measurements in the previous work are given. Moreover, when the tip is closer to the sample surface and the van der Waals force has a primary influence, it is shown that abundant bifurcation behavior and chaotic motions occur.

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We propose a new control method of the micro cantilever probe in atomic force microscopy (AFM) for biologic imaging. The observation is concerned with operation in water or aqueous bufferin where the Q value of the cantilever is reduced. In this situation, it is very difficult to obtain the natural frequency of the micro cantilever probe. The utilization of self-excited oscillation is known as a method to overcome the difficulty. Furthermore, for the detection of the characteristics of soft biological material, the non-contact mode, that the probe does not contact to the material, is required for avoidance of local deformation and destruction of the material. In this study, for realizing the no contact mode of the self-excited micro cantilever probe, van der Pol type self-excited micro cantilever beam is designed by bifurcation control due to linear-plus-nonlinear feedback control.

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A PZT self-actuation self-detection-type AFM probe-cantilever has attracted the attention of many researchers because liquid AFM measurements can use advantages of the piezoelectric cantilever, e.g., laser light focusing is not necessary, as it is with conventional optical lever method. Moreover, to avoid damaging a bio-related sample during highly accurate observations in liquid, the vibration amplitude of the cantilever must be firmly stable and sufficiently small. To date, PZT self-actuation self-detection microcantilevers have been prototyped, and experiments have shown that a positive velocity feedback loop using a self-detected signal induces self-excited oscillation in the microcantilever.

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There have been researches on a self-excited cantilever beam for atomic force microscopy (AFM), in order to increase the low quality factor Q of the cantilever in liquid enviroments. For the realization of the non-contact AFM, it is necessary to control the stable steady state amplitude of the self-excited cantilever to be small. We proposed that we can realize the stable steady state amplitude of of the self-excited cantilever by applying nonlinear feedback proportional to the squared deflection and the velocity. In this study, we develop the AFM using a "van der Pol" type self-excited cantilever beam. Then, we confirm the availability and the advantage of the "van der Pol" type self-excited cantilever beam.

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This research deals with nonlinear dynamics of a rotating magnet levitated above a high-Tc superconducting bulk. Under no contact support by magnetic force, the magnet levitates stably without control. Such a low-damping system can show complex dynamical behaviors, because of nonlinearity of the magnetic force. In multi-degree-of-freedom nonlinear systems one can find energy transfer between modes through nonlinear coupling, which is called internal resonance. In this research, mechanism of the internal resonance was discussed from the equations of motion. This resonance was confirmed by numerical analyses and experiments.

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We generally use a damper and linear vibration absorber to prevent resonance. In this paper, we focus on resonance of forced vibration and parametrical resonance in mass spring system. We propose a nonlinear vibration absorber utilizing a nonlinear coupling so called internal resonance between mass spring system and absorber. We use a pendulum as a nonlinear vibration absorber. Theoretical results clarities the effect of the absorber for the resonances.

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Hamiltonian formalism and the infinite-dimensional modal system describing nonlinear sloshing an imcompressible fluid with irrotational flow partially occupying a tank is derived in general form. The tank has vertical walls near the free surface. The derivation is based on the V.Zhakarov (1967) and W.Craig (1994). The free surface elevation (canonical coordinate) and velocity potential on the free surface (canonical momentum) are expanded in generalized Fourier series. Hamiltonian is expressed in modal coordinates of the free surface elevation and velocity potential on the free surface. The theory is invalid when either the wave angle is large (more than 45 degree). Next, Normal Mode was applied to the obtained canonical equation. As a result, an important mode was clarified.

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This paper studies a method for evaluating convergence time to reach the noise-induced synchronization. For this purpose, we evaluate the variance of responses of our synchronization system through the use of the statistical equivalent linearization. The convergence time significantly increases when the variance undergoes hysteric jump phenomena in the sense of the statistical equivalent linearization.

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This paper describes the phenomenon called the inharmonicity for struck and plucked strings. Its spectral components consist of two inharmonic peak series: 'first partials' due to the elastic stiffness of a string and 'second partials'. Experimental tests for examining the mechanism of second partials were performed with a monochord string. The experiments suggest that second partials are those that have frequencies equal to the sum of two normal first partials. Further numerical simulations were done by nonlinear wave equations involving both longitudinal and transverse vibrations of large deflected string.

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This paper presents the nonlinear characteristics of the parametric resonance of a simply supported beam which is inextensible beam. For the beam model, the order-three expanded equation of motion has been determined in a form amenable to a perturbation treatment. The equation of motion is derived by a special Cosserat theory. The method of multiple scales is used to determine the equations that describe to the first-order modulation of the amplitude of simply supported beam. The stability and the bifurcation points of the system are investigated applying the frequency response function.

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The contact problems between a rigid trolley and a pantograph in a current railway system are studied from the viewpoint of nonlinear dynamics. It is assumed that there are impact oscillations between the contact rigid trolley and the pantograph under the state of contact loss. The rigid trolley pantograph system is modeled with a spring-supported mass excited by an oscillating plate. Using this simple model, the bouncing phenomena between a spring-supported mass and an oscillating plate are examined theoretically and numerically. Moreover, the experiments are conducted with the simple experimental model.

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Analytical results are presented on nonlinear coupled vibrations of a post-buckled clamped beam with a tip-mass constrained by an axial spring. First, governing equations of the beam are derived including both effects of the axial inertia force and the geometrical nonlinearity of the beam. The modified Galerkin procedure is applied to the governing equation by introducing a coordinate function for the axial displacement considering the quadratic nonlinear coupling with the deflection. Nonlinear periodic responses are calculated with the harmonic balance method. Owing to the axial inertia of the tip-mass, the amplitude of the principal resonance of the beam is increased, which agrees well with the experimental results formerly presented.

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This paper proposes a model order reduction procedure based on nonlinear balanced truncation which preserves the port-Hamiltonian structure of the original model. This method allows us to preserve the energy variable which will be useful in controlling the reduced order model. A numerical simulation shows how the proposed method works.

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An underactuated manipulator is defined as a manipulator with fewer actuators than degree of freedom of the system, which, for example, corresponds to the situation that some of actuators of a manipulator breaks down. Because it is especially hard to fix the broken actuator in space, control methods of the underactuated manipulator are generally considered to be employed as emergency control methods in space. In this paper, a control method of a two-link underactuated manipulator under zero gravity condition is proposed. By utilizing high-frequency excitation for the underactuated manipulator mounted on a base rotating at a constant angular velocity and experiencing centrifugal force, bifurcation phenomena occurs in the free link. We control the bifurcation phenomena and change stable equilibrium points of the free link where position of the link converges. The control method is theoretically clarified and also experimentally confirmed.

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In this paper, the modelling of one-degree-of-freedom magnetically levitated system considering the PI control characteristics of power amplifier and delay characteristic of magnetic flux density is performed, and nonlinear resonance phenomena and bifurcation phenomena are studied. From theoretical results, it is clarified that the shape of resonance curve becomes soft type, and also the influences of dynamical parameters on the nonlinear vibration phenomena are clarified. Furthermore, a experiment is performed, and obtained theoretical results are validated.

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This paper describes a method to select one of multiple periodic responses caused by hysteric jump phenomena of nonlinear vibration systems with backlash. Sweeping frequency of external forcing, it is possible to select a desired periodic state from the other states. In the same manner, it is also possible to select the desired state by sweeping system parameters such as spring stiffness.

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In this paper, we investigate holding by free links connected to the other active links through joints that lack not only acutuators but also sensors. In the previous reseach, we propose an open-loop control method for the two-link underactuated manipulator in order to swing up and stabilize at the upright position of its unactuated link, that is to say free link. We suggest a mechanism of gripper by using this method.

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Multibody Dynamics Simulation system in the environment of FEM was developed. Multibody Dynamics model can be created in the FEM preprocessor. The body properties such as center of gravity location, mass and inertia are able to be changed easily by the design parameters based on FEM meshes. This system allows the FEM users to apply multibody dynamics analysis in their familiar FEM environment. This paper shows an application of the developed system for single cylinder engine using the morphing technology for piston shape modification based on FEM mesh.

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This paper proposes a modeling method of extended reduced-order physical model (extended model) with arbitrary boundary condition. A novel formulation to identify mass and inertia matrices is presented that utilizes constraint conditions for the original object subjected to different boundary conditions. The effectiveness of the presented formulation is examined by using a simple cantilever and a two-link flexible arm. Numerical analysis is carried out and the effectiveness of the presented modeling procedure is verified.

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There are several formulations for beam element in the large deformation and displacement problem. Recently, the absolute nodal coordinate formulations are studied for such problems. In this paper, the anthers try to newly formulate the beam element for which the shape function is expressed with the quadratic function in the absolute nodal coordinate approach. The usefulness of the proposed formulation is verified by the numerical simulations.

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This paper is concerned with the development of a curved beam element in the analysis of large deformation multibody system dynamics. The absolute nodal coordinate formulation which has been used in the large deformation analysis of multibody systems is generalized to the curved beam element which does not suffer from some of existing numerical problems. Using the position vector gradient coordinates used in the absolute nodal coordinate formulation, the rotation and deformation field within the element can be uniquely defined, and this formulation leads to a constant mass matrix for fully nonlinear dynamics problems. In existing beam elements in this formulation, however, since the elastic forces are defined using the Green-Lagrange strain tensor as a volume element, locking phenomenon associated with the shear and membrane forces leads to erroneously stiffer bending characteristics. In order to avoid this drawback, Hellinger-Reissner variational principle is applied to modify the shear stress distribution, while the assumed strain method is employed to avoid the membrane locking associated with the cross-section deformation. Numerical examples are presented in order to demonstrate the performance of the curved beam formulation developed in this investigation.

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The paper proposes a new modeling method for elastic vehicles. While the vehicle designed lightly to improve fuel economy, it becomes flexible in nature. For obtaining the riding comfort of elastic vehicles, there is a necessity to control vibration and motion. For vibration control, the deformation of the vehicle body must be described. Meanwhile, from the viewpoint of vehicle control, the orientation of the body must also be described. Therefore, we need such a vehicle model that can describe the deformation and the orientation simultaneously. So, in this research, 'Extended Reduced Order Physical Model is applied. Using Extended Reduced Order Physical Model, the mechanical model of the body can be obtained. Then, the equations of motion of the experimental system are derived using multibody dynamics and its linearization is performed. Consequently, the active suspension control is introduced for vibration control. Effectiveness of the control is demonstrated by simulation.

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This paper presents the sensitivity analysis of multi-body dynamics (MBD) model for automobile suspension systems, where the geometry of joint as well as mass, stiffness and damping coefficients are design parameters. By this method, we can ascertain which elements contribute for the dynamic characteristics of the system. This paper mainly focuses on the effectiveness and advantages of sensitivity analysis. The effectiveness of the sensitivity analysis for MBD system is verified by comparing with the response surface approach. The optimization of dynamic properties of the suspension system based on the sensitivity analysis is also examined.

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In this paper we formulate an equation of motion of a four-wheel vehicle taking account of its suspension and steering geometry by applying the multibody dynamics analysis (MBD). In a control system design for active suspension or vehicle stability control, evaluation of the controller taking account of the geometry in the simulation based on the equation of motion obtained may reduce trial and error by iteration of the evaluation and the improvement in vehicle running tests. Also it may be possible to design the controller considering a nonlinearity caused by the geometry in advance. We carry out simulations based on the differential and algebraic equations of motion obtained from MBD and the simulation results are compared with those of the marketed software of dynamical analysis. It is verified that the equation of motion obtained is reliable to be used in the evaluation of the controller design.

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In this paper, we discuss the dynamic performance of a compact size bicycle using a developed multibody simulation model. In this study, a three-dimensional multibody bicycle model is developed to account for the large rotational motion of the bicycle. The equations of motion for the constrained multibody system are obtained using the D'Alembert's principle. The dynamic performance of a compact size bicycle is discussed using the developed simulation model for several different conditions. In particular, the effect of the following parameters on the dynamic performance of bicycles is discussed: the diameter of a tire which becomes smaller when downsizing a bicycle; the offset and trail which are affected by the change in the diameter of a tire. The effect of such parameters on the dynamics characteristics of compact size bicycle is discussed for developing a compact and high-performance bicycle.

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This paper describes Cell Dynamic Research from the viewpoint of mechanical dynamics. In these days, Life Science has got much attention from lots of researchers in various fields such as molecular biology, agriculture, chemical engineering, or computer science. Though it is usually thought that life science may be out of field for mechanical engineers, several parts of life science have had close relation to mechanical engineering. A cell is the most basic element for living things, and it may sense its circumstance, and actuate or control by itself In this sense, a cell may be a typical example of micro-or nano-machines. But, to the best of my knowledge, very few reseachers have interested in the dynamic properties of a cell. Some example studies are introduced in this article, and I would like to introduce you the world of Cell Dynamics.

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In order to clarify the effects of mechanical vibration on osteoblast-like cells on the basis of the dynamic properties of the cells, sinusoidal excitation was applied to the cells. The cells were cultured under sinusoidal vibration for 24 hours a day, 28 days at frequency of 12.5 or 100 Hz, setting an acceleration amplitude as constant of 0.5 G The cell density of the vibrating groups was higher than that of the non-vibrating group after 18-day cultivation by counting the cells and checking their morphology through an optical microscope. The amount of generated calcium salts in the vibrating groups was shown more than that in the non-vibrating group using alizarin red S stain solution on 28-day cultivation. It was found that the bone generation was promoted by the mechanical vibrating stimulation.

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This paper describes an online measurement method of time-varying viscoelasticity of subcutaneous tissues by external stimulation. Time-varying dynamic stiffness in subcutaneous tissues may be estimated by using the self-excited vibration generated by the positive feedback of velocity. Then we showed that viscoelastic coefficients in subcutaneous tissues, which didn't depend on measurement conditions, could be quantified with the estimated dynamic stiffness, based on the Hertz's formula and the correspondence principle between the theory of elasticity and viscoelasticity. In this report, we show that spring constant may be rapidly measured by the frequency estimation using Kalman filter as an adaptive filter, and that time-varying viscoelasticity on human body by muscular contraction can be measured by this technique.

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In this study, tensile properties of a cultured osteoblast, which is one of bone cells, were measured with tensile and creep tests. As a result, the load-elongation and stress-strain diagram of the cell were obtained. In addition to the tensile test, the increase of the elongation of the cell was measured keeping the tensile load as constant in the creep test. Using these experimental results, a three-element model of the cell for viscoelasticity was derived and the value of each parameter was identified.

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In this study, a new low-invasive micro sensor is developed to detect compliance of a single cell by using dynamic response of piezoelectric vibrator. The bending mode of vibration, excited by piezoelectric ceramics, is utilized in a small beam type vibrator. This sensor can also enforce dynamic stimulations as the micro actuator. The actuator-sensor was controlled by micromanipulator system, while dimensions and morphologies of a minute cell were measured by inverted phase contract microscope system. The experimental results have shown capabilities as a micro sensor to detect mechanical properties of a human osteoblast, which are stimulated dynamically by the micro actuator.

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In this study, a new device utilizing micro three-dimensional vibration stage is developed to control cell culture. This device is able to enforce three-dimensional dynamic stimulations to the cell. Experimental studies have been carried out by using normal human osteoblast. Developed vibration stage, in which doubly L-shaped clamped-free beam type vibrator is utilized, has quite simple structure and is able to sterilize itself easily. The studies have shown that the cell has capability to detect dynamic stimulations and to change its own figure.

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Kinetic analysis based on compartment model is one of the effective pharmacokinetics methods for quantitative physiologic analyses of nuclear medicine data, such as positron emission tomography data. A typical tracer kinetic modeling with an arterial input function is to represent tracer up take in brain tissue as a three compartment model including rate constants. In this study, the effect of the approximation of the input function on estimating the rate constants is numerically investigated by using FDG-PET data. Imaging the regional metabolism of glucose in the human brain uses ^<18>F-FDG, because FDG is transported and phosphorylated by the same pathways as glucose. Numerical simulation results indicate that the estimation of rate constants are depend on the approximation of the input function.

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In this study, a new non-invasive micro sensor system is developed to detect compliance of minute living cells and tissues by using dynamic response of piezoelectric vibrator. 3-D micro actuator is also developed to enforce dynamic stimulations. The sensor was controlled by micromanipulator system, while dimensions and morphologies of the cells were measured by inverted phase contract microscope system. The method has shown that the reaction of living cells might have frequency dependence against vibrating stimulations by the actuator. Also, experimental studies have shown that dynamic stimulations accelerate damage recovery of minute living cells.

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This study focuses on the vibration response estimation for an exhaust gas system of passenger vehicles using the neural network technique. At first, FEM (Finite Element Method) calculations of the transient response for an impact load were carried out to the representative exhaust gas systems. These calculated data were used as the teacher's data of the neural network, and a computer program was developed to obtain the vibration amplitude for similar exhaust gas system. If a designer repeats the input to this neural network model for various support conditions, the optional support position can be gained without carrying out such complex FEM analysis repeatedly.

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In this paper, an optimality condition for the sound pressure minimization is considered. The sound pressure in the frequency domain is expressed by a scalar product of the structural frequency response function (FRF) and the acoustic FRF. Therefore, the optimality condition is that the amplitude of the sound pressure is zero when the structural FRF and the acoustic FRF are orthogonal. From this viewpoint, a contour plot which shows optimal state of the sound pressure minimization is introduced. And a novel optimization approach based on the optimality condition is proposed.

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This paper discusses two high-speed and high-accuracy positioning actuators for magnetic recording test stands. Both actuators consist of two multilayer piezoelectric elements (PZTs) and a displacement amplifier which amplifies the displacement of the PZT. One of them has been designed with a diamond-shaped link mechanism with flexure hinges which is adopted as the displacement amplifier. The other one has been designed with a shape optimization method in which the shape of the displacement amplifier is defined like as a skeleton and meats and a genetic algorithm (GA) is used to search the combination of the skeleton and meats. Both structures are axisymmetrical to two orthogonal axes. In previous studies, the effectiveness of the axisymmetrical structures has been verified in high-speed positioning actuators. The actively controlled mechanical system of each actuator has been designed by using the integrated design concept of plant and controller. In this paper, the fundamental characteristics of the two actuators are experimentally tested, and it is shown that the robustness of the actuator designed with a shape optimization method is superior to that of the actuator designed with a diamond-shaped-link mechanism.

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The identification of an input load, which means that an input load to a structure is obtained from its response, is tried by using a Wavelet and a neural network. In this study the load is given to a plate and its response is calculated by using FEM. The response is analyzed by Wavelet packet analysis and the distribution of energies are obtained. The energies and the input load are trained by neural network and from energies of a given response the unknown load is identified.

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This paper describes about the structural optimization of a three axes tactile sensor. This tactile sensor can detect three axes forces simultaneously by strain gauges. The sensor consists of a top surface and four legs which are made of brass. In this paper, based on the output principles of the tactile sensor, the relationship between the responses and the design variables is clarified by FEM and DOE. Additionally approximate expressions are obtained by GLM. Using these results, the best design variables of the three axes tactile sensor are obtained.

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In recent years, A. Ganek proposes general concepts of the Autonomic Computing for reducing total cost of ownership, improving quality of services, accelerating time to value and managing IT complexity. The autonomic computing introduces four characteristics: self-configuring, self-healing, self-optimizing and self-protecting. Authors propose to introduce the self-optimizing for optimal design problems with uncertainty. The proposed method is applied to a control problem of Harmonic Drive System to check the performance of convergence, and the validity of the proposed method is discussed.

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This paper deal with the time history of liquid surface wave motion in a rectangular tank which is oscillated horizontally. In theoretical analysis, the governing equations of liquid surface wave motion are derived by applying the variational principle. The nonlinear ordinary differential equations of time which govern liquid surface wave motion are derived by using Dirichlet-Neumann operators. An experiment was carried out using a model tank. The frequency components are observed by applying the discrete Fourier Transform to the theoretical results and the experimental results. The high-frequency components are observed at the both results. And, these results are in good agreement qualitatively.

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This study describes the nonlinear vibration response of a cylindrical water storage tank caused by coupling effect between the beam-type and the oval-type vibrations. The results of the frequency sweep tests with the large input acceleration demonstrate the resonance frequency of the tank shifts to the lower frequency region and the magnification factor is smaller. Considering the out-of-plane of the tank-wall induced by the oval-type vibration, a simplified model having the spring constant dependent on the amplitude of the oval-type vibration is proposed, and then the numerical simulation using this model is conducted.

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When a teardrop tank system undergoes a rotational unbalance due to the detachment of an object from a spinning satellite, we encounter a problem that some of the tanks empty due to the liquid propellant migration and the tilt of the principal inertia axis becomes large. To solve this problem, a method is proposed that supplies pressurized gas to the ullage in each tank and confines the gas by closing the valves among the tanks. The effectiveness of this control method is ascertained by numerical computation. Furthermore, the influences of the difference among the gas temperatures in the tanks and the solubility of a pressurant in the propellant are examined.

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This paper deals with suppression effect of residual sloshing in a liquid transport container by a bulkhead which divides the container vertically into two sections. The sloshing mode is separated into two modes by the bulkhead; the one is the sloshing mode of liquid column in a U-tube, and the other is the sloshing mode in the separated container. The effect of aperture ratio and type of the bulkhead on the suppression of residual sloshing is examined experimentally.

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In the present paper the attention is focused on similarity between the phenomena of acoustic resonance which occurred in actual boiler plant and that of the two-dimensional model of boiler. We measured a gap velocity, sound pressure level, acoustic mode shape, spectrum and phase delay of velocity fluctuations in the tube banks. As a result it was made clear that the phenomenon of acoustic resonance in the model is similar with that of the actual plant. The relation between vortex shedding phenomena inside of in-line tube banks and acoustic resonance in the model was experimentally examined.

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This paper shows vibration behavior of circular cylinders subjected to jet-flow from a narrow gap in the vicinity of wall by using computational fluid dynamics (CFD) simulation. We investigated the effects of the distance between the centerline of jet-flow and the cylinder center. And these CFD simulation results are comparred with the experiments in published papers. As a result, the vortex shedding vibration phenomena and the fluid elastic vibration phenomena can be confirmed in circular cylinders subjected to jet-flow from a narrow gap as well as in the case of the experiments.

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Vibrational behavior and unstable phenomena of multi-connected bodies supported by damper-spring elements moving in a narrow flow passage are reported. These vibrational phenomena have been often observed in high-speed trains running in tunnels, cleaning robots going through pipings, medical machines in human blood vessels and core internal structures in nuclear reactor vessels. The fluid forces acting on the multi-connected rigid bodies are obtained analytically on the basis of the Navier-Stokes equations applied to a narrow flow passage. The equations of coupled motion of the multi-connected bodies and fluid are derived. Using coupled equation, a stability analysis is performed. The effect of the flow velocity and number of bodies on the coupled mode is investigated. The relation between the vibrational behavior of bodies and unsteady fluid pressure.

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This paper deals with an experimental study of the active feedback control of leakage-flow-induced web flutter. The leakage-flow-induced web flutter is suppressed by the active feedback to the injection (and suction) of the fluid at the inlet, intermediate, and outlet, multipoint of inlet (or intermediate) and outlet of the passage. The stability boundary, displacement of the system with the active control is examined with varying the controller gain and phase-shift angle. As a result, it is indicated experimentally that the leakage-flow-induced web flutter is suppressed.

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The stability analysis is carried out on a piping system equipped with a press-open-type valve at the exit. The equation of motion of the valve is included in the boundary condition at the exit together with the flow characteristics. The constant pressure is assumed at the pipe inlet. The characteristic equation is obtained to analyze the stability of the pipe-valve system. As it is a transcendental equation, including the hyperbolic cotangent, the conventional method could not be applied to the stability analysis. A newly developed method, in which the conditions of neutral stability are searched, by adding pseudo damping to the valve, is applied to analyze the present characteristic equation, and the ranges of instability are determined. The complex fluid force (pressure) acting on the valve is obtained and it is shown that the equivalent negative damping is generated for the instability ranges.

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A steam control valve is used to control the steam flow from a steam generator to a turbine in power plants. The flow field in the steam control valve is usually complex and transonic. A flow-induced vibration can occur in the valve and causes unexpected shutdown. An experimental and numerical study is conducted to clarify the characteristics of the transonic unsteady flow in the steam control valve. The results show the existence of a steady flow pattern and five unsteady patterns depending on opening ratios and pressure ratios. Both the experimental and numerical results indicate that even under the same condition, different flow pattern may appear depending on the process of changing the pressure ratio.

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This paper deals with self-excited vibration of an overflow pipe due to fluid discharge. In this study, the experiments and analysis are carried out to determine the relation among the lag time, the inflow rate, the flow velocity, the fluid force at elbow part and fall height of the fluid falling along the vertical pipe. The excitation mechanism of the self-excited vibrations is discussed experimentally and theoretically. And, self-excited vibrations of overflow pipes are suppressed by the stabilizer at the end of the horizontal pipe. As a result, the stabilizing performance is examined experimentally.

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